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stage2: implement cmpxchg and improve comptime eval

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* Implement Sema for `@cmpxchgWeak` and `@cmpxchgStrong`. Both runtime
   and comptime codepaths are implement.
 * Implement Codegen for LLVM backend and C backend.
 * Add LazySrcLoc.node_offset_builtin_call_argX 3...5
 * Sema: rework comptime control flow.
   - `error.ComptimeReturn` is used to signal that a comptime function
     call has returned a result (stored in the Inlining struct).
     `analyzeCall` notices this and handles the result.
   - The ZIR instructions `break_inline`, `block_inline`,
     `condbr_inline` are now redundant and can be deleted. `break`,
     `block`, and `condbr` function equivalently inside a comptime scope.
   - The ZIR instructions `loop` and `repeat` also are modified to
     directly perform comptime control flow inside a comptime scope,
     skipping an unnecessary mechanism for analysis of runtime code.
     This makes Zig perform closer to an interpreter when evaluating
     comptime code.
 * Sema: zirRetErrValue looks at Sema.ret_fn_ty rather than sema.func
   for adding to the inferred error set. This fixes a bug for
    inlined/comptime function calls.
 * Implement ZIR printing for cmpxchg.
 * stage1: make cmpxchg respect --single-threaded
   - Our LLVM C++ API wrapper failed to expose this boolean flag before.
 * Fix AIR printing for struct fields showing incorrect liveness data.
This commit is contained in:
Andrew Kelley 2021-09-14 21:58:22 -07:00
parent 5d14590ed1
commit 0395b35cee
19 changed files with 682 additions and 115 deletions
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23
src/Air.zig
View File

@ -309,6 +309,10 @@ pub const Inst = struct {
/// Given a pointer to an array, return a slice.
/// Uses the `ty_op` field.
array_to_slice,
/// Uses the `ty_pl` field with payload `Cmpxchg`.
cmpxchg_weak,
/// Uses the `ty_pl` field with payload `Cmpxchg`.
cmpxchg_strong,
pub fn fromCmpOp(op: std.math.CompareOperator) Tag {
return switch (op) {
@ -443,6 +447,23 @@ pub const Asm = struct {
zir_index: u32,
};
pub const Cmpxchg = struct {
ptr: Inst.Ref,
expected_value: Inst.Ref,
new_value: Inst.Ref,
/// 0b00000000000000000000000000000XXX - success_order
/// 0b00000000000000000000000000XXX000 - failure_order
flags: u32,
pub fn successOrder(self: Cmpxchg) std.builtin.AtomicOrder {
return @intToEnum(std.builtin.AtomicOrder, @truncate(u3, self.flags));
}
pub fn failureOrder(self: Cmpxchg) std.builtin.AtomicOrder {
return @intToEnum(std.builtin.AtomicOrder, @truncate(u3, self.flags >> 3));
}
};
pub fn getMainBody(air: Air) []const Air.Inst.Index {
const body_index = air.extra[@enumToInt(ExtraIndex.main_block)];
const extra = air.extraData(Block, body_index);
@ -507,6 +528,8 @@ pub fn typeOfIndex(air: Air, inst: Air.Inst.Index) Type {
.struct_field_ptr,
.struct_field_val,
.ptr_elem_ptr,
.cmpxchg_weak,
.cmpxchg_strong,
=> return air.getRefType(datas[inst].ty_pl.ty),
.not,

11
src/AstGen.zig
View File

@ -7542,6 +7542,7 @@ fn cmpxchg(
tag: Zir.Inst.Tag,
) InnerError!Zir.Inst.Ref {
const int_type = try typeExpr(gz, scope, params[0]);
// TODO: allow this to be volatile
const ptr_type = try gz.add(.{ .tag = .ptr_type_simple, .data = .{
.ptr_type_simple = .{
.is_allowzero = false,
@ -7553,11 +7554,11 @@ fn cmpxchg(
} });
const result = try gz.addPlNode(tag, node, Zir.Inst.Cmpxchg{
// zig fmt: off
.ptr = try expr(gz, scope, .{ .ty = ptr_type }, params[1]),
.expected_value = try expr(gz, scope, .{ .ty = int_type }, params[2]),
.new_value = try expr(gz, scope, .{ .ty = int_type }, params[3]),
.success_order = try expr(gz, scope, .{ .ty = .atomic_order_type }, params[4]),
.fail_order = try expr(gz, scope, .{ .ty = .atomic_order_type }, params[5]),
.ptr = try expr(gz, scope, .{ .coerced_ty = ptr_type }, params[1]),
.expected_value = try expr(gz, scope, .{ .coerced_ty = int_type }, params[2]),
.new_value = try expr(gz, scope, .{ .coerced_ty = int_type }, params[3]),
.success_order = try expr(gz, scope, .{ .coerced_ty = .atomic_order_type }, params[4]),
.failure_order = try expr(gz, scope, .{ .coerced_ty = .atomic_order_type }, params[5]),
// zig fmt: on
});
return rvalue(gz, rl, result, node);

4
src/Liveness.zig
View File

@ -340,6 +340,10 @@ fn analyzeInst(
const extra = a.air.extraData(Air.Bin, inst_datas[inst].ty_pl.payload).data;
return trackOperands(a, new_set, inst, main_tomb, .{ extra.lhs, extra.rhs, .none });
},
.cmpxchg_strong, .cmpxchg_weak => {
const extra = a.air.extraData(Air.Cmpxchg, inst_datas[inst].ty_pl.payload).data;
return trackOperands(a, new_set, inst, main_tomb, .{ extra.ptr, extra.expected_value, extra.new_value });
},
.br => {
const br = inst_datas[inst].br;
return trackOperands(a, new_set, inst, main_tomb, .{ br.operand, .none, .none });

