shader: Decode SUST and implement backing image functionality

src/video_core/shader/decode.cpp

@@ -169,6 +169,7 @@ u32 ShaderIR::DecodeInstr(NodeBlock& bb, u32 pc) {
         {OpCode::Type::Conversion, &ShaderIR::DecodeConversion},
         {OpCode::Type::Memory, &ShaderIR::DecodeMemory},
         {OpCode::Type::Texture, &ShaderIR::DecodeTexture},
+        {OpCode::Type::Image, &ShaderIR::DecodeImage},
         {OpCode::Type::FloatSetPredicate, &ShaderIR::DecodeFloatSetPredicate},
         {OpCode::Type::IntegerSetPredicate, &ShaderIR::DecodeIntegerSetPredicate},
         {OpCode::Type::HalfSetPredicate, &ShaderIR::DecodeHalfSetPredicate},

src/video_core/shader/decode/image.cpp

@@ -0,0 +1,89 @@
+// Copyright 2019 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <algorithm>
+
+#include "common/assert.h"
+#include "common/common_types.h"
+#include "video_core/engines/shader_bytecode.h"
+#include "video_core/shader/shader_ir.h"
+
+namespace VideoCommon::Shader {
+
+using Tegra::Shader::Instruction;
+using Tegra::Shader::OpCode;
+
+namespace {
+std::size_t GetImageTypeNumCoordinates(Tegra::Shader::ImageType image_type) {
+    switch (image_type) {
+    case Tegra::Shader::ImageType::Texture1D:
+    case Tegra::Shader::ImageType::TextureBuffer:
+        return 1;
+    case Tegra::Shader::ImageType::Texture1DArray:
+    case Tegra::Shader::ImageType::Texture2D:
+        return 2;
+    case Tegra::Shader::ImageType::Texture2DArray:
+    case Tegra::Shader::ImageType::Texture3D:
+        return 3;
+    }
+    UNREACHABLE();
+    return 1;
+}
+} // Anonymous namespace
+
+u32 ShaderIR::DecodeImage(NodeBlock& bb, u32 pc) {
+    const Instruction instr = {program_code[pc]};
+    const auto opcode = OpCode::Decode(instr);
+
+    switch (opcode->get().GetId()) {
+    case OpCode::Id::SUST: {
+        UNIMPLEMENTED_IF(instr.sust.mode != Tegra::Shader::SurfaceDataMode::P);
+        UNIMPLEMENTED_IF(instr.sust.image_type == Tegra::Shader::ImageType::TextureBuffer);
+        UNIMPLEMENTED_IF(instr.sust.out_of_bounds_store != Tegra::Shader::OutOfBoundsStore::Ignore);
+        UNIMPLEMENTED_IF(instr.sust.component_mask_selector != 0xf); // Ensure we have an RGBA store
+
+        std::vector<Node> values;
+        constexpr std::size_t hardcoded_size{4};
+        for (std::size_t i = 0; i < hardcoded_size; ++i) {
+            values.push_back(GetRegister(instr.gpr0.Value() + i));
+        }
+
+        std::vector<Node> coords;
+        const std::size_t num_coords{GetImageTypeNumCoordinates(instr.sust.image_type)};
+        for (std::size_t i = 0; i < num_coords; ++i) {
+            coords.push_back(GetRegister(instr.gpr8.Value() + i));
+        }
+
+        ASSERT(instr.sust.is_immediate);
+        const auto& image{GetImage(instr.image, instr.sust.image_type)};
+        MetaImage meta{image, values};
+        const Node store{Operation(OperationCode::ImageStore, meta, std::move(coords))};
+        bb.push_back(store);
+        break;
+    }
+    default:
+        UNIMPLEMENTED_MSG("Unhandled conversion instruction: {}", opcode->get().GetName());
+    }
+
+    return pc;
+}
+
+const Image& ShaderIR::GetImage(Tegra::Shader::Image image, Tegra::Shader::ImageType type) {
+    const auto offset{static_cast<std::size_t>(image.index.Value())};
+
+    // If this image has already been used, return the existing mapping.
+    const auto itr{std::find_if(used_images.begin(), used_images.end(),
+                                [=](const Image& entry) { return entry.GetOffset() == offset; })};
+    if (itr != used_images.end()) {
+        ASSERT(itr->GetType() == type);
+        return *itr;
+    }
+
+    // Otherwise create a new mapping for this image.
+    const std::size_t next_index{used_images.size()};
+    const Image entry{offset, next_index, type};
+    return *used_images.emplace(entry).first;
+}
+
+} // namespace VideoCommon::Shader

src/video_core/shader/node.h

@@ -146,6 +146,8 @@ enum class OperationCode {
     TextureQueryLod,        /// (MetaTexture, float[N] coords) -> float4
     TexelFetch,             /// (MetaTexture, int[N], int) -> float4
 
