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zig/src/arch/wasm/CodeGen.zig
Jacob Young aa688567f5 Air: replace .dbg_inline_* with .dbg_inline_block 
This prevents the possibility of not emitting a `.dbg_inline_end`
instruction and reduces the allocation requirements of the backends.

Closes #19093
2024-03-02 21:19:34 -08:00

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const std = @import("std");
const builtin = @import("builtin");
const Allocator = std.mem.Allocator;
const ArrayList = std.ArrayList;
const assert = std.debug.assert;
const testing = std.testing;
const leb = std.leb;
const mem = std.mem;
const wasm = std.wasm;
const log = std.log.scoped(.codegen);
const codegen = @import("../../codegen.zig");
const Module = @import("../../Module.zig");
const InternPool = @import("../../InternPool.zig");
const Decl = Module.Decl;
const Type = @import("../../type.zig").Type;
const Value = @import("../../Value.zig");
const Compilation = @import("../../Compilation.zig");
const LazySrcLoc = std.zig.LazySrcLoc;
const link = @import("../../link.zig");
const TypedValue = @import("../../TypedValue.zig");
const Air = @import("../../Air.zig");
const Liveness = @import("../../Liveness.zig");
const target_util = @import("../../target.zig");
const Mir = @import("Mir.zig");
const Emit = @import("Emit.zig");
const abi = @import("abi.zig");
const Alignment = InternPool.Alignment;
const errUnionPayloadOffset = codegen.errUnionPayloadOffset;
const errUnionErrorOffset = codegen.errUnionErrorOffset;
/// Wasm Value, created when generating an instruction
const WValue = union(enum) {
/// `WValue` which has been freed and may no longer hold
/// any references.
dead: void,
/// May be referenced but is unused
none: void,
/// The value lives on top of the stack
stack: void,
/// Index of the local
local: struct {
/// Contains the index to the local
value: u32,
/// The amount of instructions referencing this `WValue`
references: u32,
},
/// An immediate 32bit value
imm32: u32,
/// An immediate 64bit value
imm64: u64,
/// Index into the list of simd128 immediates. This `WValue` is
/// only possible in very rare cases, therefore it would be
/// a waste of memory to store the value in a 128 bit integer.
imm128: u32,
/// A constant 32bit float value
float32: f32,
/// A constant 64bit float value
float64: f64,
/// A value that represents a pointer to the data section
/// Note: The value contains the symbol index, rather than the actual address
/// as we use this to perform the relocation.
memory: u32,
/// A value that represents a parent pointer and an offset
/// from that pointer. i.e. when slicing with constant values.
memory_offset: struct {
/// The symbol of the parent pointer
pointer: u32,
/// Offset will be set as addend when relocating
offset: u32,
},
/// Represents a function pointer
/// In wasm function pointers are indexes into a function table,
/// rather than an address in the data section.
function_index: u32,
/// Offset from the bottom of the virtual stack, with the offset
/// pointing to where the value lives.
stack_offset: struct {
/// Contains the actual value of the offset
value: u32,
/// The amount of instructions referencing this `WValue`
references: u32,
},
/// Returns the offset from the bottom of the stack. This is useful when
/// we use the load or store instruction to ensure we retrieve the value
/// from the correct position, rather than the value that lives at the
/// bottom of the stack. For instances where `WValue` is not `stack_value`
/// this will return 0, which allows us to simply call this function for all
/// loads and stores without requiring checks everywhere.
fn offset(value: WValue) u32 {
switch (value) {
.stack_offset => |stack_offset| return stack_offset.value,
.dead => unreachable,
else => return 0,
}
}
/// Promotes a `WValue` to a local when given value is on top of the stack.
/// When encountering a `local` or `stack_offset` this is essentially a no-op.
/// All other tags are illegal.
fn toLocal(value: WValue, gen: *CodeGen, ty: Type) InnerError!WValue {
switch (value) {
.stack => {
const new_local = try gen.allocLocal(ty);
try gen.addLabel(.local_set, new_local.local.value);
return new_local;
},
.local, .stack_offset => return value,
else => unreachable,
}
}
/// Marks a local as no longer being referenced and essentially allows
/// us to re-use it somewhere else within the function.
/// The valtype of the local is deducted by using the index of the given `WValue`.
fn free(value: *WValue, gen: *CodeGen) void {
if (value.* != .local) return;
const local_value = value.local.value;
const reserved = gen.args.len + @intFromBool(gen.return_value != .none);
if (local_value < reserved + 2) return; // reserved locals may never be re-used. Also accounts for 2 stack locals.
const index = local_value - reserved;
const valtype = @as(wasm.Valtype, @enumFromInt(gen.locals.items[index]));
switch (valtype) {
.i32 => gen.free_locals_i32.append(gen.gpa, local_value) catch return, // It's ok to fail any of those, a new local can be allocated instead
.i64 => gen.free_locals_i64.append(gen.gpa, local_value) catch return,
.f32 => gen.free_locals_f32.append(gen.gpa, local_value) catch return,
.f64 => gen.free_locals_f64.append(gen.gpa, local_value) catch return,
.v128 => gen.free_locals_v128.append(gen.gpa, local_value) catch return,
}
log.debug("freed local ({d}) of type {}", .{ local_value, valtype });
value.* = .dead;
}
};
/// Wasm ops, but without input/output/signedness information
/// Used for `buildOpcode`
const Op = enum {
@"unreachable",
nop,
block,
loop,
@"if",
@"else",
end,
br,
br_if,
br_table,
@"return",
call,
call_indirect,
drop,
select,
local_get,
local_set,
local_tee,
global_get,
global_set,
load,
store,
memory_size,
memory_grow,
@"const",
eqz,
eq,
ne,
lt,
gt,
le,
ge,
clz,
ctz,
popcnt,
add,
sub,
mul,
div,
rem,
@"and",
@"or",
xor,
shl,
shr,
rotl,
rotr,
abs,
neg,
ceil,
floor,
trunc,
nearest,
sqrt,
min,
max,
copysign,
wrap,
convert,
demote,
promote,
reinterpret,
extend,
};
/// Contains the settings needed to create an `Opcode` using `buildOpcode`.
///
/// The fields correspond to the opcode name. Here is an example
/// i32_trunc_f32_s
/// ^ ^ ^ ^
/// | | | |
/// valtype1 | | |
/// = .i32 | | |
/// | | |
/// op | |
/// = .trunc | |
/// | |
/// valtype2 |
/// = .f32 |
/// |
/// width |
/// = null |
/// |
/// signed
/// = true
///
/// There can be missing fields, here are some more examples:
/// i64_load8_u
/// --> .{ .valtype1 = .i64, .op = .load, .width = 8, signed = false }
/// i32_mul
/// --> .{ .valtype1 = .i32, .op = .trunc }
/// nop
/// --> .{ .op = .nop }
const OpcodeBuildArguments = struct {
/// First valtype in the opcode (usually represents the type of the output)
valtype1: ?wasm.Valtype = null,
/// The operation (e.g. call, unreachable, div, min, sqrt, etc.)
op: Op,
/// Width of the operation (e.g. 8 for i32_load8_s, 16 for i64_extend16_i32_s)
width: ?u8 = null,
/// Second valtype in the opcode name (usually represents the type of the input)
valtype2: ?wasm.Valtype = null,
/// Signedness of the op
signedness: ?std.builtin.Signedness = null,
};
/// Helper function that builds an Opcode given the arguments needed
fn buildOpcode(args: OpcodeBuildArguments) wasm.Opcode {
switch (args.op) {
.@"unreachable" => return .@"unreachable",
.nop => return .nop,
.block => return .block,
.loop => return .loop,
.@"if" => return .@"if",
.@"else" => return .@"else",
.end => return .end,
.br => return .br,
.br_if => return .br_if,
.br_table => return .br_table,
.@"return" => return .@"return",
.call => return .call,
.call_indirect => return .call_indirect,
.drop => return .drop,
.select => return .select,
.local_get => return .local_get,
.local_set => return .local_set,
.local_tee => return .local_tee,
.global_get => return .global_get,
.global_set => return .global_set,
.load => if (args.width) |width| switch (width) {
8 => switch (args.valtype1.?) {
.i32 => if (args.signedness.? == .signed) return .i32_load8_s else return .i32_load8_u,
.i64 => if (args.signedness.? == .signed) return .i64_load8_s else return .i64_load8_u,
.f32, .f64, .v128 => unreachable,
},
16 => switch (args.valtype1.?) {
.i32 => if (args.signedness.? == .signed) return .i32_load16_s else return .i32_load16_u,
.i64 => if (args.signedness.? == .signed) return .i64_load16_s else return .i64_load16_u,
.f32, .f64, .v128 => unreachable,
},
32 => switch (args.valtype1.?) {
.i64 => if (args.signedness.? == .signed) return .i64_load32_s else return .i64_load32_u,
.i32 => return .i32_load,
.f32 => return .f32_load,
.f64, .v128 => unreachable,
},
64 => switch (args.valtype1.?) {
.i64 => return .i64_load,
.f64 => return .f64_load,
else => unreachable,
},
else => unreachable,
} else switch (args.valtype1.?) {
.i32 => return .i32_load,
.i64 => return .i64_load,
.f32 => return .f32_load,
.f64 => return .f64_load,
.v128 => unreachable, // handled independently
},
.store => if (args.width) |width| {
switch (width) {
8 => switch (args.valtype1.?) {
.i32 => return .i32_store8,
.i64 => return .i64_store8,
.f32, .f64, .v128 => unreachable,
},
16 => switch (args.valtype1.?) {
.i32 => return .i32_store16,
.i64 => return .i64_store16,
.f32, .f64, .v128 => unreachable,
},
32 => switch (args.valtype1.?) {
.i64 => return .i64_store32,
.i32 => return .i32_store,
.f32 => return .f32_store,
.f64, .v128 => unreachable,
},
64 => switch (args.valtype1.?) {
.i64 => return .i64_store,
.f64 => return .f64_store,
else => unreachable,
},
else => unreachable,
}
} else {
switch (args.valtype1.?) {
.i32 => return .i32_store,
.i64 => return .i64_store,
.f32 => return .f32_store,
.f64 => return .f64_store,
.v128 => unreachable, // handled independently
}
},
.memory_size => return .memory_size,
.memory_grow => return .memory_grow,
.@"const" => switch (args.valtype1.?) {
.i32 => return .i32_const,
.i64 => return .i64_const,
.f32 => return .f32_const,
.f64 => return .f64_const,
.v128 => unreachable, // handled independently
},
.eqz => switch (args.valtype1.?) {
.i32 => return .i32_eqz,
.i64 => return .i64_eqz,
.f32, .f64, .v128 => unreachable,
},
.eq => switch (args.valtype1.?) {
.i32 => return .i32_eq,
.i64 => return .i64_eq,
.f32 => return .f32_eq,
.f64 => return .f64_eq,
.v128 => unreachable, // handled independently
},
.ne => switch (args.valtype1.?) {
.i32 => return .i32_ne,
.i64 => return .i64_ne,
.f32 => return .f32_ne,
.f64 => return .f64_ne,
.v128 => unreachable, // handled independently
},
.lt => switch (args.valtype1.?) {
.i32 => if (args.signedness.? == .signed) return .i32_lt_s else return .i32_lt_u,
.i64 => if (args.signedness.? == .signed) return .i64_lt_s else return .i64_lt_u,
.f32 => return .f32_lt,
.f64 => return .f64_lt,
.v128 => unreachable, // handled independently
},
.gt => switch (args.valtype1.?) {
.i32 => if (args.signedness.? == .signed) return .i32_gt_s else return .i32_gt_u,
.i64 => if (args.signedness.? == .signed) return .i64_gt_s else return .i64_gt_u,
.f32 => return .f32_gt,
.f64 => return .f64_gt,
.v128 => unreachable, // handled independently
},
.le => switch (args.valtype1.?) {
.i32 => if (args.signedness.? == .signed) return .i32_le_s else return .i32_le_u,
.i64 => if (args.signedness.? == .signed) return .i64_le_s else return .i64_le_u,
.f32 => return .f32_le,
.f64 => return .f64_le,
.v128 => unreachable, // handled independently
},
.ge => switch (args.valtype1.?) {
.i32 => if (args.signedness.? == .signed) return .i32_ge_s else return .i32_ge_u,
.i64 => if (args.signedness.? == .signed) return .i64_ge_s else return .i64_ge_u,
.f32 => return .f32_ge,
.f64 => return .f64_ge,
.v128 => unreachable, // handled independently
},
.clz => switch (args.valtype1.?) {
.i32 => return .i32_clz,
.i64 => return .i64_clz,
.f32, .f64 => unreachable,
.v128 => unreachable, // handled independently
},
.ctz => switch (args.valtype1.?) {
.i32 => return .i32_ctz,
.i64 => return .i64_ctz,
.f32, .f64 => unreachable,
.v128 => unreachable, // handled independently
},
.popcnt => switch (args.valtype1.?) {
.i32 => return .i32_popcnt,
.i64 => return .i64_popcnt,
.f32, .f64 => unreachable,
.v128 => unreachable, // handled independently
},
.add => switch (args.valtype1.?) {
.i32 => return .i32_add,
.i64 => return .i64_add,
.f32 => return .f32_add,
.f64 => return .f64_add,
.v128 => unreachable, // handled independently
},
.sub => switch (args.valtype1.?) {
.i32 => return .i32_sub,
.i64 => return .i64_sub,
.f32 => return .f32_sub,
.f64 => return .f64_sub,
.v128 => unreachable, // handled independently
},
.mul => switch (args.valtype1.?) {
.i32 => return .i32_mul,
.i64 => return .i64_mul,
.f32 => return .f32_mul,
.f64 => return .f64_mul,
.v128 => unreachable, // handled independently
},
.div => switch (args.valtype1.?) {
.i32 => if (args.signedness.? == .signed) return .i32_div_s else return .i32_div_u,
.i64 => if (args.signedness.? == .signed) return .i64_div_s else return .i64_div_u,
.f32 => return .f32_div,
.f64 => return .f64_div,
.v128 => unreachable, // handled independently
},
.rem => switch (args.valtype1.?) {
.i32 => if (args.signedness.? == .signed) return .i32_rem_s else return .i32_rem_u,
.i64 => if (args.signedness.? == .signed) return .i64_rem_s else return .i64_rem_u,
.f32, .f64 => unreachable,
.v128 => unreachable, // handled independently
},
.@"and" => switch (args.valtype1.?) {
.i32 => return .i32_and,
.i64 => return .i64_and,
.f32, .f64 => unreachable,
.v128 => unreachable, // handled independently
},
.@"or" => switch (args.valtype1.?) {
.i32 => return .i32_or,
.i64 => return .i64_or,
.f32, .f64 => unreachable,
.v128 => unreachable, // handled independently
},
.xor => switch (args.valtype1.?) {
.i32 => return .i32_xor,
.i64 => return .i64_xor,
.f32, .f64 => unreachable,
.v128 => unreachable, // handled independently
},
.shl => switch (args.valtype1.?) {
.i32 => return .i32_shl,
.i64 => return .i64_shl,
.f32, .f64 => unreachable,
.v128 => unreachable, // handled independently
},
.shr => switch (args.valtype1.?) {
.i32 => if (args.signedness.? == .signed) return .i32_shr_s else return .i32_shr_u,
.i64 => if (args.signedness.? == .signed) return .i64_shr_s else return .i64_shr_u,
.f32, .f64 => unreachable,
.v128 => unreachable, // handled independently
},
.rotl => switch (args.valtype1.?) {
.i32 => return .i32_rotl,
.i64 => return .i64_rotl,
.f32, .f64 => unreachable,
.v128 => unreachable, // handled independently
},
.rotr => switch (args.valtype1.?) {
.i32 => return .i32_rotr,
.i64 => return .i64_rotr,
.f32, .f64 => unreachable,
.v128 => unreachable, // handled independently
},
.abs => switch (args.valtype1.?) {
.i32, .i64 => unreachable,
.f32 => return .f32_abs,
.f64 => return .f64_abs,
.v128 => unreachable, // handled independently
},
.neg => switch (args.valtype1.?) {
.i32, .i64 => unreachable,
.f32 => return .f32_neg,
.f64 => return .f64_neg,
.v128 => unreachable, // handled independently
},
.ceil => switch (args.valtype1.?) {
.i64 => unreachable,
.i32 => return .f32_ceil, // when valtype is f16, we store it in i32.
.f32 => return .f32_ceil,
.f64 => return .f64_ceil,
.v128 => unreachable, // handled independently
},
.floor => switch (args.valtype1.?) {
.i64 => unreachable,
.i32 => return .f32_floor, // when valtype is f16, we store it in i32.
.f32 => return .f32_floor,
.f64 => return .f64_floor,
.v128 => unreachable, // handled independently
},
.trunc => switch (args.valtype1.?) {
.i32 => if (args.valtype2) |valty| switch (valty) {
.i32 => unreachable,
.i64 => unreachable,
.f32 => if (args.signedness.? == .signed) return .i32_trunc_f32_s else return .i32_trunc_f32_u,
.f64 => if (args.signedness.? == .signed) return .i32_trunc_f64_s else return .i32_trunc_f64_u,
.v128 => unreachable, // handled independently
} else return .f32_trunc, // when no valtype2, it's an f16 instead which is stored in an i32.
.i64 => switch (args.valtype2.?) {
.i32 => unreachable,
.i64 => unreachable,
.f32 => if (args.signedness.? == .signed) return .i64_trunc_f32_s else return .i64_trunc_f32_u,
.f64 => if (args.signedness.? == .signed) return .i64_trunc_f64_s else return .i64_trunc_f64_u,
.v128 => unreachable, // handled independently
},
.f32 => return .f32_trunc,
.f64 => return .f64_trunc,
.v128 => unreachable, // handled independently
},
.nearest => switch (args.valtype1.?) {
.i32, .i64 => unreachable,
.f32 => return .f32_nearest,
.f64 => return .f64_nearest,
.v128 => unreachable, // handled independently
},
.sqrt => switch (args.valtype1.?) {
.i32, .i64 => unreachable,
.f32 => return .f32_sqrt,
.f64 => return .f64_sqrt,
.v128 => unreachable, // handled independently
},
.min => switch (args.valtype1.?) {
.i32, .i64 => unreachable,
.f32 => return .f32_min,
.f64 => return .f64_min,
.v128 => unreachable, // handled independently
},
.max => switch (args.valtype1.?) {
.i32, .i64 => unreachable,
.f32 => return .f32_max,
.f64 => return .f64_max,
.v128 => unreachable, // handled independently
},
.copysign => switch (args.valtype1.?) {
.i32, .i64 => unreachable,
.f32 => return .f32_copysign,
.f64 => return .f64_copysign,
.v128 => unreachable, // handled independently
},
.wrap => switch (args.valtype1.?) {
.i32 => switch (args.valtype2.?) {
.i32 => unreachable,
.i64 => return .i32_wrap_i64,
.f32, .f64 => unreachable,
.v128 => unreachable, // handled independently
},
.i64, .f32, .f64 => unreachable,
.v128 => unreachable, // handled independently
},
.convert => switch (args.valtype1.?) {
.i32, .i64 => unreachable,
.f32 => switch (args.valtype2.?) {
.i32 => if (args.signedness.? == .signed) return .f32_convert_i32_s else return .f32_convert_i32_u,
.i64 => if (args.signedness.? == .signed) return .f32_convert_i64_s else return .f32_convert_i64_u,
.f32, .f64 => unreachable,
.v128 => unreachable, // handled independently
},
.f64 => switch (args.valtype2.?) {
.i32 => if (args.signedness.? == .signed) return .f64_convert_i32_s else return .f64_convert_i32_u,
.i64 => if (args.signedness.? == .signed) return .f64_convert_i64_s else return .f64_convert_i64_u,
.f32, .f64 => unreachable,
.v128 => unreachable, // handled independently
},
.v128 => unreachable, // handled independently
},
.demote => if (args.valtype1.? == .f32 and args.valtype2.? == .f64) return .f32_demote_f64 else unreachable,
.promote => if (args.valtype1.? == .f64 and args.valtype2.? == .f32) return .f64_promote_f32 else unreachable,
.reinterpret => switch (args.valtype1.?) {
.i32 => if (args.valtype2.? == .f32) return .i32_reinterpret_f32 else unreachable,
.i64 => if (args.valtype2.? == .f64) return .i64_reinterpret_f64 else unreachable,
.f32 => if (args.valtype2.? == .i32) return .f32_reinterpret_i32 else unreachable,
.f64 => if (args.valtype2.? == .i64) return .f64_reinterpret_i64 else unreachable,
.v128 => unreachable, // handled independently
},
.extend => switch (args.valtype1.?) {
.i32 => switch (args.width.?) {
8 => if (args.signedness.? == .signed) return .i32_extend8_s else unreachable,
16 => if (args.signedness.? == .signed) return .i32_extend16_s else unreachable,
else => unreachable,
},
.i64 => switch (args.width.?) {
8 => if (args.signedness.? == .signed) return .i64_extend8_s else unreachable,
16 => if (args.signedness.? == .signed) return .i64_extend16_s else unreachable,
32 => if (args.signedness.? == .signed) return .i64_extend32_s else unreachable,
else => unreachable,
},
.f32, .f64 => unreachable,
.v128 => unreachable, // handled independently
},
}
}
test "Wasm - buildOpcode" {
// Make sure buildOpcode is referenced, and test some examples
const i32_const = buildOpcode(.{ .op = .@"const", .valtype1 = .i32 });
const end = buildOpcode(.{ .op = .end });
const local_get = buildOpcode(.{ .op = .local_get });
const i64_extend32_s = buildOpcode(.{ .op = .extend, .valtype1 = .i64, .width = 32, .signedness = .signed });
const f64_reinterpret_i64 = buildOpcode(.{ .op = .reinterpret, .valtype1 = .f64, .valtype2 = .i64 });
try testing.expectEqual(@as(wasm.Opcode, .i32_const), i32_const);
try testing.expectEqual(@as(wasm.Opcode, .end), end);
try testing.expectEqual(@as(wasm.Opcode, .local_get), local_get);
try testing.expectEqual(@as(wasm.Opcode, .i64_extend32_s), i64_extend32_s);
try testing.expectEqual(@as(wasm.Opcode, .f64_reinterpret_i64), f64_reinterpret_i64);
}
/// Hashmap to store generated `WValue` for each `Air.Inst.Ref`
pub const ValueTable = std.AutoArrayHashMapUnmanaged(Air.Inst.Ref, WValue);
const CodeGen = @This();
/// Reference to the function declaration the code
/// section belongs to
decl: *Decl,
decl_index: InternPool.DeclIndex,
/// Current block depth. Used to calculate the relative difference between a break
/// and block
block_depth: u32 = 0,
air: Air,
liveness: Liveness,
gpa: mem.Allocator,
debug_output: codegen.DebugInfoOutput,
func_index: InternPool.Index,
/// Contains a list of current branches.
/// When we return from a branch, the branch will be popped from this list,
/// which means branches can only contain references from within its own branch,
/// or a branch higher (lower index) in the tree.
branches: std.ArrayListUnmanaged(Branch) = .{},
/// Table to save `WValue`'s generated by an `Air.Inst`
// values: ValueTable,
/// Mapping from Air.Inst.Index to block ids
blocks: std.AutoArrayHashMapUnmanaged(Air.Inst.Index, struct {
label: u32,
value: WValue,
}) = .{},
/// `bytes` contains the wasm bytecode belonging to the 'code' section.
code: *ArrayList(u8),
/// The index the next local generated will have
/// NOTE: arguments share the index with locals therefore the first variable
/// will have the index that comes after the last argument's index
local_index: u32 = 0,
/// The index of the current argument.
/// Used to track which argument is being referenced in `airArg`.
arg_index: u32 = 0,
/// If codegen fails, an error messages will be allocated and saved in `err_msg`
err_msg: *Module.ErrorMsg,
/// List of all locals' types generated throughout this declaration
/// used to emit locals count at start of 'code' section.
locals: std.ArrayListUnmanaged(u8),
/// List of simd128 immediates. Each value is stored as an array of bytes.
/// This list will only be populated for 128bit-simd values when the target features
/// are enabled also.
simd_immediates: std.ArrayListUnmanaged([16]u8) = .{},
/// The Target we're emitting (used to call intInfo)
target: std.Target,
/// Represents the wasm binary file that is being linked.
bin_file: *link.File.Wasm,
/// List of MIR Instructions
mir_instructions: std.MultiArrayList(Mir.Inst) = .{},
/// Contains extra data for MIR
mir_extra: std.ArrayListUnmanaged(u32) = .{},
/// When a function is executing, we store the the current stack pointer's value within this local.
/// This value is then used to restore the stack pointer to the original value at the return of the function.
initial_stack_value: WValue = .none,
/// The current stack pointer substracted with the stack size. From this value, we will calculate
/// all offsets of the stack values.
bottom_stack_value: WValue = .none,
/// Arguments of this function declaration
/// This will be set after `resolveCallingConventionValues`
args: []WValue = &.{},
/// This will only be `.none` if the function returns void, or returns an immediate.
/// When it returns a pointer to the stack, the `.local` tag will be active and must be populated
/// before this function returns its execution to the caller.
return_value: WValue = .none,
/// The size of the stack this function occupies. In the function prologue
/// we will move the stack pointer by this number, forward aligned with the `stack_alignment`.
stack_size: u32 = 0,
/// The stack alignment, which is 16 bytes by default. This is specified by the
/// tool-conventions: https://github.com/WebAssembly/tool-conventions/blob/main/BasicCABI.md
/// and also what the llvm backend will emit.
/// However, local variables or the usage of `@setAlignStack` can overwrite this default.
stack_alignment: Alignment = .@"16",
// For each individual Wasm valtype we store a seperate free list which
// allows us to re-use locals that are no longer used. e.g. a temporary local.
/// A list of indexes which represents a local of valtype `i32`.
/// It is illegal to store a non-i32 valtype in this list.
free_locals_i32: std.ArrayListUnmanaged(u32) = .{},
/// A list of indexes which represents a local of valtype `i64`.
/// It is illegal to store a non-i64 valtype in this list.
free_locals_i64: std.ArrayListUnmanaged(u32) = .{},
/// A list of indexes which represents a local of valtype `f32`.
/// It is illegal to store a non-f32 valtype in this list.
free_locals_f32: std.ArrayListUnmanaged(u32) = .{},
/// A list of indexes which represents a local of valtype `f64`.
/// It is illegal to store a non-f64 valtype in this list.
free_locals_f64: std.ArrayListUnmanaged(u32) = .{},
/// A list of indexes which represents a local of valtype `v127`.
/// It is illegal to store a non-v128 valtype in this list.
free_locals_v128: std.ArrayListUnmanaged(u32) = .{},
/// When in debug mode, this tracks if no `finishAir` was missed.
/// Forgetting to call `finishAir` will cause the result to not be
/// stored in our `values` map and therefore cause bugs.
air_bookkeeping: @TypeOf(bookkeeping_init) = bookkeeping_init,
const bookkeeping_init = if (std.debug.runtime_safety) @as(usize, 0) else {};
const InnerError = error{
OutOfMemory,
/// An error occurred when trying to lower AIR to MIR.
CodegenFail,
/// Compiler implementation could not handle a large integer.
Overflow,
};
pub fn deinit(func: *CodeGen) void {
// in case of an error and we still have branches
for (func.branches.items) |*branch| {
branch.deinit(func.gpa);
}
func.branches.deinit(func.gpa);
func.blocks.deinit(func.gpa);
func.locals.deinit(func.gpa);
func.simd_immediates.deinit(func.gpa);
func.mir_instructions.deinit(func.gpa);
func.mir_extra.deinit(func.gpa);
func.free_locals_i32.deinit(func.gpa);
func.free_locals_i64.deinit(func.gpa);
func.free_locals_f32.deinit(func.gpa);
func.free_locals_f64.deinit(func.gpa);
func.free_locals_v128.deinit(func.gpa);
func.* = undefined;
}
/// Sets `err_msg` on `CodeGen` and returns `error.CodegenFail` which is caught in link/Wasm.zig
fn fail(func: *CodeGen, comptime fmt: []const u8, args: anytype) InnerError {
const mod = func.bin_file.base.comp.module.?;
const src_loc = func.decl.srcLoc(mod);
func.err_msg = try Module.ErrorMsg.create(func.gpa, src_loc, fmt, args);
return error.CodegenFail;
}
/// Resolves the `WValue` for the given instruction `inst`
/// When the given instruction has a `Value`, it returns a constant instead
fn resolveInst(func: *CodeGen, ref: Air.Inst.Ref) InnerError!WValue {
var branch_index = func.branches.items.len;
while (branch_index > 0) : (branch_index -= 1) {
const branch = func.branches.items[branch_index - 1];
if (branch.values.get(ref)) |value| {
return value;
}
}
// when we did not find an existing instruction, it
// means we must generate it from a constant.
// We always store constants in the most outer branch as they must never
// be removed. The most outer branch is always at index 0.
const gop = try func.branches.items[0].values.getOrPut(func.gpa, ref);
assert(!gop.found_existing);
const mod = func.bin_file.base.comp.module.?;
const val = (try func.air.value(ref, mod)).?;
const ty = func.typeOf(ref);
if (!ty.hasRuntimeBitsIgnoreComptime(mod) and !ty.isInt(mod) and !ty.isError(mod)) {
gop.value_ptr.* = WValue{ .none = {} };
return gop.value_ptr.*;
}
// When we need to pass the value by reference (such as a struct), we will
// leverage `generateSymbol` to lower the constant to bytes and emit it
// to the 'rodata' section. We then return the index into the section as `WValue`.
//
// In the other cases, we will simply lower the constant to a value that fits
// into a single local (such as a pointer, integer, bool, etc).
const result = if (isByRef(ty, mod)) blk: {
const sym_index = try func.bin_file.lowerUnnamedConst(.{ .ty = ty, .val = val }, func.decl_index);
break :blk WValue{ .memory = sym_index };
} else try func.lowerConstant(val, ty);
gop.value_ptr.* = result;
return result;
}
fn finishAir(func: *CodeGen, inst: Air.Inst.Index, result: WValue, operands: []const Air.Inst.Ref) void {
assert(operands.len <= Liveness.bpi - 1);
var tomb_bits = func.liveness.getTombBits(inst);
for (operands) |operand| {
const dies = @as(u1, @truncate(tomb_bits)) != 0;
tomb_bits >>= 1;
if (!dies) continue;
processDeath(func, operand);
}
// results of `none` can never be referenced.
if (result != .none) {
assert(result != .stack); // it's illegal to store a stack value as we cannot track its position
const branch = func.currentBranch();
branch.values.putAssumeCapacityNoClobber(inst.toRef(), result);
}
if (std.debug.runtime_safety) {
func.air_bookkeeping += 1;
}
}
const Branch = struct {
values: ValueTable = .{},
fn deinit(branch: *Branch, gpa: Allocator) void {
branch.values.deinit(gpa);
branch.* = undefined;
}
};
inline fn currentBranch(func: *CodeGen) *Branch {
return &func.branches.items[func.branches.items.len - 1];
}
const BigTomb = struct {
gen: *CodeGen,
inst: Air.Inst.Index,
lbt: Liveness.BigTomb,
fn feed(bt: *BigTomb, op_ref: Air.Inst.Ref) void {
const dies = bt.lbt.feed();
if (!dies) return;
// This will be a nop for interned constants.
processDeath(bt.gen, op_ref);
}
fn finishAir(bt: *BigTomb, result: WValue) void {
assert(result != .stack);
if (result != .none) {
bt.gen.currentBranch().values.putAssumeCapacityNoClobber(bt.inst.toRef(), result);
}
if (std.debug.runtime_safety) {
bt.gen.air_bookkeeping += 1;
}
}
};
fn iterateBigTomb(func: *CodeGen, inst: Air.Inst.Index, operand_count: usize) !BigTomb {
try func.currentBranch().values.ensureUnusedCapacity(func.gpa, operand_count + 1);
return BigTomb{
.gen = func,
.inst = inst,
.lbt = func.liveness.iterateBigTomb(inst),
};
}
fn processDeath(func: *CodeGen, ref: Air.Inst.Ref) void {
if (ref.toIndex() == null) return;
// Branches are currently only allowed to free locals allocated
// within their own branch.
// TODO: Upon branch consolidation free any locals if needed.
const value = func.currentBranch().values.getPtr(ref) orelse return;
if (value.* != .local) return;
const reserved_indexes = func.args.len + @intFromBool(func.return_value != .none);
if (value.local.value < reserved_indexes) {
return; // function arguments can never be re-used
}
log.debug("Decreasing reference for ref: %{d}, using local '{d}'", .{ @intFromEnum(ref.toIndex().?), value.local.value });
value.local.references -= 1; // if this panics, a call to `reuseOperand` was forgotten by the developer
if (value.local.references == 0) {
value.free(func);
}
}
/// Appends a MIR instruction and returns its index within the list of instructions
fn addInst(func: *CodeGen, inst: Mir.Inst) error{OutOfMemory}!void {
try func.mir_instructions.append(func.gpa, inst);
}
fn addTag(func: *CodeGen, tag: Mir.Inst.Tag) error{OutOfMemory}!void {
try func.addInst(.{ .tag = tag, .data = .{ .tag = {} } });
}
fn addExtended(func: *CodeGen, opcode: wasm.MiscOpcode) error{OutOfMemory}!void {
const extra_index = @as(u32, @intCast(func.mir_extra.items.len));
try func.mir_extra.append(func.gpa, @intFromEnum(opcode));
try func.addInst(.{ .tag = .misc_prefix, .data = .{ .payload = extra_index } });
}
fn addLabel(func: *CodeGen, tag: Mir.Inst.Tag, label: u32) error{OutOfMemory}!void {
try func.addInst(.{ .tag = tag, .data = .{ .label = label } });
}
fn addImm32(func: *CodeGen, imm: i32) error{OutOfMemory}!void {
try func.addInst(.{ .tag = .i32_const, .data = .{ .imm32 = imm } });
}
/// Accepts an unsigned 64bit integer rather than a signed integer to
/// prevent us from having to bitcast multiple times as most values
/// within codegen are represented as unsigned rather than signed.
fn addImm64(func: *CodeGen, imm: u64) error{OutOfMemory}!void {
const extra_index = try func.addExtra(Mir.Imm64.fromU64(imm));
try func.addInst(.{ .tag = .i64_const, .data = .{ .payload = extra_index } });
}
/// Accepts the index into the list of 128bit-immediates
fn addImm128(func: *CodeGen, index: u32) error{OutOfMemory}!void {
const simd_values = func.simd_immediates.items[index];
const extra_index = @as(u32, @intCast(func.mir_extra.items.len));
// tag + 128bit value
try func.mir_extra.ensureUnusedCapacity(func.gpa, 5);
func.mir_extra.appendAssumeCapacity(std.wasm.simdOpcode(.v128_const));
func.mir_extra.appendSliceAssumeCapacity(@alignCast(mem.bytesAsSlice(u32, &simd_values)));
try func.addInst(.{ .tag = .simd_prefix, .data = .{ .payload = extra_index } });
}
fn addFloat64(func: *CodeGen, float: f64) error{OutOfMemory}!void {
const extra_index = try func.addExtra(Mir.Float64.fromFloat64(float));
try func.addInst(.{ .tag = .f64_const, .data = .{ .payload = extra_index } });
}
/// Inserts an instruction to load/store from/to wasm's linear memory dependent on the given `tag`.
fn addMemArg(func: *CodeGen, tag: Mir.Inst.Tag, mem_arg: Mir.MemArg) error{OutOfMemory}!void {
const extra_index = try func.addExtra(mem_arg);
try func.addInst(.{ .tag = tag, .data = .{ .payload = extra_index } });
}
/// Inserts an instruction from the 'atomics' feature which accesses wasm's linear memory dependent on the
/// given `tag`.
fn addAtomicMemArg(func: *CodeGen, tag: wasm.AtomicsOpcode, mem_arg: Mir.MemArg) error{OutOfMemory}!void {
const extra_index = try func.addExtra(@as(struct { val: u32 }, .{ .val = wasm.atomicsOpcode(tag) }));
_ = try func.addExtra(mem_arg);
try func.addInst(.{ .tag = .atomics_prefix, .data = .{ .payload = extra_index } });
}
/// Helper function to emit atomic mir opcodes.
fn addAtomicTag(func: *CodeGen, tag: wasm.AtomicsOpcode) error{OutOfMemory}!void {
const extra_index = try func.addExtra(@as(struct { val: u32 }, .{ .val = wasm.atomicsOpcode(tag) }));
try func.addInst(.{ .tag = .atomics_prefix, .data = .{ .payload = extra_index } });
}
/// Appends entries to `mir_extra` based on the type of `extra`.
/// Returns the index into `mir_extra`
fn addExtra(func: *CodeGen, extra: anytype) error{OutOfMemory}!u32 {
const fields = std.meta.fields(@TypeOf(extra));
try func.mir_extra.ensureUnusedCapacity(func.gpa, fields.len);
return func.addExtraAssumeCapacity(extra);
}
/// Appends entries to `mir_extra` based on the type of `extra`.
/// Returns the index into `mir_extra`
fn addExtraAssumeCapacity(func: *CodeGen, extra: anytype) error{OutOfMemory}!u32 {
const fields = std.meta.fields(@TypeOf(extra));
const result = @as(u32, @intCast(func.mir_extra.items.len));
inline for (fields) |field| {
func.mir_extra.appendAssumeCapacity(switch (field.type) {
u32 => @field(extra, field.name),
else => |field_type| @compileError("Unsupported field type " ++ @typeName(field_type)),
});
}
return result;
}
/// Using a given `Type`, returns the corresponding type
fn typeToValtype(ty: Type, mod: *Module) wasm.Valtype {
const target = mod.getTarget();
const ip = &mod.intern_pool;
return switch (ty.zigTypeTag(mod)) {
.Float => switch (ty.floatBits(target)) {
16 => wasm.Valtype.i32, // stored/loaded as u16
32 => wasm.Valtype.f32,
64 => wasm.Valtype.f64,
80, 128 => wasm.Valtype.i64,
else => unreachable,
},
.Int, .Enum => blk: {
const info = ty.intInfo(mod);
if (info.bits <= 32) break :blk wasm.Valtype.i32;
if (info.bits > 32 and info.bits <= 128) break :blk wasm.Valtype.i64;
break :blk wasm.Valtype.i32; // represented as pointer to stack
},
.Struct => {
if (mod.typeToPackedStruct(ty)) |packed_struct| {
return typeToValtype(Type.fromInterned(packed_struct.backingIntType(ip).*), mod);
} else {
return wasm.Valtype.i32;
}
},
.Vector => switch (determineSimdStoreStrategy(ty, mod)) {
.direct => wasm.Valtype.v128,
.unrolled => wasm.Valtype.i32,
},
.Union => switch (ty.containerLayout(mod)) {
.Packed => {
const int_ty = mod.intType(.unsigned, @as(u16, @intCast(ty.bitSize(mod)))) catch @panic("out of memory");
return typeToValtype(int_ty, mod);
},
else => wasm.Valtype.i32,
},
else => wasm.Valtype.i32, // all represented as reference/immediate
};
}
/// Using a given `Type`, returns the byte representation of its wasm value type
fn genValtype(ty: Type, mod: *Module) u8 {
return wasm.valtype(typeToValtype(ty, mod));
}
/// Using a given `Type`, returns the corresponding wasm value type
/// Differently from `genValtype` this also allows `void` to create a block
/// with no return type
fn genBlockType(ty: Type, mod: *Module) u8 {
return switch (ty.ip_index) {
.void_type, .noreturn_type => wasm.block_empty,
else => genValtype(ty, mod),
};
}
/// Writes the bytecode depending on the given `WValue` in `val`
fn emitWValue(func: *CodeGen, value: WValue) InnerError!void {
switch (value) {
.dead => unreachable, // reference to free'd `WValue` (missing reuseOperand?)