88
src/Module.zig
View File

@ -1321,6 +1321,7 @@ pub const Scope = struct {
/// It is shared among all the blocks in an inline or comptime called
/// function.
pub const Inlining = struct {
comptime_result: Air.Inst.Ref,
merges: Merges,
};
@ -1643,36 +1644,12 @@ pub const SrcLoc = struct {
const token_starts = tree.tokens.items(.start);
return token_starts[tok_index];
},
.node_offset_builtin_call_arg0 => |node_off| {
const tree = try src_loc.file_scope.getTree(gpa);
const node_datas = tree.nodes.items(.data);
const node_tags = tree.nodes.items(.tag);
const node = src_loc.declRelativeToNodeIndex(node_off);
const param = switch (node_tags[node]) {
.builtin_call_two, .builtin_call_two_comma => node_datas[node].lhs,
.builtin_call, .builtin_call_comma => tree.extra_data[node_datas[node].lhs],
else => unreachable,
};
const main_tokens = tree.nodes.items(.main_token);
const tok_index = main_tokens[param];
const token_starts = tree.tokens.items(.start);
return token_starts[tok_index];
},
.node_offset_builtin_call_arg1 => |node_off| {
const tree = try src_loc.file_scope.getTree(gpa);
const node_datas = tree.nodes.items(.data);
const node_tags = tree.nodes.items(.tag);
const node = src_loc.declRelativeToNodeIndex(node_off);
const param = switch (node_tags[node]) {
.builtin_call_two, .builtin_call_two_comma => node_datas[node].rhs,
.builtin_call, .builtin_call_comma => tree.extra_data[node_datas[node].lhs + 1],
else => unreachable,
};
const main_tokens = tree.nodes.items(.main_token);
const tok_index = main_tokens[param];
const token_starts = tree.tokens.items(.start);
return token_starts[tok_index];
},
.node_offset_builtin_call_arg0 => |n| return src_loc.byteOffsetBuiltinCallArg(gpa, n, 0),
.node_offset_builtin_call_arg1 => |n| return src_loc.byteOffsetBuiltinCallArg(gpa, n, 1),
.node_offset_builtin_call_arg2 => |n| return src_loc.byteOffsetBuiltinCallArg(gpa, n, 2),
.node_offset_builtin_call_arg3 => |n| return src_loc.byteOffsetBuiltinCallArg(gpa, n, 3),
.node_offset_builtin_call_arg4 => |n| return src_loc.byteOffsetBuiltinCallArg(gpa, n, 4),
.node_offset_builtin_call_arg5 => |n| return src_loc.byteOffsetBuiltinCallArg(gpa, n, 5),
.node_offset_array_access_index => |node_off| {
const tree = try src_loc.file_scope.getTree(gpa);
const node_datas = tree.nodes.items(.data);
@ -1965,6 +1942,31 @@ pub const SrcLoc = struct {
},
}
}
pub fn byteOffsetBuiltinCallArg(
src_loc: SrcLoc,
gpa: *Allocator,
node_off: i32,
arg_index: u32,
) !u32 {
const tree = try src_loc.file_scope.getTree(gpa);
const node_datas = tree.nodes.items(.data);
const node_tags = tree.nodes.items(.tag);
const node = src_loc.declRelativeToNodeIndex(node_off);
const param = switch (node_tags[node]) {
.builtin_call_two, .builtin_call_two_comma => switch (arg_index) {
0 => node_datas[node].lhs,
1 => node_datas[node].rhs,
else => unreachable,
},
.builtin_call, .builtin_call_comma => tree.extra_data[node_datas[node].lhs + arg_index],
else => unreachable,
};
const main_tokens = tree.nodes.items(.main_token);
const tok_index = main_tokens[param];
const token_starts = tree.tokens.items(.start);
return token_starts[tok_index];
}
};
/// Resolving a source location into a byte offset may require doing work
@ -2032,6 +2034,10 @@ pub const LazySrcLoc = union(enum) {
node_offset_builtin_call_arg0: i32,
/// Same as `node_offset_builtin_call_arg0` except arg index 1.
node_offset_builtin_call_arg1: i32,
node_offset_builtin_call_arg2: i32,
node_offset_builtin_call_arg3: i32,
node_offset_builtin_call_arg4: i32,
node_offset_builtin_call_arg5: i32,
/// The source location points to the index expression of an array access
/// expression, found by taking this AST node index offset from the containing
/// Decl AST node, which points to an array access AST node. Next, navigate
@ -2157,6 +2163,10 @@ pub const LazySrcLoc = union(enum) {
.node_offset_for_cond,
.node_offset_builtin_call_arg0,
.node_offset_builtin_call_arg1,
.node_offset_builtin_call_arg2,
.node_offset_builtin_call_arg3,
.node_offset_builtin_call_arg4,
.node_offset_builtin_call_arg5,
.node_offset_array_access_index,
.node_offset_slice_sentinel,
.node_offset_call_func,
@ -2205,6 +2215,10 @@ pub const LazySrcLoc = union(enum) {
.node_offset_for_cond,
.node_offset_builtin_call_arg0,
.node_offset_builtin_call_arg1,
.node_offset_builtin_call_arg2,
.node_offset_builtin_call_arg3,
.node_offset_builtin_call_arg4,
.node_offset_builtin_call_arg5,
.node_offset_array_access_index,
.node_offset_slice_sentinel,
.node_offset_call_func,
@ -2246,6 +2260,9 @@ pub const CompileError = error{
/// because the function is generic. This is only seen when analyzing the body of a param
/// instruction.
GenericPoison,
/// In a comptime scope, a return instruction was encountered. This error is only seen when
/// doing a comptime function call.
ComptimeReturn,
};
pub fn deinit(mod: *Module) void {
@ -3928,8 +3945,10 @@ pub fn analyzeFnBody(mod: *Module, decl: *Decl, func: *Fn) SemaError!Air {
log.debug("set {s} to in_progress", .{decl.name});
_ = sema.analyzeBody(&inner_block, fn_info.body) catch |err| switch (err) {
// TODO make these unreachable instead of @panic
error.NeededSourceLocation => @panic("zig compiler bug: NeededSourceLocation"),
error.GenericPoison => @panic("zig compiler bug: GenericPoison"),
error.ComptimeReturn => @panic("zig compiler bug: ComptimeReturn"),
else => |e| return e,
};
@ -4534,7 +4553,6 @@ pub const PeerTypeCandidateSrc = union(enum) {
self: PeerTypeCandidateSrc,
gpa: *Allocator,
decl: *Decl,
candidates: usize,
candidate_i: usize,
) ?LazySrcLoc {
@setCold(true);
@ -4547,12 +4565,14 @@ pub const PeerTypeCandidateSrc = union(enum) {
return candidate_srcs[candidate_i];
},
.typeof_builtin_call_node_offset => |node_offset| {
if (candidates <= 2) {
switch (candidate_i) {
0 => return LazySrcLoc{ .node_offset_builtin_call_arg0 = node_offset },
1 => return LazySrcLoc{ .node_offset_builtin_call_arg1 = node_offset },
else => unreachable,
}
2 => return LazySrcLoc{ .node_offset_builtin_call_arg2 = node_offset },
3 => return LazySrcLoc{ .node_offset_builtin_call_arg3 = node_offset },
4 => return LazySrcLoc{ .node_offset_builtin_call_arg4 = node_offset },
5 => return LazySrcLoc{ .node_offset_builtin_call_arg5 = node_offset },
else => {},
}
const tree = decl.namespace.file_scope.getTree(gpa) catch |err| {

