1 files changed, 327 insertions, 0 deletions

diff --git a/src/shader_recompiler/ir_opt/rescaling_pass.cpp b/src/shader_recompiler/ir_opt/rescaling_pass.cpp
new file mode 100644
index 000000000..c28500dd1
--- /dev/null
+++ b/src/shader_recompiler/ir_opt/rescaling_pass.cpp
@@ -0,0 +1,327 @@
+// Copyright 2021 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include "common/alignment.h"
+#include "common/settings.h"
+#include "shader_recompiler/environment.h"
+#include "shader_recompiler/frontend/ir/ir_emitter.h"
+#include "shader_recompiler/frontend/ir/modifiers.h"
+#include "shader_recompiler/frontend/ir/program.h"
+#include "shader_recompiler/frontend/ir/value.h"
+#include "shader_recompiler/ir_opt/passes.h"
+#include "shader_recompiler/shader_info.h"
+
+namespace Shader::Optimization {
+namespace {
+[[nodiscard]] bool IsTextureTypeRescalable(TextureType type) {
+    switch (type) {
+    case TextureType::Color2D:
+    case TextureType::ColorArray2D:
+        return true;
+    case TextureType::Color1D:
+    case TextureType::ColorArray1D:
+    case TextureType::Color3D:
+    case TextureType::ColorCube:
+    case TextureType::ColorArrayCube:
+    case TextureType::Buffer:
+        break;
+    }
+    return false;
+}
+
+void VisitMark(IR::Block& block, IR::Inst& inst) {
+    switch (inst.GetOpcode()) {
+    case IR::Opcode::ShuffleIndex:
+    case IR::Opcode::ShuffleUp:
+    case IR::Opcode::ShuffleDown:
+    case IR::Opcode::ShuffleButterfly: {
+        const IR::Value shfl_arg{inst.Arg(0)};
+        if (shfl_arg.IsImmediate()) {
+            break;
+        }
+        const IR::Inst* const arg_inst{shfl_arg.InstRecursive()};
+        if (arg_inst->GetOpcode() != IR::Opcode::BitCastU32F32) {
+            break;
+        }
+        const IR::Value bitcast_arg{arg_inst->Arg(0)};
+        if (bitcast_arg.IsImmediate()) {
+            break;
+        }
+        IR::Inst* const bitcast_inst{bitcast_arg.InstRecursive()};
+        bool must_patch_outside = false;
+        if (bitcast_inst->GetOpcode() == IR::Opcode::GetAttribute) {
+            const IR::Attribute attr{bitcast_inst->Arg(0).Attribute()};
+            switch (attr) {
+            case IR::Attribute::PositionX:
+            case IR::Attribute::PositionY:
+                bitcast_inst->SetFlags<u32>(0xDEADBEEF);
+                must_patch_outside = true;
+                break;
+            default:
+                break;
+            }
+        }
+        if (must_patch_outside) {
+            const auto it{IR::Block::InstructionList::s_iterator_to(inst)};
+            IR::IREmitter ir{block, IR::Block::InstructionList::s_iterator_to(inst)};
+            const IR::F32 new_inst{&*block.PrependNewInst(it, inst)};
+            const IR::F32 up_factor{ir.FPRecip(ir.ResolutionDownFactor())};
+            const IR::Value converted{ir.FPMul(new_inst, up_factor)};
+            inst.ReplaceUsesWith(converted);
+        }
+        break;
+    }
+
+    default:
+        break;
+    }
+}
+
+void PatchFragCoord(IR::Block& block, IR::Inst& inst) {
+    IR::IREmitter ir{block, IR::Block::InstructionList::s_iterator_to(inst)};
+    const IR::F32 down_factor{ir.ResolutionDownFactor()};
