| // Copyright 2021 The Tint Authors. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| #include "src/tint/lang/wgsl/ast/transform/canonicalize_entry_point_io.h" |
| |
| #include <algorithm> |
| #include <string> |
| #include <unordered_set> |
| #include <utility> |
| #include <vector> |
| |
| #include "src/tint/lang/core/builtin_value.h" |
| #include "src/tint/lang/wgsl/ast/disable_validation_attribute.h" |
| #include "src/tint/lang/wgsl/ast/transform/unshadow.h" |
| #include "src/tint/lang/wgsl/program/clone_context.h" |
| #include "src/tint/lang/wgsl/program/program_builder.h" |
| #include "src/tint/lang/wgsl/resolver/resolve.h" |
| #include "src/tint/lang/wgsl/sem/function.h" |
| |
| using namespace tint::number_suffixes; // NOLINT |
| |
| TINT_INSTANTIATE_TYPEINFO(tint::ast::transform::CanonicalizeEntryPointIO); |
| TINT_INSTANTIATE_TYPEINFO(tint::ast::transform::CanonicalizeEntryPointIO::Config); |
| |
| namespace tint::ast::transform { |
| |
| CanonicalizeEntryPointIO::CanonicalizeEntryPointIO() = default; |
| CanonicalizeEntryPointIO::~CanonicalizeEntryPointIO() = default; |
| |
| namespace { |
| |
| /// Info for a struct member |
| struct MemberInfo { |
| /// The struct member item |
| const StructMember* member; |
| /// The struct member location if provided |
| std::optional<uint32_t> location; |
| /// The struct member index if provided |
| std::optional<uint32_t> index; |
| }; |
| |
| /// FXC is sensitive to field order in structures, this is used by StructMemberComparator to ensure |
| /// that FXC is happy with the order of emitted fields. |
| uint32_t BuiltinOrder(core::BuiltinValue builtin) { |
| switch (builtin) { |
| case core::BuiltinValue::kPosition: |
| return 1; |
| case core::BuiltinValue::kVertexIndex: |
| return 2; |
| case core::BuiltinValue::kInstanceIndex: |
| return 3; |
| case core::BuiltinValue::kFrontFacing: |
| return 4; |
| case core::BuiltinValue::kFragDepth: |
| return 5; |
| case core::BuiltinValue::kLocalInvocationId: |
| return 6; |
| case core::BuiltinValue::kLocalInvocationIndex: |
| return 7; |
| case core::BuiltinValue::kGlobalInvocationId: |
| return 8; |
| case core::BuiltinValue::kWorkgroupId: |
| return 9; |
| case core::BuiltinValue::kNumWorkgroups: |
| return 10; |
| case core::BuiltinValue::kSampleIndex: |
| return 11; |
| case core::BuiltinValue::kSampleMask: |
| return 12; |
| case core::BuiltinValue::kPointSize: |
| return 13; |
| default: |
| break; |
| } |
| return 0; |
| } |
| |
| // Returns true if `attr` is a shader IO attribute. |
| bool IsShaderIOAttribute(const Attribute* attr) { |
| return attr->IsAnyOf<BuiltinAttribute, InterpolateAttribute, InvariantAttribute, |
| LocationAttribute, IndexAttribute>(); |
| } |
| |
| } // namespace |
| |
| /// PIMPL state for the transform |
| struct CanonicalizeEntryPointIO::State { |
| /// OutputValue represents a shader result that the wrapper function produces. |
| struct OutputValue { |
| /// The name of the output value. |
| std::string name; |
| /// The type of the output value. |
| Type type; |
| /// The shader IO attributes. |
| tint::Vector<const Attribute*, 8> attributes; |
| /// The value itself. |
| const Expression* value; |
| /// The output location. |
| std::optional<uint32_t> location; |
| /// The output index. |
| std::optional<uint32_t> index; |
| }; |
| |
| /// The clone context. |
| program::CloneContext& ctx; |
| /// The program builder |
| ProgramBuilder& b; |
| /// The transform config. |
| CanonicalizeEntryPointIO::Config const cfg; |
| /// The entry point function (AST). |
| const Function* func_ast; |
| /// The entry point function (SEM). |
| const sem::Function* func_sem; |
| |
| /// The new entry point wrapper function's parameters. |
| tint::Vector<const Parameter*, 8> wrapper_ep_parameters; |
| |
| /// The members of the wrapper function's struct parameter. |
| tint::Vector<MemberInfo, 8> wrapper_struct_param_members; |
| /// The name of the wrapper function's struct parameter. |
| Symbol wrapper_struct_param_name; |
| /// The parameters that will be passed to the original function. |
| tint::Vector<const Expression*, 8> inner_call_parameters; |
| /// The members of the wrapper function's struct return type. |
