vk_shader_decompiler: Implement declarations

src/video_core/renderer_vulkan/vk_shader_decompiler.cpp

@@ -2,38 +2,492 @@
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
+#include <functional>
+#include <map>
+#include <set>
+
+#include <fmt/format.h>
+
 #include <sirit/sirit.h>
 
+#include "common/alignment.h"
 #include "common/assert.h"
+#include "common/common_types.h"
+#include "common/logging/log.h"
 #include "video_core/engines/maxwell_3d.h"
+#include "video_core/engines/shader_bytecode.h"
 #include "video_core/engines/shader_header.h"
 #include "video_core/renderer_vulkan/vk_shader_decompiler.h"
 #include "video_core/shader/shader_ir.h"
 
 namespace Vulkan::VKShader {
 
+using Sirit::Id;
+using Tegra::Shader::Attribute;
+using Tegra::Shader::AttributeUse;
+using Tegra::Shader::Register;
 using namespace VideoCommon::Shader;
 
+using Maxwell = Tegra::Engines::Maxwell3D::Regs;
 using ShaderStage = Tegra::Engines::Maxwell3D::Regs::ShaderStage;
 
+// TODO(Rodrigo): Use rasterizer's value
+constexpr u32 MAX_CONSTBUFFER_ELEMENTS = 0x1000;
+constexpr u32 STAGE_BINDING_STRIDE = 0x100;
+
+enum class Type { Bool, Bool2, Float, Int, Uint, HalfFloat };
+
+struct SamplerImage {
+    Id image_type;
+    Id sampled_image_type;
+    Id sampler;
+};
+
+namespace {
+
+spv::Dim GetSamplerDim(const Sampler& sampler) {
+    switch (sampler.GetType()) {
+    case Tegra::Shader::TextureType::Texture1D:
+        return spv::Dim::Dim1D;
+    case Tegra::Shader::TextureType::Texture2D:
+        return spv::Dim::Dim2D;
+    case Tegra::Shader::TextureType::Texture3D:
+        return spv::Dim::Dim3D;
+    case Tegra::Shader::TextureType::TextureCube:
+        return spv::Dim::Cube;
+    default:
+        UNIMPLEMENTED_MSG("Unimplemented sampler type={}", static_cast<u32>(sampler.GetType()));
+        return spv::Dim::Dim2D;
+    }
+}
+
+/// Returns true if an attribute index is one of the 32 generic attributes
+constexpr bool IsGenericAttribute(Attribute::Index attribute) {
+    return attribute >= Attribute::Index::Attribute_0 &&
+           attribute <= Attribute::Index::Attribute_31;
+}
+
+/// Returns the location of a generic attribute
+constexpr u32 GetGenericAttributeLocation(Attribute::Index attribute) {
+    ASSERT(IsGenericAttribute(attribute));
+    return static_cast<u32>(attribute) - static_cast<u32>(Attribute::Index::Attribute_0);
+}
+
+} // namespace
+
 class SPIRVDecompiler : public Sirit::Module {
 public:
     explicit SPIRVDecompiler(const ShaderIR& ir, ShaderStage stage)
-        : Module(0x00010300), ir{ir}, stage{stage}, header{ir.GetHeader()} {}
+        : Module(0x00010300), ir{ir}, stage{stage}, header{ir.GetHeader()} {
+        AddCapability(spv::Capability::Shader);
+        AddExtension("SPV_KHR_storage_buffer_storage_class");
+        AddExtension("SPV_KHR_variable_pointers");
+    }
 
     void Decompile() {
+        AllocateBindings();
+
+        DeclareVertex();
+        DeclareGeometry();
+        DeclareFragment();
+        DeclareRegisters();
+        DeclarePredicates();
+        DeclareLocalMemory();
+        DeclareInternalFlags();
+        DeclareInputAttributes();
+        DeclareOutputAttributes();
+        DeclareConstantBuffers();
+        DeclareGlobalBuffers();
+        DeclareSamplers();
+
         UNIMPLEMENTED();
     }
 
