src/tint/lang/spirv/writer/raise/shader_io.cc - dawn - Git at Google

 // 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,
 // OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // 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 == 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->IsIntegerScalarOrVector()) {
                     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.MatchWidth(ty.f32(), io.type);
                 }
             }

             // 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(io.attributes);
             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
     const core::type::Type* FinalizeOutputs() override {
         MakeVars(output_vars, outputs, core::AddressSpace::kOut, core::Access::kWrite, "_Output");
         return ty.void_();
     }

     /// @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);

         // SampleMask becomes an array for SPIR-V, so load from the first element.
         if (inputs[idx].attributes.builtin == core::BuiltinValue::kSampleMask) {
             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);

         // SampleMask becomes an array for SPIR-V, so store to the first element.
         if (outputs[idx].attributes.builtin == core::BuiltinValue::kSampleMask) {
             to = builder.Access(ptr, to, 0_u)->Result(0);
         }

         // Clamp frag_depth values if necessary.
         if (outputs[idx].attributes.builtin == 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
	// 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,
	// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	// 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 == 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->IsIntegerScalarOrVector()) {
	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.MatchWidth(ty.f32(), io.type);
	}
	}

	// 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(io.attributes);
	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
	const core::type::Type* FinalizeOutputs() override {
	MakeVars(output_vars, outputs, core::AddressSpace::kOut, core::Access::kWrite, "_Output");
	return ty.void_();
	}

	/// @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);

	// SampleMask becomes an array for SPIR-V, so load from the first element.
	if (inputs[idx].attributes.builtin == core::BuiltinValue::kSampleMask) {
	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);

	// SampleMask becomes an array for SPIR-V, so store to the first element.
	if (outputs[idx].attributes.builtin == core::BuiltinValue::kSampleMask) {
	to = builder.Access(ptr, to, 0_u)->Result(0);
	}

	// Clamp frag_depth values if necessary.
	if (outputs[idx].attributes.builtin == 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