| tint::Vector<MemberInfo, 8> wrapper_struct_output_members; |
| /// The wrapper function output values. |
| tint::Vector<OutputValue, 8> wrapper_output_values; |
| /// The body of the wrapper function. |
| tint::Vector<const Statement*, 8> wrapper_body; |
| /// Input names used by the entrypoint |
| std::unordered_set<std::string> input_names; |
| /// A map of cloned attribute to builtin value |
| Hashmap<const BuiltinAttribute*, core::BuiltinValue, 16> builtin_attrs; |
| |
| /// Constructor |
| /// @param context the clone context |
| /// @param builder the program builder |
| /// @param config the transform config |
| /// @param function the entry point function |
| State(program::CloneContext& context, |
| ProgramBuilder& builder, |
| const CanonicalizeEntryPointIO::Config& config, |
| const Function* function) |
| : ctx(context), |
| b(builder), |
| cfg(config), |
| func_ast(function), |
| func_sem(ctx.src->Sem().Get(function)) {} |
| |
| /// Clones the attributes from @p in and adds it to @p out. If @p in is a builtin attribute, |
| /// then builtin_attrs is updated with the builtin information. |
| /// @param in the attribute to clone |
| /// @param out the output Attributes |
| template <size_t N> |
| void CloneAttribute(const Attribute* in, tint::Vector<const Attribute*, N>& out) { |
| auto* cloned = ctx.Clone(in); |
| out.Push(cloned); |
| if (auto* builtin = in->As<BuiltinAttribute>()) { |
| builtin_attrs.Add(cloned->As<BuiltinAttribute>(), ctx.src->Sem().Get(builtin)->Value()); |
| } |
| } |
| |
| /// Clones the shader IO attributes from @p in. |
| /// @param in the attributes to clone |
| /// @param do_interpolate whether to clone InterpolateAttribute |
| /// @return the cloned attributes |
| template <size_t N> |
| auto CloneShaderIOAttributes(const tint::Vector<const Attribute*, N> in, bool do_interpolate) { |
| tint::Vector<const Attribute*, N> out; |
| for (auto* attr : in) { |
| if (IsShaderIOAttribute(attr) && |
| (do_interpolate || !attr->template Is<InterpolateAttribute>())) { |
| CloneAttribute(attr, out); |
| } |
| } |
| return out; |
| } |
| |
| /// @param attr the input attribute |
| /// @returns the builtin value of the attribute |
| core::BuiltinValue BuiltinOf(const BuiltinAttribute* attr) { |
| if (attr->generation_id == b.ID()) { |
| // attr belongs to the target program. |
| // Obtain the builtin value from #builtin_attrs. |
| if (auto builtin = builtin_attrs.Get(attr)) { |
| return *builtin; |
| } |
| } else { |
| // attr belongs to the source program. |
| // Obtain the builtin value from the semantic info. |
| return ctx.src->Sem().Get(attr)->Value(); |
| } |
| TINT_ICE() << "could not obtain builtin value from attribute"; |
| return core::BuiltinValue::kUndefined; |
| } |
| |
| /// @param attrs the input attribute list |
| /// @returns the builtin value if any of the attributes in @p attrs is a builtin attribute, |
| /// otherwise core::BuiltinValue::kUndefined |
| core::BuiltinValue BuiltinOf(VectorRef<const Attribute*> attrs) { |
| if (auto* builtin = GetAttribute<BuiltinAttribute>(attrs)) { |
| return BuiltinOf(builtin); |
| } |
| return core::BuiltinValue::kUndefined; |
| } |
| |
| /// Create or return a symbol for the wrapper function's struct parameter. |
| /// @returns the symbol for the struct parameter |
| Symbol InputStructSymbol() { |
| if (!wrapper_struct_param_name.IsValid()) { |
| wrapper_struct_param_name = b.Sym(); |
| } |
| return wrapper_struct_param_name; |
| } |
| |
| /// Add a shader input to the entry point. |
| /// @param name the name of the shader input |
| /// @param type the type of the shader input |
| /// @param location the location if provided |
| /// @param attrs the attributes to apply to the shader input |
| /// @returns an expression which evaluates to the value of the shader input |
| const Expression* AddInput(std::string name, |
| const type::Type* type, |
| std::optional<uint32_t> location, |
| tint::Vector<const Attribute*, 8> attrs) { |
| auto ast_type = CreateASTTypeFor(ctx, type); |
| |
| auto builtin_attr = BuiltinOf(attrs); |
| |
| if (cfg.shader_style == ShaderStyle::kSpirv || cfg.shader_style == ShaderStyle::kGlsl) { |
