5 files changed, 191 insertions, 0 deletions

diff --git a/src/shader_recompiler/CMakeLists.txt b/src/shader_recompiler/CMakeLists.txt
index 525b2363c..03f69c191 100644
--- a/src/shader_recompiler/CMakeLists.txt
+++ b/src/shader_recompiler/CMakeLists.txt
@@ -223,6 +223,7 @@ add_library(shader_recompiler STATIC
     ir_opt/identity_removal_pass.cpp
     ir_opt/layer_pass.cpp
     ir_opt/lower_fp16_to_fp32.cpp
+    ir_opt/lower_fp64_to_fp32.cpp
     ir_opt/lower_int64_to_int32.cpp
     ir_opt/passes.h
     ir_opt/position_pass.cpp
diff --git a/src/shader_recompiler/frontend/maxwell/translate_program.cpp b/src/shader_recompiler/frontend/maxwell/translate_program.cpp
index 17a6d4888..00d00e9f5 100644
--- a/src/shader_recompiler/frontend/maxwell/translate_program.cpp
+++ b/src/shader_recompiler/frontend/maxwell/translate_program.cpp
@@ -280,6 +280,9 @@ IR::Program TranslateProgram(ObjectPool<IR::Inst>& inst_pool, ObjectPool<IR::Blo
     RemoveUnreachableBlocks(program);
 
     // Replace instructions before the SSA rewrite
+    if (!host_info.support_float64) {
+        Optimization::LowerFp64ToFp32(program);
+    }
     if (!host_info.support_float16) {
         Optimization::LowerFp16ToFp32(program);
     }
diff --git a/src/shader_recompiler/host_translate_info.h b/src/shader_recompiler/host_translate_info.h
index 2aaa6c5ea..4c6322904 100644
--- a/src/shader_recompiler/host_translate_info.h
+++ b/src/shader_recompiler/host_translate_info.h
@@ -10,6 +10,7 @@ namespace Shader {
 
 /// Misc information about the host
 struct HostTranslateInfo {
+    bool support_float64{};      ///< True when the device supports 64-bit floats
     bool support_float16{};      ///< True when the device supports 16-bit floats
     bool support_int64{};        ///< True when the device supports 64-bit integers
     bool needs_demote_reorder{}; ///< True when the device needs DemoteToHelperInvocation reordered
diff --git a/src/shader_recompiler/ir_opt/lower_fp64_to_fp32.cpp b/src/shader_recompiler/ir_opt/lower_fp64_to_fp32.cpp
new file mode 100644
index 000000000..5db7a38ad
--- /dev/null
+++ b/src/shader_recompiler/ir_opt/lower_fp64_to_fp32.cpp
@@ -0,0 +1,185 @@
+// SPDX-FileCopyrightText: Copyright 2023 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "shader_recompiler/frontend/ir/ir_emitter.h"
+#include "shader_recompiler/frontend/ir/opcodes.h"
+#include "shader_recompiler/frontend/ir/value.h"
+#include "shader_recompiler/ir_opt/passes.h"
+
+namespace Shader::Optimization {
+namespace {
+
+constexpr s32 F64ToF32Exp = +1023 - 127;
+constexpr s32 F32ToF64Exp = +127 - 1023;
+
+IR::F32 PackedF64ToF32(IR::IREmitter& ir, const IR::Value& packed) {
+    const IR::U32 lo{ir.CompositeExtract(packed, 0)};
+    const IR::U32 hi{ir.CompositeExtract(packed, 1)};
+    const IR::U32 sign{ir.BitFieldExtract(hi, ir.Imm32(31), ir.Imm32(1))};
+    const IR::U32 exp{ir.BitFieldExtract(hi, ir.Imm32(20), ir.Imm32(11))};
+    const IR::U32 mantissa_hi{ir.BitFieldExtract(hi, ir.Imm32(0), ir.Imm32(20))};
+    const IR::U32 mantissa_lo{ir.BitFieldExtract(lo, ir.Imm32(29), ir.Imm32(3))};
+    const IR::U32 mantissa{
+        ir.BitwiseOr(ir.ShiftLeftLogical(mantissa_hi, ir.Imm32(3)), mantissa_lo)};