258
src/Sema.zig
View File

@ -159,7 +159,6 @@ pub fn analyzeBody(
.bit_or => try sema.zirBitwise(block, inst, .bit_or),
.bitcast => try sema.zirBitcast(block, inst),
.bitcast_result_ptr => try sema.zirBitcastResultPtr(block, inst),
.block => try sema.zirBlock(block, inst),
.suspend_block => try sema.zirSuspendBlock(block, inst),
.bool_not => try sema.zirBoolNot(block, inst),
.bool_br_and => try sema.zirBoolBr(block, inst, false),
@ -215,7 +214,6 @@ pub fn analyzeBody(
.is_non_err_ptr => try sema.zirIsNonErrPtr(block, inst),
.is_non_null => try sema.zirIsNonNull(block, inst),
.is_non_null_ptr => try sema.zirIsNonNullPtr(block, inst),
.loop => try sema.zirLoop(block, inst),
.merge_error_sets => try sema.zirMergeErrorSets(block, inst),
.negate => try sema.zirNegate(block, inst, .sub),
.negate_wrap => try sema.zirNegate(block, inst, .subwrap),
@ -308,8 +306,8 @@ pub fn analyzeBody(
.shr_exact => try sema.zirShrExact(block, inst),
.bit_offset_of => try sema.zirBitOffsetOf(block, inst),
.offset_of => try sema.zirOffsetOf(block, inst),
.cmpxchg_strong => try sema.zirCmpxchg(block, inst),
.cmpxchg_weak => try sema.zirCmpxchg(block, inst),
.cmpxchg_strong => try sema.zirCmpxchg(block, inst, .cmpxchg_strong),
.cmpxchg_weak => try sema.zirCmpxchg(block, inst, .cmpxchg_weak),
.splat => try sema.zirSplat(block, inst),
.reduce => try sema.zirReduce(block, inst),
.shuffle => try sema.zirShuffle(block, inst),
@ -364,16 +362,12 @@ pub fn analyzeBody(
// Instructions that we know to *always* be noreturn based solely on their tag.
// These functions match the return type of analyzeBody so that we can
// tail call them here.
.break_inline => return inst,
.condbr => return sema.zirCondbr(block, inst),
.@"break" => return sema.zirBreak(block, inst),
.compile_error => return sema.zirCompileError(block, inst),
.ret_coerce => return sema.zirRetCoerce(block, inst),
.ret_node => return sema.zirRetNode(block, inst),
.ret_load => return sema.zirRetLoad(block, inst),
.ret_err_value => return sema.zirRetErrValue(block, inst),
.@"unreachable" => return sema.zirUnreachable(block, inst),
.repeat => return sema.zirRepeat(block, inst),
.panic => return sema.zirPanic(block, inst),
// zig fmt: on
@ -499,6 +493,28 @@ pub fn analyzeBody(
},
// Special case instructions to handle comptime control flow.
.@"break" => {
if (block.is_comptime) {
return inst; // same as break_inline
} else {
return sema.zirBreak(block, inst);
}
},
.break_inline => return inst,
.repeat => {
if (block.is_comptime) {
// Send comptime control flow back to the beginning of this block.
const src: LazySrcLoc = .{ .node_offset = datas[inst].node };
try sema.emitBackwardBranch(block, src);
i = 0;
continue;
} else {
const src_node = sema.code.instructions.items(.data)[inst].node;
const src: LazySrcLoc = .{ .node_offset = src_node };
try sema.requireRuntimeBlock(block, src);
return always_noreturn;
}
},
.repeat_inline => {
// Send comptime control flow back to the beginning of this block.
const src: LazySrcLoc = .{ .node_offset = datas[inst].node };
@ -506,6 +522,34 @@ pub fn analyzeBody(
i = 0;
continue;
},
.loop => blk: {
if (!block.is_comptime) break :blk try sema.zirLoop(block, inst);
// Same as `block_inline`. TODO https://github.com/ziglang/zig/issues/8220
const inst_data = datas[inst].pl_node;
const extra = sema.code.extraData(Zir.Inst.Block, inst_data.payload_index);
const inline_body = sema.code.extra[extra.end..][0..extra.data.body_len];
const break_inst = try sema.analyzeBody(block, inline_body);
const break_data = datas[break_inst].@"break";
if (inst == break_data.block_inst) {
break :blk sema.resolveInst(break_data.operand);
} else {
return break_inst;
}
},
.block => blk: {
if (!block.is_comptime) break :blk try sema.zirBlock(block, inst);
// Same as `block_inline`. TODO https://github.com/ziglang/zig/issues/8220
const inst_data = datas[inst].pl_node;
const extra = sema.code.extraData(Zir.Inst.Block, inst_data.payload_index);
const inline_body = sema.code.extra[extra.end..][0..extra.data.body_len];
const break_inst = try sema.analyzeBody(block, inline_body);
const break_data = datas[break_inst].@"break";
if (inst == break_data.block_inst) {
break :blk sema.resolveInst(break_data.operand);
} else {
return break_inst;
}
},
.block_inline => blk: {
// Directly analyze the block body without introducing a new block.
const inst_data = datas[inst].pl_node;
@ -519,6 +563,24 @@ pub fn analyzeBody(
return break_inst;
}
},
.condbr => blk: {
if (!block.is_comptime) return sema.zirCondbr(block, inst);
// Same as condbr_inline. TODO https://github.com/ziglang/zig/issues/8220
const inst_data = datas[inst].pl_node;
const cond_src: LazySrcLoc = .{ .node_offset_if_cond = inst_data.src_node };
const extra = sema.code.extraData(Zir.Inst.CondBr, inst_data.payload_index);
const then_body = sema.code.extra[extra.end..][0..extra.data.then_body_len];
const else_body = sema.code.extra[extra.end + then_body.len ..][0..extra.data.else_body_len];
const cond = try sema.resolveInstConst(block, cond_src, extra.data.condition);
const inline_body = if (cond.val.toBool()) then_body else else_body;
const break_inst = try sema.analyzeBody(block, inline_body);
const break_data = datas[break_inst].@"break";
if (inst == break_data.block_inst) {
break :blk sema.resolveInst(break_data.operand);
} else {
return break_inst;
}
},
.condbr_inline => blk: {
const inst_data = datas[inst].pl_node;
const cond_src: LazySrcLoc = .{ .node_offset_if_cond = inst_data.src_node };
@ -1933,16 +1995,6 @@ fn zirCompileLog(
return Air.Inst.Ref.void_value;
}
fn zirRepeat(sema: *Sema, block: *Scope.Block, inst: Zir.Inst.Index) CompileError!Zir.Inst.Index {
const tracy = trace(@src());
defer tracy.end();
const src_node = sema.code.instructions.items(.data)[inst].node;
const src: LazySrcLoc = .{ .node_offset = src_node };
try sema.requireRuntimeBlock(block, src);
return always_noreturn;
}
fn zirPanic(sema: *Sema, block: *Scope.Block, inst: Zir.Inst.Index) CompileError!Zir.Inst.Index {
const inst_data = sema.code.instructions.items(.data)[inst].un_node;
const src: LazySrcLoc = inst_data.src();
@ -2003,7 +2055,6 @@ fn zirLoop(sema: *Sema, parent_block: *Scope.Block, inst: Zir.Inst.Index) Compil
_ = try sema.analyzeBody(&loop_block, body);
// Loop repetition is implied so the last instruction may or may not be a noreturn instruction.
try child_block.instructions.append(gpa, loop_inst);
try sema.air_extra.ensureUnusedCapacity(gpa, @typeInfo(Air.Block).Struct.fields.len +
@ -2615,6 +2666,7 @@ fn analyzeCall(
// This one is shared among sub-blocks within the same callee, but not
// shared among the entire inline/comptime call stack.
var inlining: Scope.Block.Inlining = .{
.comptime_result = undefined,
.merges = .{
.results = .{},
.br_list = .{},
@ -2770,8 +2822,13 @@ fn analyzeCall(
}
}
_ = try sema.analyzeBody(&child_block, fn_info.body);
const result = try sema.analyzeBlockBody(block, call_src, &child_block, merges);
const result = result: {
_ = sema.analyzeBody(&child_block, fn_info.body) catch |err| switch (err) {
error.ComptimeReturn => break :result inlining.comptime_result,
else => |e| return e,
};
break :result try sema.analyzeBlockBody(block, call_src, &child_block, merges);
};
if (is_comptime_call) {
const result_val = try sema.resolveConstMaybeUndefVal(block, call_src, result);
@ -6662,9 +6719,9 @@ fn zirRetErrValue(