.none, .stack => {}, // no-op
.local => |idx| try func.addLabel(.local_get, idx.value),
.imm32 => |val| try func.addImm32(@as(i32, @bitCast(val))),
.imm64 => |val| try func.addImm64(val),
.imm128 => |val| try func.addImm128(val),
.float32 => |val| try func.addInst(.{ .tag = .f32_const, .data = .{ .float32 = val } }),
.float64 => |val| try func.addFloat64(val),
.memory => |ptr| {
const extra_index = try func.addExtra(Mir.Memory{ .pointer = ptr, .offset = 0 });
try func.addInst(.{ .tag = .memory_address, .data = .{ .payload = extra_index } });
},
.memory_offset => |mem_off| {
const extra_index = try func.addExtra(Mir.Memory{ .pointer = mem_off.pointer, .offset = mem_off.offset });
try func.addInst(.{ .tag = .memory_address, .data = .{ .payload = extra_index } });
},
.function_index => |index| try func.addLabel(.function_index, index), // write function index and generate relocation
.stack_offset => try func.addLabel(.local_get, func.bottom_stack_value.local.value), // caller must ensure to address the offset
}
}
/// If given a local or stack-offset, increases the reference count by 1.
/// The old `WValue` found at instruction `ref` is then replaced by the
/// modified `WValue` and returned. When given a non-local or non-stack-offset,
/// returns the given `operand` itfunc instead.
fn reuseOperand(func: *CodeGen, ref: Air.Inst.Ref, operand: WValue) WValue {
if (operand != .local and operand != .stack_offset) return operand;
var new_value = operand;
switch (new_value) {
.local => |*local| local.references += 1,
.stack_offset => |*stack_offset| stack_offset.references += 1,
else => unreachable,
}
const old_value = func.getResolvedInst(ref);
old_value.* = new_value;
return new_value;
}
/// From a reference, returns its resolved `WValue`.
/// It's illegal to provide a `Air.Inst.Ref` that hasn't been resolved yet.
fn getResolvedInst(func: *CodeGen, ref: Air.Inst.Ref) *WValue {
var index = func.branches.items.len;
while (index > 0) : (index -= 1) {
const branch = func.branches.items[index - 1];
if (branch.values.getPtr(ref)) |value| {
return value;
}
}
unreachable; // developer-error: This can only be called on resolved instructions. Use `resolveInst` instead.
}
/// Creates one locals for a given `Type`.
/// Returns a corresponding `Wvalue` with `local` as active tag
fn allocLocal(func: *CodeGen, ty: Type) InnerError!WValue {
const mod = func.bin_file.base.comp.module.?;
const valtype = typeToValtype(ty, mod);
switch (valtype) {
.i32 => if (func.free_locals_i32.popOrNull()) |index| {
log.debug("reusing local ({d}) of type {}", .{ index, valtype });
return WValue{ .local = .{ .value = index, .references = 1 } };
},
.i64 => if (func.free_locals_i64.popOrNull()) |index| {
log.debug("reusing local ({d}) of type {}", .{ index, valtype });
return WValue{ .local = .{ .value = index, .references = 1 } };
},
.f32 => if (func.free_locals_f32.popOrNull()) |index| {
log.debug("reusing local ({d}) of type {}", .{ index, valtype });
return WValue{ .local = .{ .value = index, .references = 1 } };
},
.f64 => if (func.free_locals_f64.popOrNull()) |index| {
log.debug("reusing local ({d}) of type {}", .{ index, valtype });
return WValue{ .local = .{ .value = index, .references = 1 } };
},
.v128 => if (func.free_locals_v128.popOrNull()) |index| {
log.debug("reusing local ({d}) of type {}", .{ index, valtype });
return WValue{ .local = .{ .value = index, .references = 1 } };
},
}
log.debug("new local of type {}", .{valtype});
// no local was free to be re-used, so allocate a new local instead
return func.ensureAllocLocal(ty);
}
/// Ensures a new local will be created. This is useful when it's useful
/// to use a zero-initialized local.
fn ensureAllocLocal(func: *CodeGen, ty: Type) InnerError!WValue {
const mod = func.bin_file.base.comp.module.?;
try func.locals.append(func.gpa, genValtype(ty, mod));
const initial_index = func.local_index;
func.local_index += 1;
return WValue{ .local = .{ .value = initial_index, .references = 1 } };
}
/// Generates a `wasm.Type` from a given function type.
/// Memory is owned by the caller.
fn genFunctype(
gpa: Allocator,
cc: std.builtin.CallingConvention,
params: []const InternPool.Index,
return_type: Type,
mod: *Module,
) !wasm.Type {
var temp_params = std.ArrayList(wasm.Valtype).init(gpa);
defer temp_params.deinit();
var returns = std.ArrayList(wasm.Valtype).init(gpa);
defer returns.deinit();
if (firstParamSRet(cc, return_type, mod)) {
try temp_params.append(.i32); // memory address is always a 32-bit handle
} else if (return_type.hasRuntimeBitsIgnoreComptime(mod)) {
if (cc == .C) {
const res_classes = abi.classifyType(return_type, mod);
assert(res_classes[0] == .direct and res_classes[1] == .none);
const scalar_type = abi.scalarType(return_type, mod);
try returns.append(typeToValtype(scalar_type, mod));
} else {
try returns.append(typeToValtype(return_type, mod));
}
} else if (return_type.isError(mod)) {
try returns.append(.i32);
}
// param types
for (params) |param_type_ip| {
const param_type = Type.fromInterned(param_type_ip);
if (!param_type.hasRuntimeBitsIgnoreComptime(mod)) continue;
switch (cc) {
.C => {
const param_classes = abi.classifyType(param_type, mod);
for (param_classes) |class| {
if (class == .none) continue;
if (class == .direct) {
const scalar_type = abi.scalarType(param_type, mod);
try temp_params.append(typeToValtype(scalar_type, mod));
} else {
try temp_params.append(typeToValtype(param_type, mod));
}
}
},
else => if (isByRef(param_type, mod))
try temp_params.append(.i32)
else
try temp_params.append(typeToValtype(param_type, mod)),
}
}
return wasm.Type{
.params = try temp_params.toOwnedSlice(),
.returns = try returns.toOwnedSlice(),
};
}
pub fn generate(
bin_file: *link.File,
src_loc: Module.SrcLoc,
func_index: InternPool.Index,
air: Air,
liveness: Liveness,
code: *std.ArrayList(u8),
debug_output: codegen.DebugInfoOutput,
) codegen.CodeGenError!codegen.Result {
_ = src_loc;
const comp = bin_file.comp;
const gpa = comp.gpa;
const mod = comp.module.?;
const func = mod.funcInfo(func_index);
const decl = mod.declPtr(func.owner_decl);
const namespace = mod.namespacePtr(decl.src_namespace);
const target = namespace.file_scope.mod.resolved_target.result;
var code_gen: CodeGen = .{
.gpa = gpa,
.air = air,
.liveness = liveness,
.code = code,
.decl_index = func.owner_decl,
.decl = decl,
.err_msg = undefined,
.locals = .{},
.target = target,
.bin_file = bin_file.cast(link.File.Wasm).?,
.debug_output = debug_output,
.func_index = func_index,
};
defer code_gen.deinit();
genFunc(&code_gen) catch |err| switch (err) {
error.CodegenFail => return codegen.Result{ .fail = code_gen.err_msg },
else => |e| return e,
};
return codegen.Result.ok;
}
fn genFunc(func: *CodeGen) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const ip = &mod.intern_pool;
const fn_info = mod.typeToFunc(func.decl.ty).?;
var func_type = try genFunctype(func.gpa, fn_info.cc, fn_info.param_types.get(ip), Type.fromInterned(fn_info.return_type), mod);
defer func_type.deinit(func.gpa);
_ = try func.bin_file.storeDeclType(func.decl_index, func_type);
var cc_result = try func.resolveCallingConventionValues(func.decl.ty);
defer cc_result.deinit(func.gpa);
func.args = cc_result.args;
func.return_value = cc_result.return_value;
try func.addTag(.dbg_prologue_end);
try func.branches.append(func.gpa, .{});
// clean up outer branch
defer {
var outer_branch = func.branches.pop();
outer_branch.deinit(func.gpa);
assert(func.branches.items.len == 0); // missing branch merge
}
// Generate MIR for function body
try func.genBody(func.air.getMainBody());
// In case we have a return value, but the last instruction is a noreturn (such as a while loop)
// we emit an unreachable instruction to tell the stack validator that part will never be reached.
if (func_type.returns.len != 0 and func.air.instructions.len > 0) {
const inst: Air.Inst.Index = @enumFromInt(func.air.instructions.len - 1);
const last_inst_ty = func.typeOfIndex(inst);
if (!last_inst_ty.hasRuntimeBitsIgnoreComptime(mod) or last_inst_ty.isNoReturn(mod)) {
try func.addTag(.@"unreachable");
}
}
// End of function body
try func.addTag(.end);
try func.addTag(.dbg_epilogue_begin);
// check if we have to initialize and allocate anything into the stack frame.
// If so, create enough stack space and insert the instructions at the front of the list.
if (func.initial_stack_value != .none) {
var prologue = std.ArrayList(Mir.Inst).init(func.gpa);
defer prologue.deinit();
const sp = @intFromEnum(func.bin_file.zigObjectPtr().?.stack_pointer_sym);
// load stack pointer
try prologue.append(.{ .tag = .global_get, .data = .{ .label = sp } });
// store stack pointer so we can restore it when we return from the function
try prologue.append(.{ .tag = .local_tee, .data = .{ .label = func.initial_stack_value.local.value } });
// get the total stack size
const aligned_stack = func.stack_alignment.forward(func.stack_size);
try prologue.append(.{ .tag = .i32_const, .data = .{ .imm32 = @intCast(aligned_stack) } });
// subtract it from the current stack pointer
try prologue.append(.{ .tag = .i32_sub, .data = .{ .tag = {} } });
// Get negative stack aligment
try prologue.append(.{ .tag = .i32_const, .data = .{ .imm32 = @as(i32, @intCast(func.stack_alignment.toByteUnitsOptional().?)) * -1 } });
// Bitwise-and the value to get the new stack pointer to ensure the pointers are aligned with the abi alignment
try prologue.append(.{ .tag = .i32_and, .data = .{ .tag = {} } });
// store the current stack pointer as the bottom, which will be used to calculate all stack pointer offsets
try prologue.append(.{ .tag = .local_tee, .data = .{ .label = func.bottom_stack_value.local.value } });
// Store the current stack pointer value into the global stack pointer so other function calls will
// start from this value instead and not overwrite the current stack.
try prologue.append(.{ .tag = .global_set, .data = .{ .label = sp } });
// reserve space and insert all prologue instructions at the front of the instruction list
// We insert them in reserve order as there is no insertSlice in multiArrayList.
try func.mir_instructions.ensureUnusedCapacity(func.gpa, prologue.items.len);
for (prologue.items, 0..) |_, index| {
const inst = prologue.items[prologue.items.len - 1 - index];
func.mir_instructions.insertAssumeCapacity(0, inst);
}
}
var mir: Mir = .{
.instructions = func.mir_instructions.toOwnedSlice(),
.extra = try func.mir_extra.toOwnedSlice(func.gpa),
};
defer mir.deinit(func.gpa);
var emit: Emit = .{
.mir = mir,
.bin_file = func.bin_file,
.code = func.code,
.locals = func.locals.items,
.decl_index = func.decl_index,
.dbg_output = func.debug_output,
.prev_di_line = 0,
.prev_di_column = 0,
.prev_di_offset = 0,
};
emit.emitMir() catch |err| switch (err) {
error.EmitFail => {
func.err_msg = emit.error_msg.?;
return error.CodegenFail;
},
else => |e| return e,
};
}
const CallWValues = struct {
args: []WValue,
return_value: WValue,
fn deinit(values: *CallWValues, gpa: Allocator) void {
gpa.free(values.args);
values.* = undefined;
}
};
fn resolveCallingConventionValues(func: *CodeGen, fn_ty: Type) InnerError!CallWValues {
const mod = func.bin_file.base.comp.module.?;
const ip = &mod.intern_pool;
const fn_info = mod.typeToFunc(fn_ty).?;
const cc = fn_info.cc;
var result: CallWValues = .{
.args = &.{},
.return_value = .none,
};
if (cc == .Naked) return result;
var args = std.ArrayList(WValue).init(func.gpa);
defer args.deinit();
// Check if we store the result as a pointer to the stack rather than
// by value
if (firstParamSRet(fn_info.cc, Type.fromInterned(fn_info.return_type), mod)) {
// the sret arg will be passed as first argument, therefore we
// set the `return_value` before allocating locals for regular args.
result.return_value = .{ .local = .{ .value = func.local_index, .references = 1 } };
func.local_index += 1;
}
switch (cc) {
.Unspecified => {
for (fn_info.param_types.get(ip)) |ty| {
if (!Type.fromInterned(ty).hasRuntimeBitsIgnoreComptime(mod)) {
continue;
}
try args.append(.{ .local = .{ .value = func.local_index, .references = 1 } });
func.local_index += 1;
}
},
.C => {
for (fn_info.param_types.get(ip)) |ty| {
const ty_classes = abi.classifyType(Type.fromInterned(ty), mod);
for (ty_classes) |class| {
if (class == .none) continue;
try args.append(.{ .local = .{ .value = func.local_index, .references = 1 } });
func.local_index += 1;
}
}
},
else => return func.fail("calling convention '{s}' not supported for Wasm", .{@tagName(cc)}),
}
result.args = try args.toOwnedSlice();
return result;
}
fn firstParamSRet(cc: std.builtin.CallingConvention, return_type: Type, mod: *Module) bool {
switch (cc) {
.Unspecified, .Inline => return isByRef(return_type, mod),
.C => {
const ty_classes = abi.classifyType(return_type, mod);
if (ty_classes[0] == .indirect) return true;
if (ty_classes[0] == .direct and ty_classes[1] == .direct) return true;
return false;
},
else => return false,
}
}
/// Lowers a Zig type and its value based on a given calling convention to ensure
/// it matches the ABI.
fn lowerArg(func: *CodeGen, cc: std.builtin.CallingConvention, ty: Type, value: WValue) !void {
if (cc != .C) {
return func.lowerToStack(value);
}
const mod = func.bin_file.base.comp.module.?;
const ty_classes = abi.classifyType(ty, mod);
assert(ty_classes[0] != .none);
switch (ty.zigTypeTag(mod)) {
.Struct, .Union => {
if (ty_classes[0] == .indirect) {
return func.lowerToStack(value);
}
assert(ty_classes[0] == .direct);
const scalar_type = abi.scalarType(ty, mod);
switch (value) {
.memory,
.memory_offset,
.stack_offset,
=> _ = try func.load(value, scalar_type, 0),
.dead => unreachable,
else => try func.emitWValue(value),
}
},
.Int, .Float => {
if (ty_classes[1] == .none) {
return func.lowerToStack(value);
}
assert(ty_classes[0] == .direct and ty_classes[1] == .direct);
assert(ty.abiSize(mod) == 16);
// in this case we have an integer or float that must be lowered as 2 i64's.
try func.emitWValue(value);
try func.addMemArg(.i64_load, .{ .offset = value.offset(), .alignment = 8 });
try func.emitWValue(value);
try func.addMemArg(.i64_load, .{ .offset = value.offset() + 8, .alignment = 8 });
},
else => return func.lowerToStack(value),
}
}
/// Lowers a `WValue` to the stack. This means when the `value` results in
/// `.stack_offset` we calculate the pointer of this offset and use that.
/// The value is left on the stack, and not stored in any temporary.
fn lowerToStack(func: *CodeGen, value: WValue) !void {
switch (value) {
.stack_offset => |offset| {
try func.emitWValue(value);
if (offset.value > 0) {
switch (func.arch()) {
.wasm32 => {
try func.addImm32(@as(i32, @bitCast(offset.value)));
try func.addTag(.i32_add);
},
.wasm64 => {
try func.addImm64(offset.value);
try func.addTag(.i64_add);
},
else => unreachable,
}
}
},
else => try func.emitWValue(value),
}
}
/// Creates a local for the initial stack value
/// Asserts `initial_stack_value` is `.none`
fn initializeStack(func: *CodeGen) !void {
assert(func.initial_stack_value == .none);
// Reserve a local to store the current stack pointer
// We can later use this local to set the stack pointer back to the value
// we have stored here.
func.initial_stack_value = try func.ensureAllocLocal(Type.usize);
// Also reserve a local to store the bottom stack value
func.bottom_stack_value = try func.ensureAllocLocal(Type.usize);
}
/// Reads the stack pointer from `Context.initial_stack_value` and writes it
/// to the global stack pointer variable
fn restoreStackPointer(func: *CodeGen) !void {
// only restore the pointer if it was initialized
if (func.initial_stack_value == .none) return;
// Get the original stack pointer's value
try func.emitWValue(func.initial_stack_value);
// save its value in the global stack pointer
try func.addLabel(.global_set, @intFromEnum(func.bin_file.zigObjectPtr().?.stack_pointer_sym));
}
/// From a given type, will create space on the virtual stack to store the value of such type.
/// This returns a `WValue` with its active tag set to `local`, containing the index to the local
/// that points to the position on the virtual stack. This function should be used instead of
/// moveStack unless a local was already created to store the pointer.
///
/// Asserts Type has codegenbits
fn allocStack(func: *CodeGen, ty: Type) !WValue {
const mod = func.bin_file.base.comp.module.?;
assert(ty.hasRuntimeBitsIgnoreComptime(mod));
if (func.initial_stack_value == .none) {
try func.initializeStack();
}
const abi_size = std.math.cast(u32, ty.abiSize(mod)) orelse {
return func.fail("Type {} with ABI size of {d} exceeds stack frame size", .{
ty.fmt(mod), ty.abiSize(mod),
});
};
const abi_align = ty.abiAlignment(mod);
func.stack_alignment = func.stack_alignment.max(abi_align);
const offset: u32 = @intCast(abi_align.forward(func.stack_size));
defer func.stack_size = offset + abi_size;
return WValue{ .stack_offset = .{ .value = offset, .references = 1 } };
}
/// From a given AIR instruction generates a pointer to the stack where
/// the value of its type will live.
/// This is different from allocStack where this will use the pointer's alignment
/// if it is set, to ensure the stack alignment will be set correctly.
fn allocStackPtr(func: *CodeGen, inst: Air.Inst.Index) !WValue {
const mod = func.bin_file.base.comp.module.?;
const ptr_ty = func.typeOfIndex(inst);
const pointee_ty = ptr_ty.childType(mod);
if (func.initial_stack_value == .none) {
try func.initializeStack();
}
if (!pointee_ty.hasRuntimeBitsIgnoreComptime(mod)) {
return func.allocStack(Type.usize); // create a value containing just the stack pointer.
}
const abi_alignment = ptr_ty.ptrAlignment(mod);
const abi_size = std.math.cast(u32, pointee_ty.abiSize(mod)) orelse {
return func.fail("Type {} with ABI size of {d} exceeds stack frame size", .{
pointee_ty.fmt(mod), pointee_ty.abiSize(mod),
});
};
func.stack_alignment = func.stack_alignment.max(abi_alignment);
const offset: u32 = @intCast(abi_alignment.forward(func.stack_size));
defer func.stack_size = offset + abi_size;
return WValue{ .stack_offset = .{ .value = offset, .references = 1 } };
}
/// From given zig bitsize, returns the wasm bitsize
fn toWasmBits(bits: u16) ?u16 {
return for ([_]u16{ 32, 64, 128 }) |wasm_bits| {
if (bits <= wasm_bits) return wasm_bits;
} else null;
}
/// Performs a copy of bytes for a given type. Copying all bytes
/// from rhs to lhs.
fn memcpy(func: *CodeGen, dst: WValue, src: WValue, len: WValue) !void {
// When bulk_memory is enabled, we lower it to wasm's memcpy instruction.
// If not, we lower it ourselves manually
if (std.Target.wasm.featureSetHas(func.target.cpu.features, .bulk_memory)) {
try func.lowerToStack(dst);
try func.lowerToStack(src);
try func.emitWValue(len);
try func.addExtended(.memory_copy);
return;
}
// when the length is comptime-known, rather than a runtime value, we can optimize the generated code by having
// the loop during codegen, rather than inserting a runtime loop into the binary.
switch (len) {
.imm32, .imm64 => blk: {
const length = switch (len) {
.imm32 => |val| val,
.imm64 => |val| val,
else => unreachable,
};
// if the size (length) is more than 32 bytes, we use a runtime loop instead to prevent
// binary size bloat.
if (length > 32) break :blk;
var offset: u32 = 0;
const lhs_base = dst.offset();
const rhs_base = src.offset();
while (offset < length) : (offset += 1) {
// get dst's address to store the result
try func.emitWValue(dst);
// load byte from src's address
try func.emitWValue(src);
switch (func.arch()) {
.wasm32 => {
try func.addMemArg(.i32_load8_u, .{ .offset = rhs_base + offset, .alignment = 1 });
try func.addMemArg(.i32_store8, .{ .offset = lhs_base + offset, .alignment = 1 });
},
.wasm64 => {
try func.addMemArg(.i64_load8_u, .{ .offset = rhs_base + offset, .alignment = 1 });
try func.addMemArg(.i64_store8, .{ .offset = lhs_base + offset, .alignment = 1 });
},
else => unreachable,
}
}
return;
},
else => {},
}
// allocate a local for the offset, and set it to 0.
// This to ensure that inside loops we correctly re-set the counter.
var offset = try func.allocLocal(Type.usize); // local for counter
defer offset.free(func);
switch (func.arch()) {
.wasm32 => try func.addImm32(0),
.wasm64 => try func.addImm64(0),
else => unreachable,
}
try func.addLabel(.local_set, offset.local.value);
// outer block to jump to when loop is done
try func.startBlock(.block, wasm.block_empty);
try func.startBlock(.loop, wasm.block_empty);
// loop condition (offset == length -> break)
{
try func.emitWValue(offset);
try func.emitWValue(len);
switch (func.arch()) {
.wasm32 => try func.addTag(.i32_eq),
.wasm64 => try func.addTag(.i64_eq),
else => unreachable,
}
try func.addLabel(.br_if, 1); // jump out of loop into outer block (finished)
}
// get dst ptr
{
try func.emitWValue(dst);
try func.emitWValue(offset);
switch (func.arch()) {
.wasm32 => try func.addTag(.i32_add),
.wasm64 => try func.addTag(.i64_add),
else => unreachable,
}
}
// get src value and also store in dst
{
try func.emitWValue(src);
try func.emitWValue(offset);
switch (func.arch()) {
.wasm32 => {
try func.addTag(.i32_add);
try func.addMemArg(.i32_load8_u, .{ .offset = src.offset(), .alignment = 1 });
try func.addMemArg(.i32_store8, .{ .offset = dst.offset(), .alignment = 1 });
},
.wasm64 => {
try func.addTag(.i64_add);
try func.addMemArg(.i64_load8_u, .{ .offset = src.offset(), .alignment = 1 });
try func.addMemArg(.i64_store8, .{ .offset = dst.offset(), .alignment = 1 });
},
else => unreachable,
}
}
// increment loop counter
{
try func.emitWValue(offset);
switch (func.arch()) {
.wasm32 => {
try func.addImm32(1);
try func.addTag(.i32_add);
},
.wasm64 => {
try func.addImm64(1);
try func.addTag(.i64_add);
},
else => unreachable,
}
try func.addLabel(.local_set, offset.local.value);
try func.addLabel(.br, 0); // jump to start of loop
}
try func.endBlock(); // close off loop block
try func.endBlock(); // close off outer block
}
fn ptrSize(func: *const CodeGen) u16 {
return @divExact(func.target.ptrBitWidth(), 8);
}
fn arch(func: *const CodeGen) std.Target.Cpu.Arch {
return func.target.cpu.arch;
}
/// For a given `Type`, will return true when the type will be passed
/// by reference, rather than by value
fn isByRef(ty: Type, mod: *Module) bool {
const ip = &mod.intern_pool;
const target = mod.getTarget();
switch (ty.zigTypeTag(mod)) {
.Type,
.ComptimeInt,
.ComptimeFloat,
.EnumLiteral,
.Undefined,
.Null,
.Opaque,
=> unreachable,
.NoReturn,
.Void,
.Bool,
.ErrorSet,
.Fn,
.Enum,
.AnyFrame,
=> return false,
.Array,
.Frame,
=> return ty.hasRuntimeBitsIgnoreComptime(mod),
.Union => {
if (mod.typeToUnion(ty)) |union_obj| {
if (union_obj.getLayout(ip) == .Packed) {
return ty.abiSize(mod) > 8;
}
}
return ty.hasRuntimeBitsIgnoreComptime(mod);
},
.Struct => {
if (mod.typeToPackedStruct(ty)) |packed_struct| {
return isByRef(Type.fromInterned(packed_struct.backingIntType(ip).*), mod);
}
return ty.hasRuntimeBitsIgnoreComptime(mod);
},
.Vector => return determineSimdStoreStrategy(ty, mod) == .unrolled,
.Int => return ty.intInfo(mod).bits > 64,
.Float => return ty.floatBits(target) > 64,
.ErrorUnion => {
const pl_ty = ty.errorUnionPayload(mod);
if (!pl_ty.hasRuntimeBitsIgnoreComptime(mod)) {
return false;
}
return true;
},
.Optional => {
if (ty.isPtrLikeOptional(mod)) return false;
const pl_type = ty.optionalChild(mod);
if (pl_type.zigTypeTag(mod) == .ErrorSet) return false;
return pl_type.hasRuntimeBitsIgnoreComptime(mod);
},
.Pointer => {
// Slices act like struct and will be passed by reference
if (ty.isSlice(mod)) return true;
return false;
},
}
}
const SimdStoreStrategy = enum {
direct,
unrolled,
};
/// For a given vector type, returns the `SimdStoreStrategy`.
/// This means when a given type is 128 bits and either the simd128 or relaxed-simd
/// features are enabled, the function will return `.direct`. This would allow to store
/// it using a instruction, rather than an unrolled version.
fn determineSimdStoreStrategy(ty: Type, mod: *Module) SimdStoreStrategy {
std.debug.assert(ty.zigTypeTag(mod) == .Vector);
if (ty.bitSize(mod) != 128) return .unrolled;
const hasFeature = std.Target.wasm.featureSetHas;
const target = mod.getTarget();
const features = target.cpu.features;
if (hasFeature(features, .relaxed_simd) or hasFeature(features, .simd128)) {
return .direct;
}
return .unrolled;
}
/// Creates a new local for a pointer that points to memory with given offset.
/// This can be used to get a pointer to a struct field, error payload, etc.
/// By providing `modify` as action, it will modify the given `ptr_value` instead of making a new
/// local value to store the pointer. This allows for local re-use and improves binary size.
fn buildPointerOffset(func: *CodeGen, ptr_value: WValue, offset: u64, action: enum { modify, new }) InnerError!WValue {
// do not perform arithmetic when offset is 0.
if (offset == 0 and ptr_value.offset() == 0 and action == .modify) return ptr_value;
const result_ptr: WValue = switch (action) {
.new => try func.ensureAllocLocal(Type.usize),
.modify => ptr_value,
};
try func.emitWValue(ptr_value);
if (offset + ptr_value.offset() > 0) {
switch (func.arch()) {
.wasm32 => {
try func.addImm32(@as(i32, @bitCast(@as(u32, @intCast(offset + ptr_value.offset())))));
try func.addTag(.i32_add);
},
.wasm64 => {
try func.addImm64(offset + ptr_value.offset());
try func.addTag(.i64_add);
},
else => unreachable,
}
}
try func.addLabel(.local_set, result_ptr.local.value);
return result_ptr;
}
fn genInst(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const air_tags = func.air.instructions.items(.tag);
return switch (air_tags[@intFromEnum(inst)]) {
.inferred_alloc, .inferred_alloc_comptime => unreachable,
.add => func.airBinOp(inst, .add),
.add_sat => func.airSatBinOp(inst, .add),
.add_wrap => func.airWrapBinOp(inst, .add),
.sub => func.airBinOp(inst, .sub),
.sub_sat => func.airSatBinOp(inst, .sub),
.sub_wrap => func.airWrapBinOp(inst, .sub),
.mul => func.airBinOp(inst, .mul),
.mul_wrap => func.airWrapBinOp(inst, .mul),
.div_float, .div_exact => func.airDiv(inst),
.div_trunc => func.airDivTrunc(inst),
.div_floor => func.airDivFloor(inst),
.bit_and => func.airBinOp(inst, .@"and"),
.bit_or => func.airBinOp(inst, .@"or"),
.bool_and => func.airBinOp(inst, .@"and"),
.bool_or => func.airBinOp(inst, .@"or"),
.rem => func.airBinOp(inst, .rem),
.mod => func.airMod(inst),
.shl => func.airWrapBinOp(inst, .shl),
.shl_exact => func.airBinOp(inst, .shl),
.shl_sat => func.airShlSat(inst),
.shr, .shr_exact => func.airBinOp(inst, .shr),
.xor => func.airBinOp(inst, .xor),
.max => func.airMaxMin(inst, .max),
.min => func.airMaxMin(inst, .min),
.mul_add => func.airMulAdd(inst),
.sqrt => func.airUnaryFloatOp(inst, .sqrt),
.sin => func.airUnaryFloatOp(inst, .sin),
.cos => func.airUnaryFloatOp(inst, .cos),
.tan => func.airUnaryFloatOp(inst, .tan),
.exp => func.airUnaryFloatOp(inst, .exp),
.exp2 => func.airUnaryFloatOp(inst, .exp2),
.log => func.airUnaryFloatOp(inst, .log),
.log2 => func.airUnaryFloatOp(inst, .log2),
.log10 => func.airUnaryFloatOp(inst, .log10),
.floor => func.airUnaryFloatOp(inst, .floor),
.ceil => func.airUnaryFloatOp(inst, .ceil),
.round => func.airUnaryFloatOp(inst, .round),
.trunc_float => func.airUnaryFloatOp(inst, .trunc),
.neg => func.airUnaryFloatOp(inst, .neg),
.abs => func.airAbs(inst),
.add_with_overflow => func.airAddSubWithOverflow(inst, .add),
.sub_with_overflow => func.airAddSubWithOverflow(inst, .sub),
.shl_with_overflow => func.airShlWithOverflow(inst),
.mul_with_overflow => func.airMulWithOverflow(inst),
.clz => func.airClz(inst),
.ctz => func.airCtz(inst),
.cmp_eq => func.airCmp(inst, .eq),
.cmp_gte => func.airCmp(inst, .gte),
.cmp_gt => func.airCmp(inst, .gt),
.cmp_lte => func.airCmp(inst, .lte),
.cmp_lt => func.airCmp(inst, .lt),
.cmp_neq => func.airCmp(inst, .neq),
.cmp_vector => func.airCmpVector(inst),
.cmp_lt_errors_len => func.airCmpLtErrorsLen(inst),
.array_elem_val => func.airArrayElemVal(inst),
.array_to_slice => func.airArrayToSlice(inst),
.alloc => func.airAlloc(inst),
.arg => func.airArg(inst),
.bitcast => func.airBitcast(inst),
.block => func.airBlock(inst),
.trap => func.airTrap(inst),
.breakpoint => func.airBreakpoint(inst),
.br => func.airBr(inst),
.int_from_bool => func.airIntFromBool(inst),
.cond_br => func.airCondBr(inst),
.intcast => func.airIntcast(inst),
.fptrunc => func.airFptrunc(inst),
.fpext => func.airFpext(inst),
.int_from_float => func.airIntFromFloat(inst),
.float_from_int => func.airFloatFromInt(inst),
.get_union_tag => func.airGetUnionTag(inst),
.@"try" => func.airTry(inst),
.try_ptr => func.airTryPtr(inst),
.dbg_stmt => func.airDbgStmt(inst),
.dbg_inline_block => func.airDbgInlineBlock(inst),
.dbg_var_ptr => func.airDbgVar(inst, true),
.dbg_var_val => func.airDbgVar(inst, false),
.call => func.airCall(inst, .auto),
.call_always_tail => func.airCall(inst, .always_tail),
.call_never_tail => func.airCall(inst, .never_tail),
.call_never_inline => func.airCall(inst, .never_inline),
.is_err => func.airIsErr(inst, .i32_ne),
.is_non_err => func.airIsErr(inst, .i32_eq),
.is_null => func.airIsNull(inst, .i32_eq, .value),
.is_non_null => func.airIsNull(inst, .i32_ne, .value),
.is_null_ptr => func.airIsNull(inst, .i32_eq, .ptr),
.is_non_null_ptr => func.airIsNull(inst, .i32_ne, .ptr),
.load => func.airLoad(inst),
.loop => func.airLoop(inst),
.memset => func.airMemset(inst, false),
.memset_safe => func.airMemset(inst, true),
.not => func.airNot(inst),
.optional_payload => func.airOptionalPayload(inst),
.optional_payload_ptr => func.airOptionalPayloadPtr(inst),
.optional_payload_ptr_set => func.airOptionalPayloadPtrSet(inst),
.ptr_add => func.airPtrBinOp(inst, .add),
.ptr_sub => func.airPtrBinOp(inst, .sub),
.ptr_elem_ptr => func.airPtrElemPtr(inst),
.ptr_elem_val => func.airPtrElemVal(inst),
.int_from_ptr => func.airIntFromPtr(inst),
.ret => func.airRet(inst),
.ret_safe => func.airRet(inst), // TODO
.ret_ptr => func.airRetPtr(inst),
.ret_load => func.airRetLoad(inst),
.splat => func.airSplat(inst),
.select => func.airSelect(inst),
.shuffle => func.airShuffle(inst),
.reduce => func.airReduce(inst),
.aggregate_init => func.airAggregateInit(inst),
.union_init => func.airUnionInit(inst),
.prefetch => func.airPrefetch(inst),
.popcount => func.airPopcount(inst),
.byte_swap => func.airByteSwap(inst),
.slice => func.airSlice(inst),
.slice_len => func.airSliceLen(inst),
.slice_elem_val => func.airSliceElemVal(inst),
.slice_elem_ptr => func.airSliceElemPtr(inst),
.slice_ptr => func.airSlicePtr(inst),
.ptr_slice_len_ptr => func.airPtrSliceFieldPtr(inst, func.ptrSize()),
.ptr_slice_ptr_ptr => func.airPtrSliceFieldPtr(inst, 0),
.store => func.airStore(inst, false),
.store_safe => func.airStore(inst, true),
.set_union_tag => func.airSetUnionTag(inst),
.struct_field_ptr => func.airStructFieldPtr(inst),
.struct_field_ptr_index_0 => func.airStructFieldPtrIndex(inst, 0),
.struct_field_ptr_index_1 => func.airStructFieldPtrIndex(inst, 1),
.struct_field_ptr_index_2 => func.airStructFieldPtrIndex(inst, 2),
.struct_field_ptr_index_3 => func.airStructFieldPtrIndex(inst, 3),
.struct_field_val => func.airStructFieldVal(inst),
.field_parent_ptr => func.airFieldParentPtr(inst),
.switch_br => func.airSwitchBr(inst),
.trunc => func.airTrunc(inst),
.unreach => func.airUnreachable(inst),
.wrap_optional => func.airWrapOptional(inst),
.unwrap_errunion_payload => func.airUnwrapErrUnionPayload(inst, false),
.unwrap_errunion_payload_ptr => func.airUnwrapErrUnionPayload(inst, true),
.unwrap_errunion_err => func.airUnwrapErrUnionError(inst, false),
.unwrap_errunion_err_ptr => func.airUnwrapErrUnionError(inst, true),
.wrap_errunion_payload => func.airWrapErrUnionPayload(inst),
.wrap_errunion_err => func.airWrapErrUnionErr(inst),
.errunion_payload_ptr_set => func.airErrUnionPayloadPtrSet(inst),
.error_name => func.airErrorName(inst),
.wasm_memory_size => func.airWasmMemorySize(inst),
.wasm_memory_grow => func.airWasmMemoryGrow(inst),
.memcpy => func.airMemcpy(inst),
.ret_addr => func.airRetAddr(inst),
.tag_name => func.airTagName(inst),
.error_set_has_value => func.airErrorSetHasValue(inst),
.frame_addr => func.airFrameAddress(inst),
.mul_sat,
.assembly,
.bit_reverse,
.is_err_ptr,
.is_non_err_ptr,
.err_return_trace,
.set_err_return_trace,
.save_err_return_trace_index,
.is_named_enum_value,
.addrspace_cast,
.vector_store_elem,
.c_va_arg,
.c_va_copy,
.c_va_end,
.c_va_start,
=> |tag| return func.fail("TODO: Implement wasm inst: {s}", .{@tagName(tag)}),
.atomic_load => func.airAtomicLoad(inst),
.atomic_store_unordered,
.atomic_store_monotonic,
.atomic_store_release,
.atomic_store_seq_cst,
// in WebAssembly, all atomic instructions are sequentially ordered.