+    const IR::U32 exp_if_subnorm{
+        ir.Select(ir.IEqual(exp, ir.Imm32(0)), ir.Imm32(0), ir.IAdd(exp, ir.Imm32(F64ToF32Exp)))};
+    const IR::U32 exp_if_infnan{
+        ir.Select(ir.IEqual(exp, ir.Imm32(0x7ff)), ir.Imm32(0xff), exp_if_subnorm)};
+    const IR::U32 result{
+        ir.BitwiseOr(ir.ShiftLeftLogical(sign, ir.Imm32(31)),
+                     ir.BitwiseOr(ir.ShiftLeftLogical(exp_if_infnan, ir.Imm32(23)), mantissa))};
+    return ir.BitCast<IR::F32>(result);
+}
+
+IR::Value F32ToPackedF64(IR::IREmitter& ir, const IR::Value& raw) {
+    const IR::U32 value{ir.BitCast<IR::U32>(IR::F32(raw))};
+    const IR::U32 sign{ir.BitFieldExtract(value, ir.Imm32(31), ir.Imm32(1))};
+    const IR::U32 exp{ir.BitFieldExtract(value, ir.Imm32(23), ir.Imm32(8))};
+    const IR::U32 mantissa{ir.BitFieldExtract(value, ir.Imm32(0), ir.Imm32(23))};
+    const IR::U32 mantissa_hi{ir.BitFieldExtract(mantissa, ir.Imm32(3), ir.Imm32(20))};
+    const IR::U32 mantissa_lo{ir.BitFieldExtract(mantissa, ir.Imm32(0), ir.Imm32(3))};
+    const IR::U32 exp_if_subnorm{
+        ir.Select(ir.IEqual(exp, ir.Imm32(0)), ir.Imm32(0), ir.IAdd(exp, ir.Imm32(F32ToF64Exp)))};
+    const IR::U32 exp_if_infnan{
+        ir.Select(ir.IEqual(exp, ir.Imm32(0xff)), ir.Imm32(0x7ff), exp_if_subnorm)};
+    const IR::U32 lo{ir.ShiftLeftLogical(mantissa_lo, ir.Imm32(29))};
+    const IR::U32 hi{
+        ir.BitwiseOr(ir.ShiftLeftLogical(sign, ir.Imm32(31)),
+                     ir.BitwiseOr(ir.ShiftLeftLogical(exp_if_infnan, ir.Imm32(20)), mantissa_hi))};
+    return ir.CompositeConstruct(lo, hi);
+}
+
+IR::Opcode Replace(IR::Opcode op) {
+    switch (op) {
+    case IR::Opcode::FPAbs64:
+        return IR::Opcode::FPAbs32;
+    case IR::Opcode::FPAdd64:
+        return IR::Opcode::FPAdd32;
+    case IR::Opcode::FPCeil64:
+        return IR::Opcode::FPCeil32;
+    case IR::Opcode::FPFloor64:
+        return IR::Opcode::FPFloor32;
+    case IR::Opcode::FPFma64:
+        return IR::Opcode::FPFma32;
+    case IR::Opcode::FPMul64:
+        return IR::Opcode::FPMul32;
+    case IR::Opcode::FPNeg64:
+        return IR::Opcode::FPNeg32;
+    case IR::Opcode::FPRoundEven64:
+        return IR::Opcode::FPRoundEven32;
+    case IR::Opcode::FPSaturate64:
+        return IR::Opcode::FPSaturate32;
+    case IR::Opcode::FPClamp64:
+        return IR::Opcode::FPClamp32;
+    case IR::Opcode::FPTrunc64:
+        return IR::Opcode::FPTrunc32;
+    case IR::Opcode::CompositeConstructF64x2:
+        return IR::Opcode::CompositeConstructF32x2;
+    case IR::Opcode::CompositeConstructF64x3:
+        return IR::Opcode::CompositeConstructF32x3;
+    case IR::Opcode::CompositeConstructF64x4:
+        return IR::Opcode::CompositeConstructF32x4;
+    case IR::Opcode::CompositeExtractF64x2:
+        return IR::Opcode::CompositeExtractF32x2;
+    case IR::Opcode::CompositeExtractF64x3:
+        return IR::Opcode::CompositeExtractF32x3;
+    case IR::Opcode::CompositeExtractF64x4:
+        return IR::Opcode::CompositeExtractF32x4;
+    case IR::Opcode::CompositeInsertF64x2:
+        return IR::Opcode::CompositeInsertF32x2;
+    case IR::Opcode::CompositeInsertF64x3:
+        return IR::Opcode::CompositeInsertF32x3;