| // Vulkan requires that integer user-defined fragment inputs are always decorated with |
| // `Flat`. See: |
| // https://www.khronos.org/registry/vulkan/specs/1.3-extensions/man/html/StandaloneSpirv.html#VUID-StandaloneSpirv-Flat-04744 |
| // TODO(crbug.com/tint/1224): Remove this once a flat interpolation attribute is |
| // required for integers. |
| if (func_ast->PipelineStage() == PipelineStage::kFragment && |
| type->is_integer_scalar_or_vector() && !HasAttribute<InterpolateAttribute>(attrs) && |
| (HasAttribute<LocationAttribute>(attrs) || |
| cfg.shader_style == ShaderStyle::kSpirv)) { |
| attrs.Push(b.Interpolate(core::InterpolationType::kFlat, |
| core::InterpolationSampling::kUndefined)); |
| } |
| |
| // Disable validation for use of the `input` address space. |
| attrs.Push(b.Disable(DisabledValidation::kIgnoreAddressSpace)); |
| |
| // In GLSL, if it's a builtin, override the name with the |
| // corresponding gl_ builtin name |
| if (cfg.shader_style == ShaderStyle::kGlsl && |
| builtin_attr != core::BuiltinValue::kUndefined) { |
| name = GLSLBuiltinToString(builtin_attr, func_ast->PipelineStage(), |
| core::AddressSpace::kIn); |
| } |
| auto symbol = b.Symbols().New(name); |
| |
| // Create the global variable and use its value for the shader input. |
| const Expression* value = b.Expr(symbol); |
| |
| if (builtin_attr != core::BuiltinValue::kUndefined) { |
| if (cfg.shader_style == ShaderStyle::kGlsl) { |
| value = FromGLSLBuiltin(builtin_attr, value, ast_type); |
| } else if (builtin_attr == core::BuiltinValue::kSampleMask) { |
| // Vulkan requires the type of a SampleMask builtin to be an array. |
| // Declare it as array<u32, 1> and then load the first element. |
| ast_type = b.ty.array(ast_type, 1_u); |
| value = b.IndexAccessor(value, 0_i); |
| } |
| } |
| b.GlobalVar(symbol, ast_type, core::AddressSpace::kIn, std::move(attrs)); |
| return value; |
| } else if (cfg.shader_style == ShaderStyle::kMsl && |
| builtin_attr != core::BuiltinValue::kUndefined) { |
| // If this input is a builtin and we are targeting MSL, then add it to the |
| // parameter list and pass it directly to the inner function. |
| Symbol symbol = input_names.emplace(name).second ? b.Symbols().Register(name) |
| : b.Symbols().New(name); |
| wrapper_ep_parameters.Push(b.Param(symbol, ast_type, std::move(attrs))); |
| return b.Expr(symbol); |
| } else { |
| // Otherwise, move it to the new structure member list. |
| Symbol symbol = input_names.emplace(name).second ? b.Symbols().Register(name) |
| : b.Symbols().New(name); |
| wrapper_struct_param_members.Push( |
| {b.Member(symbol, ast_type, std::move(attrs)), location, std::nullopt}); |
| return b.MemberAccessor(InputStructSymbol(), symbol); |
| } |
| } |
| |
| /// Add a shader output to the entry point. |
| /// @param name the name of the shader output |
| /// @param type the type of the shader output |
| /// @param location the location if provided |
| /// @param index the index if provided |
| /// @param attrs the attributes to apply to the shader output |
| /// @param value the value of the shader output |
| void AddOutput(std::string name, |
| const type::Type* type, |
| std::optional<uint32_t> location, |
| std::optional<uint32_t> index, |
| tint::Vector<const Attribute*, 8> attrs, |
| const Expression* value) { |
| auto builtin_attr = BuiltinOf(attrs); |
| // Vulkan requires that integer user-defined vertex outputs are always decorated with |
| // `Flat`. |
| // TODO(crbug.com/tint/1224): Remove this once a flat interpolation attribute is required |
| // for integers. |
| if (cfg.shader_style == ShaderStyle::kSpirv && |
| func_ast->PipelineStage() == PipelineStage::kVertex && |
| type->is_integer_scalar_or_vector() && HasAttribute<LocationAttribute>(attrs) && |
| !HasAttribute<InterpolateAttribute>(attrs)) { |
| attrs.Push(b.Interpolate(core::InterpolationType::kFlat, |
| core::InterpolationSampling::kUndefined)); |
| } |
| |
| // In GLSL, if it's a builtin, override the name with the |
| // corresponding gl_ builtin name |
| if (cfg.shader_style == ShaderStyle::kGlsl) { |
| if (builtin_attr != core::BuiltinValue::kUndefined) { |
| name = GLSLBuiltinToString(builtin_attr, func_ast->PipelineStage(), |
| core::AddressSpace::kOut); |