=> func.airAtomicStore(inst),
.atomic_rmw => func.airAtomicRmw(inst),
.cmpxchg_weak => func.airCmpxchg(inst),
.cmpxchg_strong => func.airCmpxchg(inst),
.fence => func.airFence(inst),
.add_optimized,
.sub_optimized,
.mul_optimized,
.div_float_optimized,
.div_trunc_optimized,
.div_floor_optimized,
.div_exact_optimized,
.rem_optimized,
.mod_optimized,
.neg_optimized,
.cmp_lt_optimized,
.cmp_lte_optimized,
.cmp_eq_optimized,
.cmp_gte_optimized,
.cmp_gt_optimized,
.cmp_neq_optimized,
.cmp_vector_optimized,
.reduce_optimized,
.int_from_float_optimized,
=> return func.fail("TODO implement optimized float mode", .{}),
.add_safe,
.sub_safe,
.mul_safe,
=> return func.fail("TODO implement safety_checked_instructions", .{}),
.work_item_id,
.work_group_size,
.work_group_id,
=> unreachable,
};
}
fn genBody(func: *CodeGen, body: []const Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const ip = &mod.intern_pool;
for (body) |inst| {
if (func.liveness.isUnused(inst) and !func.air.mustLower(inst, ip)) {
continue;
}
const old_bookkeeping_value = func.air_bookkeeping;
try func.currentBranch().values.ensureUnusedCapacity(func.gpa, Liveness.bpi);
try func.genInst(inst);
if (std.debug.runtime_safety and func.air_bookkeeping < old_bookkeeping_value + 1) {
std.debug.panic("Missing call to `finishAir` in AIR instruction %{d} ('{}')", .{
inst,
func.air.instructions.items(.tag)[@intFromEnum(inst)],
});
}
}
}
fn airRet(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const un_op = func.air.instructions.items(.data)[@intFromEnum(inst)].un_op;
const operand = try func.resolveInst(un_op);
const fn_info = mod.typeToFunc(func.decl.ty).?;
const ret_ty = Type.fromInterned(fn_info.return_type);
// result must be stored in the stack and we return a pointer
// to the stack instead
if (func.return_value != .none) {
try func.store(func.return_value, operand, ret_ty, 0);
} else if (fn_info.cc == .C and ret_ty.hasRuntimeBitsIgnoreComptime(mod)) {
switch (ret_ty.zigTypeTag(mod)) {
// Aggregate types can be lowered as a singular value
.Struct, .Union => {
const scalar_type = abi.scalarType(ret_ty, mod);
try func.emitWValue(operand);
const opcode = buildOpcode(.{
.op = .load,
.width = @as(u8, @intCast(scalar_type.abiSize(mod) * 8)),
.signedness = if (scalar_type.isSignedInt(mod)) .signed else .unsigned,
.valtype1 = typeToValtype(scalar_type, mod),
});
try func.addMemArg(Mir.Inst.Tag.fromOpcode(opcode), .{
.offset = operand.offset(),
.alignment = @intCast(scalar_type.abiAlignment(mod).toByteUnitsOptional().?),
});
},
else => try func.emitWValue(operand),
}
} else {
if (!ret_ty.hasRuntimeBitsIgnoreComptime(mod) and ret_ty.isError(mod)) {
try func.addImm32(0);
} else {
try func.emitWValue(operand);
}
}
try func.restoreStackPointer();
try func.addTag(.@"return");
func.finishAir(inst, .none, &.{un_op});
}
fn airRetPtr(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const child_type = func.typeOfIndex(inst).childType(mod);
const result = result: {
if (!child_type.isFnOrHasRuntimeBitsIgnoreComptime(mod)) {
break :result try func.allocStack(Type.usize); // create pointer to void
}
const fn_info = mod.typeToFunc(func.decl.ty).?;
if (firstParamSRet(fn_info.cc, Type.fromInterned(fn_info.return_type), mod)) {
break :result func.return_value;
}
break :result try func.allocStackPtr(inst);
};
func.finishAir(inst, result, &.{});
}
fn airRetLoad(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const un_op = func.air.instructions.items(.data)[@intFromEnum(inst)].un_op;
const operand = try func.resolveInst(un_op);
const ret_ty = func.typeOf(un_op).childType(mod);
const fn_info = mod.typeToFunc(func.decl.ty).?;
if (!ret_ty.hasRuntimeBitsIgnoreComptime(mod)) {
if (ret_ty.isError(mod)) {
try func.addImm32(0);
}
} else if (!firstParamSRet(fn_info.cc, Type.fromInterned(fn_info.return_type), mod)) {
// leave on the stack
_ = try func.load(operand, ret_ty, 0);
}
try func.restoreStackPointer();
try func.addTag(.@"return");
return func.finishAir(inst, .none, &.{un_op});
}
fn airCall(func: *CodeGen, inst: Air.Inst.Index, modifier: std.builtin.CallModifier) InnerError!void {
if (modifier == .always_tail) return func.fail("TODO implement tail calls for wasm", .{});
const pl_op = func.air.instructions.items(.data)[@intFromEnum(inst)].pl_op;
const extra = func.air.extraData(Air.Call, pl_op.payload);
const args = @as([]const Air.Inst.Ref, @ptrCast(func.air.extra[extra.end..][0..extra.data.args_len]));
const ty = func.typeOf(pl_op.operand);
const mod = func.bin_file.base.comp.module.?;
const ip = &mod.intern_pool;
const fn_ty = switch (ty.zigTypeTag(mod)) {
.Fn => ty,
.Pointer => ty.childType(mod),
else => unreachable,
};
const ret_ty = fn_ty.fnReturnType(mod);
const fn_info = mod.typeToFunc(fn_ty).?;
const first_param_sret = firstParamSRet(fn_info.cc, Type.fromInterned(fn_info.return_type), mod);
const callee: ?InternPool.DeclIndex = blk: {
const func_val = (try func.air.value(pl_op.operand, mod)) orelse break :blk null;
if (func_val.getFunction(mod)) |function| {
_ = try func.bin_file.getOrCreateAtomForDecl(function.owner_decl);
break :blk function.owner_decl;
} else if (func_val.getExternFunc(mod)) |extern_func| {
const ext_decl = mod.declPtr(extern_func.decl);
const ext_info = mod.typeToFunc(ext_decl.ty).?;
var func_type = try genFunctype(func.gpa, ext_info.cc, ext_info.param_types.get(ip), Type.fromInterned(ext_info.return_type), mod);
defer func_type.deinit(func.gpa);
const atom_index = try func.bin_file.getOrCreateAtomForDecl(extern_func.decl);
const atom = func.bin_file.getAtomPtr(atom_index);
const type_index = try func.bin_file.storeDeclType(extern_func.decl, func_type);
try func.bin_file.addOrUpdateImport(
mod.intern_pool.stringToSlice(ext_decl.name),
atom.sym_index,
mod.intern_pool.stringToSliceUnwrap(ext_decl.getOwnedExternFunc(mod).?.lib_name),
type_index,
);
break :blk extern_func.decl;
} else switch (mod.intern_pool.indexToKey(func_val.ip_index)) {
.ptr => |ptr| switch (ptr.addr) {
.decl => |decl| {
_ = try func.bin_file.getOrCreateAtomForDecl(decl);
break :blk decl;
},
else => {},
},
else => {},
}
return func.fail("Expected a function, but instead found type '{}'", .{func_val.tag()});
};
const sret = if (first_param_sret) blk: {
const sret_local = try func.allocStack(ret_ty);
try func.lowerToStack(sret_local);
break :blk sret_local;
} else WValue{ .none = {} };
for (args) |arg| {
const arg_val = try func.resolveInst(arg);
const arg_ty = func.typeOf(arg);
if (!arg_ty.hasRuntimeBitsIgnoreComptime(mod)) continue;
try func.lowerArg(mod.typeToFunc(fn_ty).?.cc, arg_ty, arg_val);
}
if (callee) |direct| {
const atom_index = func.bin_file.zigObjectPtr().?.decls_map.get(direct).?.atom;
try func.addLabel(.call, @intFromEnum(func.bin_file.getAtom(atom_index).sym_index));
} else {
// in this case we call a function pointer
// so load its value onto the stack
std.debug.assert(ty.zigTypeTag(mod) == .Pointer);
const operand = try func.resolveInst(pl_op.operand);
try func.emitWValue(operand);
var fn_type = try genFunctype(func.gpa, fn_info.cc, fn_info.param_types.get(ip), Type.fromInterned(fn_info.return_type), mod);
defer fn_type.deinit(func.gpa);
const fn_type_index = try func.bin_file.zigObjectPtr().?.putOrGetFuncType(func.gpa, fn_type);
try func.addLabel(.call_indirect, fn_type_index);
}
const result_value = result_value: {
if (!ret_ty.hasRuntimeBitsIgnoreComptime(mod) and !ret_ty.isError(mod)) {
break :result_value WValue{ .none = {} };
} else if (ret_ty.isNoReturn(mod)) {
try func.addTag(.@"unreachable");
break :result_value WValue{ .none = {} };
} else if (first_param_sret) {
break :result_value sret;
// TODO: Make this less fragile and optimize
} else if (mod.typeToFunc(fn_ty).?.cc == .C and ret_ty.zigTypeTag(mod) == .Struct or ret_ty.zigTypeTag(mod) == .Union) {
const result_local = try func.allocLocal(ret_ty);
try func.addLabel(.local_set, result_local.local.value);
const scalar_type = abi.scalarType(ret_ty, mod);
const result = try func.allocStack(scalar_type);
try func.store(result, result_local, scalar_type, 0);
break :result_value result;
} else {
const result_local = try func.allocLocal(ret_ty);
try func.addLabel(.local_set, result_local.local.value);
break :result_value result_local;
}
};
var bt = try func.iterateBigTomb(inst, 1 + args.len);
bt.feed(pl_op.operand);
for (args) |arg| bt.feed(arg);
return bt.finishAir(result_value);
}
fn airAlloc(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const value = try func.allocStackPtr(inst);
func.finishAir(inst, value, &.{});
}
fn airStore(func: *CodeGen, inst: Air.Inst.Index, safety: bool) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
if (safety) {
// TODO if the value is undef, write 0xaa bytes to dest
} else {
// TODO if the value is undef, don't lower this instruction
}
const bin_op = func.air.instructions.items(.data)[@intFromEnum(inst)].bin_op;
const lhs = try func.resolveInst(bin_op.lhs);
const rhs = try func.resolveInst(bin_op.rhs);
const ptr_ty = func.typeOf(bin_op.lhs);
const ptr_info = ptr_ty.ptrInfo(mod);
const ty = ptr_ty.childType(mod);
if (ptr_info.packed_offset.host_size == 0) {
try func.store(lhs, rhs, ty, 0);
} else {
// at this point we have a non-natural alignment, we must
// load the value, and then shift+or the rhs into the result location.
const int_elem_ty = try mod.intType(.unsigned, ptr_info.packed_offset.host_size * 8);
if (isByRef(int_elem_ty, mod)) {
return func.fail("TODO: airStore for pointers to bitfields with backing type larger than 64bits", .{});
}
var mask = @as(u64, @intCast((@as(u65, 1) << @as(u7, @intCast(ty.bitSize(mod)))) - 1));
mask <<= @as(u6, @intCast(ptr_info.packed_offset.bit_offset));
mask ^= ~@as(u64, 0);
const shift_val = if (ptr_info.packed_offset.host_size <= 4)
WValue{ .imm32 = ptr_info.packed_offset.bit_offset }
else
WValue{ .imm64 = ptr_info.packed_offset.bit_offset };
const mask_val = if (ptr_info.packed_offset.host_size <= 4)
WValue{ .imm32 = @as(u32, @truncate(mask)) }
else
WValue{ .imm64 = mask };
try func.emitWValue(lhs);
const loaded = try func.load(lhs, int_elem_ty, 0);
const anded = try func.binOp(loaded, mask_val, int_elem_ty, .@"and");
const extended_value = try func.intcast(rhs, ty, int_elem_ty);
const shifted_value = if (ptr_info.packed_offset.bit_offset > 0) shifted: {
break :shifted try func.binOp(extended_value, shift_val, int_elem_ty, .shl);
} else extended_value;
const result = try func.binOp(anded, shifted_value, int_elem_ty, .@"or");
// lhs is still on the stack
try func.store(.stack, result, int_elem_ty, lhs.offset());
}
func.finishAir(inst, .none, &.{ bin_op.lhs, bin_op.rhs });
}
fn store(func: *CodeGen, lhs: WValue, rhs: WValue, ty: Type, offset: u32) InnerError!void {
assert(!(lhs != .stack and rhs == .stack));
const mod = func.bin_file.base.comp.module.?;
const abi_size = ty.abiSize(mod);
switch (ty.zigTypeTag(mod)) {
.ErrorUnion => {
const pl_ty = ty.errorUnionPayload(mod);
if (!pl_ty.hasRuntimeBitsIgnoreComptime(mod)) {
return func.store(lhs, rhs, Type.anyerror, 0);
}
const len = @as(u32, @intCast(abi_size));
return func.memcpy(lhs, rhs, .{ .imm32 = len });
},
.Optional => {
if (ty.isPtrLikeOptional(mod)) {
return func.store(lhs, rhs, Type.usize, 0);
}
const pl_ty = ty.optionalChild(mod);
if (!pl_ty.hasRuntimeBitsIgnoreComptime(mod)) {
return func.store(lhs, rhs, Type.u8, 0);
}
if (pl_ty.zigTypeTag(mod) == .ErrorSet) {
return func.store(lhs, rhs, Type.anyerror, 0);
}
const len = @as(u32, @intCast(abi_size));
return func.memcpy(lhs, rhs, .{ .imm32 = len });
},
.Struct, .Array, .Union => if (isByRef(ty, mod)) {
const len = @as(u32, @intCast(abi_size));
return func.memcpy(lhs, rhs, .{ .imm32 = len });
},
.Vector => switch (determineSimdStoreStrategy(ty, mod)) {
.unrolled => {
const len: u32 = @intCast(abi_size);
return func.memcpy(lhs, rhs, .{ .imm32 = len });
},
.direct => {
try func.emitWValue(lhs);
try func.lowerToStack(rhs);
// TODO: Add helper functions for simd opcodes
const extra_index: u32 = @intCast(func.mir_extra.items.len);
// stores as := opcode, offset, alignment (opcode::memarg)
try func.mir_extra.appendSlice(func.gpa, &[_]u32{
std.wasm.simdOpcode(.v128_store),
offset + lhs.offset(),
@intCast(ty.abiAlignment(mod).toByteUnits(0)),
});
return func.addInst(.{ .tag = .simd_prefix, .data = .{ .payload = extra_index } });
},
},
.Pointer => {
if (ty.isSlice(mod)) {
// store pointer first
// lower it to the stack so we do not have to store rhs into a local first
try func.emitWValue(lhs);
const ptr_local = try func.load(rhs, Type.usize, 0);
try func.store(.{ .stack = {} }, ptr_local, Type.usize, 0 + lhs.offset());
// retrieve length from rhs, and store that alongside lhs as well
try func.emitWValue(lhs);
const len_local = try func.load(rhs, Type.usize, func.ptrSize());
try func.store(.{ .stack = {} }, len_local, Type.usize, func.ptrSize() + lhs.offset());
return;
}
},
.Int, .Float => if (abi_size > 8 and abi_size <= 16) {
try func.emitWValue(lhs);
const lsb = try func.load(rhs, Type.u64, 0);
try func.store(.{ .stack = {} }, lsb, Type.u64, 0 + lhs.offset());
try func.emitWValue(lhs);
const msb = try func.load(rhs, Type.u64, 8);
try func.store(.{ .stack = {} }, msb, Type.u64, 8 + lhs.offset());
return;
} else if (abi_size > 16) {
try func.memcpy(lhs, rhs, .{ .imm32 = @as(u32, @intCast(ty.abiSize(mod))) });
},
else => if (abi_size > 8) {
return func.fail("TODO: `store` for type `{}` with abisize `{d}`", .{
ty.fmt(func.bin_file.base.comp.module.?),
abi_size,
});
},
}
try func.emitWValue(lhs);
// In this case we're actually interested in storing the stack position
// into lhs, so we calculate that and emit that instead
try func.lowerToStack(rhs);
const valtype = typeToValtype(ty, mod);
const opcode = buildOpcode(.{
.valtype1 = valtype,
.width = @as(u8, @intCast(abi_size * 8)),
.op = .store,
});
// store rhs value at stack pointer's location in memory
try func.addMemArg(
Mir.Inst.Tag.fromOpcode(opcode),
.{
.offset = offset + lhs.offset(),
.alignment = @intCast(ty.abiAlignment(mod).toByteUnitsOptional().?),
},
);
}
fn airLoad(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const ty_op = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_op;
const operand = try func.resolveInst(ty_op.operand);
const ty = ty_op.ty.toType();
const ptr_ty = func.typeOf(ty_op.operand);
const ptr_info = ptr_ty.ptrInfo(mod);
if (!ty.hasRuntimeBitsIgnoreComptime(mod)) return func.finishAir(inst, .none, &.{ty_op.operand});
const result = result: {
if (isByRef(ty, mod)) {
const new_local = try func.allocStack(ty);
try func.store(new_local, operand, ty, 0);
break :result new_local;
}
if (ptr_info.packed_offset.host_size == 0) {
const stack_loaded = try func.load(operand, ty, 0);
break :result try stack_loaded.toLocal(func, ty);
}
// at this point we have a non-natural alignment, we must
// shift the value to obtain the correct bit.
const int_elem_ty = try mod.intType(.unsigned, ptr_info.packed_offset.host_size * 8);
const shift_val = if (ptr_info.packed_offset.host_size <= 4)
WValue{ .imm32 = ptr_info.packed_offset.bit_offset }
else if (ptr_info.packed_offset.host_size <= 8)
WValue{ .imm64 = ptr_info.packed_offset.bit_offset }
else
return func.fail("TODO: airLoad where ptr to bitfield exceeds 64 bits", .{});
const stack_loaded = try func.load(operand, int_elem_ty, 0);
const shifted = try func.binOp(stack_loaded, shift_val, int_elem_ty, .shr);
const result = try func.trunc(shifted, ty, int_elem_ty);
// const wrapped = try func.wrapOperand(shifted, ty);
break :result try result.toLocal(func, ty);
};
func.finishAir(inst, result, &.{ty_op.operand});
}
/// Loads an operand from the linear memory section.
/// NOTE: Leaves the value on the stack.
fn load(func: *CodeGen, operand: WValue, ty: Type, offset: u32) InnerError!WValue {
const mod = func.bin_file.base.comp.module.?;
// load local's value from memory by its stack position
try func.emitWValue(operand);
if (ty.zigTypeTag(mod) == .Vector) {
// TODO: Add helper functions for simd opcodes
const extra_index = @as(u32, @intCast(func.mir_extra.items.len));
// stores as := opcode, offset, alignment (opcode::memarg)
try func.mir_extra.appendSlice(func.gpa, &[_]u32{
std.wasm.simdOpcode(.v128_load),
offset + operand.offset(),
@intCast(ty.abiAlignment(mod).toByteUnitsOptional().?),
});
try func.addInst(.{ .tag = .simd_prefix, .data = .{ .payload = extra_index } });
return WValue{ .stack = {} };
}
const abi_size: u8 = @intCast(ty.abiSize(mod));
const opcode = buildOpcode(.{
.valtype1 = typeToValtype(ty, mod),
.width = abi_size * 8,
.op = .load,
.signedness = .unsigned,
});
try func.addMemArg(
Mir.Inst.Tag.fromOpcode(opcode),
.{
.offset = offset + operand.offset(),
.alignment = @intCast(ty.abiAlignment(mod).toByteUnitsOptional().?),
},
);
return WValue{ .stack = {} };
}
fn airArg(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const arg_index = func.arg_index;
const arg = func.args[arg_index];
const cc = mod.typeToFunc(func.decl.ty).?.cc;
const arg_ty = func.typeOfIndex(inst);
if (cc == .C) {
const arg_classes = abi.classifyType(arg_ty, mod);
for (arg_classes) |class| {
if (class != .none) {
func.arg_index += 1;
}
}
// When we have an argument that's passed using more than a single parameter,
// we combine them into a single stack value
if (arg_classes[0] == .direct and arg_classes[1] == .direct) {
if (arg_ty.zigTypeTag(mod) != .Int and arg_ty.zigTypeTag(mod) != .Float) {
return func.fail(
"TODO: Implement C-ABI argument for type '{}'",
.{arg_ty.fmt(func.bin_file.base.comp.module.?)},
);
}
const result = try func.allocStack(arg_ty);
try func.store(result, arg, Type.u64, 0);
try func.store(result, func.args[arg_index + 1], Type.u64, 8);
return func.finishAir(inst, result, &.{});
}
} else {
func.arg_index += 1;
}
switch (func.debug_output) {
.dwarf => |dwarf| {
const src_index = func.air.instructions.items(.data)[@intFromEnum(inst)].arg.src_index;
const name = mod.getParamName(func.func_index, src_index);
try dwarf.genArgDbgInfo(name, arg_ty, mod.funcOwnerDeclIndex(func.func_index), .{
.wasm_local = arg.local.value,
});
},
else => {},
}
func.finishAir(inst, arg, &.{});
}
fn airBinOp(func: *CodeGen, inst: Air.Inst.Index, op: Op) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const bin_op = func.air.instructions.items(.data)[@intFromEnum(inst)].bin_op;
const lhs = try func.resolveInst(bin_op.lhs);
const rhs = try func.resolveInst(bin_op.rhs);
const lhs_ty = func.typeOf(bin_op.lhs);
const rhs_ty = func.typeOf(bin_op.rhs);
// For certain operations, such as shifting, the types are different.
// When converting this to a WebAssembly type, they *must* match to perform
// an operation. For this reason we verify if the WebAssembly type is different, in which
// case we first coerce the operands to the same type before performing the operation.
// For big integers we can ignore this as we will call into compiler-rt which handles this.
const result = switch (op) {
.shr, .shl => res: {
const lhs_wasm_bits = toWasmBits(@as(u16, @intCast(lhs_ty.bitSize(mod)))) orelse {
return func.fail("TODO: implement '{s}' for types larger than 128 bits", .{@tagName(op)});
};
const rhs_wasm_bits = toWasmBits(@as(u16, @intCast(rhs_ty.bitSize(mod)))).?;
const new_rhs = if (lhs_wasm_bits != rhs_wasm_bits and lhs_wasm_bits != 128) blk: {
const tmp = try func.intcast(rhs, rhs_ty, lhs_ty);
break :blk try tmp.toLocal(func, lhs_ty);
} else rhs;
const stack_result = try func.binOp(lhs, new_rhs, lhs_ty, op);
break :res try stack_result.toLocal(func, lhs_ty);
},
else => res: {
const stack_result = try func.binOp(lhs, rhs, lhs_ty, op);
break :res try stack_result.toLocal(func, lhs_ty);
},
};
func.finishAir(inst, result, &.{ bin_op.lhs, bin_op.rhs });
}
/// Performs a binary operation on the given `WValue`'s
/// NOTE: THis leaves the value on top of the stack.
fn binOp(func: *CodeGen, lhs: WValue, rhs: WValue, ty: Type, op: Op) InnerError!WValue {
const mod = func.bin_file.base.comp.module.?;
assert(!(lhs != .stack and rhs == .stack));
if (ty.isAnyFloat()) {
const float_op = FloatOp.fromOp(op);
return func.floatOp(float_op, ty, &.{ lhs, rhs });
}
if (isByRef(ty, mod)) {
if (ty.zigTypeTag(mod) == .Int) {
return func.binOpBigInt(lhs, rhs, ty, op);
} else {
return func.fail(
"TODO: Implement binary operation for type: {}",
.{ty.fmt(func.bin_file.base.comp.module.?)},
);
}
}
const opcode: wasm.Opcode = buildOpcode(.{
.op = op,
.valtype1 = typeToValtype(ty, mod),
.signedness = if (ty.isSignedInt(mod)) .signed else .unsigned,
});
try func.emitWValue(lhs);
try func.emitWValue(rhs);
try func.addTag(Mir.Inst.Tag.fromOpcode(opcode));
return WValue{ .stack = {} };
}
fn binOpBigInt(func: *CodeGen, lhs: WValue, rhs: WValue, ty: Type, op: Op) InnerError!WValue {
const mod = func.bin_file.base.comp.module.?;
const int_info = ty.intInfo(mod);
if (int_info.bits > 128) {
return func.fail("TODO: Implement binary operation for big integers larger than 128 bits", .{});
}
switch (op) {
.mul => return func.callIntrinsic("__multi3", &.{ ty.toIntern(), ty.toIntern() }, ty, &.{ lhs, rhs }),
.div => switch (int_info.signedness) {
.signed => return func.callIntrinsic("__udivti3", &.{ ty.toIntern(), ty.toIntern() }, ty, &.{ lhs, rhs }),
.unsigned => return func.callIntrinsic("__divti3", &.{ ty.toIntern(), ty.toIntern() }, ty, &.{ lhs, rhs }),
},
.rem => return func.callIntrinsic("__umodti3", &.{ ty.toIntern(), ty.toIntern() }, ty, &.{ lhs, rhs }),
.shr => return func.callIntrinsic("__lshrti3", &.{ ty.toIntern(), .i32_type }, ty, &.{ lhs, rhs }),
.shl => return func.callIntrinsic("__ashlti3", &.{ ty.toIntern(), .i32_type }, ty, &.{ lhs, rhs }),
.xor => {
const result = try func.allocStack(ty);
try func.emitWValue(result);
const lhs_high_bit = try func.load(lhs, Type.u64, 0);
const rhs_high_bit = try func.load(rhs, Type.u64, 0);
const xor_high_bit = try func.binOp(lhs_high_bit, rhs_high_bit, Type.u64, .xor);
try func.store(.stack, xor_high_bit, Type.u64, result.offset());
try func.emitWValue(result);
const lhs_low_bit = try func.load(lhs, Type.u64, 8);
const rhs_low_bit = try func.load(rhs, Type.u64, 8);
const xor_low_bit = try func.binOp(lhs_low_bit, rhs_low_bit, Type.u64, .xor);
try func.store(.stack, xor_low_bit, Type.u64, result.offset() + 8);
return result;
},
.add, .sub => {
const result = try func.allocStack(ty);
var lhs_high_bit = try (try func.load(lhs, Type.u64, 0)).toLocal(func, Type.u64);
defer lhs_high_bit.free(func);
var rhs_high_bit = try (try func.load(rhs, Type.u64, 0)).toLocal(func, Type.u64);
defer rhs_high_bit.free(func);
var high_op_res = try (try func.binOp(lhs_high_bit, rhs_high_bit, Type.u64, op)).toLocal(func, Type.u64);
defer high_op_res.free(func);
const lhs_low_bit = try func.load(lhs, Type.u64, 8);
const rhs_low_bit = try func.load(rhs, Type.u64, 8);
const low_op_res = try func.binOp(lhs_low_bit, rhs_low_bit, Type.u64, op);
const lt = if (op == .add) blk: {
break :blk try func.cmp(high_op_res, rhs_high_bit, Type.u64, .lt);
} else if (op == .sub) blk: {
break :blk try func.cmp(lhs_high_bit, rhs_high_bit, Type.u64, .lt);
} else unreachable;
const tmp = try func.intcast(lt, Type.u32, Type.u64);
var tmp_op = try (try func.binOp(low_op_res, tmp, Type.u64, op)).toLocal(func, Type.u64);
defer tmp_op.free(func);
try func.store(result, high_op_res, Type.u64, 0);
try func.store(result, tmp_op, Type.u64, 8);
return result;
},
else => return func.fail("TODO: Implement binary operation for big integers: '{s}'", .{@tagName(op)}),
}
}
const FloatOp = enum {
add,
ceil,
cos,
div,
exp,
exp2,
fabs,
floor,
fma,
fmax,
fmin,
fmod,
log,
log10,
log2,
mul,
neg,
round,
sin,
sqrt,
sub,
tan,
trunc,
pub fn fromOp(op: Op) FloatOp {
return switch (op) {
.add => .add,
.ceil => .ceil,
.div => .div,
.abs => .fabs,
.floor => .floor,
.max => .fmax,
.min => .fmin,
.mul => .mul,
.neg => .neg,
.nearest => .round,
.sqrt => .sqrt,
.sub => .sub,
.trunc => .trunc,
else => unreachable,
};
}
pub fn toOp(float_op: FloatOp) ?Op {
return switch (float_op) {
.add => .add,
.ceil => .ceil,
.div => .div,
.fabs => .abs,
.floor => .floor,
.fmax => .max,
.fmin => .min,
.mul => .mul,
.neg => .neg,
.round => .nearest,
.sqrt => .sqrt,
.sub => .sub,
.trunc => .trunc,
.cos,
.exp,
.exp2,
.fma,
.fmod,
.log,
.log10,
.log2,
.sin,
.tan,
=> null,
};
}
};
fn airAbs(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const ty_op = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_op;
const operand = try func.resolveInst(ty_op.operand);
const ty = func.typeOf(ty_op.operand);
const scalar_ty = ty.scalarType(mod);
switch (scalar_ty.zigTypeTag(mod)) {
.Int => if (ty.zigTypeTag(mod) == .Vector) {
return func.fail("TODO implement airAbs for {}", .{ty.fmt(mod)});
} else {
const int_bits = ty.intInfo(mod).bits;
const wasm_bits = toWasmBits(int_bits) orelse {
return func.fail("TODO: airAbs for signed integers larger than '{d}' bits", .{int_bits});
};
const op = try operand.toLocal(func, ty);
try func.emitWValue(op);
switch (wasm_bits) {
32 => {
if (wasm_bits != int_bits) {
try func.addImm32(wasm_bits - int_bits);
try func.addTag(.i32_shl);
}
try func.addImm32(31);
try func.addTag(.i32_shr_s);
const tmp = try func.allocLocal(ty);
try func.addLabel(.local_tee, tmp.local.value);
try func.emitWValue(op);
try func.addTag(.i32_xor);
try func.emitWValue(tmp);
try func.addTag(.i32_sub);
if (int_bits != wasm_bits) {
try func.emitWValue(WValue{ .imm32 = (@as(u32, 1) << @intCast(int_bits)) - 1 });
try func.addTag(.i32_and);
}
},
64 => {
if (wasm_bits != int_bits) {
try func.addImm64(wasm_bits - int_bits);
try func.addTag(.i64_shl);
}
try func.addImm64(63);
try func.addTag(.i64_shr_s);
const tmp = try func.allocLocal(ty);
try func.addLabel(.local_tee, tmp.local.value);
try func.emitWValue(op);
try func.addTag(.i64_xor);
try func.emitWValue(tmp);
try func.addTag(.i64_sub);
if (int_bits != wasm_bits) {
try func.emitWValue(WValue{ .imm64 = (@as(u64, 1) << @intCast(int_bits)) - 1 });
try func.addTag(.i64_and);
}
},
else => return func.fail("TODO: Implement airAbs for {}", .{ty.fmt(mod)}),
}
const result = try (WValue{ .stack = {} }).toLocal(func, ty);
func.finishAir(inst, result, &.{ty_op.operand});
},
.Float => {
const result = try (try func.floatOp(.fabs, ty, &.{operand})).toLocal(func, ty);
func.finishAir(inst, result, &.{ty_op.operand});
},
else => unreachable,
}
}
fn airUnaryFloatOp(func: *CodeGen, inst: Air.Inst.Index, op: FloatOp) InnerError!void {
const un_op = func.air.instructions.items(.data)[@intFromEnum(inst)].un_op;
const operand = try func.resolveInst(un_op);
const ty = func.typeOf(un_op);
const result = try (try func.floatOp(op, ty, &.{operand})).toLocal(func, ty);
func.finishAir(inst, result, &.{un_op});
}
fn floatOp(func: *CodeGen, float_op: FloatOp, ty: Type, args: []const WValue) InnerError!WValue {
const mod = func.bin_file.base.comp.module.?;
if (ty.zigTypeTag(mod) == .Vector) {
return func.fail("TODO: Implement floatOps for vectors", .{});
}
const float_bits = ty.floatBits(func.target);
if (float_op == .neg) {
return func.floatNeg(ty, args[0]);
}
if (float_bits == 32 or float_bits == 64) {
if (float_op.toOp()) |op| {
for (args) |operand| {
try func.emitWValue(operand);
}
const opcode = buildOpcode(.{ .op = op, .valtype1 = typeToValtype(ty, mod) });
try func.addTag(Mir.Inst.Tag.fromOpcode(opcode));
return .stack;
}
}
var fn_name_buf: [64]u8 = undefined;
const fn_name = switch (float_op) {
.add,
.sub,
.div,
.mul,
=> std.fmt.bufPrint(&fn_name_buf, "__{s}{s}f3", .{
@tagName(float_op), target_util.compilerRtFloatAbbrev(float_bits),
}) catch unreachable,
.ceil,
.cos,
.exp,
.exp2,
.fabs,
.floor,
.fma,
.fmax,
.fmin,
.fmod,
.log,
.log10,
.log2,
.round,
.sin,
.sqrt,
.tan,
.trunc,
=> std.fmt.bufPrint(&fn_name_buf, "{s}{s}{s}", .{
target_util.libcFloatPrefix(float_bits), @tagName(float_op), target_util.libcFloatSuffix(float_bits),
}) catch unreachable,
.neg => unreachable, // handled above
};
// fma requires three operands
var param_types_buffer: [3]InternPool.Index = .{ ty.ip_index, ty.ip_index, ty.ip_index };
const param_types = param_types_buffer[0..args.len];
return func.callIntrinsic(fn_name, param_types, ty, args);
}
/// NOTE: The result value remains on top of the stack.
fn floatNeg(func: *CodeGen, ty: Type, arg: WValue) InnerError!WValue {
const float_bits = ty.floatBits(func.target);
switch (float_bits) {
16 => {
try func.emitWValue(arg);
try func.addImm32(std.math.minInt(i16));
try func.addTag(.i32_xor);
return .stack;
},
32, 64 => {
try func.emitWValue(arg);
const val_type: wasm.Valtype = if (float_bits == 32) .f32 else .f64;
const opcode = buildOpcode(.{ .op = .neg, .valtype1 = val_type });
try func.addTag(Mir.Inst.Tag.fromOpcode(opcode));
return .stack;
},
80, 128 => {
const result = try func.allocStack(ty);
try func.emitWValue(result);
try func.emitWValue(arg);
try func.addMemArg(.i64_load, .{ .offset = 0 + arg.offset(), .alignment = 2 });
try func.addMemArg(.i64_store, .{ .offset = 0 + result.offset(), .alignment = 2 });
try func.emitWValue(result);
try func.emitWValue(arg);
try func.addMemArg(.i64_load, .{ .offset = 8 + arg.offset(), .alignment = 2 });
if (float_bits == 80) {
try func.addImm64(0x8000);
try func.addTag(.i64_xor);
try func.addMemArg(.i64_store16, .{ .offset = 8 + result.offset(), .alignment = 2 });
} else {
try func.addImm64(0x8000000000000000);
try func.addTag(.i64_xor);
try func.addMemArg(.i64_store, .{ .offset = 8 + result.offset(), .alignment = 2 });
}
return result;
},
else => unreachable,
}
}
fn airWrapBinOp(func: *CodeGen, inst: Air.Inst.Index, op: Op) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const bin_op = func.air.instructions.items(.data)[@intFromEnum(inst)].bin_op;
const lhs = try func.resolveInst(bin_op.lhs);
const rhs = try func.resolveInst(bin_op.rhs);
const lhs_ty = func.typeOf(bin_op.lhs);
const rhs_ty = func.typeOf(bin_op.rhs);
if (lhs_ty.zigTypeTag(mod) == .Vector or rhs_ty.zigTypeTag(mod) == .Vector) {
return func.fail("TODO: Implement wrapping arithmetic for vectors", .{});
}
// For certain operations, such as shifting, the types are different.
// When converting this to a WebAssembly type, they *must* match to perform
// an operation. For this reason we verify if the WebAssembly type is different, in which
// case we first coerce the operands to the same type before performing the operation.
// For big integers we can ignore this as we will call into compiler-rt which handles this.
const result = switch (op) {
.shr, .shl => res: {
const lhs_wasm_bits = toWasmBits(@as(u16, @intCast(lhs_ty.bitSize(mod)))) orelse {
return func.fail("TODO: implement '{s}' for types larger than 128 bits", .{@tagName(op)});
};
const rhs_wasm_bits = toWasmBits(@as(u16, @intCast(rhs_ty.bitSize(mod)))).?;
const new_rhs = if (lhs_wasm_bits != rhs_wasm_bits and lhs_wasm_bits != 128) blk: {
const tmp = try func.intcast(rhs, rhs_ty, lhs_ty);
break :blk try tmp.toLocal(func, lhs_ty);
} else rhs;
const stack_result = try func.wrapBinOp(lhs, new_rhs, lhs_ty, op);
break :res try stack_result.toLocal(func, lhs_ty);
},
else => res: {
const stack_result = try func.wrapBinOp(lhs, rhs, lhs_ty, op);
break :res try stack_result.toLocal(func, lhs_ty);
},
};
return func.finishAir(inst, result, &.{ bin_op.lhs, bin_op.rhs });
}
/// Performs a wrapping binary operation.
/// Asserts rhs is not a stack value when lhs also isn't.
/// NOTE: Leaves the result on the stack when its Type is <= 64 bits
fn wrapBinOp(func: *CodeGen, lhs: WValue, rhs: WValue, ty: Type, op: Op) InnerError!WValue {
const bin_local = try func.binOp(lhs, rhs, ty, op);
return func.wrapOperand(bin_local, ty);
}
/// Wraps an operand based on a given type's bitsize.
/// Asserts `Type` is <= 128 bits.