const src = inst_data.src();
// Add the error tag to the inferred error set of the in-scope function.
if (sema.func) |func| {
if (func.getInferredErrorSet()) |map| {
_ = try map.getOrPut(sema.gpa, err_name);
if (sema.fn_ret_ty.zigTypeTag() == .ErrorUnion) {
if (sema.fn_ret_ty.errorUnionSet().castTag(.error_set_inferred)) |payload| {
_ = try payload.data.map.getOrPut(sema.gpa, err_name);
}
}
// Return the error code from the function.
@ -6699,6 +6756,10 @@ fn zirRetNode(sema: *Sema, block: *Scope.Block, inst: Zir.Inst.Index) CompileErr
const operand = sema.resolveInst(inst_data.operand);
const src = inst_data.src();
// TODO: we pass false here for the `need_coercion` boolean, but I'm pretty sure we need
// to remove this parameter entirely. Observe the problem by looking at the incorrect compile
// error that occurs when a behavior test case being executed at comptime fails, e.g.
// `test { comptime foo(); } fn foo() { try expect(false); }`
return sema.analyzeRet(block, operand, src, false);
}
@ -6730,6 +6791,10 @@ fn analyzeRet(
try sema.coerce(block, sema.fn_ret_ty, uncasted_operand, src);
if (block.inlining) |inlining| {
if (block.is_comptime) {
inlining.comptime_result = operand;
return error.ComptimeReturn;
}
// We are inlining a function call; rewrite the `ret` as a `break`.
try inlining.merges.results.append(sema.gpa, operand);
_ = try block.addBr(inlining.merges.block_inst, operand);
@ -7425,10 +7490,149 @@ fn zirOffsetOf(sema: *Sema, block: *Scope.Block, inst: Zir.Inst.Index) CompileEr
return sema.mod.fail(&block.base, src, "TODO: Sema.zirOffsetOf", .{});
}
fn zirCmpxchg(sema: *Sema, block: *Scope.Block, inst: Zir.Inst.Index) CompileError!Air.Inst.Ref {
fn checkAtomicOperandType(
sema: *Sema,
block: *Scope.Block,
ty_src: LazySrcLoc,
ty: Type,
) CompileError!void {
var buffer: Type.Payload.Bits = undefined;
const target = sema.mod.getTarget();
const max_atomic_bits = target_util.largestAtomicBits(target);
const int_ty = switch (ty.zigTypeTag()) {
.Int => ty,
.Enum => ty.enumTagType(&buffer),
.Float => {
const bit_count = ty.floatBits(target);
if (bit_count > max_atomic_bits) {
return sema.mod.fail(
&block.base,
ty_src,
"expected {d}-bit float type or smaller; found {d}-bit float type",
.{ max_atomic_bits, bit_count },
);
}
return;
},
.Bool => return, // Will be treated as `u8`.
else => return sema.mod.fail(
&block.base,
ty_src,
"expected bool, integer, float, enum, or pointer type; found {}",
.{ty},
),
};
const bit_count = int_ty.intInfo(target).bits;
if (bit_count > max_atomic_bits) {
return sema.mod.fail(
&block.base,
ty_src,
"expected {d}-bit integer type or smaller; found {d}-bit integer type",
.{ max_atomic_bits, bit_count },
);
}
}
fn resolveAtomicOrder(
sema: *Sema,
block: *Scope.Block,
src: LazySrcLoc,
zir_ref: Zir.Inst.Ref,
) CompileError!std.builtin.AtomicOrder {
const atomic_order_ty = try sema.getBuiltinType(block, src, "AtomicOrder");
const air_ref = sema.resolveInst(zir_ref);
const coerced = try sema.coerce(block, atomic_order_ty, air_ref, src);
const val = try sema.resolveConstValue(block, src, coerced);
return val.toEnum(std.builtin.AtomicOrder);
}
fn zirCmpxchg(
sema: *Sema,
block: *Scope.Block,
inst: Zir.Inst.Index,
air_tag: Air.Inst.Tag,
) CompileError!Air.Inst.Ref {
const mod = sema.mod;
const inst_data = sema.code.instructions.items(.data)[inst].pl_node;
const extra = sema.code.extraData(Zir.Inst.Cmpxchg, inst_data.payload_index).data;
const src = inst_data.src();
return sema.mod.fail(&block.base, src, "TODO: Sema.zirCmpxchg", .{});
// zig fmt: off
const elem_ty_src : LazySrcLoc = .{ .node_offset_builtin_call_arg0 = inst_data.src_node };
const ptr_src : LazySrcLoc = .{ .node_offset_builtin_call_arg1 = inst_data.src_node };
const expected_src : LazySrcLoc = .{ .node_offset_builtin_call_arg2 = inst_data.src_node };
const new_value_src : LazySrcLoc = .{ .node_offset_builtin_call_arg3 = inst_data.src_node };
const success_order_src: LazySrcLoc = .{ .node_offset_builtin_call_arg4 = inst_data.src_node };
const failure_order_src: LazySrcLoc = .{ .node_offset_builtin_call_arg5 = inst_data.src_node };
// zig fmt: on
const ptr = sema.resolveInst(extra.ptr);
const elem_ty = sema.typeOf(ptr).elemType();
try sema.checkAtomicOperandType(block, elem_ty_src, elem_ty);
if (elem_ty.zigTypeTag() == .Float) {
return mod.fail(
&block.base,
elem_ty_src,
"expected bool, integer, enum, or pointer type; found '{}'",
.{elem_ty},
);
}
const expected_value = try sema.coerce(block, elem_ty, sema.resolveInst(extra.expected_value), expected_src);
const new_value = try sema.coerce(block, elem_ty, sema.resolveInst(extra.new_value), new_value_src);
const success_order = try sema.resolveAtomicOrder(block, success_order_src, extra.success_order);
const failure_order = try sema.resolveAtomicOrder(block, failure_order_src, extra.failure_order);
if (@enumToInt(success_order) < @enumToInt(std.builtin.AtomicOrder.Monotonic)) {
return mod.fail(&block.base, success_order_src, "success atomic ordering must be Monotonic or stricter", .{});
}
if (@enumToInt(failure_order) < @enumToInt(std.builtin.AtomicOrder.Monotonic)) {
return mod.fail(&block.base, failure_order_src, "failure atomic ordering must be Monotonic or stricter", .{});
}
if (@enumToInt(failure_order) > @enumToInt(success_order)) {
return mod.fail(&block.base, failure_order_src, "failure atomic ordering must be no stricter than success", .{});
}
if (failure_order == .Release or failure_order == .AcqRel) {
return mod.fail(&block.base, failure_order_src, "failure atomic ordering must not be Release or AcqRel", .{});
}
const result_ty = try Module.optionalType(sema.arena, elem_ty);
// special case zero bit types
if ((try sema.typeHasOnePossibleValue(block, elem_ty_src, elem_ty)) != null) {
return sema.addConstant(result_ty, Value.initTag(.null_value));
}
const runtime_src = if (try sema.resolveDefinedValue(block, ptr_src, ptr)) |ptr_val| rs: {
if (try sema.resolveMaybeUndefVal(block, expected_src, expected_value)) |expected_val| {
if (try sema.resolveMaybeUndefVal(block, new_value_src, new_value)) |new_val| {
if (expected_val.isUndef() or new_val.isUndef()) {
return sema.addConstUndef(result_ty);
}
const stored_val = (try ptr_val.pointerDeref(sema.arena)) orelse break :rs ptr_src;
const result_val = if (stored_val.eql(expected_val, elem_ty)) blk: {
try sema.storePtr(block, src, ptr, new_value);
break :blk Value.initTag(.null_value);
} else try Value.Tag.opt_payload.create(sema.arena, stored_val);
return sema.addConstant(result_ty, result_val);
} else break :rs new_value_src;
} else break :rs expected_src;
} else ptr_src;
const flags: u32 = @as(u32, @enumToInt(success_order)) |
(@as(u32, @enumToInt(failure_order)) << 3);
try sema.requireRuntimeBlock(block, runtime_src);
return block.addInst(.{
.tag = air_tag,
.data = .{ .ty_pl = .{
.ty = try sema.addType(result_ty),
.payload = try sema.addExtra(Air.Cmpxchg{
.ptr = ptr,
.expected_value = expected_value,
.new_value = new_value,
.flags = flags,
}),
} },
});
}
fn zirSplat(sema: *Sema, block: *Scope.Block, inst: Zir.Inst.Index) CompileError!Air.Inst.Ref {
@ -9576,13 +9780,11 @@ fn resolvePeerTypes(
const chosen_src = candidate_srcs.resolve(
sema.gpa,
block.src_decl,
instructions.len,
chosen_i,
);
const candidate_src = candidate_srcs.resolve(
sema.gpa,
block.src_decl,
instructions.len,
candidate_i + 1,
);