+    const IR::F32 frag_coord{ir.GetAttribute(inst.Arg(0).Attribute())};
+    const IR::F32 downscaled_frag_coord{ir.FPMul(frag_coord, down_factor)};
+    inst.ReplaceUsesWith(downscaled_frag_coord);
+}
+
+void PatchPointSize(IR::Block& block, IR::Inst& inst) {
+    IR::IREmitter ir{block, IR::Block::InstructionList::s_iterator_to(inst)};
+    const IR::F32 point_value{inst.Arg(1)};
+    const IR::F32 up_factor{ir.FPRecip(ir.ResolutionDownFactor())};
+    const IR::F32 upscaled_point_value{ir.FPMul(point_value, up_factor)};
+    inst.SetArg(1, upscaled_point_value);
+}
+
+[[nodiscard]] IR::U32 Scale(IR::IREmitter& ir, const IR::U1& is_scaled, const IR::U32& value) {
+    IR::U32 scaled_value{value};
+    if (const u32 up_scale = Settings::values.resolution_info.up_scale; up_scale != 1) {
+        scaled_value = ir.IMul(scaled_value, ir.Imm32(up_scale));
+    }
+    if (const u32 down_shift = Settings::values.resolution_info.down_shift; down_shift != 0) {
+        scaled_value = ir.ShiftRightArithmetic(scaled_value, ir.Imm32(down_shift));
+    }
+    return IR::U32{ir.Select(is_scaled, scaled_value, value)};
+}
+
+[[nodiscard]] IR::U32 SubScale(IR::IREmitter& ir, const IR::U1& is_scaled, const IR::U32& value,
+                               const IR::Attribute attrib) {
+    const IR::F32 up_factor{ir.Imm32(Settings::values.resolution_info.up_factor)};
+    const IR::F32 base{ir.FPMul(ir.ConvertUToF(32, 32, value), up_factor)};
+    const IR::F32 frag_coord{ir.GetAttribute(attrib)};
+    const IR::F32 down_factor{ir.Imm32(Settings::values.resolution_info.down_factor)};
+    const IR::F32 floor{ir.FPMul(up_factor, ir.FPFloor(ir.FPMul(frag_coord, down_factor)))};
+    const IR::F16F32F64 deviation{ir.FPAdd(base, ir.FPAdd(frag_coord, ir.FPNeg(floor)))};
+    return IR::U32{ir.Select(is_scaled, ir.ConvertFToU(32, deviation), value)};
+}
+
+[[nodiscard]] IR::U32 DownScale(IR::IREmitter& ir, const IR::U1& is_scaled, const IR::U32& value) {
+    IR::U32 scaled_value{value};
+    if (const u32 down_shift = Settings::values.resolution_info.down_shift; down_shift != 0) {
+        scaled_value = ir.ShiftLeftLogical(scaled_value, ir.Imm32(down_shift));
+    }
+    if (const u32 up_scale = Settings::values.resolution_info.up_scale; up_scale != 1) {
+        scaled_value = ir.IDiv(scaled_value, ir.Imm32(up_scale));
+    }
+    return IR::U32{ir.Select(is_scaled, scaled_value, value)};
+}
+
+void PatchImageQueryDimensions(IR::Block& block, IR::Inst& inst) {
+    const auto it{IR::Block::InstructionList::s_iterator_to(inst)};
+    IR::IREmitter ir{block, IR::Block::InstructionList::s_iterator_to(inst)};
+    const auto info{inst.Flags<IR::TextureInstInfo>()};
+    const IR::U1 is_scaled{ir.IsTextureScaled(ir.Imm32(info.descriptor_index))};
+    switch (info.type) {
+    case TextureType::Color2D:
+    case TextureType::ColorArray2D: {
+        const IR::Value new_inst{&*block.PrependNewInst(it, inst)};
+        const IR::U32 width{DownScale(ir, is_scaled, IR::U32{ir.CompositeExtract(new_inst, 0)})};
+        const IR::U32 height{DownScale(ir, is_scaled, IR::U32{ir.CompositeExtract(new_inst, 1)})};
+        const IR::Value replacement{ir.CompositeConstruct(