/// NOTE: When the Type is <= 64 bits, leaves the value on top of the stack.
fn wrapOperand(func: *CodeGen, operand: WValue, ty: Type) InnerError!WValue {
const mod = func.bin_file.base.comp.module.?;
assert(ty.abiSize(mod) <= 16);
const bitsize = @as(u16, @intCast(ty.bitSize(mod)));
const wasm_bits = toWasmBits(bitsize) orelse {
return func.fail("TODO: Implement wrapOperand for bitsize '{d}'", .{bitsize});
};
if (wasm_bits == bitsize) return operand;
if (wasm_bits == 128) {
assert(operand != .stack);
const lsb = try func.load(operand, Type.u64, 8);
const result_ptr = try func.allocStack(ty);
try func.emitWValue(result_ptr);
try func.store(.{ .stack = {} }, lsb, Type.u64, 8 + result_ptr.offset());
const result = (@as(u64, 1) << @as(u6, @intCast(64 - (wasm_bits - bitsize)))) - 1;
try func.emitWValue(result_ptr);
_ = try func.load(operand, Type.u64, 0);
try func.addImm64(result);
try func.addTag(.i64_and);
try func.addMemArg(.i64_store, .{ .offset = result_ptr.offset(), .alignment = 8 });
return result_ptr;
}
const result = (@as(u64, 1) << @as(u6, @intCast(bitsize))) - 1;
try func.emitWValue(operand);
if (bitsize <= 32) {
try func.addImm32(@as(i32, @bitCast(@as(u32, @intCast(result)))));
try func.addTag(.i32_and);
} else if (bitsize <= 64) {
try func.addImm64(result);
try func.addTag(.i64_and);
} else unreachable;
return WValue{ .stack = {} };
}
fn lowerParentPtr(func: *CodeGen, ptr_val: Value, offset: u32) InnerError!WValue {
const mod = func.bin_file.base.comp.module.?;
const ptr = mod.intern_pool.indexToKey(ptr_val.ip_index).ptr;
switch (ptr.addr) {
.decl => |decl_index| {
return func.lowerParentPtrDecl(ptr_val, decl_index, offset);
},
.anon_decl => |ad| return func.lowerAnonDeclRef(ad, offset),
.mut_decl => |mut_decl| {
const decl_index = mut_decl.decl;
return func.lowerParentPtrDecl(ptr_val, decl_index, offset);
},
.eu_payload => |tag| return func.fail("TODO: Implement lowerParentPtr for {}", .{tag}),
.int => |base| return func.lowerConstant(Value.fromInterned(base), Type.usize),
.opt_payload => |base_ptr| return func.lowerParentPtr(Value.fromInterned(base_ptr), offset),
.comptime_field => unreachable,
.elem => |elem| {
const index = elem.index;
const elem_type = Type.fromInterned(mod.intern_pool.typeOf(elem.base)).elemType2(mod);
const elem_offset = index * elem_type.abiSize(mod);
return func.lowerParentPtr(Value.fromInterned(elem.base), @as(u32, @intCast(elem_offset + offset)));
},
.field => |field| {
const parent_ptr_ty = Type.fromInterned(mod.intern_pool.typeOf(field.base));
const parent_ty = parent_ptr_ty.childType(mod);
const field_index: u32 = @intCast(field.index);
const field_offset = switch (parent_ty.zigTypeTag(mod)) {
.Struct => blk: {
if (mod.typeToPackedStruct(parent_ty)) |struct_type| {
if (Type.fromInterned(ptr.ty).ptrInfo(mod).packed_offset.host_size == 0)
break :blk @divExact(mod.structPackedFieldBitOffset(struct_type, field_index) + parent_ptr_ty.ptrInfo(mod).packed_offset.bit_offset, 8)
else
break :blk 0;
}
break :blk parent_ty.structFieldOffset(field_index, mod);
},
.Union => switch (parent_ty.containerLayout(mod)) {
.Packed => 0,
else => blk: {
const layout: Module.UnionLayout = parent_ty.unionGetLayout(mod);
if (layout.payload_size == 0) break :blk 0;
if (layout.payload_align.compare(.gt, layout.tag_align)) break :blk 0;
// tag is stored first so calculate offset from where payload starts
break :blk layout.tag_align.forward(layout.tag_size);
},
},
.Pointer => switch (parent_ty.ptrSize(mod)) {
.Slice => switch (field.index) {
0 => 0,
1 => func.ptrSize(),
else => unreachable,
},
else => unreachable,
},
else => unreachable,
};
return func.lowerParentPtr(Value.fromInterned(field.base), @as(u32, @intCast(offset + field_offset)));
},
}
}
fn lowerParentPtrDecl(func: *CodeGen, ptr_val: Value, decl_index: InternPool.DeclIndex, offset: u32) InnerError!WValue {
const mod = func.bin_file.base.comp.module.?;
const decl = mod.declPtr(decl_index);
try mod.markDeclAlive(decl);
const ptr_ty = try mod.singleMutPtrType(decl.ty);
return func.lowerDeclRefValue(.{ .ty = ptr_ty, .val = ptr_val }, decl_index, offset);
}
fn lowerAnonDeclRef(
func: *CodeGen,
anon_decl: InternPool.Key.Ptr.Addr.AnonDecl,
offset: u32,
) InnerError!WValue {
const mod = func.bin_file.base.comp.module.?;
const decl_val = anon_decl.val;
const ty = Type.fromInterned(mod.intern_pool.typeOf(decl_val));
const is_fn_body = ty.zigTypeTag(mod) == .Fn;
if (!is_fn_body and !ty.hasRuntimeBitsIgnoreComptime(mod)) {
return WValue{ .imm32 = 0xaaaaaaaa };
}
const decl_align = mod.intern_pool.indexToKey(anon_decl.orig_ty).ptr_type.flags.alignment;
const res = try func.bin_file.lowerAnonDecl(decl_val, decl_align, func.decl.srcLoc(mod));
switch (res) {
.ok => {},
.fail => |em| {
func.err_msg = em;
return error.CodegenFail;
},
}
const target_atom_index = func.bin_file.zigObjectPtr().?.anon_decls.get(decl_val).?;
const target_sym_index = @intFromEnum(func.bin_file.getAtom(target_atom_index).sym_index);
if (is_fn_body) {
return WValue{ .function_index = target_sym_index };
} else if (offset == 0) {
return WValue{ .memory = target_sym_index };
} else return WValue{ .memory_offset = .{ .pointer = target_sym_index, .offset = offset } };
}
fn lowerDeclRefValue(func: *CodeGen, tv: TypedValue, decl_index: InternPool.DeclIndex, offset: u32) InnerError!WValue {
const mod = func.bin_file.base.comp.module.?;
const decl = mod.declPtr(decl_index);
// check if decl is an alias to a function, in which case we
// want to lower the actual decl, rather than the alias itself.
if (decl.val.getFunction(mod)) |func_val| {
if (func_val.owner_decl != decl_index) {
return func.lowerDeclRefValue(tv, func_val.owner_decl, offset);
}
} else if (decl.val.getExternFunc(mod)) |func_val| {
if (func_val.decl != decl_index) {
return func.lowerDeclRefValue(tv, func_val.decl, offset);
}
}
if (decl.ty.zigTypeTag(mod) != .Fn and !decl.ty.hasRuntimeBitsIgnoreComptime(mod)) {
return WValue{ .imm32 = 0xaaaaaaaa };
}
try mod.markDeclAlive(decl);
const atom_index = try func.bin_file.getOrCreateAtomForDecl(decl_index);
const atom = func.bin_file.getAtom(atom_index);
const target_sym_index = @intFromEnum(atom.sym_index);
if (decl.ty.zigTypeTag(mod) == .Fn) {
return WValue{ .function_index = target_sym_index };
} else if (offset == 0) {
return WValue{ .memory = target_sym_index };
} else return WValue{ .memory_offset = .{ .pointer = target_sym_index, .offset = offset } };
}
/// Converts a signed integer to its 2's complement form and returns
/// an unsigned integer instead.
/// Asserts bitsize <= 64
fn toTwosComplement(value: anytype, bits: u7) std.meta.Int(.unsigned, @typeInfo(@TypeOf(value)).Int.bits) {
const T = @TypeOf(value);
comptime assert(@typeInfo(T) == .Int);
comptime assert(@typeInfo(T).Int.signedness == .signed);
assert(bits <= 64);
const WantedT = std.meta.Int(.unsigned, @typeInfo(T).Int.bits);
if (value >= 0) return @as(WantedT, @bitCast(value));
const max_value = @as(u64, @intCast((@as(u65, 1) << bits) - 1));
const flipped = @as(T, @intCast((~-@as(i65, value)) + 1));
const result = @as(WantedT, @bitCast(flipped)) & max_value;
return @as(WantedT, @intCast(result));
}
/// This function is intended to assert that `isByRef` returns `false` for `ty`.
/// However such an assertion fails on the behavior tests currently.
fn lowerConstant(func: *CodeGen, val: Value, ty: Type) InnerError!WValue {
const mod = func.bin_file.base.comp.module.?;
// TODO: enable this assertion
//assert(!isByRef(ty, mod));
const ip = &mod.intern_pool;
if (val.isUndefDeep(mod)) return func.emitUndefined(ty);
switch (ip.indexToKey(val.ip_index)) {
.int_type,
.ptr_type,
.array_type,
.vector_type,
.opt_type,
.anyframe_type,
.error_union_type,
.simple_type,
.struct_type,
.anon_struct_type,
.union_type,
.opaque_type,
.enum_type,
.func_type,
.error_set_type,
.inferred_error_set_type,
=> unreachable, // types, not values
.undef => unreachable, // handled above
.simple_value => |simple_value| switch (simple_value) {
.undefined,
.void,
.null,
.empty_struct,
.@"unreachable",
.generic_poison,
=> unreachable, // non-runtime values
.false, .true => return WValue{ .imm32 = switch (simple_value) {
.false => 0,
.true => 1,
else => unreachable,
} },
},
.variable,
.extern_func,
.func,
.enum_literal,
.empty_enum_value,
=> unreachable, // non-runtime values
.int => {
const int_info = ty.intInfo(mod);
switch (int_info.signedness) {
.signed => switch (int_info.bits) {
0...32 => return WValue{ .imm32 = @as(u32, @intCast(toTwosComplement(
val.toSignedInt(mod),
@as(u6, @intCast(int_info.bits)),
))) },
33...64 => return WValue{ .imm64 = toTwosComplement(
val.toSignedInt(mod),
@as(u7, @intCast(int_info.bits)),
) },
else => unreachable,
},
.unsigned => switch (int_info.bits) {
0...32 => return WValue{ .imm32 = @as(u32, @intCast(val.toUnsignedInt(mod))) },
33...64 => return WValue{ .imm64 = val.toUnsignedInt(mod) },
else => unreachable,
},
}
},
.err => |err| {
const int = try mod.getErrorValue(err.name);
return WValue{ .imm32 = int };
},
.error_union => |error_union| {
const err_int_ty = try mod.errorIntType();
const err_tv: TypedValue = switch (error_union.val) {
.err_name => |err_name| .{
.ty = ty.errorUnionSet(mod),
.val = Value.fromInterned((try mod.intern(.{ .err = .{
.ty = ty.errorUnionSet(mod).toIntern(),
.name = err_name,
} }))),
},
.payload => .{
.ty = err_int_ty,
.val = try mod.intValue(err_int_ty, 0),
},
};
const payload_type = ty.errorUnionPayload(mod);
if (!payload_type.hasRuntimeBitsIgnoreComptime(mod)) {
// We use the error type directly as the type.
return func.lowerConstant(err_tv.val, err_tv.ty);
}
return func.fail("Wasm TODO: lowerConstant error union with non-zero-bit payload type", .{});
},
.enum_tag => |enum_tag| {
const int_tag_ty = ip.typeOf(enum_tag.int);
return func.lowerConstant(Value.fromInterned(enum_tag.int), Type.fromInterned(int_tag_ty));
},
.float => |float| switch (float.storage) {
.f16 => |f16_val| return WValue{ .imm32 = @as(u16, @bitCast(f16_val)) },
.f32 => |f32_val| return WValue{ .float32 = f32_val },
.f64 => |f64_val| return WValue{ .float64 = f64_val },
else => unreachable,
},
.slice => |slice| {
var ptr = ip.indexToKey(slice.ptr).ptr;
const owner_decl = while (true) switch (ptr.addr) {
.decl => |decl| break decl,
.mut_decl => |mut_decl| break mut_decl.decl,
.int, .anon_decl => return func.fail("Wasm TODO: lower slice where ptr is not owned by decl", .{}),
.opt_payload, .eu_payload => |base| ptr = ip.indexToKey(base).ptr,
.elem, .field => |base_index| ptr = ip.indexToKey(base_index.base).ptr,
.comptime_field => unreachable,
};
return .{ .memory = try func.bin_file.lowerUnnamedConst(.{ .ty = ty, .val = val }, owner_decl) };
},
.ptr => |ptr| switch (ptr.addr) {
.decl => |decl| return func.lowerDeclRefValue(.{ .ty = ty, .val = val }, decl, 0),
.mut_decl => |mut_decl| return func.lowerDeclRefValue(.{ .ty = ty, .val = val }, mut_decl.decl, 0),
.int => |int| return func.lowerConstant(Value.fromInterned(int), Type.fromInterned(ip.typeOf(int))),
.opt_payload, .elem, .field => return func.lowerParentPtr(val, 0),
.anon_decl => |ad| return func.lowerAnonDeclRef(ad, 0),
else => return func.fail("Wasm TODO: lowerConstant for other const addr tag {}", .{ptr.addr}),
},
.opt => if (ty.optionalReprIsPayload(mod)) {
const pl_ty = ty.optionalChild(mod);
if (val.optionalValue(mod)) |payload| {
return func.lowerConstant(payload, pl_ty);
} else {
return WValue{ .imm32 = 0 };
}
} else {
return WValue{ .imm32 = @intFromBool(!val.isNull(mod)) };
},
.aggregate => switch (ip.indexToKey(ty.ip_index)) {
.array_type => return func.fail("Wasm TODO: LowerConstant for {}", .{ty.fmt(mod)}),
.vector_type => {
assert(determineSimdStoreStrategy(ty, mod) == .direct);
var buf: [16]u8 = undefined;
val.writeToMemory(ty, mod, &buf) catch unreachable;
return func.storeSimdImmd(buf);
},
.struct_type => |struct_type| {
// non-packed structs are not handled in this function because they
// are by-ref types.
assert(struct_type.layout == .Packed);
var buf: [8]u8 = .{0} ** 8; // zero the buffer so we do not read 0xaa as integer
val.writeToPackedMemory(ty, mod, &buf, 0) catch unreachable;
const backing_int_ty = Type.fromInterned(struct_type.backingIntType(ip).*);
const int_val = try mod.intValue(
backing_int_ty,
mem.readInt(u64, &buf, .little),
);
return func.lowerConstant(int_val, backing_int_ty);
},
else => unreachable,
},
.un => |un| {
// in this case we have a packed union which will not be passed by reference.
const constant_ty = if (un.tag == .none)
try ty.unionBackingType(mod)
else field_ty: {
const union_obj = mod.typeToUnion(ty).?;
const field_index = mod.unionTagFieldIndex(union_obj, Value.fromInterned(un.tag)).?;
break :field_ty Type.fromInterned(union_obj.field_types.get(ip)[field_index]);
};
return func.lowerConstant(Value.fromInterned(un.val), constant_ty);
},
.memoized_call => unreachable,
}
}
/// Stores the value as a 128bit-immediate value by storing it inside
/// the list and returning the index into this list as `WValue`.
fn storeSimdImmd(func: *CodeGen, value: [16]u8) !WValue {
const index = @as(u32, @intCast(func.simd_immediates.items.len));
try func.simd_immediates.append(func.gpa, value);
return WValue{ .imm128 = index };
}
fn emitUndefined(func: *CodeGen, ty: Type) InnerError!WValue {
const mod = func.bin_file.base.comp.module.?;
const ip = &mod.intern_pool;
switch (ty.zigTypeTag(mod)) {
.Bool, .ErrorSet => return WValue{ .imm32 = 0xaaaaaaaa },
.Int, .Enum => switch (ty.intInfo(mod).bits) {
0...32 => return WValue{ .imm32 = 0xaaaaaaaa },
33...64 => return WValue{ .imm64 = 0xaaaaaaaaaaaaaaaa },
else => unreachable,
},
.Float => switch (ty.floatBits(func.target)) {
16 => return WValue{ .imm32 = 0xaaaaaaaa },
32 => return WValue{ .float32 = @as(f32, @bitCast(@as(u32, 0xaaaaaaaa))) },
64 => return WValue{ .float64 = @as(f64, @bitCast(@as(u64, 0xaaaaaaaaaaaaaaaa))) },
else => unreachable,
},
.Pointer => switch (func.arch()) {
.wasm32 => return WValue{ .imm32 = 0xaaaaaaaa },
.wasm64 => return WValue{ .imm64 = 0xaaaaaaaaaaaaaaaa },
else => unreachable,
},
.Optional => {
const pl_ty = ty.optionalChild(mod);
if (ty.optionalReprIsPayload(mod)) {
return func.emitUndefined(pl_ty);
}
return WValue{ .imm32 = 0xaaaaaaaa };
},
.ErrorUnion => {
return WValue{ .imm32 = 0xaaaaaaaa };
},
.Struct => {
const packed_struct = mod.typeToPackedStruct(ty).?;
return func.emitUndefined(Type.fromInterned(packed_struct.backingIntType(ip).*));
},
else => return func.fail("Wasm TODO: emitUndefined for type: {}\n", .{ty.zigTypeTag(mod)}),
}
}
/// Returns a `Value` as a signed 32 bit value.
/// It's illegal to provide a value with a type that cannot be represented
/// as an integer value.
fn valueAsI32(func: *const CodeGen, val: Value, ty: Type) i32 {
const mod = func.bin_file.base.comp.module.?;
switch (val.ip_index) {
.none => {},
.bool_true => return 1,
.bool_false => return 0,
else => return switch (mod.intern_pool.indexToKey(val.ip_index)) {
.enum_tag => |enum_tag| intIndexAsI32(&mod.intern_pool, enum_tag.int, mod),
.int => |int| intStorageAsI32(int.storage, mod),
.ptr => |ptr| intIndexAsI32(&mod.intern_pool, ptr.addr.int, mod),
.err => |err| @as(i32, @bitCast(@as(Module.ErrorInt, @intCast(mod.global_error_set.getIndex(err.name).?)))),
else => unreachable,
},
}
return switch (ty.zigTypeTag(mod)) {
.ErrorSet => @as(i32, @bitCast(val.getErrorInt(mod))),
else => unreachable, // Programmer called this function for an illegal type
};
}
fn intIndexAsI32(ip: *const InternPool, int: InternPool.Index, mod: *Module) i32 {
return intStorageAsI32(ip.indexToKey(int).int.storage, mod);
}
fn intStorageAsI32(storage: InternPool.Key.Int.Storage, mod: *Module) i32 {
return switch (storage) {
.i64 => |x| @as(i32, @intCast(x)),
.u64 => |x| @as(i32, @bitCast(@as(u32, @intCast(x)))),
.big_int => unreachable,
.lazy_align => |ty| @as(i32, @bitCast(@as(u32, @intCast(Type.fromInterned(ty).abiAlignment(mod).toByteUnits(0))))),
.lazy_size => |ty| @as(i32, @bitCast(@as(u32, @intCast(Type.fromInterned(ty).abiSize(mod))))),
};
}
fn airBlock(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const ty_pl = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_pl;
const extra = func.air.extraData(Air.Block, ty_pl.payload);
try func.lowerBlock(inst, ty_pl.ty.toType(), @ptrCast(func.air.extra[extra.end..][0..extra.data.body_len]));
}
fn lowerBlock(func: *CodeGen, inst: Air.Inst.Index, block_ty: Type, body: []const Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const wasm_block_ty = genBlockType(block_ty, mod);
// if wasm_block_ty is non-empty, we create a register to store the temporary value
const block_result: WValue = if (wasm_block_ty != wasm.block_empty) blk: {
const ty: Type = if (isByRef(block_ty, mod)) Type.u32 else block_ty;
break :blk try func.ensureAllocLocal(ty); // make sure it's a clean local as it may never get overwritten
} else WValue.none;
try func.startBlock(.block, wasm.block_empty);
// Here we set the current block idx, so breaks know the depth to jump
// to when breaking out.
try func.blocks.putNoClobber(func.gpa, inst, .{
.label = func.block_depth,
.value = block_result,
});
try func.genBody(body);
try func.endBlock();
const liveness = func.liveness.getBlock(inst);
try func.currentBranch().values.ensureUnusedCapacity(func.gpa, liveness.deaths.len);
func.finishAir(inst, block_result, &.{});
}
/// appends a new wasm block to the code section and increases the `block_depth` by 1
fn startBlock(func: *CodeGen, block_tag: wasm.Opcode, valtype: u8) !void {
func.block_depth += 1;
try func.addInst(.{
.tag = Mir.Inst.Tag.fromOpcode(block_tag),
.data = .{ .block_type = valtype },
});
}
/// Ends the current wasm block and decreases the `block_depth` by 1
fn endBlock(func: *CodeGen) !void {
try func.addTag(.end);
func.block_depth -= 1;
}
fn airLoop(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const ty_pl = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_pl;
const loop = func.air.extraData(Air.Block, ty_pl.payload);
const body: []const Air.Inst.Index = @ptrCast(func.air.extra[loop.end..][0..loop.data.body_len]);
// result type of loop is always 'noreturn', meaning we can always
// emit the wasm type 'block_empty'.
try func.startBlock(.loop, wasm.block_empty);
try func.genBody(body);
// breaking to the index of a loop block will continue the loop instead
try func.addLabel(.br, 0);
try func.endBlock();
func.finishAir(inst, .none, &.{});
}
fn airCondBr(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const pl_op = func.air.instructions.items(.data)[@intFromEnum(inst)].pl_op;
const condition = try func.resolveInst(pl_op.operand);
const extra = func.air.extraData(Air.CondBr, pl_op.payload);
const then_body: []const Air.Inst.Index = @ptrCast(func.air.extra[extra.end..][0..extra.data.then_body_len]);
const else_body: []const Air.Inst.Index = @ptrCast(func.air.extra[extra.end + then_body.len ..][0..extra.data.else_body_len]);
const liveness_condbr = func.liveness.getCondBr(inst);
// result type is always noreturn, so use `block_empty` as type.
try func.startBlock(.block, wasm.block_empty);
// emit the conditional value
try func.emitWValue(condition);
// we inserted the block in front of the condition
// so now check if condition matches. If not, break outside this block
// and continue with the then codepath
try func.addLabel(.br_if, 0);
try func.branches.ensureUnusedCapacity(func.gpa, 2);
{
func.branches.appendAssumeCapacity(.{});
try func.currentBranch().values.ensureUnusedCapacity(func.gpa, @as(u32, @intCast(liveness_condbr.else_deaths.len)));
defer {
var else_stack = func.branches.pop();
else_stack.deinit(func.gpa);
}
try func.genBody(else_body);
try func.endBlock();
}
// Outer block that matches the condition
{
func.branches.appendAssumeCapacity(.{});
try func.currentBranch().values.ensureUnusedCapacity(func.gpa, @as(u32, @intCast(liveness_condbr.then_deaths.len)));
defer {
var then_stack = func.branches.pop();
then_stack.deinit(func.gpa);
}
try func.genBody(then_body);
}
func.finishAir(inst, .none, &.{});
}
fn airCmp(func: *CodeGen, inst: Air.Inst.Index, op: std.math.CompareOperator) InnerError!void {
const bin_op = func.air.instructions.items(.data)[@intFromEnum(inst)].bin_op;
const lhs = try func.resolveInst(bin_op.lhs);
const rhs = try func.resolveInst(bin_op.rhs);
const operand_ty = func.typeOf(bin_op.lhs);
const result = try (try func.cmp(lhs, rhs, operand_ty, op)).toLocal(func, Type.u32); // comparison result is always 32 bits
func.finishAir(inst, result, &.{ bin_op.lhs, bin_op.rhs });
}
/// Compares two operands.
/// Asserts rhs is not a stack value when the lhs isn't a stack value either
/// NOTE: This leaves the result on top of the stack, rather than a new local.
fn cmp(func: *CodeGen, lhs: WValue, rhs: WValue, ty: Type, op: std.math.CompareOperator) InnerError!WValue {
assert(!(lhs != .stack and rhs == .stack));
const mod = func.bin_file.base.comp.module.?;
if (ty.zigTypeTag(mod) == .Optional and !ty.optionalReprIsPayload(mod)) {
const payload_ty = ty.optionalChild(mod);
if (payload_ty.hasRuntimeBitsIgnoreComptime(mod)) {
// When we hit this case, we must check the value of optionals
// that are not pointers. This means first checking against non-null for
// both lhs and rhs, as well as checking the payload are matching of lhs and rhs
return func.cmpOptionals(lhs, rhs, ty, op);
}
} else if (ty.isAnyFloat()) {
return func.cmpFloat(ty, lhs, rhs, op);
} else if (isByRef(ty, mod)) {
return func.cmpBigInt(lhs, rhs, ty, op);
}
const signedness: std.builtin.Signedness = blk: {
// by default we tell the operand type is unsigned (i.e. bools and enum values)
if (ty.zigTypeTag(mod) != .Int) break :blk .unsigned;
// incase of an actual integer, we emit the correct signedness
break :blk ty.intInfo(mod).signedness;
};
const extend_sign = blk: {
// do we need to extend the sign bit?
if (signedness != .signed) break :blk false;
if (op == .eq or op == .neq) break :blk false;
const int_bits = ty.intInfo(mod).bits;
const wasm_bits = toWasmBits(int_bits) orelse unreachable;
break :blk (wasm_bits != int_bits);
};
const lhs_wasm = if (extend_sign)
try func.signExtendInt(lhs, ty)
else
lhs;
const rhs_wasm = if (extend_sign)
try func.signExtendInt(rhs, ty)
else
rhs;
// ensure that when we compare pointers, we emit
// the true pointer of a stack value, rather than the stack pointer.
try func.lowerToStack(lhs_wasm);
try func.lowerToStack(rhs_wasm);
const opcode: wasm.Opcode = buildOpcode(.{
.valtype1 = typeToValtype(ty, mod),
.op = switch (op) {
.lt => .lt,
.lte => .le,
.eq => .eq,
.neq => .ne,
.gte => .ge,
.gt => .gt,
},
.signedness = signedness,
});
try func.addTag(Mir.Inst.Tag.fromOpcode(opcode));
return WValue{ .stack = {} };
}
/// Compares two floats.
/// NOTE: Leaves the result of the comparison on top of the stack.
fn cmpFloat(func: *CodeGen, ty: Type, lhs: WValue, rhs: WValue, cmp_op: std.math.CompareOperator) InnerError!WValue {
const float_bits = ty.floatBits(func.target);
const op: Op = switch (cmp_op) {
.lt => .lt,
.lte => .le,
.eq => .eq,
.neq => .ne,
.gte => .ge,
.gt => .gt,
};
switch (float_bits) {
16 => {
_ = try func.fpext(lhs, Type.f16, Type.f32);
_ = try func.fpext(rhs, Type.f16, Type.f32);
const opcode = buildOpcode(.{ .op = op, .valtype1 = .f32 });
try func.addTag(Mir.Inst.Tag.fromOpcode(opcode));
return .stack;
},
32, 64 => {
try func.emitWValue(lhs);
try func.emitWValue(rhs);
const val_type: wasm.Valtype = if (float_bits == 32) .f32 else .f64;
const opcode = buildOpcode(.{ .op = op, .valtype1 = val_type });
try func.addTag(Mir.Inst.Tag.fromOpcode(opcode));
return .stack;
},
80, 128 => {
var fn_name_buf: [32]u8 = undefined;
const fn_name = std.fmt.bufPrint(&fn_name_buf, "__{s}{s}f2", .{
@tagName(op), target_util.compilerRtFloatAbbrev(float_bits),
}) catch unreachable;
const result = try func.callIntrinsic(fn_name, &.{ ty.ip_index, ty.ip_index }, Type.bool, &.{ lhs, rhs });
return func.cmp(result, WValue{ .imm32 = 0 }, Type.i32, cmp_op);
},
else => unreachable,
}
}
fn airCmpVector(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
_ = inst;
return func.fail("TODO implement airCmpVector for wasm", .{});
}
fn airCmpLtErrorsLen(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const un_op = func.air.instructions.items(.data)[@intFromEnum(inst)].un_op;
const operand = try func.resolveInst(un_op);
const sym_index = try func.bin_file.getGlobalSymbol("__zig_errors_len", null);
const errors_len = WValue{ .memory = @intFromEnum(sym_index) };
try func.emitWValue(operand);
const mod = func.bin_file.base.comp.module.?;
const err_int_ty = try mod.errorIntType();
const errors_len_val = try func.load(errors_len, err_int_ty, 0);
const result = try func.cmp(.stack, errors_len_val, err_int_ty, .lt);
return func.finishAir(inst, try result.toLocal(func, Type.bool), &.{un_op});
}
fn airBr(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const br = func.air.instructions.items(.data)[@intFromEnum(inst)].br;
const block = func.blocks.get(br.block_inst).?;
// if operand has codegen bits we should break with a value
if (func.typeOf(br.operand).hasRuntimeBitsIgnoreComptime(mod)) {
const operand = try func.resolveInst(br.operand);
try func.lowerToStack(operand);
if (block.value != .none) {
try func.addLabel(.local_set, block.value.local.value);
}
}
// We map every block to its block index.
// We then determine how far we have to jump to it by subtracting it from current block depth
const idx: u32 = func.block_depth - block.label;
try func.addLabel(.br, idx);
func.finishAir(inst, .none, &.{br.operand});
}
fn airNot(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const ty_op = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_op;
const operand = try func.resolveInst(ty_op.operand);
const operand_ty = func.typeOf(ty_op.operand);
const mod = func.bin_file.base.comp.module.?;
const result = result: {
if (operand_ty.zigTypeTag(mod) == .Bool) {
try func.emitWValue(operand);
try func.addTag(.i32_eqz);
const not_tmp = try func.allocLocal(operand_ty);
try func.addLabel(.local_set, not_tmp.local.value);
break :result not_tmp;
} else {
const operand_bits = operand_ty.intInfo(mod).bits;
const wasm_bits = toWasmBits(operand_bits) orelse {
return func.fail("TODO: Implement binary NOT for integer with bitsize '{d}'", .{operand_bits});
};
switch (wasm_bits) {
32 => {
const bin_op = try func.binOp(operand, .{ .imm32 = ~@as(u32, 0) }, operand_ty, .xor);
break :result try (try func.wrapOperand(bin_op, operand_ty)).toLocal(func, operand_ty);
},
64 => {
const bin_op = try func.binOp(operand, .{ .imm64 = ~@as(u64, 0) }, operand_ty, .xor);
break :result try (try func.wrapOperand(bin_op, operand_ty)).toLocal(func, operand_ty);
},
128 => {
const result_ptr = try func.allocStack(operand_ty);
try func.emitWValue(result_ptr);
const msb = try func.load(operand, Type.u64, 0);
const msb_xor = try func.binOp(msb, .{ .imm64 = ~@as(u64, 0) }, Type.u64, .xor);
try func.store(.{ .stack = {} }, msb_xor, Type.u64, 0 + result_ptr.offset());
try func.emitWValue(result_ptr);
const lsb = try func.load(operand, Type.u64, 8);
const lsb_xor = try func.binOp(lsb, .{ .imm64 = ~@as(u64, 0) }, Type.u64, .xor);
try func.store(result_ptr, lsb_xor, Type.u64, 8 + result_ptr.offset());
break :result result_ptr;
},
else => unreachable,
}
}
};
func.finishAir(inst, result, &.{ty_op.operand});
}
fn airTrap(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
try func.addTag(.@"unreachable");
func.finishAir(inst, .none, &.{});
}
fn airBreakpoint(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
// unsupported by wasm itfunc. Can be implemented once we support DWARF
// for wasm
try func.addTag(.@"unreachable");
func.finishAir(inst, .none, &.{});
}
fn airUnreachable(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
try func.addTag(.@"unreachable");
func.finishAir(inst, .none, &.{});
}
fn airBitcast(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const ty_op = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_op;
const result = result: {
const operand = try func.resolveInst(ty_op.operand);
const wanted_ty = func.typeOfIndex(inst);
const given_ty = func.typeOf(ty_op.operand);
if (given_ty.isAnyFloat() or wanted_ty.isAnyFloat()) {
const bitcast_result = try func.bitcast(wanted_ty, given_ty, operand);
break :result try bitcast_result.toLocal(func, wanted_ty);
}
const mod = func.bin_file.base.comp.module.?;
if (isByRef(given_ty, mod) and !isByRef(wanted_ty, mod)) {
const loaded_memory = try func.load(operand, wanted_ty, 0);
break :result try loaded_memory.toLocal(func, wanted_ty);
}
if (!isByRef(given_ty, mod) and isByRef(wanted_ty, mod)) {
const stack_memory = try func.allocStack(wanted_ty);
try func.store(stack_memory, operand, given_ty, 0);
break :result stack_memory;
}
break :result func.reuseOperand(ty_op.operand, operand);
};
func.finishAir(inst, result, &.{ty_op.operand});
}
fn bitcast(func: *CodeGen, wanted_ty: Type, given_ty: Type, operand: WValue) InnerError!WValue {
const mod = func.bin_file.base.comp.module.?;
// if we bitcast a float to or from an integer we must use the 'reinterpret' instruction
if (!(wanted_ty.isAnyFloat() or given_ty.isAnyFloat())) return operand;
if (wanted_ty.ip_index == .f16_type or given_ty.ip_index == .f16_type) return operand;
if (wanted_ty.bitSize(mod) > 64) return operand;
assert((wanted_ty.isInt(mod) and given_ty.isAnyFloat()) or (wanted_ty.isAnyFloat() and given_ty.isInt(mod)));
const opcode = buildOpcode(.{
.op = .reinterpret,
.valtype1 = typeToValtype(wanted_ty, mod),
.valtype2 = typeToValtype(given_ty, mod),
});
try func.emitWValue(operand);
try func.addTag(Mir.Inst.Tag.fromOpcode(opcode));
return WValue{ .stack = {} };
}
fn airStructFieldPtr(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const ty_pl = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_pl;
const extra = func.air.extraData(Air.StructField, ty_pl.payload);
const struct_ptr = try func.resolveInst(extra.data.struct_operand);
const struct_ptr_ty = func.typeOf(extra.data.struct_operand);
const struct_ty = struct_ptr_ty.childType(mod);
const result = try func.structFieldPtr(inst, extra.data.struct_operand, struct_ptr, struct_ptr_ty, struct_ty, extra.data.field_index);
func.finishAir(inst, result, &.{extra.data.struct_operand});
}
fn airStructFieldPtrIndex(func: *CodeGen, inst: Air.Inst.Index, index: u32) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const ty_op = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_op;
const struct_ptr = try func.resolveInst(ty_op.operand);
const struct_ptr_ty = func.typeOf(ty_op.operand);
const struct_ty = struct_ptr_ty.childType(mod);
const result = try func.structFieldPtr(inst, ty_op.operand, struct_ptr, struct_ptr_ty, struct_ty, index);
func.finishAir(inst, result, &.{ty_op.operand});
}
fn structFieldPtr(
func: *CodeGen,
inst: Air.Inst.Index,
ref: Air.Inst.Ref,
struct_ptr: WValue,
struct_ptr_ty: Type,
struct_ty: Type,
index: u32,
) InnerError!WValue {
const mod = func.bin_file.base.comp.module.?;
const result_ty = func.typeOfIndex(inst);
const struct_ptr_ty_info = struct_ptr_ty.ptrInfo(mod);
const offset = switch (struct_ty.containerLayout(mod)) {
.Packed => switch (struct_ty.zigTypeTag(mod)) {
.Struct => offset: {
if (result_ty.ptrInfo(mod).packed_offset.host_size != 0) {
break :offset @as(u32, 0);
}
const struct_type = mod.typeToStruct(struct_ty).?;
break :offset @divExact(mod.structPackedFieldBitOffset(struct_type, index) + struct_ptr_ty_info.packed_offset.bit_offset, 8);
},
.Union => 0,
else => unreachable,
},
else => struct_ty.structFieldOffset(index, mod),
};
// save a load and store when we can simply reuse the operand
if (offset == 0) {
return func.reuseOperand(ref, struct_ptr);
}
switch (struct_ptr) {
.stack_offset => |stack_offset| {
return WValue{ .stack_offset = .{ .value = stack_offset.value + @as(u32, @intCast(offset)), .references = 1 } };
},
else => return func.buildPointerOffset(struct_ptr, offset, .new),
}
}
fn airStructFieldVal(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const ip = &mod.intern_pool;
const ty_pl = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_pl;
const struct_field = func.air.extraData(Air.StructField, ty_pl.payload).data;
const struct_ty = func.typeOf(struct_field.struct_operand);
const operand = try func.resolveInst(struct_field.struct_operand);
const field_index = struct_field.field_index;
const field_ty = struct_ty.structFieldType(field_index, mod);
if (!field_ty.hasRuntimeBitsIgnoreComptime(mod)) return func.finishAir(inst, .none, &.{struct_field.struct_operand});
const result = switch (struct_ty.containerLayout(mod)) {
.Packed => switch (struct_ty.zigTypeTag(mod)) {
.Struct => result: {
const packed_struct = mod.typeToPackedStruct(struct_ty).?;
const offset = mod.structPackedFieldBitOffset(packed_struct, field_index);
const backing_ty = Type.fromInterned(packed_struct.backingIntType(ip).*);
const wasm_bits = toWasmBits(backing_ty.intInfo(mod).bits) orelse {
return func.fail("TODO: airStructFieldVal for packed structs larger than 128 bits", .{});
};
const const_wvalue = if (wasm_bits == 32)
WValue{ .imm32 = offset }
else if (wasm_bits == 64)
WValue{ .imm64 = offset }
else
return func.fail("TODO: airStructFieldVal for packed structs larger than 64 bits", .{});
// for first field we don't require any shifting
const shifted_value = if (offset == 0)
operand
else
try func.binOp(operand, const_wvalue, backing_ty, .shr);
if (field_ty.zigTypeTag(mod) == .Float) {
const int_type = try mod.intType(.unsigned, @as(u16, @intCast(field_ty.bitSize(mod))));
const truncated = try func.trunc(shifted_value, int_type, backing_ty);
const bitcasted = try func.bitcast(field_ty, int_type, truncated);
break :result try bitcasted.toLocal(func, field_ty);
} else if (field_ty.isPtrAtRuntime(mod) and packed_struct.field_types.len == 1) {
// In this case we do not have to perform any transformations,
// we can simply reuse the operand.
break :result func.reuseOperand(struct_field.struct_operand, operand);
} else if (field_ty.isPtrAtRuntime(mod)) {
const int_type = try mod.intType(.unsigned, @as(u16, @intCast(field_ty.bitSize(mod))));
const truncated = try func.trunc(shifted_value, int_type, backing_ty);
break :result try truncated.toLocal(func, field_ty);
}
const truncated = try func.trunc(shifted_value, field_ty, backing_ty);
break :result try truncated.toLocal(func, field_ty);
},
.Union => result: {
if (isByRef(struct_ty, mod)) {
if (!isByRef(field_ty, mod)) {
const val = try func.load(operand, field_ty, 0);
break :result try val.toLocal(func, field_ty);
} else {
const new_stack_val = try func.allocStack(field_ty);
try func.store(new_stack_val, operand, field_ty, 0);
break :result new_stack_val;
}
}
const union_int_type = try mod.intType(.unsigned, @as(u16, @intCast(struct_ty.bitSize(mod))));
if (field_ty.zigTypeTag(mod) == .Float) {
const int_type = try mod.intType(.unsigned, @as(u16, @intCast(field_ty.bitSize(mod))));
const truncated = try func.trunc(operand, int_type, union_int_type);
const bitcasted = try func.bitcast(field_ty, int_type, truncated);
break :result try bitcasted.toLocal(func, field_ty);
} else if (field_ty.isPtrAtRuntime(mod)) {
const int_type = try mod.intType(.unsigned, @as(u16, @intCast(field_ty.bitSize(mod))));
const truncated = try func.trunc(operand, int_type, union_int_type);
break :result try truncated.toLocal(func, field_ty);
}
const truncated = try func.trunc(operand, field_ty, union_int_type);
break :result try truncated.toLocal(func, field_ty);
},
else => unreachable,
},
else => result: {
const offset = std.math.cast(u32, struct_ty.structFieldOffset(field_index, mod)) orelse {
return func.fail("Field type '{}' too big to fit into stack frame", .{field_ty.fmt(mod)});
};
if (isByRef(field_ty, mod)) {
switch (operand) {
.stack_offset => |stack_offset| {
break :result WValue{ .stack_offset = .{ .value = stack_offset.value + offset, .references = 1 } };
},
else => break :result try func.buildPointerOffset(operand, offset, .new),
}
}
const field = try func.load(operand, field_ty, offset);
break :result try field.toLocal(func, field_ty);
},
};
func.finishAir(inst, result, &.{struct_field.struct_operand});
}
fn airSwitchBr(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
// result type is always 'noreturn'
const blocktype = wasm.block_empty;
const pl_op = func.air.instructions.items(.data)[@intFromEnum(inst)].pl_op;
const target = try func.resolveInst(pl_op.operand);
const target_ty = func.typeOf(pl_op.operand);
const switch_br = func.air.extraData(Air.SwitchBr, pl_op.payload);
const liveness = try func.liveness.getSwitchBr(func.gpa, inst, switch_br.data.cases_len + 1);
defer func.gpa.free(liveness.deaths);
var extra_index: usize = switch_br.end;
var case_i: u32 = 0;
// a list that maps each value with its value and body based on the order inside the list.
const CaseValue = struct { integer: i32, value: Value };
var case_list = try std.ArrayList(struct {
values: []const CaseValue,
body: []const Air.Inst.Index,
}).initCapacity(func.gpa, switch_br.data.cases_len);
defer for (case_list.items) |case| {
func.gpa.free(case.values);
} else case_list.deinit();
var lowest_maybe: ?i32 = null;
var highest_maybe: ?i32 = null;
while (case_i < switch_br.data.cases_len) : (case_i += 1) {
const case = func.air.extraData(Air.SwitchBr.Case, extra_index);
const items: []const Air.Inst.Ref = @ptrCast(func.air.extra[case.end..][0..case.data.items_len]);
const case_body: []const Air.Inst.Index = @ptrCast(func.air.extra[case.end + items.len ..][0..case.data.body_len]);
extra_index = case.end + items.len + case_body.len;
const values = try func.gpa.alloc(CaseValue, items.len);
errdefer func.gpa.free(values);
for (items, 0..) |ref, i| {
const item_val = (try func.air.value(ref, mod)).?;
const int_val = func.valueAsI32(item_val, target_ty);
if (lowest_maybe == null or int_val < lowest_maybe.?) {
lowest_maybe = int_val;
}
if (highest_maybe == null or int_val > highest_maybe.?) {
highest_maybe = int_val;
}
values[i] = .{ .integer = int_val, .value = item_val };
}
case_list.appendAssumeCapacity(.{ .values = values, .body = case_body });
try func.startBlock(.block, blocktype);
}
// When highest and lowest are null, we have no cases and can use a jump table
const lowest = lowest_maybe orelse 0;
const highest = highest_maybe orelse 0;
// When the highest and lowest values are seperated by '50',
// we define it as sparse and use an if/else-chain, rather than a jump table.