+    ImageStore, /// (MetaImage, float[N] coords) -> void
+
     Branch,        /// (uint branch_target) -> void
     PushFlowStack, /// (uint branch_target) -> void
     PopFlowStack,  /// () -> void
@@ -263,6 +265,39 @@ private:
     bool is_bindless{}; ///< Whether this sampler belongs to a bindless texture or not.
 };
 
+class Image {
+public:
+    explicit Image(std::size_t offset, std::size_t index, Tegra::Shader::ImageType type)
+        : offset{offset}, index{index}, type{type}, is_bindless{false} {}
+
+    std::size_t GetOffset() const {
+        return offset;
+    }
+
+    std::size_t GetIndex() const {
+        return index;
+    }
+
+    Tegra::Shader::ImageType GetType() const {
+        return type;
+    }
+
+    bool IsBindless() const {
+        return is_bindless;
+    }
+
+    bool operator<(const Image& rhs) const {
+        return std::tie(offset, index, type, is_bindless) <
+               std::tie(rhs.offset, rhs.index, rhs.type, rhs.is_bindless);
+    }
+
+private:
+    std::size_t offset{};
+    std::size_t index{};
+    Tegra::Shader::ImageType type{};
+    bool is_bindless{};
+};
+
 struct GlobalMemoryBase {
     u32 cbuf_index{};
     u32 cbuf_offset{};
@@ -289,8 +324,13 @@ struct MetaTexture {
     u32 element{};
 };
 
+struct MetaImage {
+    const Image& image;
+    std::vector<Node> values;
+};
+
 /// Parameters that modify an operation but are not part of any particular operand
-using Meta = std::variant<MetaArithmetic, MetaTexture, MetaStackClass, Tegra::Shader::HalfType>;
+using Meta = std::variant<MetaArithmetic, MetaTexture, MetaImage, MetaStackClass, Tegra::Shader::HalfType>;
 
 /// Holds any kind of operation that can be done in the IR
 class OperationNode final {

src/video_core/shader/shader_ir.h

@@ -104,6 +104,10 @@ public:
         return used_samplers;
     }
 
+    const std::set<Image>& GetImages() const {
+        return used_images;
+    }
+
     const std::array<bool, Tegra::Engines::Maxwell3D::Regs::NumClipDistances>& GetClipDistances()
         const {
         return used_clip_distances;
@@ -154,6 +158,7 @@ private:
     u32 DecodeConversion(NodeBlock& bb, u32 pc);
     u32 DecodeMemory(NodeBlock& bb, u32 pc);
     u32 DecodeTexture(NodeBlock& bb, u32 pc);
+    u32 DecodeImage(NodeBlock& bb, u32 pc);
     u32 DecodeFloatSetPredicate(NodeBlock& bb, u32 pc);
     u32 DecodeIntegerSetPredicate(NodeBlock& bb, u32 pc);
     u32 DecodeHalfSetPredicate(NodeBlock& bb, u32 pc);
@@ -254,6 +259,9 @@ private:
                                       Tegra::Shader::TextureType type, bool is_array,
                                       bool is_shadow);
 
+    /// Accesses an image.
+    const Image& GetImage(Tegra::Shader::Image image, Tegra::Shader::ImageType type);
+
     /// Extracts a sequence of bits from a node
     Node BitfieldExtract(Node value, u32 offset, u32 bits);
 
@@ -329,6 +337,7 @@ private:
     std::set<Tegra::Shader::Attribute::Index> used_output_attributes;
     std::map<u32, ConstBuffer> used_cbufs;
     std::set<Sampler> used_samplers;
+    std::set<Image> used_images;
     std::array<bool, Tegra::Engines::Maxwell3D::Regs::NumClipDistances> used_clip_distances{};
     std::map<GlobalMemoryBase, GlobalMemoryUsage> used_global_memory;
     bool uses_physical_attributes{}; // Shader uses AL2P or physical attribute read/writes