     ShaderEntries GetShaderEntries() const {
-        UNIMPLEMENTED();
+        ShaderEntries entries;
-        return {};
+        entries.const_buffers_base_binding = const_buffers_base_binding;
+        entries.global_buffers_base_binding = global_buffers_base_binding;
+        entries.samplers_base_binding = samplers_base_binding;
+        for (const auto& cbuf : ir.GetConstantBuffers()) {
+            entries.const_buffers.emplace_back(cbuf.second, cbuf.first);
+        }
+        for (const auto& gmem : ir.GetGlobalMemoryBases()) {
+            entries.global_buffers.emplace_back(gmem.cbuf_index, gmem.cbuf_offset);
+        }
+        for (const auto& sampler : ir.GetSamplers()) {
+            entries.samplers.emplace_back(sampler);
+        }
+        for (const auto& attr : ir.GetInputAttributes()) {
+            entries.attributes.insert(GetGenericAttributeLocation(attr.first));
+        }
+        entries.clip_distances = ir.GetClipDistances();
+        entries.shader_length = ir.GetLength();
+        entries.entry_function = execute_function;
+        entries.interfaces = interfaces;
+        return entries;
     }
 
 private:
+    static constexpr auto INTERNAL_FLAGS_COUNT = static_cast<std::size_t>(InternalFlag::Amount);
+    static constexpr u32 CBUF_STRIDE = 16;
+
+    void AllocateBindings() {
+        const u32 binding_base = static_cast<u32>(stage) * STAGE_BINDING_STRIDE;
+        u32 binding_iterator = binding_base;
+
+        const auto Allocate = [&binding_iterator](std::size_t count) {
+            const u32 current_binding = binding_iterator;
+            binding_iterator += static_cast<u32>(count);
+            return current_binding;
+        };
+        const_buffers_base_binding = Allocate(ir.GetConstantBuffers().size());
+        global_buffers_base_binding = Allocate(ir.GetGlobalMemoryBases().size());
+        samplers_base_binding = Allocate(ir.GetSamplers().size());
+
+        ASSERT_MSG(binding_iterator - binding_base < STAGE_BINDING_STRIDE,
+                   "Stage binding stride is too small");
+    }
+
+    void DeclareVertex() {
+        if (stage != ShaderStage::Vertex)
+            return;
+
+        DeclareVertexRedeclarations();
+    }
+
+    void DeclareGeometry() {
+        if (stage != ShaderStage::Geometry)
+            return;
+
+        UNIMPLEMENTED();
+    }
+
+    void DeclareFragment() {
+        if (stage != ShaderStage::Fragment)
+            return;
+
+        for (u32 rt = 0; rt < static_cast<u32>(frag_colors.size()); ++rt) {
+            if (!IsRenderTargetUsed(rt)) {
+                continue;
+            }
+
+            const Id id = AddGlobalVariable(OpVariable(t_out_float4, spv::StorageClass::Output));
+            Name(id, fmt::format("frag_color{}", rt));
+            Decorate(id, spv::Decoration::Location, rt);
+
+            frag_colors[rt] = id;
+            interfaces.push_back(id);
+        }
+
+        if (header.ps.omap.depth) {
+            frag_depth = AddGlobalVariable(OpVariable(t_out_float, spv::StorageClass::Output));
+            Name(frag_depth, "frag_depth");
+            Decorate(frag_depth, spv::Decoration::BuiltIn,
+                     static_cast<u32>(spv::BuiltIn::FragDepth));
+
+            interfaces.push_back(frag_depth);
+        }
+
+        frag_coord = DeclareBuiltIn(spv::BuiltIn::FragCoord, spv::StorageClass::Input, t_in_float4,
+                                    "frag_coord");
+        front_facing = DeclareBuiltIn(spv::BuiltIn::FrontFacing, spv::StorageClass::Input,
+                                      t_in_bool, "front_facing");
+    }
+
+    void DeclareRegisters() {
+        for (const u32 gpr : ir.GetRegisters()) {
+            const Id id = OpVariable(t_prv_float, spv::StorageClass::Private, v_float_zero);
+            Name(id, fmt::format("gpr_{}", gpr));
+            registers.emplace(gpr, AddGlobalVariable(id));
+        }
+    }
+
+    void DeclarePredicates() {
+        for (const auto pred : ir.GetPredicates()) {
+            const Id id = OpVariable(t_prv_bool, spv::StorageClass::Private, v_false);
+            Name(id, fmt::format("pred_{}", static_cast<u32>(pred)));
+            predicates.emplace(pred, AddGlobalVariable(id));
