spirv: override function return type to void if it has no runtime bits

This commit is contained in:
Robin Voetter 2023-10-08 02:44:52 +02:00
parent ae3efab226
commit d2692af8e2
No known key found for this signature in database
2 changed files with 57 additions and 22 deletions

View File

@ -1180,6 +1180,22 @@ const DeclGen = struct {
return ty_ref;
}
fn resolveFnReturnType(self: *DeclGen, ret_ty: Type) !CacheRef {
const mod = self.module;
if (!ret_ty.hasRuntimeBitsIgnoreComptime(mod)) {
// If the return type is an error set or an error union, then we make this
// anyerror return type instead, so that it can be coerced into a function
// pointer type which has anyerror as the return type.
if (ret_ty.isError(mod)) {
return self.resolveType(Type.anyerror, .direct);
} else {
return self.resolveType(Type.void, .direct);
}
}
return try self.resolveType(ret_ty, .direct);
}
/// Turn a Zig type into a SPIR-V Type, and return a reference to it.
fn resolveType(self: *DeclGen, ty: Type, repr: Repr) Error!CacheRef {
const mod = self.module;
@ -1260,7 +1276,7 @@ const DeclGen = struct {
param_ty_refs[param_index] = try self.resolveType(param_ty, .direct);
param_index += 1;
}
const return_ty_ref = try self.resolveType(fn_info.return_type.toType(), .direct);
const return_ty_ref = try self.resolveFnReturnType(fn_info.return_type.toType());
const ty_ref = try self.spv.resolve(.{ .function_type = .{
.return_type = return_ty_ref,
@ -1449,9 +1465,11 @@ const DeclGen = struct {
return ty_ref;
},
.Opaque => {
return try self.spv.resolve(.{ .opaque_type = .{
.name = .none, // TODO
} });
return try self.spv.resolve(.{
.opaque_type = .{
.name = .none, // TODO
},
});
},
.Null,
@ -1677,16 +1695,17 @@ const DeclGen = struct {
if (decl.val.getFunction(mod)) |_| {
assert(decl.ty.zigTypeTag(mod) == .Fn);
const fn_info = mod.typeToFunc(decl.ty).?;
const return_ty_ref = try self.resolveFnReturnType(fn_info.return_type.toType());
const prototype_id = try self.resolveTypeId(decl.ty);
try self.func.prologue.emit(self.spv.gpa, .OpFunction, .{
.id_result_type = try self.resolveTypeId(decl.ty.fnReturnType(mod)),
.id_result_type = self.typeId(return_ty_ref),
.id_result = decl_id,
.function_control = .{}, // TODO: We can set inline here if the type requires it.
.function_type = prototype_id,
});
const fn_info = mod.typeToFunc(decl.ty).?;
try self.args.ensureUnusedCapacity(self.gpa, fn_info.param_types.len);
for (fn_info.param_types.get(ip)) |param_ty_index| {
const param_ty = param_ty_index.toType();
@ -3385,15 +3404,25 @@ const DeclGen = struct {
fn airRet(self: *DeclGen, inst: Air.Inst.Index) !void {
const operand = self.air.instructions.items(.data)[inst].un_op;
const operand_ty = self.typeOf(operand);
const ret_ty = self.typeOf(operand);
const mod = self.module;
if (operand_ty.hasRuntimeBits(mod)) {
// TODO: If we return an empty struct, this branch is also hit incorrectly.
const operand_id = try self.resolve(operand);
try self.func.body.emit(self.spv.gpa, .OpReturnValue, .{ .value = operand_id });
} else {
try self.func.body.emit(self.spv.gpa, .OpReturn, {});
if (!ret_ty.hasRuntimeBitsIgnoreComptime(mod)) {
const decl = mod.declPtr(self.decl_index);
const fn_info = mod.typeToFunc(decl.ty).?;
if (fn_info.return_type.toType().isError(mod)) {
// Functions with an empty error set are emitted with an error code
// return type and return zero so they can be function pointers coerced
// to functions that return anyerror.
const err_ty_ref = try self.resolveType(Type.anyerror, .direct);
const no_err_id = try self.constInt(err_ty_ref, 0);
return try self.func.body.emit(self.spv.gpa, .OpReturnValue, .{ .value = no_err_id });
} else {
return try self.func.body.emit(self.spv.gpa, .OpReturn, {});
}
}
const operand_id = try self.resolve(operand);
try self.func.body.emit(self.spv.gpa, .OpReturnValue, .{ .value = operand_id });
}
fn airRetLoad(self: *DeclGen, inst: Air.Inst.Index) !void {
@ -3403,8 +3432,18 @@ const DeclGen = struct {
const ret_ty = ptr_ty.childType(mod);
if (!ret_ty.hasRuntimeBitsIgnoreComptime(mod)) {
try self.func.body.emit(self.spv.gpa, .OpReturn, {});
return;
const decl = mod.declPtr(self.decl_index);
const fn_info = mod.typeToFunc(decl.ty).?;
if (fn_info.return_type.toType().isError(mod)) {
// Functions with an empty error set are emitted with an error code
// return type and return zero so they can be function pointers coerced
// to functions that return anyerror.
const err_ty_ref = try self.resolveType(Type.anyerror, .direct);
const no_err_id = try self.constInt(err_ty_ref, 0);
return try self.func.body.emit(self.spv.gpa, .OpReturnValue, .{ .value = no_err_id });
} else {
return try self.func.body.emit(self.spv.gpa, .OpReturn, {});
}
}
const ptr = try self.resolve(un_op);
@ -3991,7 +4030,7 @@ const DeclGen = struct {
const fn_info = mod.typeToFunc(zig_fn_ty).?;
const return_type = fn_info.return_type;
const result_type_id = try self.resolveTypeId(return_type.toType());
const result_type_ref = try self.resolveFnReturnType(return_type.toType());
const result_id = self.spv.allocId();
const callee_id = try self.resolve(pl_op.operand);
@ -4012,7 +4051,7 @@ const DeclGen = struct {
}
try self.func.body.emit(self.spv.gpa, .OpFunctionCall, .{
.id_result_type = result_type_id,
.id_result_type = self.typeId(result_type_ref),
.id_result = result_id,
.function = callee_id,
.id_ref_3 = params[0..n_params],

View File

@ -27,7 +27,6 @@ pub const EmptyStruct = struct {};
test "optional pointer to size zero struct" {
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_spirv64) return error.SkipZigTest;
var e = EmptyStruct{};
var o: ?*EmptyStruct = &e;
@ -152,7 +151,6 @@ fn test_cmp_optional_non_optional() !void {
test "unwrap function call with optional pointer return value" {
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_spirv64) return error.SkipZigTest;
const S = struct {
fn entry() !void {
@ -400,7 +398,6 @@ const NoReturn = struct {
test "optional of noreturn used with if" {
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_spirv64) return error.SkipZigTest;
NoReturn.a = 64;
if (NoReturn.loop()) |_| {
@ -412,7 +409,6 @@ test "optional of noreturn used with if" {
test "optional of noreturn used with orelse" {
if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_spirv64) return error.SkipZigTest;
NoReturn.a = 64;
const val = NoReturn.testOrelse();