| value = ToGLSLBuiltin(builtin_attr, value, type); |
| } |
| } |
| |
| OutputValue output; |
| output.name = name; |
| output.type = CreateASTTypeFor(ctx, type); |
| output.attributes = std::move(attrs); |
| output.value = value; |
| output.location = location; |
| output.index = index; |
| wrapper_output_values.Push(output); |
| } |
| |
| /// Process a non-struct parameter. |
| /// This creates a new object for the shader input, moving the shader IO |
| /// attributes to it. It also adds an expression to the list of parameters |
| /// that will be passed to the original function. |
| /// @param param the original function parameter |
| void ProcessNonStructParameter(const sem::Parameter* param) { |
| // Do not add interpolation attributes on vertex input |
| bool do_interpolate = func_ast->PipelineStage() != PipelineStage::kVertex; |
| // Remove the shader IO attributes from the inner function parameter, and attach them to the |
| // new object instead. |
| tint::Vector<const Attribute*, 8> attributes; |
| for (auto* attr : param->Declaration()->attributes) { |
| if (IsShaderIOAttribute(attr)) { |
| ctx.Remove(param->Declaration()->attributes, attr); |
| if ((do_interpolate || !attr->Is<InterpolateAttribute>())) { |
| CloneAttribute(attr, attributes); |
| } |
| } |
| } |
| |
| auto name = param->Declaration()->name->symbol.Name(); |
| auto* input_expr = AddInput(name, param->Type(), param->Location(), std::move(attributes)); |
| inner_call_parameters.Push(input_expr); |
| } |
| |
| /// Process a struct parameter. |
| /// This creates new objects for each struct member, moving the shader IO |
| /// attributes to them. It also creates the structure that will be passed to |
| /// the original function. |
| /// @param param the original function parameter |
| void ProcessStructParameter(const sem::Parameter* param) { |
| // Do not add interpolation attributes on vertex input |
| bool do_interpolate = func_ast->PipelineStage() != PipelineStage::kVertex; |
| |
| auto* str = param->Type()->As<sem::Struct>(); |
| |
| // Recreate struct members in the outer entry point and build an initializer |
| // list to pass them through to the inner function. |
| tint::Vector<const Expression*, 8> inner_struct_values; |
| for (auto* member : str->Members()) { |
| if (TINT_UNLIKELY(member->Type()->Is<type::Struct>())) { |
| TINT_ICE() << "nested IO struct"; |
| continue; |
| } |
| |
| auto name = member->Name().Name(); |
| |
| auto attributes = |
| CloneShaderIOAttributes(member->Declaration()->attributes, do_interpolate); |
| auto* input_expr = AddInput(name, member->Type(), member->Attributes().location, |
| std::move(attributes)); |
| inner_struct_values.Push(input_expr); |
| } |
| |
| // Construct the original structure using the new shader input objects. |
| inner_call_parameters.Push( |
| b.Call(ctx.Clone(param->Declaration()->type), inner_struct_values)); |
| } |
| |
| /// Process the entry point return type. |
| /// This generates a list of output values that are returned by the original |
| /// function. |
| /// @param inner_ret_type the original function return type |
| /// @param original_result the result object produced by the original function |
| void ProcessReturnType(const type::Type* inner_ret_type, Symbol original_result) { |
| // Do not add interpolation attributes on fragment output |
| bool do_interpolate = func_ast->PipelineStage() != PipelineStage::kFragment; |
| if (auto* str = inner_ret_type->As<sem::Struct>()) { |
| for (auto* member : str->Members()) { |
| if (TINT_UNLIKELY(member->Type()->Is<type::Struct>())) { |
| TINT_ICE() << "nested IO struct"; |
| continue; |
| } |
| |
| auto name = member->Name().Name(); |
| auto attributes = |
| CloneShaderIOAttributes(member->Declaration()->attributes, do_interpolate); |
| |
| // Extract the original structure member. |
| AddOutput(name, member->Type(), member->Attributes().location, |
| member->Attributes().index, std::move(attributes), |
| b.MemberAccessor(original_result, name)); |
| } |
| } else if (!inner_ret_type->Is<type::Void>()) { |
| auto attributes = |
| CloneShaderIOAttributes(func_ast->return_type_attributes, do_interpolate); |
| |
| // Propagate the non-struct return value as is. |