+        }
+    }
+
+    void DeclareLocalMemory() {
+        if (const u64 local_memory_size = header.GetLocalMemorySize(); local_memory_size > 0) {
+            const auto element_count = static_cast<u32>(Common::AlignUp(local_memory_size, 4) / 4);
+            const Id type_array = TypeArray(t_float, Constant(t_uint, element_count));
+            const Id type_pointer = TypePointer(spv::StorageClass::Private, type_array);
+            Name(type_pointer, "LocalMemory");
+
+            local_memory =
+                OpVariable(type_pointer, spv::StorageClass::Private, ConstantNull(type_array));
+            AddGlobalVariable(Name(local_memory, "local_memory"));
+        }
+    }
+
+    void DeclareInternalFlags() {
+        constexpr std::array<const char*, INTERNAL_FLAGS_COUNT> names = {"zero", "sign", "carry",
+                                                                         "overflow"};
+        for (std::size_t flag = 0; flag < INTERNAL_FLAGS_COUNT; ++flag) {
+            const auto flag_code = static_cast<InternalFlag>(flag);
+            const Id id = OpVariable(t_prv_bool, spv::StorageClass::Private, v_false);
+            internal_flags[flag] = AddGlobalVariable(Name(id, names[flag]));
+        }
+    }
+
+    void DeclareInputAttributes() {
+        for (const auto element : ir.GetInputAttributes()) {
+            const Attribute::Index index = element.first;
+            if (!IsGenericAttribute(index)) {
+                continue;
+            }
+
+            UNIMPLEMENTED_IF(stage == ShaderStage::Geometry);
+
+            const u32 location = GetGenericAttributeLocation(index);
+            const Id id = OpVariable(t_in_float4, spv::StorageClass::Input);
+            Name(AddGlobalVariable(id), fmt::format("in_attr{}", location));
+            input_attributes.emplace(index, id);
+            interfaces.push_back(id);
+
+            Decorate(id, spv::Decoration::Location, location);
+
+            if (stage != ShaderStage::Fragment) {
+                continue;
+            }
+            switch (header.ps.GetAttributeUse(location)) {
+            case AttributeUse::Constant:
+                Decorate(id, spv::Decoration::Flat);
+                break;
+            case AttributeUse::ScreenLinear:
+                Decorate(id, spv::Decoration::NoPerspective);
+                break;
+            case AttributeUse::Perspective:
+                // Default
+                break;
+            default:
+                UNREACHABLE_MSG("Unused attribute being fetched");
+            }
+        }
+    }
+
+    void DeclareOutputAttributes() {
+        for (const auto index : ir.GetOutputAttributes()) {
+            if (!IsGenericAttribute(index)) {
+                continue;
+            }
+            const auto location = GetGenericAttributeLocation(index);
+            const Id id = OpVariable(t_out_float4, spv::StorageClass::Output);
+            Name(AddGlobalVariable(id), fmt::format("out_attr{}", location));
+            output_attributes.emplace(index, id);
+            interfaces.push_back(id);
+
+            Decorate(id, spv::Decoration::Location, location);
+        }
+    }
+
+    void DeclareConstantBuffers() {
+        u32 binding = const_buffers_base_binding;
+        for (const auto& entry : ir.GetConstantBuffers()) {
+            const auto [index, size] = entry;
+            const Id id = OpVariable(t_cbuf_ubo, spv::StorageClass::Uniform);
+            AddGlobalVariable(Name(id, fmt::format("cbuf_{}", index)));
+
+            Decorate(id, spv::Decoration::Binding, binding++);
+            Decorate(id, spv::Decoration::DescriptorSet, DESCRIPTOR_SET);
+            constant_buffers.emplace(index, id);
+        }
+    }
+
+    void DeclareGlobalBuffers() {
+        u32 binding = global_buffers_base_binding;
+        for (const auto& entry : ir.GetGlobalMemoryBases()) {
+            const Id id = OpVariable(t_gmem_ssbo, spv::StorageClass::StorageBuffer);
+            AddGlobalVariable(
+                Name(id, fmt::format("gmem_{}_{}", entry.cbuf_index, entry.cbuf_offset)));
+
+            Decorate(id, spv::Decoration::Binding, binding++);