// When the target is an integer size larger than u32, we have no way to use the value
// as an index, therefore we also use an if/else-chain for those cases.
// TODO: Benchmark this to find a proper value, LLVM seems to draw the line at '40~45'.
const is_sparse = highest - lowest > 50 or target_ty.bitSize(mod) > 32;
const else_body: []const Air.Inst.Index = @ptrCast(func.air.extra[extra_index..][0..switch_br.data.else_body_len]);
const has_else_body = else_body.len != 0;
if (has_else_body) {
try func.startBlock(.block, blocktype);
}
if (!is_sparse) {
// Generate the jump table 'br_table' when the prongs are not sparse.
// The value 'target' represents the index into the table.
// Each index in the table represents a label to the branch
// to jump to.
try func.startBlock(.block, blocktype);
try func.emitWValue(target);
if (lowest < 0) {
// since br_table works using indexes, starting from '0', we must ensure all values
// we put inside, are atleast 0.
try func.addImm32(lowest * -1);
try func.addTag(.i32_add);
} else if (lowest > 0) {
// make the index start from 0 by substracting the lowest value
try func.addImm32(lowest);
try func.addTag(.i32_sub);
}
// Account for default branch so always add '1'
const depth = @as(u32, @intCast(highest - lowest + @intFromBool(has_else_body))) + 1;
const jump_table: Mir.JumpTable = .{ .length = depth };
const table_extra_index = try func.addExtra(jump_table);
try func.addInst(.{ .tag = .br_table, .data = .{ .payload = table_extra_index } });
try func.mir_extra.ensureUnusedCapacity(func.gpa, depth);
var value = lowest;
while (value <= highest) : (value += 1) {
// idx represents the branch we jump to
const idx = blk: {
for (case_list.items, 0..) |case, idx| {
for (case.values) |case_value| {
if (case_value.integer == value) break :blk @as(u32, @intCast(idx));
}
}
// error sets are almost always sparse so we use the default case
// for errors that are not present in any branch. This is fine as this default
// case will never be hit for those cases but we do save runtime cost and size
// by using a jump table for this instead of if-else chains.
break :blk if (has_else_body or target_ty.zigTypeTag(mod) == .ErrorSet) case_i else unreachable;
};
func.mir_extra.appendAssumeCapacity(idx);
} else if (has_else_body) {
func.mir_extra.appendAssumeCapacity(case_i); // default branch
}
try func.endBlock();
}
const signedness: std.builtin.Signedness = blk: {
// by default we tell the operand type is unsigned (i.e. bools and enum values)
if (target_ty.zigTypeTag(mod) != .Int) break :blk .unsigned;
// incase of an actual integer, we emit the correct signedness
break :blk target_ty.intInfo(mod).signedness;
};
try func.branches.ensureUnusedCapacity(func.gpa, case_list.items.len + @intFromBool(has_else_body));
for (case_list.items, 0..) |case, index| {
// when sparse, we use if/else-chain, so emit conditional checks
if (is_sparse) {
// for single value prong we can emit a simple if
if (case.values.len == 1) {
try func.emitWValue(target);
const val = try func.lowerConstant(case.values[0].value, target_ty);
try func.emitWValue(val);
const opcode = buildOpcode(.{
.valtype1 = typeToValtype(target_ty, mod),
.op = .ne, // not equal, because we want to jump out of this block if it does not match the condition.
.signedness = signedness,
});
try func.addTag(Mir.Inst.Tag.fromOpcode(opcode));
try func.addLabel(.br_if, 0);
} else {
// in multi-value prongs we must check if any prongs match the target value.
try func.startBlock(.block, blocktype);
for (case.values) |value| {
try func.emitWValue(target);
const val = try func.lowerConstant(value.value, target_ty);
try func.emitWValue(val);
const opcode = buildOpcode(.{
.valtype1 = typeToValtype(target_ty, mod),
.op = .eq,
.signedness = signedness,
});
try func.addTag(Mir.Inst.Tag.fromOpcode(opcode));
try func.addLabel(.br_if, 0);
}
// value did not match any of the prong values
try func.addLabel(.br, 1);
try func.endBlock();
}
}
func.branches.appendAssumeCapacity(.{});
try func.currentBranch().values.ensureUnusedCapacity(func.gpa, liveness.deaths[index].len);
defer {
var case_branch = func.branches.pop();
case_branch.deinit(func.gpa);
}
try func.genBody(case.body);
try func.endBlock();
}
if (has_else_body) {
func.branches.appendAssumeCapacity(.{});
const else_deaths = liveness.deaths.len - 1;
try func.currentBranch().values.ensureUnusedCapacity(func.gpa, liveness.deaths[else_deaths].len);
defer {
var else_branch = func.branches.pop();
else_branch.deinit(func.gpa);
}
try func.genBody(else_body);
try func.endBlock();
}
func.finishAir(inst, .none, &.{});
}
fn airIsErr(func: *CodeGen, inst: Air.Inst.Index, opcode: wasm.Opcode) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const un_op = func.air.instructions.items(.data)[@intFromEnum(inst)].un_op;
const operand = try func.resolveInst(un_op);
const err_union_ty = func.typeOf(un_op);
const pl_ty = err_union_ty.errorUnionPayload(mod);
const result = result: {
if (err_union_ty.errorUnionSet(mod).errorSetIsEmpty(mod)) {
switch (opcode) {
.i32_ne => break :result WValue{ .imm32 = 0 },
.i32_eq => break :result WValue{ .imm32 = 1 },
else => unreachable,
}
}
try func.emitWValue(operand);
if (pl_ty.hasRuntimeBitsIgnoreComptime(mod)) {
try func.addMemArg(.i32_load16_u, .{
.offset = operand.offset() + @as(u32, @intCast(errUnionErrorOffset(pl_ty, mod))),
.alignment = @intCast(Type.anyerror.abiAlignment(mod).toByteUnitsOptional().?),
});
}
// Compare the error value with '0'
try func.addImm32(0);
try func.addTag(Mir.Inst.Tag.fromOpcode(opcode));
const is_err_tmp = try func.allocLocal(Type.i32);
try func.addLabel(.local_set, is_err_tmp.local.value);
break :result is_err_tmp;
};
func.finishAir(inst, result, &.{un_op});
}
fn airUnwrapErrUnionPayload(func: *CodeGen, inst: Air.Inst.Index, op_is_ptr: bool) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const ty_op = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_op;
const operand = try func.resolveInst(ty_op.operand);
const op_ty = func.typeOf(ty_op.operand);
const err_ty = if (op_is_ptr) op_ty.childType(mod) else op_ty;
const payload_ty = err_ty.errorUnionPayload(mod);
const result = result: {
if (!payload_ty.hasRuntimeBitsIgnoreComptime(mod)) {
if (op_is_ptr) {
break :result func.reuseOperand(ty_op.operand, operand);
}
break :result WValue{ .none = {} };
}
const pl_offset = @as(u32, @intCast(errUnionPayloadOffset(payload_ty, mod)));
if (op_is_ptr or isByRef(payload_ty, mod)) {
break :result try func.buildPointerOffset(operand, pl_offset, .new);
}
const payload = try func.load(operand, payload_ty, pl_offset);
break :result try payload.toLocal(func, payload_ty);
};
func.finishAir(inst, result, &.{ty_op.operand});
}
fn airUnwrapErrUnionError(func: *CodeGen, inst: Air.Inst.Index, op_is_ptr: bool) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const ty_op = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_op;
const operand = try func.resolveInst(ty_op.operand);
const op_ty = func.typeOf(ty_op.operand);
const err_ty = if (op_is_ptr) op_ty.childType(mod) else op_ty;
const payload_ty = err_ty.errorUnionPayload(mod);
const result = result: {
if (err_ty.errorUnionSet(mod).errorSetIsEmpty(mod)) {
break :result WValue{ .imm32 = 0 };
}
if (op_is_ptr or !payload_ty.hasRuntimeBitsIgnoreComptime(mod)) {
break :result func.reuseOperand(ty_op.operand, operand);
}
const error_val = try func.load(operand, Type.anyerror, @as(u32, @intCast(errUnionErrorOffset(payload_ty, mod))));
break :result try error_val.toLocal(func, Type.anyerror);
};
func.finishAir(inst, result, &.{ty_op.operand});
}
fn airWrapErrUnionPayload(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const ty_op = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_op;
const operand = try func.resolveInst(ty_op.operand);
const err_ty = func.typeOfIndex(inst);
const pl_ty = func.typeOf(ty_op.operand);
const result = result: {
if (!pl_ty.hasRuntimeBitsIgnoreComptime(mod)) {
break :result func.reuseOperand(ty_op.operand, operand);
}
const err_union = try func.allocStack(err_ty);
const payload_ptr = try func.buildPointerOffset(err_union, @as(u32, @intCast(errUnionPayloadOffset(pl_ty, mod))), .new);
try func.store(payload_ptr, operand, pl_ty, 0);
// ensure we also write '0' to the error part, so any present stack value gets overwritten by it.
try func.emitWValue(err_union);
try func.addImm32(0);
const err_val_offset = @as(u32, @intCast(errUnionErrorOffset(pl_ty, mod)));
try func.addMemArg(.i32_store16, .{
.offset = err_union.offset() + err_val_offset,
.alignment = 2,
});
break :result err_union;
};
func.finishAir(inst, result, &.{ty_op.operand});
}
fn airWrapErrUnionErr(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const ty_op = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_op;
const operand = try func.resolveInst(ty_op.operand);
const err_ty = ty_op.ty.toType();
const pl_ty = err_ty.errorUnionPayload(mod);
const result = result: {
if (!pl_ty.hasRuntimeBitsIgnoreComptime(mod)) {
break :result func.reuseOperand(ty_op.operand, operand);
}
const err_union = try func.allocStack(err_ty);
// store error value
try func.store(err_union, operand, Type.anyerror, @as(u32, @intCast(errUnionErrorOffset(pl_ty, mod))));
// write 'undefined' to the payload
const payload_ptr = try func.buildPointerOffset(err_union, @as(u32, @intCast(errUnionPayloadOffset(pl_ty, mod))), .new);
const len = @as(u32, @intCast(err_ty.errorUnionPayload(mod).abiSize(mod)));
try func.memset(Type.u8, payload_ptr, .{ .imm32 = len }, .{ .imm32 = 0xaa });
break :result err_union;
};
func.finishAir(inst, result, &.{ty_op.operand});
}
fn airIntcast(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const ty_op = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_op;
const ty = ty_op.ty.toType();
const operand = try func.resolveInst(ty_op.operand);
const operand_ty = func.typeOf(ty_op.operand);
const mod = func.bin_file.base.comp.module.?;
if (ty.zigTypeTag(mod) == .Vector or operand_ty.zigTypeTag(mod) == .Vector) {
return func.fail("todo Wasm intcast for vectors", .{});
}
if (ty.abiSize(mod) > 16 or operand_ty.abiSize(mod) > 16) {
return func.fail("todo Wasm intcast for bitsize > 128", .{});
}
const op_bits = toWasmBits(@as(u16, @intCast(operand_ty.bitSize(mod)))).?;
const wanted_bits = toWasmBits(@as(u16, @intCast(ty.bitSize(mod)))).?;
const result = if (op_bits == wanted_bits and !ty.isSignedInt(mod))
func.reuseOperand(ty_op.operand, operand)
else
try (try func.intcast(operand, operand_ty, ty)).toLocal(func, ty);
func.finishAir(inst, result, &.{});
}
/// Upcasts or downcasts an integer based on the given and wanted types,
/// and stores the result in a new operand.
/// Asserts type's bitsize <= 128
/// NOTE: May leave the result on the top of the stack.
fn intcast(func: *CodeGen, operand: WValue, given: Type, wanted: Type) InnerError!WValue {
const mod = func.bin_file.base.comp.module.?;
const given_bitsize = @as(u16, @intCast(given.bitSize(mod)));
const wanted_bitsize = @as(u16, @intCast(wanted.bitSize(mod)));
assert(given_bitsize <= 128);
assert(wanted_bitsize <= 128);
const op_bits = toWasmBits(given_bitsize).?;
const wanted_bits = toWasmBits(wanted_bitsize).?;
if (op_bits == wanted_bits) {
if (given.isSignedInt(mod)) {
if (given_bitsize < wanted_bitsize) {
// signed integers are stored as two's complement,
// when we upcast from a smaller integer to larger
// integers, we must get its absolute value similar to
// i64_extend_i32_s instruction.
return func.signExtendInt(operand, given);
}
return func.wrapOperand(operand, wanted);
}
return operand;
}
if (op_bits > 32 and op_bits <= 64 and wanted_bits == 32) {
try func.emitWValue(operand);
try func.addTag(.i32_wrap_i64);
if (given.isSignedInt(mod) and wanted_bitsize < 32)
return func.wrapOperand(.{ .stack = {} }, wanted)
else
return WValue{ .stack = {} };
} else if (op_bits == 32 and wanted_bits > 32 and wanted_bits <= 64) {
const operand32 = if (given_bitsize < 32 and wanted.isSignedInt(mod))
try func.signExtendInt(operand, given)
else
operand;
try func.emitWValue(operand32);
try func.addTag(if (wanted.isSignedInt(mod)) .i64_extend_i32_s else .i64_extend_i32_u);
if (given.isSignedInt(mod) and wanted_bitsize < 64)
return func.wrapOperand(.{ .stack = {} }, wanted)
else
return WValue{ .stack = {} };
} else if (wanted_bits == 128) {
// for 128bit integers we store the integer in the virtual stack, rather than a local
const stack_ptr = try func.allocStack(wanted);
try func.emitWValue(stack_ptr);
// for 32 bit integers, we first coerce the value into a 64 bit integer before storing it
// meaning less store operations are required.
const lhs = if (op_bits == 32) blk: {
break :blk try func.intcast(operand, given, if (wanted.isSignedInt(mod)) Type.i64 else Type.u64);
} else operand;
// store msb first
try func.store(.{ .stack = {} }, lhs, Type.u64, 0 + stack_ptr.offset());
// For signed integers we shift msb by 63 (64bit integer - 1 sign bit) and store remaining value
if (wanted.isSignedInt(mod)) {
try func.emitWValue(stack_ptr);
const shr = try func.binOp(lhs, .{ .imm64 = 63 }, Type.i64, .shr);
try func.store(.{ .stack = {} }, shr, Type.u64, 8 + stack_ptr.offset());
} else {
// Ensure memory of lsb is zero'd
try func.store(stack_ptr, .{ .imm64 = 0 }, Type.u64, 8);
}
return stack_ptr;
} else return func.load(operand, wanted, 0);
}
fn airIsNull(func: *CodeGen, inst: Air.Inst.Index, opcode: wasm.Opcode, op_kind: enum { value, ptr }) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const un_op = func.air.instructions.items(.data)[@intFromEnum(inst)].un_op;
const operand = try func.resolveInst(un_op);
const op_ty = func.typeOf(un_op);
const optional_ty = if (op_kind == .ptr) op_ty.childType(mod) else op_ty;
const is_null = try func.isNull(operand, optional_ty, opcode);
const result = try is_null.toLocal(func, optional_ty);
func.finishAir(inst, result, &.{un_op});
}
/// For a given type and operand, checks if it's considered `null`.
/// NOTE: Leaves the result on the stack
fn isNull(func: *CodeGen, operand: WValue, optional_ty: Type, opcode: wasm.Opcode) InnerError!WValue {
const mod = func.bin_file.base.comp.module.?;
try func.emitWValue(operand);
const payload_ty = optional_ty.optionalChild(mod);
if (!optional_ty.optionalReprIsPayload(mod)) {
// When payload is zero-bits, we can treat operand as a value, rather than
// a pointer to the stack value
if (payload_ty.hasRuntimeBitsIgnoreComptime(mod)) {
const offset = std.math.cast(u32, payload_ty.abiSize(mod)) orelse {
return func.fail("Optional type {} too big to fit into stack frame", .{optional_ty.fmt(mod)});
};
try func.addMemArg(.i32_load8_u, .{ .offset = operand.offset() + offset, .alignment = 1 });
}
} else if (payload_ty.isSlice(mod)) {
switch (func.arch()) {
.wasm32 => try func.addMemArg(.i32_load, .{ .offset = operand.offset(), .alignment = 4 }),
.wasm64 => try func.addMemArg(.i64_load, .{ .offset = operand.offset(), .alignment = 8 }),
else => unreachable,
}
}
// Compare the null value with '0'
try func.addImm32(0);
try func.addTag(Mir.Inst.Tag.fromOpcode(opcode));
return WValue{ .stack = {} };
}
fn airOptionalPayload(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const ty_op = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_op;
const opt_ty = func.typeOf(ty_op.operand);
const payload_ty = func.typeOfIndex(inst);
if (!payload_ty.hasRuntimeBitsIgnoreComptime(mod)) {
return func.finishAir(inst, .none, &.{ty_op.operand});
}
const result = result: {
const operand = try func.resolveInst(ty_op.operand);
if (opt_ty.optionalReprIsPayload(mod)) break :result func.reuseOperand(ty_op.operand, operand);
if (isByRef(payload_ty, mod)) {
break :result try func.buildPointerOffset(operand, 0, .new);
}
const payload = try func.load(operand, payload_ty, 0);
break :result try payload.toLocal(func, payload_ty);
};
func.finishAir(inst, result, &.{ty_op.operand});
}
fn airOptionalPayloadPtr(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const ty_op = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_op;
const operand = try func.resolveInst(ty_op.operand);
const opt_ty = func.typeOf(ty_op.operand).childType(mod);
const result = result: {
const payload_ty = opt_ty.optionalChild(mod);
if (!payload_ty.hasRuntimeBitsIgnoreComptime(mod) or opt_ty.optionalReprIsPayload(mod)) {
break :result func.reuseOperand(ty_op.operand, operand);
}
break :result try func.buildPointerOffset(operand, 0, .new);
};
func.finishAir(inst, result, &.{ty_op.operand});
}
fn airOptionalPayloadPtrSet(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const ty_op = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_op;
const operand = try func.resolveInst(ty_op.operand);
const opt_ty = func.typeOf(ty_op.operand).childType(mod);
const payload_ty = opt_ty.optionalChild(mod);
if (!payload_ty.hasRuntimeBitsIgnoreComptime(mod)) {
return func.fail("TODO: Implement OptionalPayloadPtrSet for optional with zero-sized type {}", .{payload_ty.fmtDebug()});
}
if (opt_ty.optionalReprIsPayload(mod)) {
return func.finishAir(inst, operand, &.{ty_op.operand});
}
const offset = std.math.cast(u32, payload_ty.abiSize(mod)) orelse {
return func.fail("Optional type {} too big to fit into stack frame", .{opt_ty.fmt(mod)});
};
try func.emitWValue(operand);
try func.addImm32(1);
try func.addMemArg(.i32_store8, .{ .offset = operand.offset() + offset, .alignment = 1 });
const result = try func.buildPointerOffset(operand, 0, .new);
return func.finishAir(inst, result, &.{ty_op.operand});
}
fn airWrapOptional(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const ty_op = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_op;
const payload_ty = func.typeOf(ty_op.operand);
const mod = func.bin_file.base.comp.module.?;
const result = result: {
if (!payload_ty.hasRuntimeBitsIgnoreComptime(mod)) {
const non_null_bit = try func.allocStack(Type.u1);
try func.emitWValue(non_null_bit);
try func.addImm32(1);
try func.addMemArg(.i32_store8, .{ .offset = non_null_bit.offset(), .alignment = 1 });
break :result non_null_bit;
}
const operand = try func.resolveInst(ty_op.operand);
const op_ty = func.typeOfIndex(inst);
if (op_ty.optionalReprIsPayload(mod)) {
break :result func.reuseOperand(ty_op.operand, operand);
}
const offset = std.math.cast(u32, payload_ty.abiSize(mod)) orelse {
return func.fail("Optional type {} too big to fit into stack frame", .{op_ty.fmt(mod)});
};
// Create optional type, set the non-null bit, and store the operand inside the optional type
const result_ptr = try func.allocStack(op_ty);
try func.emitWValue(result_ptr);
try func.addImm32(1);
try func.addMemArg(.i32_store8, .{ .offset = result_ptr.offset() + offset, .alignment = 1 });
const payload_ptr = try func.buildPointerOffset(result_ptr, 0, .new);
try func.store(payload_ptr, operand, payload_ty, 0);
break :result result_ptr;
};
func.finishAir(inst, result, &.{ty_op.operand});
}
fn airSlice(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const ty_pl = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_pl;
const bin_op = func.air.extraData(Air.Bin, ty_pl.payload).data;
const lhs = try func.resolveInst(bin_op.lhs);
const rhs = try func.resolveInst(bin_op.rhs);
const slice_ty = func.typeOfIndex(inst);
const slice = try func.allocStack(slice_ty);
try func.store(slice, lhs, Type.usize, 0);
try func.store(slice, rhs, Type.usize, func.ptrSize());
func.finishAir(inst, slice, &.{ bin_op.lhs, bin_op.rhs });
}
fn airSliceLen(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const ty_op = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_op;
const operand = try func.resolveInst(ty_op.operand);
func.finishAir(inst, try func.sliceLen(operand), &.{ty_op.operand});
}
fn airSliceElemVal(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const bin_op = func.air.instructions.items(.data)[@intFromEnum(inst)].bin_op;
const slice_ty = func.typeOf(bin_op.lhs);
const slice = try func.resolveInst(bin_op.lhs);
const index = try func.resolveInst(bin_op.rhs);
const elem_ty = slice_ty.childType(mod);
const elem_size = elem_ty.abiSize(mod);
// load pointer onto stack
_ = try func.load(slice, Type.usize, 0);
// calculate index into slice
try func.emitWValue(index);
try func.addImm32(@as(i32, @bitCast(@as(u32, @intCast(elem_size)))));
try func.addTag(.i32_mul);
try func.addTag(.i32_add);
const result_ptr = try func.allocLocal(Type.usize);
try func.addLabel(.local_set, result_ptr.local.value);
const result = if (!isByRef(elem_ty, mod)) result: {
const elem_val = try func.load(result_ptr, elem_ty, 0);
break :result try elem_val.toLocal(func, elem_ty);
} else result_ptr;
func.finishAir(inst, result, &.{ bin_op.lhs, bin_op.rhs });
}
fn airSliceElemPtr(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const ty_pl = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_pl;
const bin_op = func.air.extraData(Air.Bin, ty_pl.payload).data;
const elem_ty = ty_pl.ty.toType().childType(mod);
const elem_size = elem_ty.abiSize(mod);
const slice = try func.resolveInst(bin_op.lhs);
const index = try func.resolveInst(bin_op.rhs);
_ = try func.load(slice, Type.usize, 0);
// calculate index into slice
try func.emitWValue(index);
try func.addImm32(@as(i32, @bitCast(@as(u32, @intCast(elem_size)))));
try func.addTag(.i32_mul);
try func.addTag(.i32_add);
const result = try func.allocLocal(Type.i32);
try func.addLabel(.local_set, result.local.value);
func.finishAir(inst, result, &.{ bin_op.lhs, bin_op.rhs });
}
fn airSlicePtr(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const ty_op = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_op;
const operand = try func.resolveInst(ty_op.operand);
func.finishAir(inst, try func.slicePtr(operand), &.{ty_op.operand});
}
fn slicePtr(func: *CodeGen, operand: WValue) InnerError!WValue {
const ptr = try func.load(operand, Type.usize, 0);
return ptr.toLocal(func, Type.usize);
}
fn sliceLen(func: *CodeGen, operand: WValue) InnerError!WValue {
const len = try func.load(operand, Type.usize, func.ptrSize());
return len.toLocal(func, Type.usize);
}
fn airTrunc(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const ty_op = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_op;
const operand = try func.resolveInst(ty_op.operand);
const wanted_ty = ty_op.ty.toType();
const op_ty = func.typeOf(ty_op.operand);
const result = try func.trunc(operand, wanted_ty, op_ty);
func.finishAir(inst, try result.toLocal(func, wanted_ty), &.{ty_op.operand});
}
/// Truncates a given operand to a given type, discarding any overflown bits.
/// NOTE: Resulting value is left on the stack.
fn trunc(func: *CodeGen, operand: WValue, wanted_ty: Type, given_ty: Type) InnerError!WValue {
const mod = func.bin_file.base.comp.module.?;
const given_bits = @as(u16, @intCast(given_ty.bitSize(mod)));
if (toWasmBits(given_bits) == null) {
return func.fail("TODO: Implement wasm integer truncation for integer bitsize: {d}", .{given_bits});
}
var result = try func.intcast(operand, given_ty, wanted_ty);
const wanted_bits = @as(u16, @intCast(wanted_ty.bitSize(mod)));
const wasm_bits = toWasmBits(wanted_bits).?;
if (wasm_bits != wanted_bits) {
result = try func.wrapOperand(result, wanted_ty);
}
return result;
}
fn airIntFromBool(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const un_op = func.air.instructions.items(.data)[@intFromEnum(inst)].un_op;
const operand = try func.resolveInst(un_op);
const result = func.reuseOperand(un_op, operand);
func.finishAir(inst, result, &.{un_op});
}
fn airArrayToSlice(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const ty_op = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_op;
const operand = try func.resolveInst(ty_op.operand);
const array_ty = func.typeOf(ty_op.operand).childType(mod);
const slice_ty = ty_op.ty.toType();
// create a slice on the stack
const slice_local = try func.allocStack(slice_ty);
// store the array ptr in the slice
if (array_ty.hasRuntimeBitsIgnoreComptime(mod)) {
try func.store(slice_local, operand, Type.usize, 0);
}
// store the length of the array in the slice
const len = WValue{ .imm32 = @as(u32, @intCast(array_ty.arrayLen(mod))) };
try func.store(slice_local, len, Type.usize, func.ptrSize());
func.finishAir(inst, slice_local, &.{ty_op.operand});
}
fn airIntFromPtr(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const un_op = func.air.instructions.items(.data)[@intFromEnum(inst)].un_op;
const operand = try func.resolveInst(un_op);
const ptr_ty = func.typeOf(un_op);
const result = if (ptr_ty.isSlice(mod))
try func.slicePtr(operand)
else switch (operand) {
// for stack offset, return a pointer to this offset.
.stack_offset => try func.buildPointerOffset(operand, 0, .new),
else => func.reuseOperand(un_op, operand),
};
func.finishAir(inst, result, &.{un_op});
}
fn airPtrElemVal(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const bin_op = func.air.instructions.items(.data)[@intFromEnum(inst)].bin_op;
const ptr_ty = func.typeOf(bin_op.lhs);
const ptr = try func.resolveInst(bin_op.lhs);
const index = try func.resolveInst(bin_op.rhs);
const elem_ty = ptr_ty.childType(mod);
const elem_size = elem_ty.abiSize(mod);
// load pointer onto the stack
if (ptr_ty.isSlice(mod)) {
_ = try func.load(ptr, Type.usize, 0);
} else {
try func.lowerToStack(ptr);
}
// calculate index into slice
try func.emitWValue(index);
try func.addImm32(@as(i32, @bitCast(@as(u32, @intCast(elem_size)))));
try func.addTag(.i32_mul);
try func.addTag(.i32_add);
const elem_result = val: {
var result = try func.allocLocal(Type.usize);
try func.addLabel(.local_set, result.local.value);
if (isByRef(elem_ty, mod)) {
break :val result;
}
defer result.free(func); // only free if it's not returned like above
const elem_val = try func.load(result, elem_ty, 0);
break :val try elem_val.toLocal(func, elem_ty);
};
func.finishAir(inst, elem_result, &.{ bin_op.lhs, bin_op.rhs });
}
fn airPtrElemPtr(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const ty_pl = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_pl;
const bin_op = func.air.extraData(Air.Bin, ty_pl.payload).data;
const ptr_ty = func.typeOf(bin_op.lhs);
const elem_ty = ty_pl.ty.toType().childType(mod);
const elem_size = elem_ty.abiSize(mod);
const ptr = try func.resolveInst(bin_op.lhs);
const index = try func.resolveInst(bin_op.rhs);
// load pointer onto the stack
if (ptr_ty.isSlice(mod)) {
_ = try func.load(ptr, Type.usize, 0);
} else {
try func.lowerToStack(ptr);
}
// calculate index into ptr
try func.emitWValue(index);
try func.addImm32(@as(i32, @bitCast(@as(u32, @intCast(elem_size)))));
try func.addTag(.i32_mul);
try func.addTag(.i32_add);
const result = try func.allocLocal(Type.i32);
try func.addLabel(.local_set, result.local.value);
func.finishAir(inst, result, &.{ bin_op.lhs, bin_op.rhs });
}
fn airPtrBinOp(func: *CodeGen, inst: Air.Inst.Index, op: Op) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const ty_pl = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_pl;
const bin_op = func.air.extraData(Air.Bin, ty_pl.payload).data;
const ptr = try func.resolveInst(bin_op.lhs);
const offset = try func.resolveInst(bin_op.rhs);
const ptr_ty = func.typeOf(bin_op.lhs);
const pointee_ty = switch (ptr_ty.ptrSize(mod)) {
.One => ptr_ty.childType(mod).childType(mod), // ptr to array, so get array element type
else => ptr_ty.childType(mod),
};
const valtype = typeToValtype(Type.usize, mod);
const mul_opcode = buildOpcode(.{ .valtype1 = valtype, .op = .mul });
const bin_opcode = buildOpcode(.{ .valtype1 = valtype, .op = op });
try func.lowerToStack(ptr);
try func.emitWValue(offset);
try func.addImm32(@as(i32, @bitCast(@as(u32, @intCast(pointee_ty.abiSize(mod))))));
try func.addTag(Mir.Inst.Tag.fromOpcode(mul_opcode));
try func.addTag(Mir.Inst.Tag.fromOpcode(bin_opcode));
const result = try func.allocLocal(Type.usize);
try func.addLabel(.local_set, result.local.value);
func.finishAir(inst, result, &.{ bin_op.lhs, bin_op.rhs });
}
fn airMemset(func: *CodeGen, inst: Air.Inst.Index, safety: bool) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
if (safety) {
// TODO if the value is undef, write 0xaa bytes to dest
} else {
// TODO if the value is undef, don't lower this instruction
}
const bin_op = func.air.instructions.items(.data)[@intFromEnum(inst)].bin_op;
const ptr = try func.resolveInst(bin_op.lhs);
const ptr_ty = func.typeOf(bin_op.lhs);
const value = try func.resolveInst(bin_op.rhs);
const len = switch (ptr_ty.ptrSize(mod)) {
.Slice => try func.sliceLen(ptr),
.One => @as(WValue, .{ .imm32 = @as(u32, @intCast(ptr_ty.childType(mod).arrayLen(mod))) }),
.C, .Many => unreachable,
};
const elem_ty = if (ptr_ty.ptrSize(mod) == .One)
ptr_ty.childType(mod).childType(mod)
else
ptr_ty.childType(mod);
const dst_ptr = try func.sliceOrArrayPtr(ptr, ptr_ty);
try func.memset(elem_ty, dst_ptr, len, value);
func.finishAir(inst, .none, &.{ bin_op.lhs, bin_op.rhs });
}
/// Sets a region of memory at `ptr` to the value of `value`
/// When the user has enabled the bulk_memory feature, we lower
/// this to wasm's memset instruction. When the feature is not present,
/// we implement it manually.
fn memset(func: *CodeGen, elem_ty: Type, ptr: WValue, len: WValue, value: WValue) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const abi_size = @as(u32, @intCast(elem_ty.abiSize(mod)));
// When bulk_memory is enabled, we lower it to wasm's memset instruction.