25
src/Zir.zig
View File

@ -2778,7 +2778,7 @@ pub const Inst = struct {
expected_value: Ref,
new_value: Ref,
success_order: Ref,
fail_order: Ref,
failure_order: Ref,
};
pub const AtomicRmw = struct {
@ -3054,8 +3054,6 @@ const Writer = struct {
.array_init_ref,
.array_init_anon_ref,
.union_init_ptr,
.cmpxchg_strong,
.cmpxchg_weak,
.shuffle,
.select,
.atomic_rmw,
@ -3072,6 +3070,10 @@ const Writer = struct {
.struct_init_ref,
=> try self.writeStructInit(stream, inst),
.cmpxchg_strong,
.cmpxchg_weak,
=> try self.writeCmpxchg(stream, inst),
.struct_init_anon,
.struct_init_anon_ref,
=> try self.writeStructInitAnon(stream, inst),
@ -3474,6 +3476,23 @@ const Writer = struct {
try self.writeSrc(stream, inst_data.src());
}
fn writeCmpxchg(self: *Writer, stream: anytype, inst: Inst.Index) !void {
const inst_data = self.code.instructions.items(.data)[inst].pl_node;
const extra = self.code.extraData(Inst.Cmpxchg, inst_data.payload_index).data;
try self.writeInstRef(stream, extra.ptr);
try stream.writeAll(", ");
try self.writeInstRef(stream, extra.expected_value);
try stream.writeAll(", ");
try self.writeInstRef(stream, extra.new_value);
try stream.writeAll(", ");
try self.writeInstRef(stream, extra.success_order);
try stream.writeAll(", ");
try self.writeInstRef(stream, extra.failure_order);
try stream.writeAll(") ");
try self.writeSrc(stream, inst_data.src());
}
fn writeStructInitAnon(self: *Writer, stream: anytype, inst: Inst.Index) !void {
const inst_data = self.code.instructions.items(.data)[inst].pl_node;
const extra = self.code.extraData(Inst.StructInitAnon, inst_data.payload_index);

13
src/codegen.zig
View File

@ -857,6 +857,8 @@ fn Function(comptime arch: std.Target.Cpu.Arch) type {
.struct_field_ptr=> try self.airStructFieldPtr(inst),
.struct_field_val=> try self.airStructFieldVal(inst),
.array_to_slice => try self.airArrayToSlice(inst),
.cmpxchg_strong => try self.airCmpxchg(inst),
.cmpxchg_weak => try self.airCmpxchg(inst),
.struct_field_ptr_index_0 => try self.airStructFieldPtrIndex(inst, 0),
.struct_field_ptr_index_1 => try self.airStructFieldPtrIndex(inst, 1),
@ -4751,6 +4753,17 @@ fn Function(comptime arch: std.Target.Cpu.Arch) type {
return self.finishAir(inst, result, .{ ty_op.operand, .none, .none });
}
fn airCmpxchg(self: *Self, inst: Air.Inst.Index) !void {
const ty_pl = self.air.instructions.items(.data)[inst].ty_pl;
const extra = self.air.extraData(Air.Block, ty_pl.payload);
const result: MCValue = switch (arch) {
else => return self.fail("TODO implement airCmpxchg for {}", .{
self.target.cpu.arch,
}),
};
return self.finishAir(inst, result, .{ extra.ptr, extra.expected_value, extra.new_value });
}
fn resolveInst(self: *Self, inst: Air.Inst.Ref) InnerError!MCValue {
// First section of indexes correspond to a set number of constant values.
const ref_int = @enumToInt(inst);