| AddOutput("value", func_sem->ReturnType(), func_sem->ReturnLocation(), |
| func_sem->ReturnIndex(), std::move(attributes), b.Expr(original_result)); |
| } |
| } |
| |
| /// Add a fixed sample mask to the wrapper function output. |
| /// If there is already a sample mask, bitwise-and it with the fixed mask. |
| /// Otherwise, create a new output value from the fixed mask. |
| void AddFixedSampleMask() { |
| // Check the existing output values for a sample mask builtin. |
| for (auto& outval : wrapper_output_values) { |
| if (BuiltinOf(outval.attributes) == core::BuiltinValue::kSampleMask) { |
| // Combine the authored sample mask with the fixed mask. |
| outval.value = b.And(outval.value, u32(cfg.fixed_sample_mask)); |
| return; |
| } |
| } |
| |
| // No existing sample mask builtin was found, so create a new output value using the fixed |
| // sample mask. |
| auto* builtin = b.Builtin(core::BuiltinValue::kSampleMask); |
| builtin_attrs.Add(builtin, core::BuiltinValue::kSampleMask); |
| AddOutput("fixed_sample_mask", b.create<type::U32>(), std::nullopt, std::nullopt, {builtin}, |
| b.Expr(u32(cfg.fixed_sample_mask))); |
| } |
| |
| /// Add a point size builtin to the wrapper function output. |
| void AddVertexPointSize() { |
| // Create a new output value and assign it a literal 1.0 value. |
| auto* builtin = b.Builtin(core::BuiltinValue::kPointSize); |
| builtin_attrs.Add(builtin, core::BuiltinValue::kPointSize); |
| AddOutput("vertex_point_size", b.create<type::F32>(), std::nullopt, std::nullopt, {builtin}, |
| b.Expr(1_f)); |
| } |
| |
| /// Create an expression for gl_Position.[component] |
| /// @param component the component of gl_Position to access |
| /// @returns the new expression |
| const Expression* GLPosition(const char* component) { |
| Symbol pos = b.Symbols().Register("gl_Position"); |
| Symbol c = b.Symbols().Register(component); |
| return b.MemberAccessor(b.Expr(pos), c); |
| } |
| |
| /// Comparison function used to reorder struct members such that all members with |
| /// location attributes appear first (ordered by location slot), followed by |
| /// those with builtin attributes. |
| /// @param x a struct member |
| /// @param y another struct member |
| /// @returns true if a comes before b |
| bool StructMemberComparator(const MemberInfo& x, const MemberInfo& y) { |
| auto* x_loc = GetAttribute<LocationAttribute>(x.member->attributes); |
| auto* y_loc = GetAttribute<LocationAttribute>(y.member->attributes); |
| auto* x_blt = GetAttribute<BuiltinAttribute>(x.member->attributes); |
| auto* y_blt = GetAttribute<BuiltinAttribute>(y.member->attributes); |
| if (x_loc) { |
| if (!y_loc) { |
| // `a` has location attribute and `b` does not: `a` goes first. |
| return true; |
| } |
| // Both have location attributes: smallest goes first. |
| return x.location < y.location; |
| } else { |
| if (y_loc) { |
| // `b` has location attribute and `a` does not: `b` goes first. |
| return false; |
| } |
| // Both are builtins: order matters for FXC. |
| auto builtin_a = BuiltinOf(x_blt); |
| auto builtin_b = BuiltinOf(y_blt); |
| return BuiltinOrder(builtin_a) < BuiltinOrder(builtin_b); |
| } |
| } |
| /// Create the wrapper function's struct parameter and type objects. |
| void CreateInputStruct() { |
| // Sort the struct members to satisfy HLSL interfacing matching rules. |
| std::sort(wrapper_struct_param_members.begin(), wrapper_struct_param_members.end(), |
| [&](auto& x, auto& y) { return StructMemberComparator(x, y); }); |
| |
| tint::Vector<const StructMember*, 8> members; |
| for (auto& mem : wrapper_struct_param_members) { |
| members.Push(mem.member); |
| } |
| |
| // Create the new struct type. |
| auto struct_name = b.Sym(); |
| auto* in_struct = b.create<Struct>(b.Ident(struct_name), std::move(members), Empty); |
| ctx.InsertBefore(ctx.src->AST().GlobalDeclarations(), func_ast, in_struct); |
| |
| // Create a new function parameter using this struct type. |
| auto* param = b.Param(InputStructSymbol(), b.ty(struct_name)); |
| wrapper_ep_parameters.Push(param); |
| } |
| |
| /// Create and return the wrapper function's struct result object. |
| /// @returns the struct type |
| Struct* CreateOutputStruct() { |