// If not, we lower it ourselves.
if (std.Target.wasm.featureSetHas(func.target.cpu.features, .bulk_memory) and abi_size == 1) {
try func.lowerToStack(ptr);
try func.emitWValue(value);
try func.emitWValue(len);
try func.addExtended(.memory_fill);
return;
}
const final_len = switch (len) {
.imm32 => |val| WValue{ .imm32 = val * abi_size },
.imm64 => |val| WValue{ .imm64 = val * abi_size },
else => if (abi_size != 1) blk: {
const new_len = try func.ensureAllocLocal(Type.usize);
try func.emitWValue(len);
switch (func.arch()) {
.wasm32 => {
try func.emitWValue(.{ .imm32 = abi_size });
try func.addTag(.i32_mul);
},
.wasm64 => {
try func.emitWValue(.{ .imm64 = abi_size });
try func.addTag(.i64_mul);
},
else => unreachable,
}
try func.addLabel(.local_set, new_len.local.value);
break :blk new_len;
} else len,
};
var end_ptr = try func.allocLocal(Type.usize);
defer end_ptr.free(func);
var new_ptr = try func.buildPointerOffset(ptr, 0, .new);
defer new_ptr.free(func);
// get the loop conditional: if current pointer address equals final pointer's address
try func.lowerToStack(ptr);
try func.emitWValue(final_len);
switch (func.arch()) {
.wasm32 => try func.addTag(.i32_add),
.wasm64 => try func.addTag(.i64_add),
else => unreachable,
}
try func.addLabel(.local_set, end_ptr.local.value);
// outer block to jump to when loop is done
try func.startBlock(.block, wasm.block_empty);
try func.startBlock(.loop, wasm.block_empty);
// check for codition for loop end
try func.emitWValue(new_ptr);
try func.emitWValue(end_ptr);
switch (func.arch()) {
.wasm32 => try func.addTag(.i32_eq),
.wasm64 => try func.addTag(.i64_eq),
else => unreachable,
}
try func.addLabel(.br_if, 1); // jump out of loop into outer block (finished)
// store the value at the current position of the pointer
try func.store(new_ptr, value, elem_ty, 0);
// move the pointer to the next element
try func.emitWValue(new_ptr);
switch (func.arch()) {
.wasm32 => {
try func.emitWValue(.{ .imm32 = abi_size });
try func.addTag(.i32_add);
},
.wasm64 => {
try func.emitWValue(.{ .imm64 = abi_size });
try func.addTag(.i64_add);
},
else => unreachable,
}
try func.addLabel(.local_set, new_ptr.local.value);
// end of loop
try func.addLabel(.br, 0); // jump to start of loop
try func.endBlock();
try func.endBlock();
}
fn airArrayElemVal(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const bin_op = func.air.instructions.items(.data)[@intFromEnum(inst)].bin_op;
const array_ty = func.typeOf(bin_op.lhs);
const array = try func.resolveInst(bin_op.lhs);
const index = try func.resolveInst(bin_op.rhs);
const elem_ty = array_ty.childType(mod);
const elem_size = elem_ty.abiSize(mod);
if (isByRef(array_ty, mod)) {
try func.lowerToStack(array);
try func.emitWValue(index);
try func.addImm32(@as(i32, @bitCast(@as(u32, @intCast(elem_size)))));
try func.addTag(.i32_mul);
try func.addTag(.i32_add);
} else {
std.debug.assert(array_ty.zigTypeTag(mod) == .Vector);
switch (index) {
inline .imm32, .imm64 => |lane| {
const opcode: wasm.SimdOpcode = switch (elem_ty.bitSize(mod)) {
8 => if (elem_ty.isSignedInt(mod)) .i8x16_extract_lane_s else .i8x16_extract_lane_u,
16 => if (elem_ty.isSignedInt(mod)) .i16x8_extract_lane_s else .i16x8_extract_lane_u,
32 => if (elem_ty.isInt(mod)) .i32x4_extract_lane else .f32x4_extract_lane,
64 => if (elem_ty.isInt(mod)) .i64x2_extract_lane else .f64x2_extract_lane,
else => unreachable,
};
var operands = [_]u32{ std.wasm.simdOpcode(opcode), @as(u8, @intCast(lane)) };
try func.emitWValue(array);
const extra_index = @as(u32, @intCast(func.mir_extra.items.len));
try func.mir_extra.appendSlice(func.gpa, &operands);
try func.addInst(.{ .tag = .simd_prefix, .data = .{ .payload = extra_index } });
return func.finishAir(inst, try WValue.toLocal(.stack, func, elem_ty), &.{ bin_op.lhs, bin_op.rhs });
},
else => {
const stack_vec = try func.allocStack(array_ty);
try func.store(stack_vec, array, array_ty, 0);
// Is a non-unrolled vector (v128)
try func.lowerToStack(stack_vec);
try func.emitWValue(index);
try func.addImm32(@as(i32, @bitCast(@as(u32, @intCast(elem_size)))));
try func.addTag(.i32_mul);
try func.addTag(.i32_add);
},
}
}
const elem_result = val: {
var result = try func.allocLocal(Type.usize);
try func.addLabel(.local_set, result.local.value);
if (isByRef(elem_ty, mod)) {
break :val result;
}
defer result.free(func); // only free if no longer needed and not returned like above
const elem_val = try func.load(result, elem_ty, 0);
break :val try elem_val.toLocal(func, elem_ty);
};
func.finishAir(inst, elem_result, &.{ bin_op.lhs, bin_op.rhs });
}
fn airIntFromFloat(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const ty_op = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_op;
const operand = try func.resolveInst(ty_op.operand);
const op_ty = func.typeOf(ty_op.operand);
const op_bits = op_ty.floatBits(func.target);
const dest_ty = func.typeOfIndex(inst);
const dest_info = dest_ty.intInfo(mod);
if (dest_info.bits > 128) {
return func.fail("TODO: intFromFloat for integers/floats with bitsize {}", .{dest_info.bits});
}
if ((op_bits != 32 and op_bits != 64) or dest_info.bits > 64) {
const dest_bitsize = if (dest_info.bits <= 16) 16 else std.math.ceilPowerOfTwoAssert(u16, dest_info.bits);
var fn_name_buf: [16]u8 = undefined;
const fn_name = std.fmt.bufPrint(&fn_name_buf, "__fix{s}{s}f{s}i", .{
switch (dest_info.signedness) {
.signed => "",
.unsigned => "uns",
},
target_util.compilerRtFloatAbbrev(op_bits),
target_util.compilerRtIntAbbrev(dest_bitsize),
}) catch unreachable;
const result = try (try func.callIntrinsic(fn_name, &.{op_ty.ip_index}, dest_ty, &.{operand})).toLocal(func, dest_ty);
return func.finishAir(inst, result, &.{ty_op.operand});
}
try func.emitWValue(operand);
const op = buildOpcode(.{
.op = .trunc,
.valtype1 = typeToValtype(dest_ty, mod),
.valtype2 = typeToValtype(op_ty, mod),
.signedness = dest_info.signedness,
});
try func.addTag(Mir.Inst.Tag.fromOpcode(op));
const wrapped = try func.wrapOperand(.{ .stack = {} }, dest_ty);
const result = try wrapped.toLocal(func, dest_ty);
func.finishAir(inst, result, &.{ty_op.operand});
}
fn airFloatFromInt(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const ty_op = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_op;
const operand = try func.resolveInst(ty_op.operand);
const op_ty = func.typeOf(ty_op.operand);
const op_info = op_ty.intInfo(mod);
const dest_ty = func.typeOfIndex(inst);
const dest_bits = dest_ty.floatBits(func.target);
if (op_info.bits > 128) {
return func.fail("TODO: floatFromInt for integers/floats with bitsize {d} bits", .{op_info.bits});
}
if (op_info.bits > 64 or (dest_bits > 64 or dest_bits < 32)) {
const op_bitsize = if (op_info.bits <= 16) 16 else std.math.ceilPowerOfTwoAssert(u16, op_info.bits);
var fn_name_buf: [16]u8 = undefined;
const fn_name = std.fmt.bufPrint(&fn_name_buf, "__float{s}{s}i{s}f", .{
switch (op_info.signedness) {
.signed => "",
.unsigned => "un",
},
target_util.compilerRtIntAbbrev(op_bitsize),
target_util.compilerRtFloatAbbrev(dest_bits),
}) catch unreachable;
const result = try (try func.callIntrinsic(fn_name, &.{op_ty.ip_index}, dest_ty, &.{operand})).toLocal(func, dest_ty);
return func.finishAir(inst, result, &.{ty_op.operand});
}
try func.emitWValue(operand);
const op = buildOpcode(.{
.op = .convert,
.valtype1 = typeToValtype(dest_ty, mod),
.valtype2 = typeToValtype(op_ty, mod),
.signedness = op_info.signedness,
});
try func.addTag(Mir.Inst.Tag.fromOpcode(op));
const result = try func.allocLocal(dest_ty);
try func.addLabel(.local_set, result.local.value);
func.finishAir(inst, result, &.{ty_op.operand});
}
fn airSplat(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const ty_op = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_op;
const operand = try func.resolveInst(ty_op.operand);
const ty = func.typeOfIndex(inst);
const elem_ty = ty.childType(mod);
if (determineSimdStoreStrategy(ty, mod) == .direct) blk: {
switch (operand) {
// when the operand lives in the linear memory section, we can directly
// load and splat the value at once. Meaning we do not first have to load
// the scalar value onto the stack.
.stack_offset, .memory, .memory_offset => {
const opcode = switch (elem_ty.bitSize(mod)) {
8 => std.wasm.simdOpcode(.v128_load8_splat),
16 => std.wasm.simdOpcode(.v128_load16_splat),
32 => std.wasm.simdOpcode(.v128_load32_splat),
64 => std.wasm.simdOpcode(.v128_load64_splat),
else => break :blk, // Cannot make use of simd-instructions
};
const result = try func.allocLocal(ty);
try func.emitWValue(operand);
// TODO: Add helper functions for simd opcodes
const extra_index = @as(u32, @intCast(func.mir_extra.items.len));
// stores as := opcode, offset, alignment (opcode::memarg)
try func.mir_extra.appendSlice(func.gpa, &[_]u32{
opcode,
operand.offset(),
@intCast(elem_ty.abiAlignment(mod).toByteUnitsOptional().?),
});
try func.addInst(.{ .tag = .simd_prefix, .data = .{ .payload = extra_index } });
try func.addLabel(.local_set, result.local.value);
return func.finishAir(inst, result, &.{ty_op.operand});
},
.local => {
const opcode = switch (elem_ty.bitSize(mod)) {
8 => std.wasm.simdOpcode(.i8x16_splat),
16 => std.wasm.simdOpcode(.i16x8_splat),
32 => if (elem_ty.isInt(mod)) std.wasm.simdOpcode(.i32x4_splat) else std.wasm.simdOpcode(.f32x4_splat),
64 => if (elem_ty.isInt(mod)) std.wasm.simdOpcode(.i64x2_splat) else std.wasm.simdOpcode(.f64x2_splat),
else => break :blk, // Cannot make use of simd-instructions
};
const result = try func.allocLocal(ty);
try func.emitWValue(operand);
const extra_index = @as(u32, @intCast(func.mir_extra.items.len));
try func.mir_extra.append(func.gpa, opcode);
try func.addInst(.{ .tag = .simd_prefix, .data = .{ .payload = extra_index } });
try func.addLabel(.local_set, result.local.value);
return func.finishAir(inst, result, &.{ty_op.operand});
},
else => unreachable,
}
}
const elem_size = elem_ty.bitSize(mod);
const vector_len = @as(usize, @intCast(ty.vectorLen(mod)));
if ((!std.math.isPowerOfTwo(elem_size) or elem_size % 8 != 0) and vector_len > 1) {
return func.fail("TODO: WebAssembly `@splat` for arbitrary element bitsize {d}", .{elem_size});
}
const result = try func.allocStack(ty);
const elem_byte_size = @as(u32, @intCast(elem_ty.abiSize(mod)));
var index: usize = 0;
var offset: u32 = 0;
while (index < vector_len) : (index += 1) {
try func.store(result, operand, elem_ty, offset);
offset += elem_byte_size;
}
return func.finishAir(inst, result, &.{ty_op.operand});
}
fn airSelect(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const pl_op = func.air.instructions.items(.data)[@intFromEnum(inst)].pl_op;
const operand = try func.resolveInst(pl_op.operand);
_ = operand;
return func.fail("TODO: Implement wasm airSelect", .{});
}
fn airShuffle(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const inst_ty = func.typeOfIndex(inst);
const ty_pl = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_pl;
const extra = func.air.extraData(Air.Shuffle, ty_pl.payload).data;
const a = try func.resolveInst(extra.a);
const b = try func.resolveInst(extra.b);
const mask = Value.fromInterned(extra.mask);
const mask_len = extra.mask_len;
const child_ty = inst_ty.childType(mod);
const elem_size = child_ty.abiSize(mod);
// TODO: One of them could be by ref; handle in loop
if (isByRef(func.typeOf(extra.a), mod) or isByRef(inst_ty, mod)) {
const result = try func.allocStack(inst_ty);
for (0..mask_len) |index| {
const value = (try mask.elemValue(mod, index)).toSignedInt(mod);
try func.emitWValue(result);
const loaded = if (value >= 0)
try func.load(a, child_ty, @as(u32, @intCast(@as(i64, @intCast(elem_size)) * value)))
else
try func.load(b, child_ty, @as(u32, @intCast(@as(i64, @intCast(elem_size)) * ~value)));
try func.store(.stack, loaded, child_ty, result.stack_offset.value + @as(u32, @intCast(elem_size)) * @as(u32, @intCast(index)));
}
return func.finishAir(inst, result, &.{ extra.a, extra.b });
} else {
var operands = [_]u32{
std.wasm.simdOpcode(.i8x16_shuffle),
} ++ [1]u32{undefined} ** 4;
var lanes = mem.asBytes(operands[1..]);
for (0..@as(usize, @intCast(mask_len))) |index| {
const mask_elem = (try mask.elemValue(mod, index)).toSignedInt(mod);
const base_index = if (mask_elem >= 0)
@as(u8, @intCast(@as(i64, @intCast(elem_size)) * mask_elem))
else
16 + @as(u8, @intCast(@as(i64, @intCast(elem_size)) * ~mask_elem));
for (0..@as(usize, @intCast(elem_size))) |byte_offset| {
lanes[index * @as(usize, @intCast(elem_size)) + byte_offset] = base_index + @as(u8, @intCast(byte_offset));
}
}
try func.emitWValue(a);
try func.emitWValue(b);
const extra_index = @as(u32, @intCast(func.mir_extra.items.len));
try func.mir_extra.appendSlice(func.gpa, &operands);
try func.addInst(.{ .tag = .simd_prefix, .data = .{ .payload = extra_index } });
return func.finishAir(inst, try WValue.toLocal(.stack, func, inst_ty), &.{ extra.a, extra.b });
}
}
fn airReduce(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const reduce = func.air.instructions.items(.data)[@intFromEnum(inst)].reduce;
const operand = try func.resolveInst(reduce.operand);
_ = operand;
return func.fail("TODO: Implement wasm airReduce", .{});
}
fn airAggregateInit(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const ip = &mod.intern_pool;
const ty_pl = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_pl;
const result_ty = func.typeOfIndex(inst);
const len = @as(usize, @intCast(result_ty.arrayLen(mod)));
const elements = @as([]const Air.Inst.Ref, @ptrCast(func.air.extra[ty_pl.payload..][0..len]));
const result: WValue = result_value: {
switch (result_ty.zigTypeTag(mod)) {
.Array => {
const result = try func.allocStack(result_ty);
const elem_ty = result_ty.childType(mod);
const elem_size = @as(u32, @intCast(elem_ty.abiSize(mod)));
const sentinel = if (result_ty.sentinel(mod)) |sent| blk: {
break :blk try func.lowerConstant(sent, elem_ty);
} else null;
// When the element type is by reference, we must copy the entire
// value. It is therefore safer to move the offset pointer and store
// each value individually, instead of using store offsets.
if (isByRef(elem_ty, mod)) {
// copy stack pointer into a temporary local, which is
// moved for each element to store each value in the right position.
const offset = try func.buildPointerOffset(result, 0, .new);
for (elements, 0..) |elem, elem_index| {
const elem_val = try func.resolveInst(elem);
try func.store(offset, elem_val, elem_ty, 0);
if (elem_index < elements.len - 1 and sentinel == null) {
_ = try func.buildPointerOffset(offset, elem_size, .modify);
}
}
if (sentinel) |sent| {
try func.store(offset, sent, elem_ty, 0);
}
} else {
var offset: u32 = 0;
for (elements) |elem| {
const elem_val = try func.resolveInst(elem);
try func.store(result, elem_val, elem_ty, offset);
offset += elem_size;
}
if (sentinel) |sent| {
try func.store(result, sent, elem_ty, offset);
}
}
break :result_value result;
},
.Struct => switch (result_ty.containerLayout(mod)) {
.Packed => {
if (isByRef(result_ty, mod)) {
return func.fail("TODO: airAggregateInit for packed structs larger than 64 bits", .{});
}
const packed_struct = mod.typeToPackedStruct(result_ty).?;
const field_types = packed_struct.field_types;
const backing_type = Type.fromInterned(packed_struct.backingIntType(ip).*);
// ensure the result is zero'd
const result = try func.allocLocal(backing_type);
if (backing_type.bitSize(mod) <= 32)
try func.addImm32(0)
else
try func.addImm64(0);
try func.addLabel(.local_set, result.local.value);
var current_bit: u16 = 0;
for (elements, 0..) |elem, elem_index| {
const field_ty = Type.fromInterned(field_types.get(ip)[elem_index]);
if (!field_ty.hasRuntimeBitsIgnoreComptime(mod)) continue;
const shift_val = if (backing_type.bitSize(mod) <= 32)
WValue{ .imm32 = current_bit }
else
WValue{ .imm64 = current_bit };
const value = try func.resolveInst(elem);
const value_bit_size: u16 = @intCast(field_ty.bitSize(mod));
const int_ty = try mod.intType(.unsigned, value_bit_size);
// load our current result on stack so we can perform all transformations
// using only stack values. Saving the cost of loads and stores.
try func.emitWValue(result);
const bitcasted = try func.bitcast(int_ty, field_ty, value);
const extended_val = try func.intcast(bitcasted, int_ty, backing_type);
// no need to shift any values when the current offset is 0
const shifted = if (current_bit != 0) shifted: {
break :shifted try func.binOp(extended_val, shift_val, backing_type, .shl);
} else extended_val;
// we ignore the result as we keep it on the stack to assign it directly to `result`
_ = try func.binOp(.stack, shifted, backing_type, .@"or");
try func.addLabel(.local_set, result.local.value);
current_bit += value_bit_size;
}
break :result_value result;
},
else => {
const result = try func.allocStack(result_ty);
const offset = try func.buildPointerOffset(result, 0, .new); // pointer to offset
var prev_field_offset: u64 = 0;
for (elements, 0..) |elem, elem_index| {
if ((try result_ty.structFieldValueComptime(mod, elem_index)) != null) continue;
const elem_ty = result_ty.structFieldType(elem_index, mod);
const field_offset = result_ty.structFieldOffset(elem_index, mod);
_ = try func.buildPointerOffset(offset, @intCast(field_offset - prev_field_offset), .modify);
prev_field_offset = field_offset;
const value = try func.resolveInst(elem);
try func.store(offset, value, elem_ty, 0);
}
break :result_value result;
},
},
.Vector => return func.fail("TODO: Wasm backend: implement airAggregateInit for vectors", .{}),
else => unreachable,
}
};
if (elements.len <= Liveness.bpi - 1) {
var buf = [1]Air.Inst.Ref{.none} ** (Liveness.bpi - 1);
@memcpy(buf[0..elements.len], elements);
return func.finishAir(inst, result, &buf);
}
var bt = try func.iterateBigTomb(inst, elements.len);
for (elements) |arg| bt.feed(arg);
return bt.finishAir(result);
}
fn airUnionInit(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const ip = &mod.intern_pool;
const ty_pl = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_pl;
const extra = func.air.extraData(Air.UnionInit, ty_pl.payload).data;
const result = result: {
const union_ty = func.typeOfIndex(inst);
const layout = union_ty.unionGetLayout(mod);
const union_obj = mod.typeToUnion(union_ty).?;
const field_ty = Type.fromInterned(union_obj.field_types.get(ip)[extra.field_index]);
const field_name = union_obj.field_names.get(ip)[extra.field_index];
const tag_int = blk: {
const tag_ty = union_ty.unionTagTypeHypothetical(mod);
const enum_field_index = tag_ty.enumFieldIndex(field_name, mod).?;
const tag_val = try mod.enumValueFieldIndex(tag_ty, enum_field_index);
break :blk try func.lowerConstant(tag_val, tag_ty);
};
if (layout.payload_size == 0) {
if (layout.tag_size == 0) {
break :result WValue{ .none = {} };
}
assert(!isByRef(union_ty, mod));
break :result tag_int;
}
if (isByRef(union_ty, mod)) {
const result_ptr = try func.allocStack(union_ty);
const payload = try func.resolveInst(extra.init);
if (layout.tag_align.compare(.gte, layout.payload_align)) {
if (isByRef(field_ty, mod)) {
const payload_ptr = try func.buildPointerOffset(result_ptr, layout.tag_size, .new);
try func.store(payload_ptr, payload, field_ty, 0);
} else {
try func.store(result_ptr, payload, field_ty, @intCast(layout.tag_size));
}
if (layout.tag_size > 0) {
try func.store(result_ptr, tag_int, Type.fromInterned(union_obj.enum_tag_ty), 0);
}
} else {
try func.store(result_ptr, payload, field_ty, 0);
if (layout.tag_size > 0) {
try func.store(
result_ptr,
tag_int,
Type.fromInterned(union_obj.enum_tag_ty),
@intCast(layout.payload_size),
);
}
}
break :result result_ptr;
} else {
const operand = try func.resolveInst(extra.init);
const union_int_type = try mod.intType(.unsigned, @as(u16, @intCast(union_ty.bitSize(mod))));
if (field_ty.zigTypeTag(mod) == .Float) {
const int_type = try mod.intType(.unsigned, @intCast(field_ty.bitSize(mod)));
const bitcasted = try func.bitcast(field_ty, int_type, operand);
const casted = try func.trunc(bitcasted, int_type, union_int_type);
break :result try casted.toLocal(func, field_ty);
} else if (field_ty.isPtrAtRuntime(mod)) {
const int_type = try mod.intType(.unsigned, @intCast(field_ty.bitSize(mod)));
const casted = try func.intcast(operand, int_type, union_int_type);
break :result try casted.toLocal(func, field_ty);
}
const casted = try func.intcast(operand, field_ty, union_int_type);
break :result try casted.toLocal(func, field_ty);
}
};
return func.finishAir(inst, result, &.{extra.init});
}
fn airPrefetch(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const prefetch = func.air.instructions.items(.data)[@intFromEnum(inst)].prefetch;
func.finishAir(inst, .none, &.{prefetch.ptr});
}
fn airWasmMemorySize(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const pl_op = func.air.instructions.items(.data)[@intFromEnum(inst)].pl_op;
const result = try func.allocLocal(func.typeOfIndex(inst));
try func.addLabel(.memory_size, pl_op.payload);
try func.addLabel(.local_set, result.local.value);
func.finishAir(inst, result, &.{pl_op.operand});
}
fn airWasmMemoryGrow(func: *CodeGen, inst: Air.Inst.Index) !void {
const pl_op = func.air.instructions.items(.data)[@intFromEnum(inst)].pl_op;
const operand = try func.resolveInst(pl_op.operand);
const result = try func.allocLocal(func.typeOfIndex(inst));
try func.emitWValue(operand);
try func.addLabel(.memory_grow, pl_op.payload);
try func.addLabel(.local_set, result.local.value);
func.finishAir(inst, result, &.{pl_op.operand});
}
fn cmpOptionals(func: *CodeGen, lhs: WValue, rhs: WValue, operand_ty: Type, op: std.math.CompareOperator) InnerError!WValue {
const mod = func.bin_file.base.comp.module.?;
assert(operand_ty.hasRuntimeBitsIgnoreComptime(mod));
assert(op == .eq or op == .neq);
const payload_ty = operand_ty.optionalChild(mod);
// We store the final result in here that will be validated
// if the optional is truly equal.
var result = try func.ensureAllocLocal(Type.i32);
defer result.free(func);
try func.startBlock(.block, wasm.block_empty);
_ = try func.isNull(lhs, operand_ty, .i32_eq);
_ = try func.isNull(rhs, operand_ty, .i32_eq);
try func.addTag(.i32_ne); // inverse so we can exit early
try func.addLabel(.br_if, 0);
_ = try func.load(lhs, payload_ty, 0);
_ = try func.load(rhs, payload_ty, 0);
const opcode = buildOpcode(.{ .op = .ne, .valtype1 = typeToValtype(payload_ty, mod) });
try func.addTag(Mir.Inst.Tag.fromOpcode(opcode));
try func.addLabel(.br_if, 0);
try func.addImm32(1);
try func.addLabel(.local_set, result.local.value);
try func.endBlock();
try func.emitWValue(result);
try func.addImm32(0);
try func.addTag(if (op == .eq) .i32_ne else .i32_eq);
return WValue{ .stack = {} };
}
/// Compares big integers by checking both its high bits and low bits.
/// NOTE: Leaves the result of the comparison on top of the stack.
/// TODO: Lower this to compiler_rt call when bitsize > 128
fn cmpBigInt(func: *CodeGen, lhs: WValue, rhs: WValue, operand_ty: Type, op: std.math.CompareOperator) InnerError!WValue {
const mod = func.bin_file.base.comp.module.?;
assert(operand_ty.abiSize(mod) >= 16);
assert(!(lhs != .stack and rhs == .stack));
if (operand_ty.bitSize(mod) > 128) {
return func.fail("TODO: Support cmpBigInt for integer bitsize: '{d}'", .{operand_ty.bitSize(mod)});
}
var lhs_high_bit = try (try func.load(lhs, Type.u64, 0)).toLocal(func, Type.u64);
defer lhs_high_bit.free(func);
var rhs_high_bit = try (try func.load(rhs, Type.u64, 0)).toLocal(func, Type.u64);
defer rhs_high_bit.free(func);
switch (op) {
.eq, .neq => {
const xor_high = try func.binOp(lhs_high_bit, rhs_high_bit, Type.u64, .xor);
const lhs_low_bit = try func.load(lhs, Type.u64, 8);
const rhs_low_bit = try func.load(rhs, Type.u64, 8);
const xor_low = try func.binOp(lhs_low_bit, rhs_low_bit, Type.u64, .xor);
const or_result = try func.binOp(xor_high, xor_low, Type.u64, .@"or");
switch (op) {
.eq => return func.cmp(or_result, .{ .imm64 = 0 }, Type.u64, .eq),
.neq => return func.cmp(or_result, .{ .imm64 = 0 }, Type.u64, .neq),
else => unreachable,
}
},
else => {
const ty = if (operand_ty.isSignedInt(mod)) Type.i64 else Type.u64;
// leave those value on top of the stack for '.select'
const lhs_low_bit = try func.load(lhs, Type.u64, 8);
const rhs_low_bit = try func.load(rhs, Type.u64, 8);
_ = try func.cmp(lhs_low_bit, rhs_low_bit, ty, op);
_ = try func.cmp(lhs_high_bit, rhs_high_bit, ty, op);
_ = try func.cmp(lhs_high_bit, rhs_high_bit, ty, .eq);
try func.addTag(.select);
},
}
return WValue{ .stack = {} };
}
fn airSetUnionTag(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const bin_op = func.air.instructions.items(.data)[@intFromEnum(inst)].bin_op;
const un_ty = func.typeOf(bin_op.lhs).childType(mod);
const tag_ty = func.typeOf(bin_op.rhs);
const layout = un_ty.unionGetLayout(mod);
if (layout.tag_size == 0) return func.finishAir(inst, .none, &.{ bin_op.lhs, bin_op.rhs });
const union_ptr = try func.resolveInst(bin_op.lhs);
const new_tag = try func.resolveInst(bin_op.rhs);
if (layout.payload_size == 0) {
try func.store(union_ptr, new_tag, tag_ty, 0);
return func.finishAir(inst, .none, &.{ bin_op.lhs, bin_op.rhs });
}
// when the tag alignment is smaller than the payload, the field will be stored
// after the payload.
const offset: u32 = if (layout.tag_align.compare(.lt, layout.payload_align)) blk: {
break :blk @intCast(layout.payload_size);
} else 0;
try func.store(union_ptr, new_tag, tag_ty, offset);
func.finishAir(inst, .none, &.{ bin_op.lhs, bin_op.rhs });
}
fn airGetUnionTag(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const ty_op = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_op;
const un_ty = func.typeOf(ty_op.operand);
const tag_ty = func.typeOfIndex(inst);
const layout = un_ty.unionGetLayout(mod);
if (layout.tag_size == 0) return func.finishAir(inst, .none, &.{ty_op.operand});
const operand = try func.resolveInst(ty_op.operand);
// when the tag alignment is smaller than the payload, the field will be stored
// after the payload.
const offset: u32 = if (layout.tag_align.compare(.lt, layout.payload_align)) blk: {
break :blk @intCast(layout.payload_size);
} else 0;
const tag = try func.load(operand, tag_ty, offset);
const result = try tag.toLocal(func, tag_ty);
func.finishAir(inst, result, &.{ty_op.operand});
}
fn airFpext(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const ty_op = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_op;
const dest_ty = func.typeOfIndex(inst);
const operand = try func.resolveInst(ty_op.operand);
const extended = try func.fpext(operand, func.typeOf(ty_op.operand), dest_ty);
const result = try extended.toLocal(func, dest_ty);
func.finishAir(inst, result, &.{ty_op.operand});
}
/// Extends a float from a given `Type` to a larger wanted `Type`
/// NOTE: Leaves the result on the stack
fn fpext(func: *CodeGen, operand: WValue, given: Type, wanted: Type) InnerError!WValue {
const given_bits = given.floatBits(func.target);
const wanted_bits = wanted.floatBits(func.target);
if (wanted_bits == 64 and given_bits == 32) {
try func.emitWValue(operand);
try func.addTag(.f64_promote_f32);
return WValue{ .stack = {} };
} else if (given_bits == 16 and wanted_bits <= 64) {
// call __extendhfsf2(f16) f32
const f32_result = try func.callIntrinsic(
"__extendhfsf2",
&.{.f16_type},
Type.f32,
&.{operand},
);
std.debug.assert(f32_result == .stack);
if (wanted_bits == 64) {
try func.addTag(.f64_promote_f32);
}
return WValue{ .stack = {} };
}
var fn_name_buf: [13]u8 = undefined;
const fn_name = std.fmt.bufPrint(&fn_name_buf, "__extend{s}f{s}f2", .{
target_util.compilerRtFloatAbbrev(given_bits),
target_util.compilerRtFloatAbbrev(wanted_bits),
}) catch unreachable;
return func.callIntrinsic(fn_name, &.{given.ip_index}, wanted, &.{operand});
}
fn airFptrunc(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const ty_op = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_op;
const dest_ty = func.typeOfIndex(inst);
const operand = try func.resolveInst(ty_op.operand);
const truncated = try func.fptrunc(operand, func.typeOf(ty_op.operand), dest_ty);
const result = try truncated.toLocal(func, dest_ty);
func.finishAir(inst, result, &.{ty_op.operand});
}
/// Truncates a float from a given `Type` to its wanted `Type`
/// NOTE: The result value remains on the stack
fn fptrunc(func: *CodeGen, operand: WValue, given: Type, wanted: Type) InnerError!WValue {
const given_bits = given.floatBits(func.target);
const wanted_bits = wanted.floatBits(func.target);
if (wanted_bits == 32 and given_bits == 64) {
try func.emitWValue(operand);
try func.addTag(.f32_demote_f64);
return WValue{ .stack = {} };
} else if (wanted_bits == 16 and given_bits <= 64) {
const op: WValue = if (given_bits == 64) blk: {
try func.emitWValue(operand);
try func.addTag(.f32_demote_f64);
break :blk WValue{ .stack = {} };
} else operand;
// call __truncsfhf2(f32) f16
return func.callIntrinsic("__truncsfhf2", &.{.f32_type}, Type.f16, &.{op});
}
var fn_name_buf: [12]u8 = undefined;
const fn_name = std.fmt.bufPrint(&fn_name_buf, "__trunc{s}f{s}f2", .{
target_util.compilerRtFloatAbbrev(given_bits),
target_util.compilerRtFloatAbbrev(wanted_bits),
}) catch unreachable;
return func.callIntrinsic(fn_name, &.{given.ip_index}, wanted, &.{operand});
}
fn airErrUnionPayloadPtrSet(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const ty_op = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_op;
const err_set_ty = func.typeOf(ty_op.operand).childType(mod);
const payload_ty = err_set_ty.errorUnionPayload(mod);
const operand = try func.resolveInst(ty_op.operand);
// set error-tag to '0' to annotate error union is non-error
try func.store(
operand,
.{ .imm32 = 0 },
Type.anyerror,
@as(u32, @intCast(errUnionErrorOffset(payload_ty, mod))),
);
const result = result: {
if (!payload_ty.hasRuntimeBitsIgnoreComptime(mod)) {
break :result func.reuseOperand(ty_op.operand, operand);
}
break :result try func.buildPointerOffset(operand, @as(u32, @intCast(errUnionPayloadOffset(payload_ty, mod))), .new);
};
func.finishAir(inst, result, &.{ty_op.operand});
}
fn airFieldParentPtr(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const ty_pl = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_pl;
const extra = func.air.extraData(Air.FieldParentPtr, ty_pl.payload).data;
const field_ptr = try func.resolveInst(extra.field_ptr);
const parent_ty = ty_pl.ty.toType().childType(mod);
const field_offset = parent_ty.structFieldOffset(extra.field_index, mod);
const result = if (field_offset != 0) result: {
const base = try func.buildPointerOffset(field_ptr, 0, .new);
try func.addLabel(.local_get, base.local.value);
try func.addImm32(@as(i32, @bitCast(@as(u32, @intCast(field_offset)))));
try func.addTag(.i32_sub);
try func.addLabel(.local_set, base.local.value);
break :result base;
} else func.reuseOperand(extra.field_ptr, field_ptr);
func.finishAir(inst, result, &.{extra.field_ptr});
}
fn sliceOrArrayPtr(func: *CodeGen, ptr: WValue, ptr_ty: Type) InnerError!WValue {
const mod = func.bin_file.base.comp.module.?;
if (ptr_ty.isSlice(mod)) {
return func.slicePtr(ptr);
} else {
return ptr;
}
}
fn airMemcpy(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const bin_op = func.air.instructions.items(.data)[@intFromEnum(inst)].bin_op;
const dst = try func.resolveInst(bin_op.lhs);
const dst_ty = func.typeOf(bin_op.lhs);
const ptr_elem_ty = dst_ty.childType(mod);
const src = try func.resolveInst(bin_op.rhs);
const src_ty = func.typeOf(bin_op.rhs);
const len = switch (dst_ty.ptrSize(mod)) {
.Slice => blk: {
const slice_len = try func.sliceLen(dst);
if (ptr_elem_ty.abiSize(mod) != 1) {
try func.emitWValue(slice_len);
try func.emitWValue(.{ .imm32 = @as(u32, @intCast(ptr_elem_ty.abiSize(mod))) });
try func.addTag(.i32_mul);
try func.addLabel(.local_set, slice_len.local.value);
}
break :blk slice_len;
},
.One => @as(WValue, .{
.imm32 = @as(u32, @intCast(ptr_elem_ty.arrayLen(mod) * ptr_elem_ty.childType(mod).abiSize(mod))),
}),
.C, .Many => unreachable,
};
const dst_ptr = try func.sliceOrArrayPtr(dst, dst_ty);
const src_ptr = try func.sliceOrArrayPtr(src, src_ty);
try func.memcpy(dst_ptr, src_ptr, len);
func.finishAir(inst, .none, &.{ bin_op.lhs, bin_op.rhs });
}
fn airRetAddr(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
// TODO: Implement this properly once stack serialization is solved
func.finishAir(inst, switch (func.arch()) {
.wasm32 => .{ .imm32 = 0 },
.wasm64 => .{ .imm64 = 0 },
else => unreachable,
}, &.{});
}
fn airPopcount(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const ty_op = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_op;
const operand = try func.resolveInst(ty_op.operand);
const op_ty = func.typeOf(ty_op.operand);
const result_ty = func.typeOfIndex(inst);
if (op_ty.zigTypeTag(mod) == .Vector) {
return func.fail("TODO: Implement @popCount for vectors", .{});
}
const int_info = op_ty.intInfo(mod);
const bits = int_info.bits;
const wasm_bits = toWasmBits(bits) orelse {
return func.fail("TODO: Implement @popCount for integers with bitsize '{d}'", .{bits});
};
switch (wasm_bits) {
128 => {
_ = try func.load(operand, Type.u64, 0);
try func.addTag(.i64_popcnt);
_ = try func.load(operand, Type.u64, 8);
try func.addTag(.i64_popcnt);
try func.addTag(.i64_add);
try func.addTag(.i32_wrap_i64);
},
else => {
try func.emitWValue(operand);
switch (wasm_bits) {
32 => try func.addTag(.i32_popcnt),
64 => {
try func.addTag(.i64_popcnt);
try func.addTag(.i32_wrap_i64);
},
else => unreachable,
}
},
}
const result = try func.allocLocal(result_ty);
try func.addLabel(.local_set, result.local.value);
func.finishAir(inst, result, &.{ty_op.operand});
}
fn airErrorName(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const un_op = func.air.instructions.items(.data)[@intFromEnum(inst)].un_op;
const operand = try func.resolveInst(un_op);
// First retrieve the symbol index to the error name table
// that will be used to emit a relocation for the pointer
// to the error name table.
//
// Each entry to this table is a slice (ptr+len).
// The operand in this instruction represents the index within this table.
// This means to get the final name, we emit the base pointer and then perform
// pointer arithmetic to find the pointer to this slice and return that.
//
// As the names are global and the slice elements are constant, we do not have
// to make a copy of the ptr+value but can point towards them directly.
const error_table_symbol = try func.bin_file.getErrorTableSymbol();
const name_ty = Type.slice_const_u8_sentinel_0;
const mod = func.bin_file.base.comp.module.?;
const abi_size = name_ty.abiSize(mod);
const error_name_value: WValue = .{ .memory = error_table_symbol }; // emitting this will create a relocation
try func.emitWValue(error_name_value);
try func.emitWValue(operand);
switch (func.arch()) {
.wasm32 => {
try func.addImm32(@as(i32, @bitCast(@as(u32, @intCast(abi_size)))));
try func.addTag(.i32_mul);
try func.addTag(.i32_add);
},
.wasm64 => {
try func.addImm64(abi_size);
try func.addTag(.i64_mul);
try func.addTag(.i64_add);
},
else => unreachable,
}
const result_ptr = try func.allocLocal(Type.usize);
try func.addLabel(.local_set, result_ptr.local.value);
func.finishAir(inst, result_ptr, &.{un_op});
}
fn airPtrSliceFieldPtr(func: *CodeGen, inst: Air.Inst.Index, offset: u32) InnerError!void {
const ty_op = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_op;
const slice_ptr = try func.resolveInst(ty_op.operand);
const result = try func.buildPointerOffset(slice_ptr, offset, .new);
func.finishAir(inst, result, &.{ty_op.operand});
}
fn airAddSubWithOverflow(func: *CodeGen, inst: Air.Inst.Index, op: Op) InnerError!void {
assert(op == .add or op == .sub);
const ty_pl = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_pl;
const extra = func.air.extraData(Air.Bin, ty_pl.payload).data;
const lhs_op = try func.resolveInst(extra.lhs);
const rhs_op = try func.resolveInst(extra.rhs);
const lhs_ty = func.typeOf(extra.lhs);
const mod = func.bin_file.base.comp.module.?;
if (lhs_ty.zigTypeTag(mod) == .Vector) {
return func.fail("TODO: Implement overflow arithmetic for vectors", .{});
}
const int_info = lhs_ty.intInfo(mod);
const is_signed = int_info.signedness == .signed;
const wasm_bits = toWasmBits(int_info.bits) orelse {
return func.fail("TODO: Implement {{add/sub}}_with_overflow for integer bitsize: {d}", .{int_info.bits});
};
if (wasm_bits == 128) {
const result = try func.addSubWithOverflowBigInt(lhs_op, rhs_op, lhs_ty, func.typeOfIndex(inst), op);
return func.finishAir(inst, result, &.{ extra.lhs, extra.rhs });
}
const zero = switch (wasm_bits) {
32 => WValue{ .imm32 = 0 },
64 => WValue{ .imm64 = 0 },
else => unreachable,
};
// for signed integers, we first apply signed shifts by the difference in bits
// to get the signed value, as we store it internally as 2's complement.
var lhs = if (wasm_bits != int_info.bits and is_signed) blk: {
break :blk try (try func.signExtendInt(lhs_op, lhs_ty)).toLocal(func, lhs_ty);
} else lhs_op;
var rhs = if (wasm_bits != int_info.bits and is_signed) blk: {
break :blk try (try func.signExtendInt(rhs_op, lhs_ty)).toLocal(func, lhs_ty);
} else rhs_op;
// in this case, we performed a signExtendInt which created a temporary local
// so let's free this so it can be re-used instead.