39
src/codegen/c.zig
View File

@ -911,6 +911,8 @@ fn genBody(o: *Object, body: []const Air.Inst.Index) error{ AnalysisFail, OutOfM
.wrap_optional => try airWrapOptional(o, inst),
.struct_field_ptr => try airStructFieldPtr(o, inst),
.array_to_slice => try airArrayToSlice(o, inst),
.cmpxchg_weak => try airCmpxchg(o, inst, "weak"),
.cmpxchg_strong => try airCmpxchg(o, inst, "strong"),
.struct_field_ptr_index_0 => try airStructFieldPtrIndex(o, inst, 0),
.struct_field_ptr_index_1 => try airStructFieldPtrIndex(o, inst, 1),
@ -1878,6 +1880,43 @@ fn airArrayToSlice(o: *Object, inst: Air.Inst.Index) !CValue {
return local;
}
fn airCmpxchg(o: *Object, inst: Air.Inst.Index, flavor: [*:0]const u8) !CValue {
const ty_pl = o.air.instructions.items(.data)[inst].ty_pl;
const extra = o.air.extraData(Air.Cmpxchg, ty_pl.payload).data;
const inst_ty = o.air.typeOfIndex(inst);
const ptr = try o.resolveInst(extra.ptr);
const expected_value = try o.resolveInst(extra.expected_value);
const new_value = try o.resolveInst(extra.new_value);
const local = try o.allocLocal(inst_ty, .Const);
const writer = o.writer();
try writer.print(" = zig_cmpxchg_{s}(", .{flavor});
try o.writeCValue(writer, ptr);
try writer.writeAll(", ");
try o.writeCValue(writer, expected_value);
try writer.writeAll(", ");
try o.writeCValue(writer, new_value);
try writer.writeAll(", ");
try writeMemoryOrder(writer, extra.successOrder());
try writer.writeAll(", ");
try writeMemoryOrder(writer, extra.failureOrder());
try writer.writeAll(");\n");
return local;
}
fn writeMemoryOrder(w: anytype, order: std.builtin.AtomicOrder) !void {
const str = switch (order) {
.Unordered => "memory_order_relaxed",
.Monotonic => "memory_order_consume",
.Acquire => "memory_order_acquire",
.Release => "memory_order_release",
.AcqRel => "memory_order_acq_rel",
.SeqCst => "memory_order_seq_cst",
};
return w.writeAll(str);
}
fn IndentWriter(comptime UnderlyingWriter: type) type {
return struct {
const Self = @This();

93
src/codegen/llvm.zig
View File

@ -389,6 +389,7 @@ pub const Object = struct {
.latest_alloca_inst = null,
.llvm_func = llvm_func,
.blocks = .{},
.single_threaded = module.comp.bin_file.options.single_threaded,
};
defer fg.deinit();
@ -906,6 +907,31 @@ pub const DeclGen = struct {
// TODO: improve this API, `addAttr(-1, attr_name)`
self.addAttr(val, std.math.maxInt(llvm.AttributeIndex), attr_name);
}
/// If the operand type of an atomic operation is not byte sized we need to
/// widen it before using it and then truncate the result.
/// RMW exchange of floating-point values is bitcasted to same-sized integer
/// types to work around a LLVM deficiency when targeting ARM/AArch64.
fn getAtomicAbiType(dg: *DeclGen, ty: Type, is_rmw_xchg: bool) ?*const llvm.Type {
const target = dg.module.getTarget();
var buffer: Type.Payload.Bits = undefined;
const int_ty = switch (ty.zigTypeTag()) {
.Int => ty,
.Enum => ty.enumTagType(&buffer),
.Float => {
if (!is_rmw_xchg) return null;
return dg.context.intType(@intCast(c_uint, ty.abiSize(target) * 8));
},
.Bool => return dg.context.intType(8),
else => return null,
};
const bit_count = int_ty.intInfo(target).bits;
if (!std.math.isPowerOfTwo(bit_count) or (bit_count % 8) != 0) {
return dg.context.intType(@intCast(c_uint, int_ty.abiSize(target) * 8));
} else {
return null;
}
}
};
pub const FuncGen = struct {
@ -940,6 +966,8 @@ pub const FuncGen = struct {
break_vals: *BreakValues,
}),
single_threaded: bool,
const BreakBasicBlocks = std.ArrayListUnmanaged(*const llvm.BasicBlock);
const BreakValues = std.ArrayListUnmanaged(*const llvm.Value);
@ -1029,6 +1057,8 @@ pub const FuncGen = struct {
.slice_ptr => try self.airSliceField(inst, 0),
.slice_len => try self.airSliceField(inst, 1),
.array_to_slice => try self.airArrayToSlice(inst),
.cmpxchg_weak => try self.airCmpxchg(inst, true),
.cmpxchg_strong => try self.airCmpxchg(inst, false),
.struct_field_ptr => try self.airStructFieldPtr(inst),
.struct_field_val => try self.airStructFieldVal(inst),
@ -1975,6 +2005,58 @@ pub const FuncGen = struct {
return null;
}
fn airCmpxchg(self: *FuncGen, inst: Air.Inst.Index, is_weak: bool) !?*const llvm.Value {
const ty_pl = self.air.instructions.items(.data)[inst].ty_pl;
const extra = self.air.extraData(Air.Cmpxchg, ty_pl.payload).data;
var ptr = try self.resolveInst(extra.ptr);
var expected_value = try self.resolveInst(extra.expected_value);
var new_value = try self.resolveInst(extra.new_value);
const operand_ty = self.air.typeOf(extra.ptr).elemType();
const opt_abi_ty = self.dg.getAtomicAbiType(operand_ty, false);
if (opt_abi_ty) |abi_ty| {
// operand needs widening and truncating
ptr = self.builder.buildBitCast(ptr, abi_ty.pointerType(0), "");
if (operand_ty.isSignedInt()) {
expected_value = self.builder.buildSExt(expected_value, abi_ty, "");
new_value = self.builder.buildSExt(new_value, abi_ty, "");
} else {
expected_value = self.builder.buildZExt(expected_value, abi_ty, "");
new_value = self.builder.buildZExt(new_value, abi_ty, "");
}
}
const success_order = toLlvmAtomicOrdering(extra.successOrder());
const failure_order = toLlvmAtomicOrdering(extra.failureOrder());
const result = self.builder.buildCmpXchg(
ptr,
expected_value,
new_value,
success_order,
failure_order,
is_weak,
self.single_threaded,
);
const optional_ty = self.air.typeOfIndex(inst);
var buffer: Type.Payload.ElemType = undefined;
const child_ty = optional_ty.optionalChild(&buffer);
var payload = self.builder.buildExtractValue(result, 0, "");
if (opt_abi_ty != null) {
payload = self.builder.buildTrunc(payload, try self.dg.llvmType(operand_ty), "");
}
const success_bit = self.builder.buildExtractValue(result, 1, "");
if (optional_ty.isPtrLikeOptional()) {
const child_llvm_ty = try self.dg.llvmType(child_ty);
return self.builder.buildSelect(success_bit, child_llvm_ty.constNull(), payload, "");
}
const optional_llvm_ty = try self.dg.llvmType(optional_ty);
const non_null_bit = self.builder.buildNot(success_bit, "");
const partial = self.builder.buildInsertValue(optional_llvm_ty.getUndef(), payload, 0, "");
return self.builder.buildInsertValue(partial, non_null_bit, 1, "");
}
fn getIntrinsic(self: *FuncGen, name: []const u8) *const llvm.Value {
const id = llvm.lookupIntrinsicID(name.ptr, name.len);
assert(id != 0);
@ -2125,3 +2207,14 @@ fn initializeLLVMTarget(arch: std.Target.Cpu.Arch) void {
.spirv64 => {},
}
}
fn toLlvmAtomicOrdering(atomic_order: std.builtin.AtomicOrder) llvm.AtomicOrdering {
return switch (atomic_order) {
.Unordered => .Unordered,
.Monotonic => .Monotonic,
.Acquire => .Acquire,
.Release => .Release,
.AcqRel => .AcquireRelease,
.SeqCst => .SequentiallyConsistent,
};
}

