mirror/zig
1
0
Fork 0
mirror of https://github.com/ziglang/zig.git synced 2026-01-21 06:45:24 +00:00
Code Issues Packages Projects Releases Wiki Activity

spirv: lower pointers to zero-bit types as undef

Browse Source
This commit is contained in:
Robin Voetter 2023-09-23 01:31:38 +02:00
parent 4e22f811e7
commit 4ea361f6dc
No known key found for this signature in database
2 changed files with 74 additions and 61 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

133
src/codegen/spirv.zig
View File

@ -521,59 +521,6 @@ pub const DeclGen = struct {
return result_id;
}
fn constructDeclRef(self: *DeclGen, ty: Type, decl_index: Decl.Index) !IdRef {
const mod = self.module;
const ty_ref = try self.resolveType(ty, .direct);
const ty_id = self.typeId(ty_ref);
const decl = mod.declPtr(decl_index);
const spv_decl_index = try self.resolveDecl(decl_index);
switch (mod.intern_pool.indexToKey(decl.val.ip_index)) {
.func => {
// TODO: Properly lower function pointers. For now we are going to hack around it and
// just generate an empty pointer. Function pointers are represented by a pointer to usize.
// TODO: Add dependency
return try self.spv.constNull(ty_ref);
},
.extern_func => unreachable, // TODO
else => {
const decl_id = self.spv.declPtr(spv_decl_index).result_id;
try self.func.decl_deps.put(self.spv.gpa, spv_decl_index, {});
const final_storage_class = spvStorageClass(decl.@"addrspace");
const decl_ty_ref = try self.resolveType(decl.ty, .indirect);
const decl_ptr_ty_ref = try self.spv.ptrType(decl_ty_ref, final_storage_class);
const ptr_id = switch (final_storage_class) {
.Generic => blk: {
// Pointer should be Generic, but is actually placed in CrossWorkgroup.
const result_id = self.spv.allocId();
try self.func.body.emit(self.spv.gpa, .OpPtrCastToGeneric, .{
.id_result_type = self.typeId(decl_ptr_ty_ref),
.id_result = result_id,
.pointer = decl_id,
});
break :blk result_id;
},
else => decl_id,
};
if (decl_ptr_ty_ref != ty_ref) {
// Differing pointer types, insert a cast.
const casted_ptr_id = self.spv.allocId();
try self.func.body.emit(self.spv.gpa, .OpBitcast, .{
.id_result_type = ty_id,
.id_result = casted_ptr_id,
.operand = ptr_id,
});
return casted_ptr_id;
} else {
return ptr_id;
}
},
}
}
/// This function generates a load for a constant in direct (ie, non-memory) representation.
/// When the constant is simple, it can be generated directly using OpConstant instructions.
/// When the constant is more complicated however, it needs to be constructed using multiple values. This
@ -796,7 +743,8 @@ pub const DeclGen = struct {
return try self.constructStruct(result_ty_ref, constituents.items);
},
.vector_type, .anon_struct_type => unreachable, // TODO
.vector_type => unreachable, // TODO
.anon_struct_type => unreachable, // TODO
else => unreachable,
},
.un => |un| {
@ -817,9 +765,9 @@ pub const DeclGen = struct {
const result_ty_ref = try self.resolveType(ptr_ty, .direct);
const mod = self.module;
switch (mod.intern_pool.indexToKey(ptr_val.toIntern()).ptr.addr) {
.decl => |decl| return try self.constructDeclRef(ptr_ty, decl),
.decl => |decl| return try self.constantDeclRef(ptr_ty, decl),
.mut_decl => |decl_mut| return try self.constantDeclRef(ptr_ty, decl_mut.decl),
.anon_decl => @panic("TODO"),
.mut_decl => |decl_mut| return try self.constructDeclRef(ptr_ty, decl_mut.decl),
.int => |int| {
const ptr_id = self.spv.allocId();
// TODO: This can probably be an OpSpecConstantOp Bitcast, but
@ -846,6 +794,65 @@ pub const DeclGen = struct {
