| // Copyright 2023 The Dawn & Tint Authors |
| // |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are met: |
| // |
| // 1. Redistributions of source code must retain the above copyright notice, this |
| // list of conditions and the following disclaimer. |
| // |
| // 2. Redistributions in binary form must reproduce the above copyright notice, |
| // this list of conditions and the following disclaimer in the documentation |
| // and/or other materials provided with the distribution. |
| // |
| // 3. Neither the name of the copyright holder nor the names of its |
| // contributors may be used to endorse or promote products derived from |
| // this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| // DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE |
| // FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| // DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR |
| // SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
| // CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, |
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| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| #include "src/tint/lang/spirv/writer/raise/shader_io.h" |
| |
| #include <memory> |
| #include <utility> |
| |
| #include "src/tint/lang/core/ir/builder.h" |
| #include "src/tint/lang/core/ir/module.h" |
| #include "src/tint/lang/core/ir/transform/shader_io.h" |
| #include "src/tint/lang/core/ir/validator.h" |
| #include "src/tint/lang/core/type/array.h" |
| |
| using namespace tint::core::fluent_types; // NOLINT |
| using namespace tint::core::number_suffixes; // NOLINT |
| |
| namespace tint::spirv::writer::raise { |
| |
| namespace { |
| |
| /// State that persists across the whole module and can be shared between entry points. |
| struct PerModuleState { |
| /// The frag_depth clamp arguments. |
| core::ir::Value* frag_depth_clamp_args = nullptr; |
| }; |
| |
| /// PIMPL state for the parts of the shader IO transform specific to SPIR-V. |
| /// For SPIR-V, we declare a global variable for each input and output. The wrapper entry point then |
| /// loads from and stores to these variables. We also modify the type of the SampleMask builtin to |
| /// be an array, as required by Vulkan. |
| struct StateImpl : core::ir::transform::ShaderIOBackendState { |
| /// The input variables. |
| Vector<core::ir::Var*, 4> input_vars; |
| /// The output variables. |
| Vector<core::ir::Var*, 4> output_vars; |
| |
| /// The configuration options. |
| const ShaderIOConfig& config; |
| |
| /// The per-module state object. |
| PerModuleState& module_state; |
| |
| /// Constructor |
| StateImpl(core::ir::Module& mod, |
| core::ir::Function* f, |
| const ShaderIOConfig& cfg, |
| PerModuleState& mod_state) |
| : ShaderIOBackendState(mod, f), config(cfg), module_state(mod_state) {} |
| |
| /// Destructor |
| ~StateImpl() override {} |
| |
| /// Declare a global variable for each IO entry listed in @p entries. |
| /// @param vars the list of variables |
| /// @param entries the entries to emit |
| /// @param addrspace the address to use for the global variables |
| /// @param access the access mode to use for the global variables |
| /// @param name_suffix the suffix to add to struct and variable names |
| void MakeVars(Vector<core::ir::Var*, 4>& vars, |
| Vector<core::type::Manager::StructMemberDesc, 4>& entries, |
| core::AddressSpace addrspace, |
| core::Access access, |
| const char* name_suffix) { |
| for (auto io : entries) { |
| StringStream name; |
| name << ir.NameOf(func).Name(); |
| |
| if (io.attributes.builtin) { |
| // SampleMask must be an array for Vulkan. |
| if (io.attributes.builtin.value() == core::BuiltinValue::kSampleMask) { |
| io.type = ty.array<u32, 1>(); |
| } |
| name << "_" << io.attributes.builtin.value(); |
| |
| // Vulkan requires that fragment integer builtin inputs be Flat decorated. |
| if (func->Stage() == core::ir::Function::PipelineStage::kFragment && |
| addrspace == core::AddressSpace::kIn && |
| io.type->is_integer_scalar_or_vector()) { |
| io.attributes.interpolation = {core::InterpolationType::kFlat}; |
| } |
| } |
| if (io.attributes.location) { |
| name << "_loc" << io.attributes.location.value(); |
| if (io.attributes.blend_src.has_value()) { |
| name << "_idx" << io.attributes.blend_src.value(); |
| } |
| } |
| name << name_suffix; |
| |
| // Replace f16 types with f32 types if necessary. |
| auto* store_type = io.type; |
| if (config.polyfill_f16_io) { |
| if (store_type->DeepestElement()->Is<core::type::F16>()) { |
| store_type = ty.f32(); |
| if (auto* vec = io.type->As<core::type::Vector>()) { |
| store_type = ty.vec(store_type, vec->Width()); |
| } |
| } |
| } |
| |
| // Create an IO variable and add it to the root block. |
| auto* ptr = ty.ptr(addrspace, store_type, access); |
| auto* var = b.Var(name.str(), ptr); |
| var->SetAttributes(core::ir::IOAttributes{ |
| io.attributes.location, |
| io.attributes.blend_src, |
| io.attributes.builtin, |