// In the other case we do not want to free it, because that would free the
// resolved instructions which may be referenced by other instructions.
defer if (wasm_bits != int_info.bits and is_signed) {
lhs.free(func);
rhs.free(func);
};
const bin_op = try (try func.binOp(lhs, rhs, lhs_ty, op)).toLocal(func, lhs_ty);
var result = if (wasm_bits != int_info.bits) blk: {
break :blk try (try func.wrapOperand(bin_op, lhs_ty)).toLocal(func, lhs_ty);
} else bin_op;
defer result.free(func);
const cmp_op: std.math.CompareOperator = if (op == .sub) .gt else .lt;
const overflow_bit: WValue = if (is_signed) blk: {
if (wasm_bits == int_info.bits) {
const cmp_zero = try func.cmp(rhs, zero, lhs_ty, cmp_op);
const lt = try func.cmp(bin_op, lhs, lhs_ty, .lt);
break :blk try func.binOp(cmp_zero, lt, Type.u32, .xor);
}
const abs = try func.signExtendInt(bin_op, lhs_ty);
break :blk try func.cmp(abs, bin_op, lhs_ty, .neq);
} else if (wasm_bits == int_info.bits)
try func.cmp(bin_op, lhs, lhs_ty, cmp_op)
else
try func.cmp(bin_op, result, lhs_ty, .neq);
var overflow_local = try overflow_bit.toLocal(func, Type.u32);
defer overflow_local.free(func);
const result_ptr = try func.allocStack(func.typeOfIndex(inst));
try func.store(result_ptr, result, lhs_ty, 0);
const offset = @as(u32, @intCast(lhs_ty.abiSize(mod)));
try func.store(result_ptr, overflow_local, Type.u1, offset);
func.finishAir(inst, result_ptr, &.{ extra.lhs, extra.rhs });
}
fn addSubWithOverflowBigInt(func: *CodeGen, lhs: WValue, rhs: WValue, ty: Type, result_ty: Type, op: Op) InnerError!WValue {
const mod = func.bin_file.base.comp.module.?;
assert(op == .add or op == .sub);
const int_info = ty.intInfo(mod);
const is_signed = int_info.signedness == .signed;
if (int_info.bits != 128) {
return func.fail("TODO: Implement @{{add/sub}}WithOverflow for integer bitsize '{d}'", .{int_info.bits});
}
var lhs_high_bit = try (try func.load(lhs, Type.u64, 0)).toLocal(func, Type.u64);
defer lhs_high_bit.free(func);
var lhs_low_bit = try (try func.load(lhs, Type.u64, 8)).toLocal(func, Type.u64);
defer lhs_low_bit.free(func);
var rhs_high_bit = try (try func.load(rhs, Type.u64, 0)).toLocal(func, Type.u64);
defer rhs_high_bit.free(func);
var rhs_low_bit = try (try func.load(rhs, Type.u64, 8)).toLocal(func, Type.u64);
defer rhs_low_bit.free(func);
var low_op_res = try (try func.binOp(lhs_low_bit, rhs_low_bit, Type.u64, op)).toLocal(func, Type.u64);
defer low_op_res.free(func);
var high_op_res = try (try func.binOp(lhs_high_bit, rhs_high_bit, Type.u64, op)).toLocal(func, Type.u64);
defer high_op_res.free(func);
var lt = if (op == .add) blk: {
break :blk try (try func.cmp(high_op_res, lhs_high_bit, Type.u64, .lt)).toLocal(func, Type.u32);
} else if (op == .sub) blk: {
break :blk try (try func.cmp(lhs_high_bit, rhs_high_bit, Type.u64, .lt)).toLocal(func, Type.u32);
} else unreachable;
defer lt.free(func);
var tmp = try (try func.intcast(lt, Type.u32, Type.u64)).toLocal(func, Type.u64);
defer tmp.free(func);
var tmp_op = try (try func.binOp(low_op_res, tmp, Type.u64, op)).toLocal(func, Type.u64);
defer tmp_op.free(func);
const overflow_bit = if (is_signed) blk: {
const xor_low = try func.binOp(lhs_low_bit, rhs_low_bit, Type.u64, .xor);
const to_wrap = if (op == .add) wrap: {
break :wrap try func.binOp(xor_low, .{ .imm64 = ~@as(u64, 0) }, Type.u64, .xor);
} else xor_low;
const xor_op = try func.binOp(lhs_low_bit, tmp_op, Type.u64, .xor);
const wrap = try func.binOp(to_wrap, xor_op, Type.u64, .@"and");
break :blk try func.cmp(wrap, .{ .imm64 = 0 }, Type.i64, .lt); // i64 because signed
} else blk: {
const first_arg = if (op == .sub) arg: {
break :arg try func.cmp(high_op_res, lhs_high_bit, Type.u64, .gt);
} else lt;
try func.emitWValue(first_arg);
_ = try func.cmp(tmp_op, lhs_low_bit, Type.u64, if (op == .add) .lt else .gt);
_ = try func.cmp(tmp_op, lhs_low_bit, Type.u64, .eq);
try func.addTag(.select);
break :blk WValue{ .stack = {} };
};
var overflow_local = try overflow_bit.toLocal(func, Type.u1);
defer overflow_local.free(func);
const result_ptr = try func.allocStack(result_ty);
try func.store(result_ptr, high_op_res, Type.u64, 0);
try func.store(result_ptr, tmp_op, Type.u64, 8);
try func.store(result_ptr, overflow_local, Type.u1, 16);
return result_ptr;
}
fn airShlWithOverflow(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const ty_pl = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_pl;
const extra = func.air.extraData(Air.Bin, ty_pl.payload).data;
const lhs = try func.resolveInst(extra.lhs);
const rhs = try func.resolveInst(extra.rhs);
const lhs_ty = func.typeOf(extra.lhs);
const rhs_ty = func.typeOf(extra.rhs);
if (lhs_ty.zigTypeTag(mod) == .Vector) {
return func.fail("TODO: Implement overflow arithmetic for vectors", .{});
}
const int_info = lhs_ty.intInfo(mod);
const is_signed = int_info.signedness == .signed;
const wasm_bits = toWasmBits(int_info.bits) orelse {
return func.fail("TODO: Implement shl_with_overflow for integer bitsize: {d}", .{int_info.bits});
};
// Ensure rhs is coerced to lhs as they must have the same WebAssembly types
// before we can perform any binary operation.
const rhs_wasm_bits = toWasmBits(rhs_ty.intInfo(mod).bits).?;
const rhs_final = if (wasm_bits != rhs_wasm_bits) blk: {
const rhs_casted = try func.intcast(rhs, rhs_ty, lhs_ty);
break :blk try rhs_casted.toLocal(func, lhs_ty);
} else rhs;
var shl = try (try func.binOp(lhs, rhs_final, lhs_ty, .shl)).toLocal(func, lhs_ty);
defer shl.free(func);
var result = if (wasm_bits != int_info.bits) blk: {
break :blk try (try func.wrapOperand(shl, lhs_ty)).toLocal(func, lhs_ty);
} else shl;
defer result.free(func); // it's a no-op to free the same local twice (when wasm_bits == int_info.bits)
const overflow_bit = if (wasm_bits != int_info.bits and is_signed) blk: {
// emit lhs to stack to we can keep 'wrapped' on the stack also
try func.emitWValue(lhs);
const abs = try func.signExtendInt(shl, lhs_ty);
const wrapped = try func.wrapBinOp(abs, rhs_final, lhs_ty, .shr);
break :blk try func.cmp(.{ .stack = {} }, wrapped, lhs_ty, .neq);
} else blk: {
try func.emitWValue(lhs);
const shr = try func.binOp(result, rhs_final, lhs_ty, .shr);
break :blk try func.cmp(.{ .stack = {} }, shr, lhs_ty, .neq);
};
var overflow_local = try overflow_bit.toLocal(func, Type.u1);
defer overflow_local.free(func);
const result_ptr = try func.allocStack(func.typeOfIndex(inst));
try func.store(result_ptr, result, lhs_ty, 0);
const offset = @as(u32, @intCast(lhs_ty.abiSize(mod)));
try func.store(result_ptr, overflow_local, Type.u1, offset);
func.finishAir(inst, result_ptr, &.{ extra.lhs, extra.rhs });
}
fn airMulWithOverflow(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const ty_pl = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_pl;
const extra = func.air.extraData(Air.Bin, ty_pl.payload).data;
const lhs = try func.resolveInst(extra.lhs);
const rhs = try func.resolveInst(extra.rhs);
const lhs_ty = func.typeOf(extra.lhs);
const mod = func.bin_file.base.comp.module.?;
if (lhs_ty.zigTypeTag(mod) == .Vector) {
return func.fail("TODO: Implement overflow arithmetic for vectors", .{});
}
// We store the bit if it's overflowed or not in this. As it's zero-initialized
// we only need to update it if an overflow (or underflow) occurred.
var overflow_bit = try func.ensureAllocLocal(Type.u1);
defer overflow_bit.free(func);
const int_info = lhs_ty.intInfo(mod);
const wasm_bits = toWasmBits(int_info.bits) orelse {
return func.fail("TODO: Implement `@mulWithOverflow` for integer bitsize: {d}", .{int_info.bits});
};
const zero = switch (wasm_bits) {
32 => WValue{ .imm32 = 0 },
64, 128 => WValue{ .imm64 = 0 },
else => unreachable,
};
// for 32 bit integers we upcast it to a 64bit integer
const bin_op = if (int_info.bits == 32) blk: {
const new_ty = if (int_info.signedness == .signed) Type.i64 else Type.u64;
const lhs_upcast = try func.intcast(lhs, lhs_ty, new_ty);
const rhs_upcast = try func.intcast(rhs, lhs_ty, new_ty);
const bin_op = try (try func.binOp(lhs_upcast, rhs_upcast, new_ty, .mul)).toLocal(func, new_ty);
if (int_info.signedness == .unsigned) {
const shr = try func.binOp(bin_op, .{ .imm64 = int_info.bits }, new_ty, .shr);
const wrap = try func.intcast(shr, new_ty, lhs_ty);
_ = try func.cmp(wrap, zero, lhs_ty, .neq);
try func.addLabel(.local_set, overflow_bit.local.value);
break :blk try func.intcast(bin_op, new_ty, lhs_ty);
} else {
const down_cast = try (try func.intcast(bin_op, new_ty, lhs_ty)).toLocal(func, lhs_ty);
var shr = try (try func.binOp(down_cast, .{ .imm32 = int_info.bits - 1 }, lhs_ty, .shr)).toLocal(func, lhs_ty);
defer shr.free(func);
const shr_res = try func.binOp(bin_op, .{ .imm64 = int_info.bits }, new_ty, .shr);
const down_shr_res = try func.intcast(shr_res, new_ty, lhs_ty);
_ = try func.cmp(down_shr_res, shr, lhs_ty, .neq);
try func.addLabel(.local_set, overflow_bit.local.value);
break :blk down_cast;
}
} else if (int_info.signedness == .signed and wasm_bits == 32) blk: {
const lhs_abs = try func.signExtendInt(lhs, lhs_ty);
const rhs_abs = try func.signExtendInt(rhs, lhs_ty);
const bin_op = try (try func.binOp(lhs_abs, rhs_abs, lhs_ty, .mul)).toLocal(func, lhs_ty);
const mul_abs = try func.signExtendInt(bin_op, lhs_ty);
_ = try func.cmp(mul_abs, bin_op, lhs_ty, .neq);
try func.addLabel(.local_set, overflow_bit.local.value);
break :blk try func.wrapOperand(bin_op, lhs_ty);
} else if (wasm_bits == 32) blk: {
var bin_op = try (try func.binOp(lhs, rhs, lhs_ty, .mul)).toLocal(func, lhs_ty);
defer bin_op.free(func);
const shift_imm = if (wasm_bits == 32)
WValue{ .imm32 = int_info.bits }
else
WValue{ .imm64 = int_info.bits };
const shr = try func.binOp(bin_op, shift_imm, lhs_ty, .shr);
_ = try func.cmp(shr, zero, lhs_ty, .neq);
try func.addLabel(.local_set, overflow_bit.local.value);
break :blk try func.wrapOperand(bin_op, lhs_ty);
} else if (int_info.bits == 64 and int_info.signedness == .unsigned) blk: {
const new_ty = Type.u128;
var lhs_upcast = try (try func.intcast(lhs, lhs_ty, new_ty)).toLocal(func, lhs_ty);
defer lhs_upcast.free(func);
var rhs_upcast = try (try func.intcast(rhs, lhs_ty, new_ty)).toLocal(func, lhs_ty);
defer rhs_upcast.free(func);
const bin_op = try func.binOp(lhs_upcast, rhs_upcast, new_ty, .mul);
const lsb = try func.load(bin_op, lhs_ty, 8);
_ = try func.cmp(lsb, zero, lhs_ty, .neq);
try func.addLabel(.local_set, overflow_bit.local.value);
break :blk try func.load(bin_op, lhs_ty, 0);
} else if (int_info.bits == 64 and int_info.signedness == .signed) blk: {
const shift_val: WValue = .{ .imm64 = 63 };
var lhs_shifted = try (try func.binOp(lhs, shift_val, lhs_ty, .shr)).toLocal(func, lhs_ty);
defer lhs_shifted.free(func);
var rhs_shifted = try (try func.binOp(rhs, shift_val, lhs_ty, .shr)).toLocal(func, lhs_ty);
defer rhs_shifted.free(func);
const bin_op = try func.callIntrinsic(
"__multi3",
&[_]InternPool.Index{.i64_type} ** 4,
Type.i128,
&.{ lhs, lhs_shifted, rhs, rhs_shifted },
);
const res = try func.allocLocal(lhs_ty);
const msb = try func.load(bin_op, lhs_ty, 0);
try func.addLabel(.local_tee, res.local.value);
const msb_shifted = try func.binOp(msb, shift_val, lhs_ty, .shr);
const lsb = try func.load(bin_op, lhs_ty, 8);
_ = try func.cmp(lsb, msb_shifted, lhs_ty, .neq);
try func.addLabel(.local_set, overflow_bit.local.value);
break :blk res;
} else if (int_info.bits == 128 and int_info.signedness == .unsigned) blk: {
var lhs_msb = try (try func.load(lhs, Type.u64, 0)).toLocal(func, Type.u64);
defer lhs_msb.free(func);
var lhs_lsb = try (try func.load(lhs, Type.u64, 8)).toLocal(func, Type.u64);
defer lhs_lsb.free(func);
var rhs_msb = try (try func.load(rhs, Type.u64, 0)).toLocal(func, Type.u64);
defer rhs_msb.free(func);
var rhs_lsb = try (try func.load(rhs, Type.u64, 8)).toLocal(func, Type.u64);
defer rhs_lsb.free(func);
const mul1 = try func.callIntrinsic(
"__multi3",
&[_]InternPool.Index{.i64_type} ** 4,
Type.i128,
&.{ lhs_lsb, zero, rhs_msb, zero },
);
const mul2 = try func.callIntrinsic(
"__multi3",
&[_]InternPool.Index{.i64_type} ** 4,
Type.i128,
&.{ rhs_lsb, zero, lhs_msb, zero },
);
const mul3 = try func.callIntrinsic(
"__multi3",
&[_]InternPool.Index{.i64_type} ** 4,
Type.i128,
&.{ lhs_msb, zero, rhs_msb, zero },
);
const rhs_lsb_not_zero = try func.cmp(rhs_lsb, zero, Type.u64, .neq);
const lhs_lsb_not_zero = try func.cmp(lhs_lsb, zero, Type.u64, .neq);
const lsb_and = try func.binOp(rhs_lsb_not_zero, lhs_lsb_not_zero, Type.bool, .@"and");
const mul1_lsb = try func.load(mul1, Type.u64, 8);
const mul1_lsb_not_zero = try func.cmp(mul1_lsb, zero, Type.u64, .neq);
const lsb_or1 = try func.binOp(lsb_and, mul1_lsb_not_zero, Type.bool, .@"or");
const mul2_lsb = try func.load(mul2, Type.u64, 8);
const mul2_lsb_not_zero = try func.cmp(mul2_lsb, zero, Type.u64, .neq);
const lsb_or = try func.binOp(lsb_or1, mul2_lsb_not_zero, Type.bool, .@"or");
const mul1_msb = try func.load(mul1, Type.u64, 0);
const mul2_msb = try func.load(mul2, Type.u64, 0);
const mul_add1 = try func.binOp(mul1_msb, mul2_msb, Type.u64, .add);
var mul3_lsb = try (try func.load(mul3, Type.u64, 8)).toLocal(func, Type.u64);
defer mul3_lsb.free(func);
var mul_add2 = try (try func.binOp(mul_add1, mul3_lsb, Type.u64, .add)).toLocal(func, Type.u64);
defer mul_add2.free(func);
const mul_add_lt = try func.cmp(mul_add2, mul3_lsb, Type.u64, .lt);
// result for overflow bit
_ = try func.binOp(lsb_or, mul_add_lt, Type.bool, .@"or");
try func.addLabel(.local_set, overflow_bit.local.value);
const tmp_result = try func.allocStack(Type.u128);
try func.emitWValue(tmp_result);
const mul3_msb = try func.load(mul3, Type.u64, 0);
try func.store(.stack, mul3_msb, Type.u64, tmp_result.offset());
try func.store(tmp_result, mul_add2, Type.u64, 8);
break :blk tmp_result;
} else return func.fail("TODO: @mulWithOverflow for integers between 32 and 64 bits", .{});
var bin_op_local = try bin_op.toLocal(func, lhs_ty);
defer bin_op_local.free(func);
const result_ptr = try func.allocStack(func.typeOfIndex(inst));
try func.store(result_ptr, bin_op_local, lhs_ty, 0);
const offset = @as(u32, @intCast(lhs_ty.abiSize(mod)));
try func.store(result_ptr, overflow_bit, Type.u1, offset);
func.finishAir(inst, result_ptr, &.{ extra.lhs, extra.rhs });
}
fn airMaxMin(func: *CodeGen, inst: Air.Inst.Index, op: Op) InnerError!void {
assert(op == .max or op == .min);
const mod = func.bin_file.base.comp.module.?;
const target = mod.getTarget();
const bin_op = func.air.instructions.items(.data)[@intFromEnum(inst)].bin_op;
const ty = func.typeOfIndex(inst);
if (ty.zigTypeTag(mod) == .Vector) {
return func.fail("TODO: `@maximum` and `@minimum` for vectors", .{});
}
if (ty.abiSize(mod) > 16) {
return func.fail("TODO: `@maximum` and `@minimum` for types larger than 16 bytes", .{});
}
const lhs = try func.resolveInst(bin_op.lhs);
const rhs = try func.resolveInst(bin_op.rhs);
if (ty.zigTypeTag(mod) == .Float) {
var fn_name_buf: [64]u8 = undefined;
const float_bits = ty.floatBits(target);
const fn_name = std.fmt.bufPrint(&fn_name_buf, "{s}f{s}{s}", .{
target_util.libcFloatPrefix(float_bits),
@tagName(op),
target_util.libcFloatSuffix(float_bits),
}) catch unreachable;
const result = try func.callIntrinsic(fn_name, &.{ ty.ip_index, ty.ip_index }, ty, &.{ lhs, rhs });
try func.lowerToStack(result);
} else {
// operands to select from
try func.lowerToStack(lhs);
try func.lowerToStack(rhs);
_ = try func.cmp(lhs, rhs, ty, if (op == .max) .gt else .lt);
// based on the result from comparison, return operand 0 or 1.
try func.addTag(.select);
}
// store result in local
const result_ty = if (isByRef(ty, mod)) Type.u32 else ty;
const result = try func.allocLocal(result_ty);
try func.addLabel(.local_set, result.local.value);
func.finishAir(inst, result, &.{ bin_op.lhs, bin_op.rhs });
}
fn airMulAdd(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const pl_op = func.air.instructions.items(.data)[@intFromEnum(inst)].pl_op;
const bin_op = func.air.extraData(Air.Bin, pl_op.payload).data;
const ty = func.typeOfIndex(inst);
if (ty.zigTypeTag(mod) == .Vector) {
return func.fail("TODO: `@mulAdd` for vectors", .{});
}
const addend = try func.resolveInst(pl_op.operand);
const lhs = try func.resolveInst(bin_op.lhs);
const rhs = try func.resolveInst(bin_op.rhs);
const result = if (ty.floatBits(func.target) == 16) fl_result: {
const rhs_ext = try func.fpext(rhs, ty, Type.f32);
const lhs_ext = try func.fpext(lhs, ty, Type.f32);
const addend_ext = try func.fpext(addend, ty, Type.f32);
// call to compiler-rt `fn fmaf(f32, f32, f32) f32`
const result = try func.callIntrinsic(
"fmaf",
&.{ .f32_type, .f32_type, .f32_type },
Type.f32,
&.{ rhs_ext, lhs_ext, addend_ext },
);
break :fl_result try (try func.fptrunc(result, Type.f32, ty)).toLocal(func, ty);
} else result: {
const mul_result = try func.binOp(lhs, rhs, ty, .mul);
break :result try (try func.binOp(mul_result, addend, ty, .add)).toLocal(func, ty);
};
func.finishAir(inst, result, &.{ bin_op.lhs, bin_op.rhs, pl_op.operand });
}
fn airClz(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const ty_op = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_op;
const ty = func.typeOf(ty_op.operand);
const result_ty = func.typeOfIndex(inst);
if (ty.zigTypeTag(mod) == .Vector) {
return func.fail("TODO: `@clz` for vectors", .{});
}
const operand = try func.resolveInst(ty_op.operand);
const int_info = ty.intInfo(mod);
const wasm_bits = toWasmBits(int_info.bits) orelse {
return func.fail("TODO: `@clz` for integers with bitsize '{d}'", .{int_info.bits});
};
switch (wasm_bits) {
32 => {
try func.emitWValue(operand);
try func.addTag(.i32_clz);
},
64 => {
try func.emitWValue(operand);
try func.addTag(.i64_clz);
try func.addTag(.i32_wrap_i64);
},
128 => {
var lsb = try (try func.load(operand, Type.u64, 8)).toLocal(func, Type.u64);
defer lsb.free(func);
try func.emitWValue(lsb);
try func.addTag(.i64_clz);
_ = try func.load(operand, Type.u64, 0);
try func.addTag(.i64_clz);
try func.emitWValue(.{ .imm64 = 64 });
try func.addTag(.i64_add);
_ = try func.cmp(lsb, .{ .imm64 = 0 }, Type.u64, .neq);
try func.addTag(.select);
try func.addTag(.i32_wrap_i64);
},
else => unreachable,
}
if (wasm_bits != int_info.bits) {
try func.emitWValue(.{ .imm32 = wasm_bits - int_info.bits });
try func.addTag(.i32_sub);
}
const result = try func.allocLocal(result_ty);
try func.addLabel(.local_set, result.local.value);
func.finishAir(inst, result, &.{ty_op.operand});
}
fn airCtz(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const ty_op = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_op;
const ty = func.typeOf(ty_op.operand);
const result_ty = func.typeOfIndex(inst);
if (ty.zigTypeTag(mod) == .Vector) {
return func.fail("TODO: `@ctz` for vectors", .{});
}
const operand = try func.resolveInst(ty_op.operand);
const int_info = ty.intInfo(mod);
const wasm_bits = toWasmBits(int_info.bits) orelse {
return func.fail("TODO: `@clz` for integers with bitsize '{d}'", .{int_info.bits});
};
switch (wasm_bits) {
32 => {
if (wasm_bits != int_info.bits) {
const val: u32 = @as(u32, 1) << @as(u5, @intCast(int_info.bits));
// leave value on the stack
_ = try func.binOp(operand, .{ .imm32 = val }, ty, .@"or");
} else try func.emitWValue(operand);
try func.addTag(.i32_ctz);
},
64 => {
if (wasm_bits != int_info.bits) {
const val: u64 = @as(u64, 1) << @as(u6, @intCast(int_info.bits));
// leave value on the stack
_ = try func.binOp(operand, .{ .imm64 = val }, ty, .@"or");
} else try func.emitWValue(operand);
try func.addTag(.i64_ctz);
try func.addTag(.i32_wrap_i64);
},
128 => {
var msb = try (try func.load(operand, Type.u64, 0)).toLocal(func, Type.u64);
defer msb.free(func);
try func.emitWValue(msb);
try func.addTag(.i64_ctz);
_ = try func.load(operand, Type.u64, 8);
if (wasm_bits != int_info.bits) {
try func.addImm64(@as(u64, 1) << @as(u6, @intCast(int_info.bits - 64)));
try func.addTag(.i64_or);
}
try func.addTag(.i64_ctz);
try func.addImm64(64);
if (wasm_bits != int_info.bits) {
try func.addTag(.i64_or);
} else {
try func.addTag(.i64_add);
}
_ = try func.cmp(msb, .{ .imm64 = 0 }, Type.u64, .neq);
try func.addTag(.select);
try func.addTag(.i32_wrap_i64);
},
else => unreachable,
}
const result = try func.allocLocal(result_ty);
try func.addLabel(.local_set, result.local.value);
func.finishAir(inst, result, &.{ty_op.operand});
}
fn airDbgStmt(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
if (func.debug_output != .dwarf) return func.finishAir(inst, .none, &.{});
const dbg_stmt = func.air.instructions.items(.data)[@intFromEnum(inst)].dbg_stmt;
try func.addInst(.{ .tag = .dbg_line, .data = .{
.payload = try func.addExtra(Mir.DbgLineColumn{
.line = dbg_stmt.line,
.column = dbg_stmt.column,
}),
} });
func.finishAir(inst, .none, &.{});
}
fn airDbgInlineBlock(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const ty_pl = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_pl;
const extra = func.air.extraData(Air.DbgInlineBlock, ty_pl.payload);
// TODO
try func.lowerBlock(inst, ty_pl.ty.toType(), @ptrCast(func.air.extra[extra.end..][0..extra.data.body_len]));
}
fn airDbgVar(func: *CodeGen, inst: Air.Inst.Index, is_ptr: bool) InnerError!void {
if (func.debug_output != .dwarf) return func.finishAir(inst, .none, &.{});
const mod = func.bin_file.base.comp.module.?;
const pl_op = func.air.instructions.items(.data)[@intFromEnum(inst)].pl_op;
const ty = func.typeOf(pl_op.operand);
const operand = try func.resolveInst(pl_op.operand);
log.debug("airDbgVar: %{d}: {}, {}", .{ inst, ty.fmtDebug(), operand });
const name = func.air.nullTerminatedString(pl_op.payload);
log.debug(" var name = ({s})", .{name});
const loc: link.File.Dwarf.DeclState.DbgInfoLoc = switch (operand) {
.local => |local| .{ .wasm_local = local.value },
else => blk: {
log.debug("TODO generate debug info for {}", .{operand});
break :blk .nop;
},
};
try func.debug_output.dwarf.genVarDbgInfo(name, ty, mod.funcOwnerDeclIndex(func.func_index), is_ptr, loc);
func.finishAir(inst, .none, &.{});
}
fn airTry(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const pl_op = func.air.instructions.items(.data)[@intFromEnum(inst)].pl_op;
const err_union = try func.resolveInst(pl_op.operand);
const extra = func.air.extraData(Air.Try, pl_op.payload);
const body: []const Air.Inst.Index = @ptrCast(func.air.extra[extra.end..][0..extra.data.body_len]);
const err_union_ty = func.typeOf(pl_op.operand);
const result = try lowerTry(func, inst, err_union, body, err_union_ty, false);
func.finishAir(inst, result, &.{pl_op.operand});
}
fn airTryPtr(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const ty_pl = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_pl;
const extra = func.air.extraData(Air.TryPtr, ty_pl.payload);
const err_union_ptr = try func.resolveInst(extra.data.ptr);
const body: []const Air.Inst.Index = @ptrCast(func.air.extra[extra.end..][0..extra.data.body_len]);
const err_union_ty = func.typeOf(extra.data.ptr).childType(mod);
const result = try lowerTry(func, inst, err_union_ptr, body, err_union_ty, true);
func.finishAir(inst, result, &.{extra.data.ptr});
}
fn lowerTry(
func: *CodeGen,
inst: Air.Inst.Index,
err_union: WValue,
body: []const Air.Inst.Index,
err_union_ty: Type,
operand_is_ptr: bool,
) InnerError!WValue {
const mod = func.bin_file.base.comp.module.?;
if (operand_is_ptr) {
return func.fail("TODO: lowerTry for pointers", .{});
}
const pl_ty = err_union_ty.errorUnionPayload(mod);
const pl_has_bits = pl_ty.hasRuntimeBitsIgnoreComptime(mod);
if (!err_union_ty.errorUnionSet(mod).errorSetIsEmpty(mod)) {
// Block we can jump out of when error is not set
try func.startBlock(.block, wasm.block_empty);
// check if the error tag is set for the error union.
try func.emitWValue(err_union);
if (pl_has_bits) {
const err_offset = @as(u32, @intCast(errUnionErrorOffset(pl_ty, mod)));
try func.addMemArg(.i32_load16_u, .{
.offset = err_union.offset() + err_offset,
.alignment = @intCast(Type.anyerror.abiAlignment(mod).toByteUnitsOptional().?),
});
}
try func.addTag(.i32_eqz);
try func.addLabel(.br_if, 0); // jump out of block when error is '0'
const liveness = func.liveness.getCondBr(inst);
try func.branches.append(func.gpa, .{});
try func.currentBranch().values.ensureUnusedCapacity(func.gpa, liveness.else_deaths.len + liveness.then_deaths.len);
defer {
var branch = func.branches.pop();
branch.deinit(func.gpa);
}
try func.genBody(body);
try func.endBlock();
}
// if we reach here it means error was not set, and we want the payload
if (!pl_has_bits) {
return WValue{ .none = {} };
}
const pl_offset = @as(u32, @intCast(errUnionPayloadOffset(pl_ty, mod)));
if (isByRef(pl_ty, mod)) {
return buildPointerOffset(func, err_union, pl_offset, .new);
}
const payload = try func.load(err_union, pl_ty, pl_offset);
return payload.toLocal(func, pl_ty);
}
fn airByteSwap(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const ty_op = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_op;
const ty = func.typeOfIndex(inst);
const operand = try func.resolveInst(ty_op.operand);
if (ty.zigTypeTag(mod) == .Vector) {
return func.fail("TODO: @byteSwap for vectors", .{});
}
const int_info = ty.intInfo(mod);
// bytes are no-op
if (int_info.bits == 8) {
return func.finishAir(inst, func.reuseOperand(ty_op.operand, operand), &.{ty_op.operand});
}
const result = result: {
switch (int_info.bits) {
16 => {
const shl_res = try func.binOp(operand, .{ .imm32 = 8 }, ty, .shl);
const lhs = try func.binOp(shl_res, .{ .imm32 = 0xFF00 }, ty, .@"and");
const shr_res = try func.binOp(operand, .{ .imm32 = 8 }, ty, .shr);
const res = if (int_info.signedness == .signed) blk: {
break :blk try func.wrapOperand(shr_res, Type.u8);
} else shr_res;
break :result try (try func.binOp(lhs, res, ty, .@"or")).toLocal(func, ty);
},
24 => {
var msb = try (try func.wrapOperand(operand, Type.u16)).toLocal(func, Type.u16);
defer msb.free(func);
const shl_res = try func.binOp(msb, .{ .imm32 = 8 }, Type.u16, .shl);
const lhs = try func.binOp(shl_res, .{ .imm32 = 0xFF0000 }, Type.u16, .@"and");
const shr_res = try func.binOp(msb, .{ .imm32 = 8 }, ty, .shr);
const res = if (int_info.signedness == .signed) blk: {
break :blk try func.wrapOperand(shr_res, Type.u8);
} else shr_res;
const lhs_tmp = try func.binOp(lhs, res, ty, .@"or");
const lhs_result = try func.binOp(lhs_tmp, .{ .imm32 = 8 }, ty, .shr);
const rhs_wrap = try func.wrapOperand(msb, Type.u8);
const rhs_result = try func.binOp(rhs_wrap, .{ .imm32 = 16 }, ty, .shl);
const lsb = try func.wrapBinOp(operand, .{ .imm32 = 16 }, Type.u8, .shr);
const tmp = try func.binOp(lhs_result, rhs_result, ty, .@"or");
break :result try (try func.binOp(tmp, lsb, ty, .@"or")).toLocal(func, ty);
},
32 => {
const shl_tmp = try func.binOp(operand, .{ .imm32 = 8 }, ty, .shl);
var lhs = try (try func.binOp(shl_tmp, .{ .imm32 = 0xFF00FF00 }, ty, .@"and")).toLocal(func, ty);
defer lhs.free(func);
const shr_tmp = try func.binOp(operand, .{ .imm32 = 8 }, ty, .shr);
var rhs = try (try func.binOp(shr_tmp, .{ .imm32 = 0xFF00FF }, ty, .@"and")).toLocal(func, ty);
defer rhs.free(func);
var tmp_or = try (try func.binOp(lhs, rhs, ty, .@"or")).toLocal(func, ty);
defer tmp_or.free(func);
const shl = try func.binOp(tmp_or, .{ .imm32 = 16 }, ty, .shl);
const shr = try func.binOp(tmp_or, .{ .imm32 = 16 }, ty, .shr);
const res = if (int_info.signedness == .signed) blk: {
break :blk try func.wrapOperand(shr, Type.u16);
} else shr;
break :result try (try func.binOp(shl, res, ty, .@"or")).toLocal(func, ty);
},
else => return func.fail("TODO: @byteSwap for integers with bitsize {d}", .{int_info.bits}),
}
};
func.finishAir(inst, result, &.{ty_op.operand});
}
fn airDiv(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const bin_op = func.air.instructions.items(.data)[@intFromEnum(inst)].bin_op;
const ty = func.typeOfIndex(inst);
const lhs = try func.resolveInst(bin_op.lhs);
const rhs = try func.resolveInst(bin_op.rhs);
const result = if (ty.isSignedInt(mod))
try func.divSigned(lhs, rhs, ty)
else
try (try func.binOp(lhs, rhs, ty, .div)).toLocal(func, ty);
func.finishAir(inst, result, &.{ bin_op.lhs, bin_op.rhs });
}
fn airDivTrunc(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const bin_op = func.air.instructions.items(.data)[@intFromEnum(inst)].bin_op;
const ty = func.typeOfIndex(inst);
const lhs = try func.resolveInst(bin_op.lhs);
const rhs = try func.resolveInst(bin_op.rhs);
const div_result = if (ty.isSignedInt(mod))
try func.divSigned(lhs, rhs, ty)
else
try (try func.binOp(lhs, rhs, ty, .div)).toLocal(func, ty);
if (ty.isAnyFloat()) {
const trunc_result = try (try func.floatOp(.trunc, ty, &.{div_result})).toLocal(func, ty);
return func.finishAir(inst, trunc_result, &.{ bin_op.lhs, bin_op.rhs });
}
return func.finishAir(inst, div_result, &.{ bin_op.lhs, bin_op.rhs });
}
fn airDivFloor(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const bin_op = func.air.instructions.items(.data)[@intFromEnum(inst)].bin_op;
const mod = func.bin_file.base.comp.module.?;
const ty = func.typeOfIndex(inst);
const lhs = try func.resolveInst(bin_op.lhs);
const rhs = try func.resolveInst(bin_op.rhs);
if (ty.isUnsignedInt(mod)) {
_ = try func.binOp(lhs, rhs, ty, .div);
} else if (ty.isSignedInt(mod)) {
const int_bits = ty.intInfo(mod).bits;
const wasm_bits = toWasmBits(int_bits) orelse {
return func.fail("TODO: `@divFloor` for signed integers larger than 64 bits ({d} bits requested)", .{int_bits});
};
if (wasm_bits > 64) {
return func.fail("TODO: `@divFloor` for signed integers larger than 64 bits ({d} bits requested)", .{int_bits});
}
const lhs_wasm = if (wasm_bits != int_bits)
try (try func.signExtendInt(lhs, ty)).toLocal(func, ty)
else
lhs;
const rhs_wasm = if (wasm_bits != int_bits)
try (try func.signExtendInt(rhs, ty)).toLocal(func, ty)
else
rhs;
const zero = switch (wasm_bits) {
32 => WValue{ .imm32 = 0 },
64 => WValue{ .imm64 = 0 },
else => unreachable,
};
// tee leaves the value on the stack and stores it in a local.
const quotient = try func.allocLocal(ty);
_ = try func.binOp(lhs_wasm, rhs_wasm, ty, .div);
try func.addLabel(.local_tee, quotient.local.value);
// select takes a 32 bit value as the condition, so in the 64 bit case we use eqz to narrow
// the 64 bit value we want to use as the condition to 32 bits.
// This also inverts the condition (non 0 => 0, 0 => 1), so we put the adjusted and
// non-adjusted quotients on the stack in the opposite order for 32 vs 64 bits.
if (wasm_bits == 64) {
try func.emitWValue(quotient);
}
// 0 if the signs of rhs_wasm and lhs_wasm are the same, 1 otherwise.
_ = try func.binOp(lhs_wasm, rhs_wasm, ty, .xor);
_ = try func.cmp(.stack, zero, ty, .lt);
switch (wasm_bits) {
32 => {
try func.addTag(.i32_sub);
try func.emitWValue(quotient);
},
64 => {
try func.addTag(.i64_extend_i32_u);
try func.addTag(.i64_sub);
},
else => unreachable,
}
_ = try func.binOp(lhs_wasm, rhs_wasm, ty, .rem);
if (wasm_bits == 64) {
try func.addTag(.i64_eqz);
}
try func.addTag(.select);
// We need to zero the high bits because N bit comparisons consider all 32 or 64 bits, and
// expect all but the lowest N bits to be 0.