| tint::Vector<const Statement*, 8> assignments; |
| |
| auto wrapper_result = b.Symbols().New("wrapper_result"); |
| |
| // Create the struct members and their corresponding assignment statements. |
| std::unordered_set<std::string> member_names; |
| for (auto& outval : wrapper_output_values) { |
| // Use the original output name, unless that is already taken. |
| Symbol name; |
| if (member_names.count(outval.name)) { |
| name = b.Symbols().New(outval.name); |
| } else { |
| name = b.Symbols().Register(outval.name); |
| } |
| member_names.insert(name.Name()); |
| |
| wrapper_struct_output_members.Push( |
| {b.Member(name, outval.type, std::move(outval.attributes)), outval.location, |
| std::nullopt}); |
| assignments.Push(b.Assign(b.MemberAccessor(wrapper_result, name), outval.value)); |
| } |
| |
| // Sort the struct members to satisfy HLSL interfacing matching rules. |
| std::sort(wrapper_struct_output_members.begin(), wrapper_struct_output_members.end(), |
| [&](auto& x, auto& y) { return StructMemberComparator(x, y); }); |
| |
| tint::Vector<const StructMember*, 8> members; |
| for (auto& mem : wrapper_struct_output_members) { |
| members.Push(mem.member); |
| } |
| |
| // Create the new struct type. |
| auto* out_struct = b.create<Struct>(b.Ident(b.Sym()), std::move(members), Empty); |
| ctx.InsertBefore(ctx.src->AST().GlobalDeclarations(), func_ast, out_struct); |
| |
| // Create the output struct object, assign its members, and return it. |
| auto* result_object = b.Var(wrapper_result, b.ty(out_struct->name->symbol)); |
| wrapper_body.Push(b.Decl(result_object)); |
| for (auto* assignment : assignments) { |
| wrapper_body.Push(assignment); |
| } |
| wrapper_body.Push(b.Return(wrapper_result)); |
| |
| return out_struct; |
| } |
| |
| /// Create and assign the wrapper function's output variables. |
| void CreateGlobalOutputVariables() { |
| for (auto& outval : wrapper_output_values) { |
| // Disable validation for use of the `output` address space. |
| auto attributes = std::move(outval.attributes); |
| attributes.Push(b.Disable(DisabledValidation::kIgnoreAddressSpace)); |
| |
| // Create the global variable and assign it the output value. |
| auto name = b.Symbols().New(outval.name); |
| Type type = outval.type; |
| const Expression* lhs = b.Expr(name); |
| if (BuiltinOf(attributes) == core::BuiltinValue::kSampleMask) { |
| // Vulkan requires the type of a SampleMask builtin to be an array. |
| // Declare it as array<u32, 1> and then store to the first element. |
| type = b.ty.array(type, 1_u); |
| lhs = b.IndexAccessor(lhs, 0_i); |
| } |
| b.GlobalVar(name, type, core::AddressSpace::kOut, std::move(attributes)); |
| wrapper_body.Push(b.Assign(lhs, outval.value)); |
| } |
| } |
| |
| // Recreate the original function without entry point attributes and call it. |
| /// @returns the inner function call expression |
| const CallExpression* CallInnerFunction() { |
| Symbol inner_name; |
| if (cfg.shader_style == ShaderStyle::kGlsl) { |
| // In GLSL, clone the original entry point name, as the wrapper will be |
| // called "main". |
| inner_name = ctx.Clone(func_ast->name->symbol); |
| } else { |
| // Add a suffix to the function name, as the wrapper function will take |
| // the original entry point name. |
| auto ep_name = func_ast->name->symbol.Name(); |
| inner_name = b.Symbols().New(ep_name + "_inner"); |
| } |
| |
| // Clone everything, dropping the function and return type attributes. |
| // The parameter attributes will have already been stripped during |
| // processing. |
| auto* inner_function = b.create<Function>(b.Ident(inner_name), ctx.Clone(func_ast->params), |
| ctx.Clone(func_ast->return_type), |
| ctx.Clone(func_ast->body), Empty, Empty); |
| ctx.Replace(func_ast, inner_function); |
| |
| // Call the function. |
| return b.Call(inner_function->name->symbol, inner_call_parameters); |
| } |
| |
| /// Process the entry point function. |
| void Process() { |
| bool needs_fixed_sample_mask = false; |
| bool needs_vertex_point_size = false; |
| if (func_ast->PipelineStage() == PipelineStage::kFragment && |
| cfg.fixed_sample_mask != 0xFFFFFFFF) { |
| needs_fixed_sample_mask = true; |
| } |