}
}
fn constantDeclRef(self: *DeclGen, ty: Type, decl_index: Decl.Index) !IdRef {
const mod = self.module;
const ty_ref = try self.resolveType(ty, .direct);
const ty_id = self.typeId(ty_ref);
const decl = mod.declPtr(decl_index);
switch (mod.intern_pool.indexToKey(decl.val.ip_index)) {
.func => {
// TODO: Properly lower function pointers. For now we are going to hack around it and
// just generate an empty pointer. Function pointers are represented by a pointer to usize.
// TODO: Add dependency
return try self.spv.constNull(ty_ref);
},
.extern_func => unreachable, // TODO
else => {},
}
if (!decl.ty.isFnOrHasRuntimeBitsIgnoreComptime(mod)) {
// Pointer to nothing - return undefined.
return self.spv.constUndef(ty_ref);
}
const spv_decl_index = try self.resolveDecl(decl_index);
const decl_id = self.spv.declPtr(spv_decl_index).result_id;
try self.func.decl_deps.put(self.spv.gpa, spv_decl_index, {});
const final_storage_class = spvStorageClass(decl.@"addrspace");
const decl_ty_ref = try self.resolveType(decl.ty, .indirect);
const decl_ptr_ty_ref = try self.spv.ptrType(decl_ty_ref, final_storage_class);
const ptr_id = switch (final_storage_class) {
.Generic => blk: {
// Pointer should be Generic, but is actually placed in CrossWorkgroup.
const result_id = self.spv.allocId();
try self.func.body.emit(self.spv.gpa, .OpPtrCastToGeneric, .{
.id_result_type = self.typeId(decl_ptr_ty_ref),
.id_result = result_id,
.pointer = decl_id,
});
break :blk result_id;
},
else => decl_id,
};
if (decl_ptr_ty_ref != ty_ref) {
// Differing pointer types, insert a cast.
const casted_ptr_id = self.spv.allocId();
try self.func.body.emit(self.spv.gpa, .OpBitcast, .{
.id_result_type = ty_id,
.id_result = casted_ptr_id,
.operand = ptr_id,
});
return casted_ptr_id;
} else {
return ptr_id;
}
}
// Turn a Zig type's name into a cache reference.
fn resolveTypeName(self: *DeclGen, ty: Type) !CacheString {
var name = std.ArrayList(u8).init(self.gpa);
@ -1126,10 +1133,16 @@ pub const DeclGen = struct {
var it = struct_type.iterateRuntimeOrder(ip);
while (it.next()) |field_index| {
const field_ty = struct_type.field_types.get(ip)[field_index];
const field_name = ip.stringToSlice(struct_type.field_names.get(ip)[field_index]);
try member_types.append(try self.resolveType(field_ty.toType(), .indirect));
try member_names.append(try self.spv.resolveString(field_name));
const field_ty = struct_type.field_types.get(ip)[field_index].toType();
if (!field_ty.hasRuntimeBitsIgnoreComptime(mod)) {
// This is a zero-bit field - we only needed it for the alignment.
continue;
}
const field_name = struct_type.fieldName(ip, field_index).unwrap() orelse
try ip.getOrPutStringFmt(mod.gpa, "{d}", .{field_index});
try member_types.append(try self.resolveType(field_ty, .indirect));
try member_names.append(try self.spv.resolveString(ip.stringToSlice(field_name)));
}
const ty_ref = try self.spv.resolve(.{ .struct_type = .{

2
src/link/SpirV.zig
View File

@ -217,7 +217,7 @@ pub fn flushModule(self: *SpirV, comp: *Compilation, prog_node: *std.Progress.No
fn writeCapabilities(spv: *SpvModule, target: std.Target) !void {
// TODO: Integrate with a hypothetical feature system
const caps: []const spec.Capability = switch (target.os.tag) {
.opencl => &.{ .Kernel, .Addresses, .Int8, .Int16, .Int64, .Float64, .GenericPointer },
.opencl => &.{ .Kernel, .Addresses, .Int8, .Int16, .Int64, .Float64, .Float16, .GenericPointer },
.glsl450 => &.{.Shader},
.vulkan => &.{.Shader},
else => unreachable, // TODO