+            Decorate(id, spv::Decoration::DescriptorSet, DESCRIPTOR_SET);
+            global_buffers.emplace(entry, id);
+        }
+    }
+
+    void DeclareSamplers() {
+        u32 binding = samplers_base_binding;
+        for (const auto& sampler : ir.GetSamplers()) {
+            const auto dim = GetSamplerDim(sampler);
+            const int depth = sampler.IsShadow() ? 1 : 0;
+            const int arrayed = sampler.IsArray() ? 1 : 0;
+            // TODO(Rodrigo): Sampled 1 indicates that the image will be used with a sampler. When
+            // SULD and SUST instructions are implemented, replace this value.
+            const int sampled = 1;
+            const Id image_type =
+                TypeImage(t_float, dim, depth, arrayed, false, sampled, spv::ImageFormat::Unknown);
+            const Id sampled_image_type = TypeSampledImage(image_type);
+            const Id pointer_type =
+                TypePointer(spv::StorageClass::UniformConstant, sampled_image_type);
+            const Id id = OpVariable(pointer_type, spv::StorageClass::UniformConstant);
+            AddGlobalVariable(Name(id, fmt::format("sampler_{}", sampler.GetIndex())));
+
+            sampler_images.insert(
+                {static_cast<u32>(sampler.GetIndex()), {image_type, sampled_image_type, id}});
+
+            Decorate(id, spv::Decoration::Binding, binding++);
+            Decorate(id, spv::Decoration::DescriptorSet, DESCRIPTOR_SET);
+        }
+    }
+
+    void DeclareVertexRedeclarations() {
+        vertex_index = DeclareBuiltIn(spv::BuiltIn::VertexIndex, spv::StorageClass::Input,
+                                      t_in_uint, "vertex_index");
+        instance_index = DeclareBuiltIn(spv::BuiltIn::InstanceIndex, spv::StorageClass::Input,
+                                        t_in_uint, "instance_index");
+
+        bool is_point_size_declared = false;
+        bool is_clip_distances_declared = false;
+        for (const auto index : ir.GetOutputAttributes()) {
+            if (index == Attribute::Index::PointSize) {
+                is_point_size_declared = true;
+            } else if (index == Attribute::Index::ClipDistances0123 ||
+                       index == Attribute::Index::ClipDistances4567) {
+                is_clip_distances_declared = true;
+            }
+        }
+
+        std::vector<Id> members;
+        members.push_back(t_float4);
+        if (is_point_size_declared) {
+            members.push_back(t_float);
+        }
+        if (is_clip_distances_declared) {
+            members.push_back(TypeArray(t_float, Constant(t_uint, 8)));
+        }
+
+        const Id gl_per_vertex_struct = Name(TypeStruct(members), "PerVertex");
+        Decorate(gl_per_vertex_struct, spv::Decoration::Block);
+
+        u32 declaration_index = 0;
+        const auto MemberDecorateBuiltIn = [&](spv::BuiltIn builtin, std::string name,
+                                               bool condition) {
+            if (!condition)
+                return u32{};
+            MemberName(gl_per_vertex_struct, declaration_index, name);
+            MemberDecorate(gl_per_vertex_struct, declaration_index, spv::Decoration::BuiltIn,
+                           static_cast<u32>(builtin));
+            return declaration_index++;
+        };
+
+        position_index = MemberDecorateBuiltIn(spv::BuiltIn::Position, "position", true);
+        point_size_index =
+            MemberDecorateBuiltIn(spv::BuiltIn::PointSize, "point_size", is_point_size_declared);
+        clip_distances_index = MemberDecorateBuiltIn(spv::BuiltIn::ClipDistance, "clip_distances",
+                                                     is_clip_distances_declared);
+
+        const Id type_pointer = TypePointer(spv::StorageClass::Output, gl_per_vertex_struct);
+        per_vertex = OpVariable(type_pointer, spv::StorageClass::Output);
+        AddGlobalVariable(Name(per_vertex, "per_vertex"));
+        interfaces.push_back(per_vertex);
+    }
+
+    Id DeclareBuiltIn(spv::BuiltIn builtin, spv::StorageClass storage, Id type,
+                      const std::string& name) {
+        const Id id = OpVariable(type, storage);
+        Decorate(id, spv::Decoration::BuiltIn, static_cast<u32>(builtin));