+            width, height, ir.CompositeExtract(new_inst, 2), ir.CompositeExtract(new_inst, 3))};
+        inst.ReplaceUsesWith(replacement);
+        break;
+    }
+    case TextureType::Color1D:
+    case TextureType::ColorArray1D:
+    case TextureType::Color3D:
+    case TextureType::ColorCube:
+    case TextureType::ColorArrayCube:
+    case TextureType::Buffer:
+        // Nothing to patch here
+        break;
+    }
+}
+
+void ScaleIntegerComposite(IR::IREmitter& ir, IR::Inst& inst, const IR::U1& is_scaled,
+                           size_t index) {
+    const IR::Value composite{inst.Arg(index)};
+    if (composite.IsEmpty()) {
+        return;
+    }
+    const auto info{inst.Flags<IR::TextureInstInfo>()};
+    const IR::U32 x{Scale(ir, is_scaled, IR::U32{ir.CompositeExtract(composite, 0)})};
+    const IR::U32 y{Scale(ir, is_scaled, IR::U32{ir.CompositeExtract(composite, 1)})};
+    switch (info.type) {
+    case TextureType::Color2D:
+        inst.SetArg(index, ir.CompositeConstruct(x, y));
+        break;
+    case TextureType::ColorArray2D: {
+        const IR::U32 z{ir.CompositeExtract(composite, 2)};
+        inst.SetArg(index, ir.CompositeConstruct(x, y, z));
+        break;
+    }
+    case TextureType::Color1D:
+    case TextureType::ColorArray1D:
+    case TextureType::Color3D:
+    case TextureType::ColorCube:
+    case TextureType::ColorArrayCube:
+    case TextureType::Buffer:
+        // Nothing to patch here
+        break;
+    }
+}
+
+void SubScaleCoord(IR::IREmitter& ir, IR::Inst& inst, const IR::U1& is_scaled) {
+    const auto info{inst.Flags<IR::TextureInstInfo>()};
+    const IR::Value coord{inst.Arg(1)};
+    const IR::U32 coord_x{ir.CompositeExtract(coord, 0)};
+    const IR::U32 coord_y{ir.CompositeExtract(coord, 1)};
+
+    const IR::U32 scaled_x{SubScale(ir, is_scaled, coord_x, IR::Attribute::PositionX)};
+    const IR::U32 scaled_y{SubScale(ir, is_scaled, coord_y, IR::Attribute::PositionY)};
+    switch (info.type) {
+    case TextureType::Color2D:
+        inst.SetArg(1, ir.CompositeConstruct(scaled_x, scaled_y));
+        break;
+    case TextureType::ColorArray2D: {
+        const IR::U32 z{ir.CompositeExtract(coord, 2)};
+        inst.SetArg(1, ir.CompositeConstruct(scaled_x, scaled_y, z));
+        break;
+    }
+    case TextureType::Color1D:
+    case TextureType::ColorArray1D:
+    case TextureType::Color3D:
+    case TextureType::ColorCube:
+    case TextureType::ColorArrayCube:
+    case TextureType::Buffer:
+        // Nothing to patch here
+        break;
+    }
+}
+
+void SubScaleImageFetch(IR::Block& block, IR::Inst& inst) {
+    IR::IREmitter ir{block, IR::Block::InstructionList::s_iterator_to(inst)};
+    const auto info{inst.Flags<IR::TextureInstInfo>()};
+    if (!IsTextureTypeRescalable(info.type)) {
+        return;
+    }
+    const IR::U1 is_scaled{ir.IsTextureScaled(ir.Imm32(info.descriptor_index))};
+    SubScaleCoord(ir, inst, is_scaled);
+    // Scale ImageFetch offset
+    ScaleIntegerComposite(ir, inst, is_scaled, 2);
+}
+
+void SubScaleImageRead(IR::Block& block, IR::Inst& inst) {
+    IR::IREmitter ir{block, IR::Block::InstructionList::s_iterator_to(inst)};
+    const auto info{inst.Flags<IR::TextureInstInfo>()};