| if (func_ast->PipelineStage() == PipelineStage::kVertex && cfg.emit_vertex_point_size) { |
| needs_vertex_point_size = true; |
| } |
| |
| // Exit early if there is no shader IO to handle. |
| if (func_sem->Parameters().Length() == 0 && func_sem->ReturnType()->Is<type::Void>() && |
| !needs_fixed_sample_mask && !needs_vertex_point_size && |
| cfg.shader_style != ShaderStyle::kGlsl) { |
| return; |
| } |
| |
| // Process the entry point parameters, collecting those that need to be |
| // aggregated into a single structure. |
| if (!func_sem->Parameters().IsEmpty()) { |
| for (auto* param : func_sem->Parameters()) { |
| if (param->Type()->Is<type::Struct>()) { |
| ProcessStructParameter(param); |
| } else { |
| ProcessNonStructParameter(param); |
| } |
| } |
| |
| // Create a structure parameter for the outer entry point if necessary. |
| if (!wrapper_struct_param_members.IsEmpty()) { |
| CreateInputStruct(); |
| } |
| } |
| |
| // Recreate the original function and call it. |
| auto* call_inner = CallInnerFunction(); |
| |
| // Process the return type, and start building the wrapper function body. |
| std::function<Type()> wrapper_ret_type = [&] { return b.ty.void_(); }; |
| if (func_sem->ReturnType()->Is<type::Void>()) { |
| // The function call is just a statement with no result. |
| wrapper_body.Push(b.CallStmt(call_inner)); |
| } else { |
| // Capture the result of calling the original function. |
| auto* inner_result = b.Let(b.Symbols().New("inner_result"), call_inner); |
| wrapper_body.Push(b.Decl(inner_result)); |
| |
| // Process the original return type to determine the outputs that the |
| // outer function needs to produce. |
| ProcessReturnType(func_sem->ReturnType(), inner_result->name->symbol); |
| } |
| |
| // Add a fixed sample mask, if necessary. |
| if (needs_fixed_sample_mask) { |
| AddFixedSampleMask(); |
| } |
| |
| // Add the pointsize builtin, if necessary. |
| if (needs_vertex_point_size) { |
| AddVertexPointSize(); |
| } |
| |
| // Produce the entry point outputs, if necessary. |
| if (!wrapper_output_values.IsEmpty()) { |
| if (cfg.shader_style == ShaderStyle::kSpirv || cfg.shader_style == ShaderStyle::kGlsl) { |
| CreateGlobalOutputVariables(); |
| } else { |
| auto* output_struct = CreateOutputStruct(); |
| wrapper_ret_type = [&, output_struct] { return b.ty(output_struct->name->symbol); }; |
| } |
| } |
| |
| if (cfg.shader_style == ShaderStyle::kGlsl && |
| func_ast->PipelineStage() == PipelineStage::kVertex) { |
| auto* pos_y = GLPosition("y"); |
| auto* negate_pos_y = b.create<UnaryOpExpression>(UnaryOp::kNegation, GLPosition("y")); |
| wrapper_body.Push(b.Assign(pos_y, negate_pos_y)); |
| |
| auto* two_z = b.Mul(b.Expr(2_f), GLPosition("z")); |
| auto* fixed_z = b.Sub(two_z, GLPosition("w")); |
| wrapper_body.Push(b.Assign(GLPosition("z"), fixed_z)); |
| } |
| |
| // Create the wrapper entry point function. |
| // For GLSL, use "main", otherwise take the name of the original |
| // entry point function. |
| Symbol name; |
| if (cfg.shader_style == ShaderStyle::kGlsl) { |
| name = b.Symbols().New("main"); |
| } else { |
| name = ctx.Clone(func_ast->name->symbol); |
| } |
| |
| auto* wrapper_func = |
| b.create<Function>(b.Ident(name), wrapper_ep_parameters, b.ty(wrapper_ret_type()), |
| b.Block(wrapper_body), ctx.Clone(func_ast->attributes), Empty); |
| ctx.InsertAfter(ctx.src->AST().GlobalDeclarations(), func_ast, wrapper_func); |
| } |
| |
| /// Retrieve the gl_ string corresponding to a builtin. |
| /// @param builtin the builtin |
| /// @param stage the current pipeline stage |
| /// @param address_space the address space (input or output) |
| /// @returns the gl_ string corresponding to that builtin |
| const char* GLSLBuiltinToString(core::BuiltinValue builtin, |
| PipelineStage stage, |
| core::AddressSpace address_space) { |
| switch (builtin) { |
| case core::BuiltinValue::kPosition: |
| switch (stage) { |
| case PipelineStage::kVertex: |
| return "gl_Position"; |
| case PipelineStage::kFragment: |
| return "gl_FragCoord"; |
| default: |
| return ""; |
| } |
| case core::BuiltinValue::kVertexIndex: |
| return "gl_VertexID"; |
| case core::BuiltinValue::kInstanceIndex: |
| return "gl_InstanceID"; |
| case core::BuiltinValue::kFrontFacing: |