39
src/codegen/llvm/bindings.zig
View File

@ -298,6 +298,14 @@ pub const Builder = opaque {
Name: [*:0]const u8,
) *const Value;
pub const buildSExt = LLVMBuildSExt;
extern fn LLVMBuildSExt(
*const Builder,
Val: *const Value,
DestTy: *const Type,
Name: [*:0]const u8,
) *const Value;
pub const buildCall = LLVMBuildCall;
extern fn LLVMBuildCall(
*const Builder,
@ -493,6 +501,27 @@ pub const Builder = opaque {
Index: c_uint,
Name: [*:0]const u8,
) *const Value;
pub const buildCmpXchg = ZigLLVMBuildCmpXchg;
extern fn ZigLLVMBuildCmpXchg(
builder: *const Builder,
ptr: *const Value,
cmp: *const Value,
new_val: *const Value,
success_ordering: AtomicOrdering,
failure_ordering: AtomicOrdering,
is_weak: bool,
is_single_threaded: bool,
) *const Value;
pub const buildSelect = LLVMBuildSelect;
extern fn LLVMBuildSelect(
*const Builder,
If: *const Value,
Then: *const Value,
Else: *const Value,
Name: [*:0]const u8,
) *const Value;
};
pub const IntPredicate = enum(c_uint) {
@ -854,3 +883,13 @@ pub const Linkage = enum(c_uint) {
LinkerPrivate,
LinkerPrivateWeak,
};
pub const AtomicOrdering = enum(c_uint) {
NotAtomic = 0,
Unordered = 1,
Monotonic = 2,
Acquire = 4,
Release = 5,
AcquireRelease = 6,
SequentiallyConsistent = 7,
};

12
src/link/C/zig.h
View File

@ -60,6 +60,18 @@
#define zig_breakpoint() raise(SIGTRAP)
#endif
#if __STDC_VERSION__ >= 201112L && !defined(__STDC_NO_ATOMICS__)
#include <stdatomic.h>
#define zig_cmpxchg_strong(obj, expected, desired, succ, fail) atomic_compare_exchange_strong_explicit(obj, expected, desired, succ, fail)
#define zig_cmpxchg_weak(obj, expected, desired, succ, fail) atomic_compare_exchange_weak_explicit(obj, expected, desired, succ, fail)
#elif __GNUC__
#define zig_cmpxchg_strong(obj, expected, desired, succ, fail) __sync_val_compare_and_swap(obj, expected, desired)
#define zig_cmpxchg_weak(obj, expected, desired, succ, fail) __sync_val_compare_and_swap(obj, expected, desired)
#else
#define zig_cmpxchg_strong(obj, expected, desired, succ, fail) zig_unimplemented()
#define zig_cmpxchg_weak(obj, expected, desired, succ, fail) zig_unimplemented()
#endif
#include <stdint.h>
#include <stddef.h>
#include <limits.h>

17
src/print_air.zig
View File

@ -191,6 +191,7 @@ const Writer = struct {
.br => try w.writeBr(s, inst),
.cond_br => try w.writeCondBr(s, inst),
.switch_br => try w.writeSwitchBr(s, inst),
.cmpxchg_weak, .cmpxchg_strong => try w.writeCmpxchg(s, inst),
}
}
@ -258,7 +259,21 @@ const Writer = struct {
try w.writeOperand(s, inst, 0, extra.lhs);
try s.writeAll(", ");
try w.writeOperand(s, inst, 0, extra.rhs);
try w.writeOperand(s, inst, 1, extra.rhs);
}
fn writeCmpxchg(w: *Writer, s: anytype, inst: Air.Inst.Index) @TypeOf(s).Error!void {
const ty_pl = w.air.instructions.items(.data)[inst].ty_pl;
const extra = w.air.extraData(Air.Cmpxchg, ty_pl.payload).data;
try w.writeOperand(s, inst, 0, extra.ptr);
try s.writeAll(", ");
try w.writeOperand(s, inst, 1, extra.expected_value);
try s.writeAll(", ");
try w.writeOperand(s, inst, 2, extra.new_value);
try s.print(", {s}, {s}", .{
@tagName(extra.successOrder()), @tagName(extra.failureOrder()),
});
}
fn writeConstant(w: *Writer, s: anytype, inst: Air.Inst.Index) @TypeOf(s).Error!void {

2
src/stage1/codegen.cpp
View File

@ -5723,7 +5723,7 @@ static LLVMValueRef ir_render_cmpxchg(CodeGen *g, Stage1Air *executable, Stage1A
LLVMAtomicOrdering failure_order = to_LLVMAtomicOrdering(instruction->failure_order);
LLVMValueRef result_val = ZigLLVMBuildCmpXchg(g->builder, ptr_val, cmp_val, new_val,
success_order, failure_order, instruction->is_weak);
success_order, failure_order, instruction->is_weak, g->is_single_threaded);
ZigType *optional_type = instruction->base.value->type;
assert(optional_type->id == ZigTypeIdOptional);

69
src/target.zig
View File

@ -475,3 +475,72 @@ pub fn clangAssemblerSupportsMcpuArg(target: std.Target) bool {
pub fn needUnwindTables(target: std.Target) bool {
return target.os.tag == .windows;
}
/// TODO this was ported from stage1 but it does not take into account CPU features,
/// which can affect this value. Audit this!
pub fn largestAtomicBits(target: std.Target) u32 {
return switch (target.cpu.arch) {
.avr,
.msp430,
.spu_2,
=> 16,
.arc,
.arm,
.armeb,
.hexagon,
.le32,
.mips,
.mipsel,
.nvptx,
.powerpc,
.powerpcle,
.r600,
.riscv32,
.sparc,
.sparcel,
.tce,
.tcele,
.thumb,
.thumbeb,
.i386,
.xcore,
.amdil,
.hsail,
.spir,
.kalimba,
.lanai,
.shave,
.wasm32,
.renderscript32,
.csky,
.spirv32,
=> 32,
.aarch64,
.aarch64_be,
.aarch64_32,
.amdgcn,
.bpfel,
.bpfeb,
.le64,
.mips64,
.mips64el,
.nvptx64,
.powerpc64,
.powerpc64le,
.riscv64,
.sparcv9,
.s390x,
.amdil64,
.hsail64,
.spir64,
.wasm64,
.renderscript64,
.ve,
.spirv64,
=> 64,
.x86_64 => 128,
};
}