// TODO: Should we be zeroing the high bits here or should we be ignoring the high bits
// when performing comparisons?
if (int_bits != wasm_bits) {
_ = try func.wrapOperand(.{ .stack = {} }, ty);
}
} else {
const float_bits = ty.floatBits(func.target);
if (float_bits > 64) {
return func.fail("TODO: `@divFloor` for floats with bitsize: {d}", .{float_bits});
}
const is_f16 = float_bits == 16;
const lhs_wasm = if (is_f16) try func.fpext(lhs, Type.f16, Type.f32) else lhs;
const rhs_wasm = if (is_f16) try func.fpext(rhs, Type.f16, Type.f32) else rhs;
try func.emitWValue(lhs_wasm);
try func.emitWValue(rhs_wasm);
switch (float_bits) {
16, 32 => {
try func.addTag(.f32_div);
try func.addTag(.f32_floor);
},
64 => {
try func.addTag(.f64_div);
try func.addTag(.f64_floor);
},
else => unreachable,
}
if (is_f16) {
_ = try func.fptrunc(.{ .stack = {} }, Type.f32, Type.f16);
}
}
const result = try func.allocLocal(ty);
try func.addLabel(.local_set, result.local.value);
func.finishAir(inst, result, &.{ bin_op.lhs, bin_op.rhs });
}
fn divSigned(func: *CodeGen, lhs: WValue, rhs: WValue, ty: Type) InnerError!WValue {
const mod = func.bin_file.base.comp.module.?;
const int_bits = ty.intInfo(mod).bits;
const wasm_bits = toWasmBits(int_bits) orelse {
return func.fail("TODO: Implement signed division for integers with bitsize '{d}'", .{int_bits});
};
if (wasm_bits == 128) {
return func.fail("TODO: Implement signed division for 128-bit integerrs", .{});
}
if (wasm_bits != int_bits) {
// Leave both values on the stack
_ = try func.signExtendInt(lhs, ty);
_ = try func.signExtendInt(rhs, ty);
} else {
try func.emitWValue(lhs);
try func.emitWValue(rhs);
}
try func.addTag(.i32_div_s);
const result = try func.allocLocal(ty);
try func.addLabel(.local_set, result.local.value);
return result;
}
/// Remainder after floor division, defined by:
/// @divFloor(a, b) * b + @mod(a, b) = a
fn airMod(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const bin_op = func.air.instructions.items(.data)[@intFromEnum(inst)].bin_op;
const mod = func.bin_file.base.comp.module.?;
const ty = func.typeOfIndex(inst);
const lhs = try func.resolveInst(bin_op.lhs);
const rhs = try func.resolveInst(bin_op.rhs);
if (ty.isUnsignedInt(mod)) {
_ = try func.binOp(lhs, rhs, ty, .rem);
} else if (ty.isSignedInt(mod)) {
// The wasm rem instruction gives the remainder after truncating division (rounding towards
// 0), equivalent to @rem.
// We make use of the fact that:
// @mod(a, b) = @rem(@rem(a, b) + b, b)
const int_bits = ty.intInfo(mod).bits;
const wasm_bits = toWasmBits(int_bits) orelse {
return func.fail("TODO: `@mod` for signed integers larger than 64 bits ({d} bits requested)", .{int_bits});
};
if (wasm_bits > 64) {
return func.fail("TODO: `@mod` for signed integers larger than 64 bits ({d} bits requested)", .{int_bits});
}
const lhs_wasm = if (wasm_bits != int_bits)
try (try func.signExtendInt(lhs, ty)).toLocal(func, ty)
else
lhs;
const rhs_wasm = if (wasm_bits != int_bits)
try (try func.signExtendInt(rhs, ty)).toLocal(func, ty)
else
rhs;
_ = try func.binOp(lhs_wasm, rhs_wasm, ty, .rem);
_ = try func.binOp(.stack, rhs_wasm, ty, .add);
_ = try func.binOp(.stack, rhs_wasm, ty, .rem);
} else {
return func.fail("TODO: implement `@mod` on floating point types for {}", .{func.target.cpu.arch});
}
const result = try func.allocLocal(ty);
try func.addLabel(.local_set, result.local.value);
func.finishAir(inst, result, &.{ bin_op.lhs, bin_op.rhs });
}
/// Sign extends an N bit signed integer and pushes the result to the stack.
/// The result will be sign extended to 32 bits if N <= 32 or 64 bits if N <= 64.
/// Support for integers wider than 64 bits has not yet been implemented.
fn signExtendInt(func: *CodeGen, operand: WValue, ty: Type) InnerError!WValue {
const mod = func.bin_file.base.comp.module.?;
const int_bits = ty.intInfo(mod).bits;
const wasm_bits = toWasmBits(int_bits) orelse {
return func.fail("TODO: signExtendInt for signed integers larger than '{d}' bits", .{int_bits});
};
const shift_val = switch (wasm_bits) {
32 => WValue{ .imm32 = wasm_bits - int_bits },
64 => WValue{ .imm64 = wasm_bits - int_bits },
else => return func.fail("TODO: signExtendInt for i128", .{}),
};
try func.emitWValue(operand);
switch (wasm_bits) {
32 => {
try func.emitWValue(shift_val);
try func.addTag(.i32_shl);
try func.emitWValue(shift_val);
try func.addTag(.i32_shr_s);
},
64 => {
try func.emitWValue(shift_val);
try func.addTag(.i64_shl);
try func.emitWValue(shift_val);
try func.addTag(.i64_shr_s);
},
else => unreachable,
}
return WValue{ .stack = {} };
}
fn airSatBinOp(func: *CodeGen, inst: Air.Inst.Index, op: Op) InnerError!void {
assert(op == .add or op == .sub);
const bin_op = func.air.instructions.items(.data)[@intFromEnum(inst)].bin_op;
const mod = func.bin_file.base.comp.module.?;
const ty = func.typeOfIndex(inst);
const lhs = try func.resolveInst(bin_op.lhs);
const rhs = try func.resolveInst(bin_op.rhs);
const int_info = ty.intInfo(mod);
const is_signed = int_info.signedness == .signed;
if (int_info.bits > 64) {
return func.fail("TODO: saturating arithmetic for integers with bitsize '{d}'", .{int_info.bits});
}
if (is_signed) {
const result = try signedSat(func, lhs, rhs, ty, op);
return func.finishAir(inst, result, &.{ bin_op.lhs, bin_op.rhs });
}
const wasm_bits = toWasmBits(int_info.bits).?;
var bin_result = try (try func.binOp(lhs, rhs, ty, op)).toLocal(func, ty);
defer bin_result.free(func);
if (wasm_bits != int_info.bits and op == .add) {
const val: u64 = @as(u64, @intCast((@as(u65, 1) << @as(u7, @intCast(int_info.bits))) - 1));
const imm_val = switch (wasm_bits) {
32 => WValue{ .imm32 = @as(u32, @intCast(val)) },
64 => WValue{ .imm64 = val },
else => unreachable,
};
try func.emitWValue(bin_result);
try func.emitWValue(imm_val);
_ = try func.cmp(bin_result, imm_val, ty, .lt);
} else {
switch (wasm_bits) {
32 => try func.addImm32(if (op == .add) @as(i32, -1) else 0),
64 => try func.addImm64(if (op == .add) @as(u64, @bitCast(@as(i64, -1))) else 0),
else => unreachable,
}
try func.emitWValue(bin_result);
_ = try func.cmp(bin_result, lhs, ty, if (op == .add) .lt else .gt);
}
try func.addTag(.select);
const result = try func.allocLocal(ty);
try func.addLabel(.local_set, result.local.value);
return func.finishAir(inst, result, &.{ bin_op.lhs, bin_op.rhs });
}
fn signedSat(func: *CodeGen, lhs_operand: WValue, rhs_operand: WValue, ty: Type, op: Op) InnerError!WValue {
const mod = func.bin_file.base.comp.module.?;
const int_info = ty.intInfo(mod);
const wasm_bits = toWasmBits(int_info.bits).?;
const is_wasm_bits = wasm_bits == int_info.bits;
const ext_ty = if (!is_wasm_bits) try mod.intType(int_info.signedness, wasm_bits) else ty;
var lhs = if (!is_wasm_bits) lhs: {
break :lhs try (try func.signExtendInt(lhs_operand, ty)).toLocal(func, ext_ty);
} else lhs_operand;
var rhs = if (!is_wasm_bits) rhs: {
break :rhs try (try func.signExtendInt(rhs_operand, ty)).toLocal(func, ext_ty);
} else rhs_operand;
const max_val: u64 = @as(u64, @intCast((@as(u65, 1) << @as(u7, @intCast(int_info.bits - 1))) - 1));
const min_val: i64 = (-@as(i64, @intCast(@as(u63, @intCast(max_val))))) - 1;
const max_wvalue = switch (wasm_bits) {
32 => WValue{ .imm32 = @as(u32, @truncate(max_val)) },
64 => WValue{ .imm64 = max_val },
else => unreachable,
};
const min_wvalue = switch (wasm_bits) {
32 => WValue{ .imm32 = @as(u32, @bitCast(@as(i32, @truncate(min_val)))) },
64 => WValue{ .imm64 = @as(u64, @bitCast(min_val)) },
else => unreachable,
};
var bin_result = try (try func.binOp(lhs, rhs, ext_ty, op)).toLocal(func, ext_ty);
if (!is_wasm_bits) {
defer bin_result.free(func); // not returned in this branch
defer lhs.free(func); // uses temporary local for absvalue
defer rhs.free(func); // uses temporary local for absvalue
try func.emitWValue(bin_result);
try func.emitWValue(max_wvalue);
_ = try func.cmp(bin_result, max_wvalue, ext_ty, .lt);
try func.addTag(.select);
try func.addLabel(.local_set, bin_result.local.value); // re-use local
try func.emitWValue(bin_result);
try func.emitWValue(min_wvalue);
_ = try func.cmp(bin_result, min_wvalue, ext_ty, .gt);
try func.addTag(.select);
try func.addLabel(.local_set, bin_result.local.value); // re-use local
return (try func.wrapOperand(bin_result, ty)).toLocal(func, ty);
} else {
const zero = switch (wasm_bits) {
32 => WValue{ .imm32 = 0 },
64 => WValue{ .imm64 = 0 },
else => unreachable,
};
try func.emitWValue(max_wvalue);
try func.emitWValue(min_wvalue);
_ = try func.cmp(bin_result, zero, ty, .lt);
try func.addTag(.select);
try func.emitWValue(bin_result);
// leave on stack
const cmp_zero_result = try func.cmp(rhs, zero, ty, if (op == .add) .lt else .gt);
const cmp_bin_result = try func.cmp(bin_result, lhs, ty, .lt);
_ = try func.binOp(cmp_zero_result, cmp_bin_result, Type.u32, .xor); // comparisons always return i32, so provide u32 as type to xor.
try func.addTag(.select);
try func.addLabel(.local_set, bin_result.local.value); // re-use local
return bin_result;
}
}
fn airShlSat(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const bin_op = func.air.instructions.items(.data)[@intFromEnum(inst)].bin_op;
const mod = func.bin_file.base.comp.module.?;
const ty = func.typeOfIndex(inst);
const int_info = ty.intInfo(mod);
const is_signed = int_info.signedness == .signed;
if (int_info.bits > 64) {
return func.fail("TODO: Saturating shifting left for integers with bitsize '{d}'", .{int_info.bits});
}
const lhs = try func.resolveInst(bin_op.lhs);
const rhs = try func.resolveInst(bin_op.rhs);
const wasm_bits = toWasmBits(int_info.bits).?;
const result = try func.allocLocal(ty);
if (wasm_bits == int_info.bits) outer_blk: {
var shl = try (try func.binOp(lhs, rhs, ty, .shl)).toLocal(func, ty);
defer shl.free(func);
var shr = try (try func.binOp(shl, rhs, ty, .shr)).toLocal(func, ty);
defer shr.free(func);
switch (wasm_bits) {
32 => blk: {
if (!is_signed) {
try func.addImm32(-1);
break :blk;
}
try func.addImm32(std.math.minInt(i32));
try func.addImm32(std.math.maxInt(i32));
_ = try func.cmp(lhs, .{ .imm32 = 0 }, ty, .lt);
try func.addTag(.select);
},
64 => blk: {
if (!is_signed) {
try func.addImm64(@as(u64, @bitCast(@as(i64, -1))));
break :blk;
}
try func.addImm64(@as(u64, @bitCast(@as(i64, std.math.minInt(i64)))));
try func.addImm64(@as(u64, @bitCast(@as(i64, std.math.maxInt(i64)))));
_ = try func.cmp(lhs, .{ .imm64 = 0 }, ty, .lt);
try func.addTag(.select);
},
else => unreachable,
}
try func.emitWValue(shl);
_ = try func.cmp(lhs, shr, ty, .neq);
try func.addTag(.select);
try func.addLabel(.local_set, result.local.value);
break :outer_blk;
} else {
const shift_size = wasm_bits - int_info.bits;
const shift_value = switch (wasm_bits) {
32 => WValue{ .imm32 = shift_size },
64 => WValue{ .imm64 = shift_size },
else => unreachable,
};
const ext_ty = try mod.intType(int_info.signedness, wasm_bits);
var shl_res = try (try func.binOp(lhs, shift_value, ext_ty, .shl)).toLocal(func, ext_ty);
defer shl_res.free(func);
var shl = try (try func.binOp(shl_res, rhs, ext_ty, .shl)).toLocal(func, ext_ty);
defer shl.free(func);
var shr = try (try func.binOp(shl, rhs, ext_ty, .shr)).toLocal(func, ext_ty);
defer shr.free(func);
switch (wasm_bits) {
32 => blk: {
if (!is_signed) {
try func.addImm32(-1);
break :blk;
}
try func.addImm32(std.math.minInt(i32));
try func.addImm32(std.math.maxInt(i32));
_ = try func.cmp(shl_res, .{ .imm32 = 0 }, ext_ty, .lt);
try func.addTag(.select);
},
64 => blk: {
if (!is_signed) {
try func.addImm64(@as(u64, @bitCast(@as(i64, -1))));
break :blk;
}
try func.addImm64(@as(u64, @bitCast(@as(i64, std.math.minInt(i64)))));
try func.addImm64(@as(u64, @bitCast(@as(i64, std.math.maxInt(i64)))));
_ = try func.cmp(shl_res, .{ .imm64 = 0 }, ext_ty, .lt);
try func.addTag(.select);
},
else => unreachable,
}
try func.emitWValue(shl);
_ = try func.cmp(shl_res, shr, ext_ty, .neq);
try func.addTag(.select);
try func.addLabel(.local_set, result.local.value);
var shift_result = try func.binOp(result, shift_value, ext_ty, .shr);
if (is_signed) {
shift_result = try func.wrapOperand(shift_result, ty);
}
try func.addLabel(.local_set, result.local.value);
}
return func.finishAir(inst, result, &.{ bin_op.lhs, bin_op.rhs });
}
/// Calls a compiler-rt intrinsic by creating an undefined symbol,
/// then lowering the arguments and calling the symbol as a function call.
/// This function call assumes the C-ABI.
/// Asserts arguments are not stack values when the return value is
/// passed as the first parameter.
/// May leave the return value on the stack.
fn callIntrinsic(
func: *CodeGen,
name: []const u8,
param_types: []const InternPool.Index,
return_type: Type,
args: []const WValue,
) InnerError!WValue {
assert(param_types.len == args.len);
const symbol_index = func.bin_file.getGlobalSymbol(name, null) catch |err| {
return func.fail("Could not find or create global symbol '{s}'", .{@errorName(err)});
};
// Always pass over C-ABI
const mod = func.bin_file.base.comp.module.?;
var func_type = try genFunctype(func.gpa, .C, param_types, return_type, mod);
defer func_type.deinit(func.gpa);
const func_type_index = try func.bin_file.zigObjectPtr().?.putOrGetFuncType(func.gpa, func_type);
try func.bin_file.addOrUpdateImport(name, symbol_index, null, func_type_index);
const want_sret_param = firstParamSRet(.C, return_type, mod);
// if we want return as first param, we allocate a pointer to stack,
// and emit it as our first argument
const sret = if (want_sret_param) blk: {
const sret_local = try func.allocStack(return_type);
try func.lowerToStack(sret_local);
break :blk sret_local;
} else WValue{ .none = {} };
// Lower all arguments to the stack before we call our function
for (args, 0..) |arg, arg_i| {
assert(!(want_sret_param and arg == .stack));
assert(Type.fromInterned(param_types[arg_i]).hasRuntimeBitsIgnoreComptime(mod));
try func.lowerArg(.C, Type.fromInterned(param_types[arg_i]), arg);
}
// Actually call our intrinsic
try func.addLabel(.call, @intFromEnum(symbol_index));
if (!return_type.hasRuntimeBitsIgnoreComptime(mod)) {
return WValue.none;
} else if (return_type.isNoReturn(mod)) {
try func.addTag(.@"unreachable");
return WValue.none;
} else if (want_sret_param) {
return sret;
} else {
return WValue{ .stack = {} };
}
}
fn airTagName(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const un_op = func.air.instructions.items(.data)[@intFromEnum(inst)].un_op;
const operand = try func.resolveInst(un_op);
const enum_ty = func.typeOf(un_op);
const func_sym_index = try func.getTagNameFunction(enum_ty);
const result_ptr = try func.allocStack(func.typeOfIndex(inst));
try func.lowerToStack(result_ptr);
try func.emitWValue(operand);
try func.addLabel(.call, func_sym_index);
return func.finishAir(inst, result_ptr, &.{un_op});
}
fn getTagNameFunction(func: *CodeGen, enum_ty: Type) InnerError!u32 {
const mod = func.bin_file.base.comp.module.?;
const ip = &mod.intern_pool;
const enum_decl_index = enum_ty.getOwnerDecl(mod);
var arena_allocator = std.heap.ArenaAllocator.init(func.gpa);
defer arena_allocator.deinit();
const arena = arena_allocator.allocator();
const fqn = ip.stringToSlice(try mod.declPtr(enum_decl_index).fullyQualifiedName(mod));
const func_name = try std.fmt.allocPrintZ(arena, "__zig_tag_name_{s}", .{fqn});
// check if we already generated code for this.
if (func.bin_file.findGlobalSymbol(func_name)) |loc| {
return @intFromEnum(loc.index);
}
const int_tag_ty = enum_ty.intTagType(mod);
if (int_tag_ty.bitSize(mod) > 64) {
return func.fail("TODO: Implement @tagName for enums with tag size larger than 64 bits", .{});
}
var relocs = std.ArrayList(link.File.Wasm.Relocation).init(func.gpa);
defer relocs.deinit();
var body_list = std.ArrayList(u8).init(func.gpa);
defer body_list.deinit();
var writer = body_list.writer();
// The locals of the function body (always 0)
try leb.writeULEB128(writer, @as(u32, 0));
// outer block
try writer.writeByte(std.wasm.opcode(.block));
try writer.writeByte(std.wasm.block_empty);
// TODO: Make switch implementation generic so we can use a jump table for this when the tags are not sparse.
// generate an if-else chain for each tag value as well as constant.
const tag_names = enum_ty.enumFields(mod);
for (0..tag_names.len) |tag_index| {
const tag_name = ip.stringToSlice(tag_names.get(ip)[tag_index]);
// for each tag name, create an unnamed const,
// and then get a pointer to its value.
const name_ty = try mod.arrayType(.{
.len = tag_name.len,
.child = .u8_type,
.sentinel = .zero_u8,
});
const name_val = try mod.intern(.{ .aggregate = .{
.ty = name_ty.toIntern(),
.storage = .{ .bytes = tag_name },
} });
const tag_sym_index = try func.bin_file.lowerUnnamedConst(
.{ .ty = name_ty, .val = Value.fromInterned(name_val) },
enum_decl_index,
);
// block for this if case
try writer.writeByte(std.wasm.opcode(.block));
try writer.writeByte(std.wasm.block_empty);
// get actual tag value (stored in 2nd parameter);
try writer.writeByte(std.wasm.opcode(.local_get));
try leb.writeULEB128(writer, @as(u32, 1));
const tag_val = try mod.enumValueFieldIndex(enum_ty, @intCast(tag_index));
const tag_value = try func.lowerConstant(tag_val, enum_ty);
switch (tag_value) {
.imm32 => |value| {
try writer.writeByte(std.wasm.opcode(.i32_const));
try leb.writeILEB128(writer, @as(i32, @bitCast(value)));
try writer.writeByte(std.wasm.opcode(.i32_ne));
},
.imm64 => |value| {
try writer.writeByte(std.wasm.opcode(.i64_const));
try leb.writeILEB128(writer, @as(i64, @bitCast(value)));
try writer.writeByte(std.wasm.opcode(.i64_ne));
},
else => unreachable,
}
// if they're not equal, break out of current branch
try writer.writeByte(std.wasm.opcode(.br_if));
try leb.writeULEB128(writer, @as(u32, 0));
// store the address of the tagname in the pointer field of the slice
// get the address twice so we can also store the length.
try writer.writeByte(std.wasm.opcode(.local_get));
try leb.writeULEB128(writer, @as(u32, 0));
try writer.writeByte(std.wasm.opcode(.local_get));
try leb.writeULEB128(writer, @as(u32, 0));
// get address of tagname and emit a relocation to it
if (func.arch() == .wasm32) {
const encoded_alignment = @ctz(@as(u32, 4));
try writer.writeByte(std.wasm.opcode(.i32_const));
try relocs.append(.{
.relocation_type = .R_WASM_MEMORY_ADDR_LEB,
.offset = @as(u32, @intCast(body_list.items.len)),
.index = tag_sym_index,
});
try writer.writeAll(&[_]u8{0} ** 5); // will be relocated
// store pointer
try writer.writeByte(std.wasm.opcode(.i32_store));
try leb.writeULEB128(writer, encoded_alignment);
try leb.writeULEB128(writer, @as(u32, 0));
// store length
try writer.writeByte(std.wasm.opcode(.i32_const));
try leb.writeULEB128(writer, @as(u32, @intCast(tag_name.len)));
try writer.writeByte(std.wasm.opcode(.i32_store));
try leb.writeULEB128(writer, encoded_alignment);
try leb.writeULEB128(writer, @as(u32, 4));
} else {
const encoded_alignment = @ctz(@as(u32, 8));
try writer.writeByte(std.wasm.opcode(.i64_const));
try relocs.append(.{
.relocation_type = .R_WASM_MEMORY_ADDR_LEB64,
.offset = @as(u32, @intCast(body_list.items.len)),
.index = tag_sym_index,
});
try writer.writeAll(&[_]u8{0} ** 10); // will be relocated
// store pointer
try writer.writeByte(std.wasm.opcode(.i64_store));
try leb.writeULEB128(writer, encoded_alignment);
try leb.writeULEB128(writer, @as(u32, 0));
// store length
try writer.writeByte(std.wasm.opcode(.i64_const));
try leb.writeULEB128(writer, @as(u64, @intCast(tag_name.len)));
try writer.writeByte(std.wasm.opcode(.i64_store));
try leb.writeULEB128(writer, encoded_alignment);
try leb.writeULEB128(writer, @as(u32, 8));
}
// break outside blocks
try writer.writeByte(std.wasm.opcode(.br));
try leb.writeULEB128(writer, @as(u32, 1));
// end the block for this case
try writer.writeByte(std.wasm.opcode(.end));
}
try writer.writeByte(std.wasm.opcode(.@"unreachable")); // tag value does not have a name
// finish outer block
try writer.writeByte(std.wasm.opcode(.end));
// finish function body
try writer.writeByte(std.wasm.opcode(.end));
const slice_ty = Type.slice_const_u8_sentinel_0;
const func_type = try genFunctype(arena, .Unspecified, &.{int_tag_ty.ip_index}, slice_ty, mod);
const sym_index = try func.bin_file.createFunction(func_name, func_type, &body_list, &relocs);
return @intFromEnum(sym_index);
}
fn airErrorSetHasValue(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const ip = &mod.intern_pool;
const ty_op = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_op;
const operand = try func.resolveInst(ty_op.operand);
const error_set_ty = ty_op.ty.toType();
const result = try func.allocLocal(Type.bool);
const names = error_set_ty.errorSetNames(mod);
var values = try std.ArrayList(u32).initCapacity(func.gpa, names.len);
defer values.deinit();
var lowest: ?u32 = null;
var highest: ?u32 = null;
for (0..names.len) |name_index| {
const err_int: Module.ErrorInt = @intCast(mod.global_error_set.getIndex(names.get(ip)[name_index]).?);
if (lowest) |*l| {
if (err_int < l.*) {
l.* = err_int;
}
} else {
lowest = err_int;
}
if (highest) |*h| {
if (err_int > h.*) {
highest = err_int;
}
} else {
highest = err_int;
}
values.appendAssumeCapacity(err_int);
}
// start block for 'true' branch
try func.startBlock(.block, wasm.block_empty);
// start block for 'false' branch
try func.startBlock(.block, wasm.block_empty);
// block for the jump table itself
try func.startBlock(.block, wasm.block_empty);
// lower operand to determine jump table target
try func.emitWValue(operand);
try func.addImm32(@as(i32, @intCast(lowest.?)));
try func.addTag(.i32_sub);
// Account for default branch so always add '1'
const depth = @as(u32, @intCast(highest.? - lowest.? + 1));
const jump_table: Mir.JumpTable = .{ .length = depth };
const table_extra_index = try func.addExtra(jump_table);
try func.addInst(.{ .tag = .br_table, .data = .{ .payload = table_extra_index } });
try func.mir_extra.ensureUnusedCapacity(func.gpa, depth);
var value: u32 = lowest.?;
while (value <= highest.?) : (value += 1) {
const idx: u32 = blk: {
for (values.items) |val| {
if (val == value) break :blk 1;
}
break :blk 0;
};
func.mir_extra.appendAssumeCapacity(idx);
}
try func.endBlock();
// 'false' branch (i.e. error set does not have value
// ensure we set local to 0 in case the local was re-used.
try func.addImm32(0);
try func.addLabel(.local_set, result.local.value);
try func.addLabel(.br, 1);
try func.endBlock();
// 'true' branch
try func.addImm32(1);
try func.addLabel(.local_set, result.local.value);
try func.addLabel(.br, 0);
try func.endBlock();
return func.finishAir(inst, result, &.{ty_op.operand});
}
inline fn useAtomicFeature(func: *const CodeGen) bool {
return std.Target.wasm.featureSetHas(func.target.cpu.features, .atomics);
}
fn airCmpxchg(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const ty_pl = func.air.instructions.items(.data)[@intFromEnum(inst)].ty_pl;
const extra = func.air.extraData(Air.Cmpxchg, ty_pl.payload).data;
const ptr_ty = func.typeOf(extra.ptr);
const ty = ptr_ty.childType(mod);
const result_ty = func.typeOfIndex(inst);
const ptr_operand = try func.resolveInst(extra.ptr);
const expected_val = try func.resolveInst(extra.expected_value);
const new_val = try func.resolveInst(extra.new_value);
const cmp_result = try func.allocLocal(Type.bool);
const ptr_val = if (func.useAtomicFeature()) val: {
const val_local = try func.allocLocal(ty);
try func.emitWValue(ptr_operand);
try func.lowerToStack(expected_val);
try func.lowerToStack(new_val);
try func.addAtomicMemArg(switch (ty.abiSize(mod)) {
1 => .i32_atomic_rmw8_cmpxchg_u,
2 => .i32_atomic_rmw16_cmpxchg_u,
4 => .i32_atomic_rmw_cmpxchg,
8 => .i32_atomic_rmw_cmpxchg,
else => |size| return func.fail("TODO: implement `@cmpxchg` for types with abi size '{d}'", .{size}),
}, .{
.offset = ptr_operand.offset(),
.alignment = @intCast(ty.abiAlignment(mod).toByteUnitsOptional().?),
});
try func.addLabel(.local_tee, val_local.local.value);
_ = try func.cmp(.stack, expected_val, ty, .eq);
try func.addLabel(.local_set, cmp_result.local.value);
break :val val_local;
} else val: {
if (ty.abiSize(mod) > 8) {
return func.fail("TODO: Implement `@cmpxchg` for types larger than abi size of 8 bytes", .{});
}
const ptr_val = try WValue.toLocal(try func.load(ptr_operand, ty, 0), func, ty);
try func.lowerToStack(ptr_operand);
try func.lowerToStack(new_val);
try func.emitWValue(ptr_val);
_ = try func.cmp(ptr_val, expected_val, ty, .eq);
try func.addLabel(.local_tee, cmp_result.local.value);
try func.addTag(.select);
try func.store(.stack, .stack, ty, 0);
break :val ptr_val;
};
const result_ptr = if (isByRef(result_ty, mod)) val: {
try func.emitWValue(cmp_result);
try func.addImm32(-1);
try func.addTag(.i32_xor);
try func.addImm32(1);
try func.addTag(.i32_and);
const and_result = try WValue.toLocal(.stack, func, Type.bool);
const result_ptr = try func.allocStack(result_ty);
try func.store(result_ptr, and_result, Type.bool, @as(u32, @intCast(ty.abiSize(mod))));
try func.store(result_ptr, ptr_val, ty, 0);
break :val result_ptr;
} else val: {
try func.addImm32(0);
try func.emitWValue(ptr_val);
try func.emitWValue(cmp_result);
try func.addTag(.select);
break :val try WValue.toLocal(.stack, func, result_ty);
};
return func.finishAir(inst, result_ptr, &.{ extra.ptr, extra.expected_value, extra.new_value });
}
fn airAtomicLoad(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const atomic_load = func.air.instructions.items(.data)[@intFromEnum(inst)].atomic_load;
const ptr = try func.resolveInst(atomic_load.ptr);
const ty = func.typeOfIndex(inst);
if (func.useAtomicFeature()) {
const tag: wasm.AtomicsOpcode = switch (ty.abiSize(mod)) {
1 => .i32_atomic_load8_u,
2 => .i32_atomic_load16_u,
4 => .i32_atomic_load,
8 => .i64_atomic_load,
else => |size| return func.fail("TODO: @atomicLoad for types with abi size {d}", .{size}),
};
try func.emitWValue(ptr);
try func.addAtomicMemArg(tag, .{
.offset = ptr.offset(),
.alignment = @intCast(ty.abiAlignment(mod).toByteUnitsOptional().?),
});
} else {
_ = try func.load(ptr, ty, 0);
}
const result = try WValue.toLocal(.stack, func, ty);
return func.finishAir(inst, result, &.{atomic_load.ptr});
}
fn airAtomicRmw(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const pl_op = func.air.instructions.items(.data)[@intFromEnum(inst)].pl_op;
const extra = func.air.extraData(Air.AtomicRmw, pl_op.payload).data;
const ptr = try func.resolveInst(pl_op.operand);
const operand = try func.resolveInst(extra.operand);
const ty = func.typeOfIndex(inst);
const op: std.builtin.AtomicRmwOp = extra.op();
if (func.useAtomicFeature()) {
switch (op) {
.Max,
.Min,
.Nand,
=> {
const tmp = try func.load(ptr, ty, 0);
const value = try tmp.toLocal(func, ty);
// create a loop to cmpxchg the new value
try func.startBlock(.loop, wasm.block_empty);
try func.emitWValue(ptr);
try func.emitWValue(value);
if (op == .Nand) {
const wasm_bits = toWasmBits(@as(u16, @intCast(ty.bitSize(mod)))).?;
const and_res = try func.binOp(value, operand, ty, .@"and");
if (wasm_bits == 32)
try func.addImm32(-1)
else if (wasm_bits == 64)
try func.addImm64(@as(u64, @bitCast(@as(i64, -1))))
else
return func.fail("TODO: `@atomicRmw` with operator `Nand` for types larger than 64 bits", .{});
_ = try func.binOp(and_res, .stack, ty, .xor);
} else {
try func.emitWValue(value);
try func.emitWValue(operand);
_ = try func.cmp(value, operand, ty, if (op == .Max) .gt else .lt);
try func.addTag(.select);
}
try func.addAtomicMemArg(
switch (ty.abiSize(mod)) {
1 => .i32_atomic_rmw8_cmpxchg_u,
2 => .i32_atomic_rmw16_cmpxchg_u,
4 => .i32_atomic_rmw_cmpxchg,
8 => .i64_atomic_rmw_cmpxchg,
else => return func.fail("TODO: implement `@atomicRmw` with operation `{s}` for types larger than 64 bits", .{@tagName(op)}),
},
.{
.offset = ptr.offset(),
.alignment = @intCast(ty.abiAlignment(mod).toByteUnitsOptional().?),
},
);
const select_res = try func.allocLocal(ty);
try func.addLabel(.local_tee, select_res.local.value);
_ = try func.cmp(.stack, value, ty, .neq); // leave on stack so we can use it for br_if
try func.emitWValue(select_res);
try func.addLabel(.local_set, value.local.value);
try func.addLabel(.br_if, 0);
try func.endBlock();
return func.finishAir(inst, value, &.{ pl_op.operand, extra.operand });
},
// the other operations have their own instructions for Wasm.
else => {
try func.emitWValue(ptr);
try func.emitWValue(operand);
const tag: wasm.AtomicsOpcode = switch (ty.abiSize(mod)) {
1 => switch (op) {
.Xchg => .i32_atomic_rmw8_xchg_u,
.Add => .i32_atomic_rmw8_add_u,
.Sub => .i32_atomic_rmw8_sub_u,
.And => .i32_atomic_rmw8_and_u,
.Or => .i32_atomic_rmw8_or_u,
.Xor => .i32_atomic_rmw8_xor_u,
else => unreachable,
},
2 => switch (op) {
.Xchg => .i32_atomic_rmw16_xchg_u,
.Add => .i32_atomic_rmw16_add_u,
.Sub => .i32_atomic_rmw16_sub_u,
.And => .i32_atomic_rmw16_and_u,
.Or => .i32_atomic_rmw16_or_u,
.Xor => .i32_atomic_rmw16_xor_u,
else => unreachable,
},
4 => switch (op) {
.Xchg => .i32_atomic_rmw_xchg,
.Add => .i32_atomic_rmw_add,
.Sub => .i32_atomic_rmw_sub,
.And => .i32_atomic_rmw_and,
.Or => .i32_atomic_rmw_or,
.Xor => .i32_atomic_rmw_xor,
else => unreachable,
},
8 => switch (op) {
.Xchg => .i64_atomic_rmw_xchg,
.Add => .i64_atomic_rmw_add,
.Sub => .i64_atomic_rmw_sub,
.And => .i64_atomic_rmw_and,
.Or => .i64_atomic_rmw_or,
.Xor => .i64_atomic_rmw_xor,
else => unreachable,
},
else => |size| return func.fail("TODO: Implement `@atomicRmw` for types with abi size {d}", .{size}),
};
try func.addAtomicMemArg(tag, .{
.offset = ptr.offset(),
.alignment = @intCast(ty.abiAlignment(mod).toByteUnitsOptional().?),
});
const result = try WValue.toLocal(.stack, func, ty);
return func.finishAir(inst, result, &.{ pl_op.operand, extra.operand });
},
}
} else {
const loaded = try func.load(ptr, ty, 0);
const result = try loaded.toLocal(func, ty);
switch (op) {
.Xchg => {
try func.store(ptr, operand, ty, 0);
},
.Add,
.Sub,
.And,
.Or,
.Xor,
=> {
try func.emitWValue(ptr);
_ = try func.binOp(result, operand, ty, switch (op) {
.Add => .add,
.Sub => .sub,
.And => .@"and",
.Or => .@"or",
.Xor => .xor,
else => unreachable,
});
if (ty.isInt(mod) and (op == .Add or op == .Sub)) {
_ = try func.wrapOperand(.stack, ty);
}
try func.store(.stack, .stack, ty, ptr.offset());
},
.Max,
.Min,
=> {
try func.emitWValue(ptr);
try func.emitWValue(result);
try func.emitWValue(operand);
_ = try func.cmp(result, operand, ty, if (op == .Max) .gt else .lt);
try func.addTag(.select);
try func.store(.stack, .stack, ty, ptr.offset());
},
.Nand => {
const wasm_bits = toWasmBits(@as(u16, @intCast(ty.bitSize(mod)))).?;
try func.emitWValue(ptr);
const and_res = try func.binOp(result, operand, ty, .@"and");
if (wasm_bits == 32)
try func.addImm32(-1)
else if (wasm_bits == 64)
try func.addImm64(@as(u64, @bitCast(@as(i64, -1))))
else
return func.fail("TODO: `@atomicRmw` with operator `Nand` for types larger than 64 bits", .{});
_ = try func.binOp(and_res, .stack, ty, .xor);
try func.store(.stack, .stack, ty, ptr.offset());
},
}
return func.finishAir(inst, result, &.{ pl_op.operand, extra.operand });
}
}
fn airFence(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const zcu = func.bin_file.base.comp.module.?;
// Only when the atomic feature is enabled, and we're not building
// for a single-threaded build, can we emit the `fence` instruction.
// In all other cases, we emit no instructions for a fence.
const func_namespace = zcu.namespacePtr(func.decl.src_namespace);
const single_threaded = func_namespace.file_scope.mod.single_threaded;
if (func.useAtomicFeature() and !single_threaded) {
try func.addAtomicTag(.atomic_fence);
}
return func.finishAir(inst, .none, &.{});
}
fn airAtomicStore(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
const mod = func.bin_file.base.comp.module.?;
const bin_op = func.air.instructions.items(.data)[@intFromEnum(inst)].bin_op;
const ptr = try func.resolveInst(bin_op.lhs);
const operand = try func.resolveInst(bin_op.rhs);
const ptr_ty = func.typeOf(bin_op.lhs);
const ty = ptr_ty.childType(mod);
if (func.useAtomicFeature()) {
const tag: wasm.AtomicsOpcode = switch (ty.abiSize(mod)) {
1 => .i32_atomic_store8,
2 => .i32_atomic_store16,
4 => .i32_atomic_store,
8 => .i64_atomic_store,
else => |size| return func.fail("TODO: @atomicLoad for types with abi size {d}", .{size}),
};
try func.emitWValue(ptr);
try func.lowerToStack(operand);
try func.addAtomicMemArg(tag, .{
.offset = ptr.offset(),
.alignment = @intCast(ty.abiAlignment(mod).toByteUnitsOptional().?),
});
} else {
try func.store(ptr, operand, ty, 0);
}
return func.finishAir(inst, .none, &.{ bin_op.lhs, bin_op.rhs });
}
fn airFrameAddress(func: *CodeGen, inst: Air.Inst.Index) InnerError!void {
if (func.initial_stack_value == .none) {
try func.initializeStack();
}
try func.emitWValue(func.bottom_stack_value);
const result = try WValue.toLocal(.stack, func, Type.usize);
return func.finishAir(inst, result, &.{});
}
fn typeOf(func: *CodeGen, inst: Air.Inst.Ref) Type {
const mod = func.bin_file.base.comp.module.?;
return func.air.typeOf(inst, &mod.intern_pool);
}
fn typeOfIndex(func: *CodeGen, inst: Air.Inst.Index) Type {
const mod = func.bin_file.base.comp.module.?;
return func.air.typeOfIndex(inst, &mod.intern_pool);
}
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