| return "gl_FrontFacing"; |
| case core::BuiltinValue::kFragDepth: |
| return "gl_FragDepth"; |
| case core::BuiltinValue::kLocalInvocationId: |
| return "gl_LocalInvocationID"; |
| case core::BuiltinValue::kLocalInvocationIndex: |
| return "gl_LocalInvocationIndex"; |
| case core::BuiltinValue::kGlobalInvocationId: |
| return "gl_GlobalInvocationID"; |
| case core::BuiltinValue::kNumWorkgroups: |
| return "gl_NumWorkGroups"; |
| case core::BuiltinValue::kWorkgroupId: |
| return "gl_WorkGroupID"; |
| case core::BuiltinValue::kSampleIndex: |
| return "gl_SampleID"; |
| case core::BuiltinValue::kSampleMask: |
| if (address_space == core::AddressSpace::kIn) { |
| return "gl_SampleMaskIn"; |
| } else { |
| return "gl_SampleMask"; |
| } |
| default: |
| return ""; |
| } |
| } |
| |
| /// Convert a given GLSL builtin value to the corresponding WGSL value. |
| /// @param builtin the builtin variable |
| /// @param value the value to convert |
| /// @param ast_type (inout) the incoming WGSL and outgoing GLSL types |
| /// @returns an expression representing the GLSL builtin converted to what |
| /// WGSL expects |
| const Expression* FromGLSLBuiltin(core::BuiltinValue builtin, |
| const Expression* value, |
| Type& ast_type) { |
| switch (builtin) { |
| case core::BuiltinValue::kVertexIndex: |
| case core::BuiltinValue::kInstanceIndex: |
| case core::BuiltinValue::kSampleIndex: |
| // GLSL uses i32 for these, so bitcast to u32. |
| value = b.Bitcast(ast_type, value); |
| ast_type = b.ty.i32(); |
| break; |
| case core::BuiltinValue::kSampleMask: |
| // gl_SampleMask is an array of i32. Retrieve the first element and |
| // bitcast it to u32. |
| value = b.IndexAccessor(value, 0_i); |
| value = b.Bitcast(ast_type, value); |
| ast_type = b.ty.array(b.ty.i32(), 1_u); |
| break; |
| default: |
| break; |
| } |
| return value; |
| } |
| |
| /// Convert a given WGSL value to the type expected when assigning to a |
| /// GLSL builtin. |
| /// @param builtin the builtin variable |
| /// @param value the value to convert |
| /// @param type (out) the type to which the value was converted |
| /// @returns the converted value which can be assigned to the GLSL builtin |
| const Expression* ToGLSLBuiltin(core::BuiltinValue builtin, |
| const Expression* value, |
| const type::Type*& type) { |
| switch (builtin) { |
| case core::BuiltinValue::kVertexIndex: |
| case core::BuiltinValue::kInstanceIndex: |
| case core::BuiltinValue::kSampleIndex: |
| case core::BuiltinValue::kSampleMask: |
| type = b.create<type::I32>(); |
| value = b.Bitcast(CreateASTTypeFor(ctx, type), value); |
| break; |
| default: |
| break; |
| } |
| return value; |
| } |
| }; |
| |
| Transform::ApplyResult CanonicalizeEntryPointIO::Apply(const Program* src, |
| const DataMap& inputs, |
| DataMap&) const { |
| ProgramBuilder b; |
| program::CloneContext ctx{&b, src, /* auto_clone_symbols */ true}; |
| |
| auto* cfg = inputs.Get<Config>(); |
| if (cfg == nullptr) { |
| b.Diagnostics().add_error(diag::System::Transform, |
| "missing transform data for " + std::string(TypeInfo().name)); |
| return resolver::Resolve(b); |
| } |
| |
| // Remove entry point IO attributes from struct declarations. |
| // New structures will be created for each entry point, as necessary. |
| for (auto* ty : src->AST().TypeDecls()) { |
| if (auto* struct_ty = ty->As<Struct>()) { |
| for (auto* member : struct_ty->members) { |
| for (auto* attr : member->attributes) { |
| if (IsShaderIOAttribute(attr)) { |
| ctx.Remove(member->attributes, attr); |
| } |
| } |
| } |
| } |
| } |
| |
| for (auto* func_ast : src->AST().Functions()) { |
| if (!func_ast->IsEntryPoint()) { |
| continue; |
| } |
| |
| State state(ctx, b, *cfg, func_ast); |
| state.Process(); |
| } |
| |
| ctx.Clone(); |
| return resolver::Resolve(b); |
| } |
| |
| CanonicalizeEntryPointIO::Config::Config(ShaderStyle style, |
| uint32_t sample_mask, |
| bool emit_point_size) |
| : shader_style(style), |
| fixed_sample_mask(sample_mask), |
| emit_vertex_point_size(emit_point_size) {} |
| |
| CanonicalizeEntryPointIO::Config::Config(const Config&) = default; |
| CanonicalizeEntryPointIO::Config::~Config() = default; |
| |
| } // namespace tint::ast::transform |