+        AddGlobalVariable(Name(id, name));
+        interfaces.push_back(id);
+        return id;
+    }
+
+    bool IsRenderTargetUsed(u32 rt) const {
+        for (u32 component = 0; component < 4; ++component) {
+            if (header.ps.IsColorComponentOutputEnabled(rt, component)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
     const ShaderIR& ir;
     const ShaderStage stage;
     const Tegra::Shader::Header header;
+
+    const Id t_void = Name(TypeVoid(), "void");
+
+    const Id t_bool = Name(TypeBool(), "bool");
+    const Id t_bool2 = Name(TypeVector(t_bool, 2), "bool2");
+
+    const Id t_int = Name(TypeInt(32, true), "int");
+    const Id t_int2 = Name(TypeVector(t_int, 2), "int2");
+    const Id t_int3 = Name(TypeVector(t_int, 3), "int3");
+    const Id t_int4 = Name(TypeVector(t_int, 4), "int4");
+
+    const Id t_uint = Name(TypeInt(32, false), "uint");
+    const Id t_uint2 = Name(TypeVector(t_uint, 2), "uint2");
+    const Id t_uint3 = Name(TypeVector(t_uint, 3), "uint3");
+    const Id t_uint4 = Name(TypeVector(t_uint, 4), "uint4");
+
+    const Id t_float = Name(TypeFloat(32), "float");
+    const Id t_float2 = Name(TypeVector(t_float, 2), "float2");
+    const Id t_float3 = Name(TypeVector(t_float, 3), "float3");
+    const Id t_float4 = Name(TypeVector(t_float, 4), "float4");
+
+    const Id t_prv_bool = Name(TypePointer(spv::StorageClass::Private, t_bool), "prv_bool");
+    const Id t_prv_float = Name(TypePointer(spv::StorageClass::Private, t_float), "prv_float");
+
+    const Id t_in_bool = Name(TypePointer(spv::StorageClass::Input, t_bool), "in_bool");
+    const Id t_in_uint = Name(TypePointer(spv::StorageClass::Input, t_uint), "in_uint");
+    const Id t_in_float = Name(TypePointer(spv::StorageClass::Input, t_float), "in_float");
+    const Id t_in_float4 = Name(TypePointer(spv::StorageClass::Input, t_float4), "in_float4");
+
+    const Id t_out_float = Name(TypePointer(spv::StorageClass::Output, t_float), "out_float");
+    const Id t_out_float4 = Name(TypePointer(spv::StorageClass::Output, t_float4), "out_float4");
+
+    const Id t_cbuf_float = TypePointer(spv::StorageClass::Uniform, t_float);
+    const Id t_cbuf_array =
+        Decorate(Name(TypeArray(t_float4, Constant(t_uint, MAX_CONSTBUFFER_ELEMENTS)), "CbufArray"),
+                 spv::Decoration::ArrayStride, CBUF_STRIDE);
+    const Id t_cbuf_struct = MemberDecorate(
+        Decorate(TypeStruct(t_cbuf_array), spv::Decoration::Block), 0, spv::Decoration::Offset, 0);
+    const Id t_cbuf_ubo = TypePointer(spv::StorageClass::Uniform, t_cbuf_struct);
+
+    const Id t_gmem_float = TypePointer(spv::StorageClass::StorageBuffer, t_float);
+    const Id t_gmem_array =
+        Name(Decorate(TypeRuntimeArray(t_float), spv::Decoration::ArrayStride, 4u), "GmemArray");
+    const Id t_gmem_struct = MemberDecorate(
+        Decorate(TypeStruct(t_gmem_array), spv::Decoration::Block), 0, spv::Decoration::Offset, 0);
+    const Id t_gmem_ssbo = TypePointer(spv::StorageClass::StorageBuffer, t_gmem_struct);
+
+    const Id v_float_zero = Constant(t_float, 0.0f);
+    const Id v_true = ConstantTrue(t_bool);
+    const Id v_false = ConstantFalse(t_bool);
+
+    Id per_vertex{};
+    std::map<u32, Id> registers;
+    std::map<Tegra::Shader::Pred, Id> predicates;
+    Id local_memory{};
+    std::array<Id, INTERNAL_FLAGS_COUNT> internal_flags{};
+    std::map<Attribute::Index, Id> input_attributes;
+    std::map<Attribute::Index, Id> output_attributes;
+    std::map<u32, Id> constant_buffers;
+    std::map<GlobalMemoryBase, Id> global_buffers;
+    std::map<u32, SamplerImage> sampler_images;
+
+    Id instance_index{};
+    Id vertex_index{};
+    std::array<Id, Maxwell::NumRenderTargets> frag_colors{};
+    Id frag_depth{};
+    Id frag_coord{};
+    Id front_facing{};
+
+    u32 position_index{};
+    u32 point_size_index{};
+    u32 clip_distances_index{};
+
+    std::vector<Id> interfaces;
+
+    u32 const_buffers_base_binding{};
+    u32 global_buffers_base_binding{};
+    u32 samplers_base_binding{};
+
+    Id execute_function{};
 };
 
 DecompilerResult Decompile(const VideoCommon::Shader::ShaderIR& ir, Maxwell::ShaderStage stage) {