29
src/type.zig
View File

@ -2886,6 +2886,35 @@ pub const Type = extern union {
}
}
/// Returns the integer tag type of the enum.
pub fn enumTagType(ty: Type, buffer: *Payload.Bits) Type {
switch (ty.tag()) {
.enum_full, .enum_nonexhaustive => {
const enum_full = ty.cast(Payload.EnumFull).?.data;
return enum_full.tag_ty;
},
.enum_simple => {
const enum_simple = ty.castTag(.enum_simple).?.data;
buffer.* = .{
.base = .{ .tag = .int_unsigned },
.data = std.math.log2_int_ceil(usize, enum_simple.fields.count()),
};
return Type.initPayload(&buffer.base);
},
.atomic_order,
.atomic_rmw_op,
.calling_convention,
.float_mode,
.reduce_op,
.call_options,
.export_options,
.extern_options,
=> @panic("TODO resolve std.builtin types"),
else => unreachable,
}
}
pub fn isNonexhaustiveEnum(ty: Type) bool {
return switch (ty.tag()) {
.enum_nonexhaustive => true,

23
src/zig_llvm.cpp
View File

@ -1087,10 +1087,12 @@ static AtomicOrdering mapFromLLVMOrdering(LLVMAtomicOrdering Ordering) {
LLVMValueRef ZigLLVMBuildCmpXchg(LLVMBuilderRef builder, LLVMValueRef ptr, LLVMValueRef cmp,
LLVMValueRef new_val, LLVMAtomicOrdering success_ordering,
LLVMAtomicOrdering failure_ordering, bool is_weak)
LLVMAtomicOrdering failure_ordering, bool is_weak, bool is_single_threaded)
{
AtomicCmpXchgInst *inst = unwrap(builder)->CreateAtomicCmpXchg(unwrap(ptr), unwrap(cmp),
unwrap(new_val), mapFromLLVMOrdering(success_ordering), mapFromLLVMOrdering(failure_ordering));
AtomicCmpXchgInst *inst = unwrap(builder)->CreateAtomicCmpXchg(unwrap(ptr),
unwrap(cmp), unwrap(new_val),
mapFromLLVMOrdering(success_ordering), mapFromLLVMOrdering(failure_ordering),
is_single_threaded ? SyncScope::SingleThread : SyncScope::System);
inst->setWeak(is_weak);
return wrap(inst);
}
@ -1308,19 +1310,6 @@ static AtomicRMWInst::BinOp toLLVMRMWBinOp(enum ZigLLVM_AtomicRMWBinOp BinOp) {
}
}
static AtomicOrdering toLLVMOrdering(LLVMAtomicOrdering Ordering) {
switch (Ordering) {
default:
case LLVMAtomicOrderingNotAtomic: return AtomicOrdering::NotAtomic;
case LLVMAtomicOrderingUnordered: return AtomicOrdering::Unordered;
case LLVMAtomicOrderingMonotonic: return AtomicOrdering::Monotonic;
case LLVMAtomicOrderingAcquire: return AtomicOrdering::Acquire;
case LLVMAtomicOrderingRelease: return AtomicOrdering::Release;
case LLVMAtomicOrderingAcquireRelease: return AtomicOrdering::AcquireRelease;
case LLVMAtomicOrderingSequentiallyConsistent: return AtomicOrdering::SequentiallyConsistent;
}
}
inline LLVMAttributeRef wrap(Attribute Attr) {
return reinterpret_cast<LLVMAttributeRef>(Attr.getRawPointer());
}
@ -1335,7 +1324,7 @@ LLVMValueRef ZigLLVMBuildAtomicRMW(LLVMBuilderRef B, enum ZigLLVM_AtomicRMWBinOp
{
AtomicRMWInst::BinOp intop = toLLVMRMWBinOp(op);
return wrap(unwrap(B)->CreateAtomicRMW(intop, unwrap(PTR),
unwrap(Val), toLLVMOrdering(ordering),
unwrap(Val), mapFromLLVMOrdering(ordering),
singleThread ? SyncScope::SingleThread : SyncScope::System));
}

2
src/zig_llvm.h
View File

@ -148,7 +148,7 @@ ZIG_EXTERN_C LLVMValueRef ZigLLVMBuildSShlSat(LLVMBuilderRef builder, LLVMValueR
ZIG_EXTERN_C LLVMValueRef ZigLLVMBuildCmpXchg(LLVMBuilderRef builder, LLVMValueRef ptr, LLVMValueRef cmp,
LLVMValueRef new_val, LLVMAtomicOrdering success_ordering,
LLVMAtomicOrdering failure_ordering, bool is_weak);
LLVMAtomicOrdering failure_ordering, bool is_weak, bool is_single_threaded);
ZIG_EXTERN_C LLVMValueRef ZigLLVMBuildNSWShl(LLVMBuilderRef builder, LLVMValueRef LHS, LLVMValueRef RHS,
const char *name);

22
test/behavior/atomics.zig
View File

@ -2,3 +2,25 @@ const std = @import("std");
const expect = std.testing.expect;
const expectEqual = std.testing.expectEqual;
const builtin = @import("builtin");
test "cmpxchg" {
try testCmpxchg();
comptime try testCmpxchg();
}
fn testCmpxchg() !void {
var x: i32 = 1234;
if (@cmpxchgWeak(i32, &x, 99, 5678, .SeqCst, .SeqCst)) |x1| {
try expect(x1 == 1234);
} else {
@panic("cmpxchg should have failed");
}
while (@cmpxchgWeak(i32, &x, 1234, 5678, .SeqCst, .SeqCst)) |x1| {
try expect(x1 == 1234);
}
try expect(x == 5678);
try expect(@cmpxchgStrong(i32, &x, 5678, 42, .SeqCst, .SeqCst) == null);
try expect(x == 42);
}

22
test/behavior/atomics_stage1.zig
View File

@ -3,28 +3,6 @@ const expect = std.testing.expect;
const expectEqual = std.testing.expectEqual;
const builtin = @import("builtin");
test "cmpxchg" {
try testCmpxchg();
comptime try testCmpxchg();
}
fn testCmpxchg() !void {
var x: i32 = 1234;
if (@cmpxchgWeak(i32, &x, 99, 5678, .SeqCst, .SeqCst)) |x1| {
try expect(x1 == 1234);
} else {
@panic("cmpxchg should have failed");
}
while (@cmpxchgWeak(i32, &x, 1234, 5678, .SeqCst, .SeqCst)) |x1| {
try expect(x1 == 1234);
}
try expect(x == 5678);
try expect(@cmpxchgStrong(i32, &x, 5678, 42, .SeqCst, .SeqCst) == null);
try expect(x == 42);
}
test "fence" {
var x: i32 = 1234;
@fence(.SeqCst);