| io.attributes.interpolation, |
| io.attributes.invariant, |
| }); |
| ir.root_block->Append(var); |
| vars.Push(var); |
| } |
| } |
| |
| /// @copydoc ShaderIO::BackendState::FinalizeInputs |
| Vector<core::ir::FunctionParam*, 4> FinalizeInputs() override { |
| MakeVars(input_vars, inputs, core::AddressSpace::kIn, core::Access::kRead, "_Input"); |
| return tint::Empty; |
| } |
| |
| /// @copydoc ShaderIO::BackendState::FinalizeOutputs |
| core::ir::Value* FinalizeOutputs() override { |
| MakeVars(output_vars, outputs, core::AddressSpace::kOut, core::Access::kWrite, "_Output"); |
| return nullptr; |
| } |
| |
| /// @copydoc ShaderIO::BackendState::GetInput |
| core::ir::Value* GetInput(core::ir::Builder& builder, uint32_t idx) override { |
| // Load the input from the global variable declared earlier. |
| auto* ptr = ty.ptr(core::AddressSpace::kIn, inputs[idx].type, core::Access::kRead); |
| auto* from = input_vars[idx]->Result(0); |
| if (inputs[idx].attributes.builtin) { |
| if (inputs[idx].attributes.builtin.value() == core::BuiltinValue::kSampleMask) { |
| // SampleMask becomes an array for SPIR-V, so load from the first element. |
| from = builder.Access(ptr, input_vars[idx], 0_u)->Result(0); |
| } |
| } |
| |
| auto* value = builder.Load(from)->Result(0); |
| |
| // Convert f32 values to f16 values if needed. |
| if (config.polyfill_f16_io && inputs[idx].type->DeepestElement()->Is<core::type::F16>()) { |
| value = builder.Convert(inputs[idx].type, value)->Result(0); |
| } |
| |
| return value; |
| } |
| |
| /// @copydoc ShaderIO::BackendState::SetOutput |
| void SetOutput(core::ir::Builder& builder, uint32_t idx, core::ir::Value* value) override { |
| // Store the output to the global variable declared earlier. |
| auto* ptr = ty.ptr(core::AddressSpace::kOut, outputs[idx].type, core::Access::kWrite); |
| auto* to = output_vars[idx]->Result(0); |
| if (outputs[idx].attributes.builtin) { |
| if (outputs[idx].attributes.builtin.value() == core::BuiltinValue::kSampleMask) { |
| // SampleMask becomes an array for SPIR-V, so store to the first element. |
| to = builder.Access(ptr, to, 0_u)->Result(0); |
| } |
| |
| // Clamp frag_depth values if necessary. |
| if (outputs[idx].attributes.builtin.value() == core::BuiltinValue::kFragDepth) { |
| value = ClampFragDepth(builder, value); |
| } |
| } |
| |
| // Convert f16 values to f32 values if needed. |
| if (config.polyfill_f16_io && value->Type()->DeepestElement()->Is<core::type::F16>()) { |
| value = builder.Convert(to->Type()->UnwrapPtr(), value)->Result(0); |
| } |
| |
| builder.Store(to, value); |
| } |
| |
| /// Clamp a frag_depth builtin value if necessary. |
| /// @param builder the builder to use for new instructions |
| /// @param frag_depth the incoming frag_depth value |
| /// @returns the clamped value |
| core::ir::Value* ClampFragDepth(core::ir::Builder& builder, core::ir::Value* frag_depth) { |
| if (!config.clamp_frag_depth) { |
| return frag_depth; |
| } |
| |
| // Create the clamp args struct and variable. |
| if (!module_state.frag_depth_clamp_args) { |
| // Check that there are no push constants in the module already. |
| for (auto* inst : *ir.root_block) { |
| if (auto* var = inst->As<core::ir::Var>()) { |
| auto* ptr = var->Result(0)->Type()->As<core::type::Pointer>(); |
| if (ptr->AddressSpace() == core::AddressSpace::kPushConstant) { |
| TINT_ICE() << "cannot clamp frag_depth with pre-existing push constants"; |
| } |
| } |
| } |
| |
| // Declare the struct. |
| auto* str = ty.Struct(ir.symbols.Register("FragDepthClampArgs"), |
| { |
| {ir.symbols.Register("min"), ty.f32()}, |
| {ir.symbols.Register("max"), ty.f32()}, |
| }); |
| str->SetStructFlag(core::type::kBlock); |
| |
| // Declare the variable. |
| auto* var = b.Var("tint_frag_depth_clamp_args", ty.ptr(push_constant, str)); |
| ir.root_block->Append(var); |
| module_state.frag_depth_clamp_args = var->Result(0); |
| } |
| |
| // Clamp the value. |
| auto* args = builder.Load(module_state.frag_depth_clamp_args); |
| auto* frag_depth_min = builder.Access(ty.f32(), args, 0_u); |
| auto* frag_depth_max = builder.Access(ty.f32(), args, 1_u); |
| return builder |
| .Call(ty.f32(), core::BuiltinFn::kClamp, frag_depth, frag_depth_min, frag_depth_max) |
| ->Result(0); |
| } |
| |
| /// @copydoc ShaderIO::BackendState::NeedsVertexPointSize |
| bool NeedsVertexPointSize() const override { return config.emit_vertex_point_size; } |
| }; |
| } // namespace |
| |
| Result<SuccessType> ShaderIO(core::ir::Module& ir, const ShaderIOConfig& config) { |
| auto result = ValidateAndDumpIfNeeded(ir, "ShaderIO transform"); |
| if (result != Success) { |
| return result; |
| } |
| |
| PerModuleState module_state; |
| core::ir::transform::RunShaderIOBase(ir, [&](core::ir::Module& mod, core::ir::Function* func) { |
| return std::make_unique<StateImpl>(mod, func, config, module_state); |
| }); |
| |
| return Success; |
| } |
| |
| } // namespace tint::spirv::writer::raise |