+    if (!IsTextureTypeRescalable(info.type)) {
+        return;
+    }
+    const IR::U1 is_scaled{ir.IsImageScaled(ir.Imm32(info.descriptor_index))};
+    SubScaleCoord(ir, inst, is_scaled);
+}
+
+void PatchImageFetch(IR::Block& block, IR::Inst& inst) {
+    IR::IREmitter ir{block, IR::Block::InstructionList::s_iterator_to(inst)};
+    const auto info{inst.Flags<IR::TextureInstInfo>()};
+    if (!IsTextureTypeRescalable(info.type)) {
+        return;
+    }
+    const IR::U1 is_scaled{ir.IsTextureScaled(ir.Imm32(info.descriptor_index))};
+    ScaleIntegerComposite(ir, inst, is_scaled, 1);
+    // Scale ImageFetch offset
+    ScaleIntegerComposite(ir, inst, is_scaled, 2);
+}
+
+void PatchImageRead(IR::Block& block, IR::Inst& inst) {
+    IR::IREmitter ir{block, IR::Block::InstructionList::s_iterator_to(inst)};
+    const auto info{inst.Flags<IR::TextureInstInfo>()};
+    if (!IsTextureTypeRescalable(info.type)) {
+        return;
+    }
+    const IR::U1 is_scaled{ir.IsImageScaled(ir.Imm32(info.descriptor_index))};
+    ScaleIntegerComposite(ir, inst, is_scaled, 1);
+}
+
+void Visit(const IR::Program& program, IR::Block& block, IR::Inst& inst) {
+    const bool is_fragment_shader{program.stage == Stage::Fragment};
+    switch (inst.GetOpcode()) {
+    case IR::Opcode::GetAttribute: {
+        const IR::Attribute attr{inst.Arg(0).Attribute()};
+        switch (attr) {
+        case IR::Attribute::PositionX:
+        case IR::Attribute::PositionY:
+            if (is_fragment_shader && inst.Flags<u32>() != 0xDEADBEEF) {
+                PatchFragCoord(block, inst);
+            }
+            break;
+        default:
+            break;
+        }
+        break;
+    }
+    case IR::Opcode::SetAttribute: {
+        const IR::Attribute attr{inst.Arg(0).Attribute()};
+        switch (attr) {
+        case IR::Attribute::PointSize:
+            if (inst.Flags<u32>() != 0xDEADBEEF) {
+                PatchPointSize(block, inst);
+            }
+            break;
+        default:
+            break;
+        }
+        break;
+    }
+    case IR::Opcode::ImageQueryDimensions:
+        PatchImageQueryDimensions(block, inst);
+        break;
+    case IR::Opcode::ImageFetch:
+        if (is_fragment_shader) {
+            SubScaleImageFetch(block, inst);
+        } else {
+            PatchImageFetch(block, inst);
+        }
+        break;
+    case IR::Opcode::ImageRead:
+        if (is_fragment_shader) {
+            SubScaleImageRead(block, inst);
+        } else {
+            PatchImageRead(block, inst);
+        }
+        break;
+    default:
+        break;
+    }
+}
+} // Anonymous namespace
+
+void RescalingPass(IR::Program& program) {
+    const bool is_fragment_shader{program.stage == Stage::Fragment};
+    if (is_fragment_shader) {
+        for (IR::Block* const block : program.post_order_blocks) {
+            for (IR::Inst& inst : block->Instructions()) {
+                VisitMark(*block, inst);
+            }
+        }
+    }
+    for (IR::Block* const block : program.post_order_blocks) {
+        for (IR::Inst& inst : block->Instructions()) {
+            Visit(program, *block, inst);
+        }
+    }
+}
+
+} // namespace Shader::Optimization