+    case IR::Opcode::CompositeInsertF64x4:
+        return IR::Opcode::CompositeInsertF32x4;
+    case IR::Opcode::FPOrdEqual64:
+        return IR::Opcode::FPOrdEqual32;
+    case IR::Opcode::FPUnordEqual64:
+        return IR::Opcode::FPUnordEqual32;
+    case IR::Opcode::FPOrdNotEqual64:
+        return IR::Opcode::FPOrdNotEqual32;
+    case IR::Opcode::FPUnordNotEqual64:
+        return IR::Opcode::FPUnordNotEqual32;
+    case IR::Opcode::FPOrdLessThan64:
+        return IR::Opcode::FPOrdLessThan32;
+    case IR::Opcode::FPUnordLessThan64:
+        return IR::Opcode::FPUnordLessThan32;
+    case IR::Opcode::FPOrdGreaterThan64:
+        return IR::Opcode::FPOrdGreaterThan32;
+    case IR::Opcode::FPUnordGreaterThan64:
+        return IR::Opcode::FPUnordGreaterThan32;
+    case IR::Opcode::FPOrdLessThanEqual64:
+        return IR::Opcode::FPOrdLessThanEqual32;
+    case IR::Opcode::FPUnordLessThanEqual64:
+        return IR::Opcode::FPUnordLessThanEqual32;
+    case IR::Opcode::FPOrdGreaterThanEqual64:
+        return IR::Opcode::FPOrdGreaterThanEqual32;
+    case IR::Opcode::FPUnordGreaterThanEqual64:
+        return IR::Opcode::FPUnordGreaterThanEqual32;
+    case IR::Opcode::FPIsNan64:
+        return IR::Opcode::FPIsNan32;
+    case IR::Opcode::ConvertS16F64:
+        return IR::Opcode::ConvertS16F32;
+    case IR::Opcode::ConvertS32F64:
+        return IR::Opcode::ConvertS32F32;
+    case IR::Opcode::ConvertS64F64:
+        return IR::Opcode::ConvertS64F32;
+    case IR::Opcode::ConvertU16F64:
+        return IR::Opcode::ConvertU16F32;
+    case IR::Opcode::ConvertU32F64:
+        return IR::Opcode::ConvertU32F32;
+    case IR::Opcode::ConvertU64F64:
+        return IR::Opcode::ConvertU64F32;
+    case IR::Opcode::ConvertF32F64:
+        return IR::Opcode::Identity;
+    case IR::Opcode::ConvertF64F32:
+        return IR::Opcode::Identity;
+    case IR::Opcode::ConvertF64S8:
+        return IR::Opcode::ConvertF32S8;
+    case IR::Opcode::ConvertF64S16:
+        return IR::Opcode::ConvertF32S16;
+    case IR::Opcode::ConvertF64S32:
+        return IR::Opcode::ConvertF32S32;
+    case IR::Opcode::ConvertF64S64:
+        return IR::Opcode::ConvertF32S64;
+    case IR::Opcode::ConvertF64U8:
+        return IR::Opcode::ConvertF32U8;
+    case IR::Opcode::ConvertF64U16:
+        return IR::Opcode::ConvertF32U16;
+    case IR::Opcode::ConvertF64U32:
+        return IR::Opcode::ConvertF32U32;
+    case IR::Opcode::ConvertF64U64:
+        return IR::Opcode::ConvertF32U64;
+    default:
+        return op;
+    }
+}
+
+void Lower(IR::Block& block, IR::Inst& inst) {
+    switch (inst.GetOpcode()) {
+    case IR::Opcode::PackDouble2x32: {
+        IR::IREmitter ir(block, IR::Block::InstructionList::s_iterator_to(inst));
+        inst.ReplaceUsesWith(PackedF64ToF32(ir, inst.Arg(0)));
+        break;
+    }
+    case IR::Opcode::UnpackDouble2x32: {
+        IR::IREmitter ir(block, IR::Block::InstructionList::s_iterator_to(inst));
+        inst.ReplaceUsesWith(F32ToPackedF64(ir, inst.Arg(0)));
+        break;
+    }
+    default:
+        inst.ReplaceOpcode(Replace(inst.GetOpcode()));
+        break;
+    }
+}
+
+} // Anonymous namespace
+
+void LowerFp64ToFp32(IR::Program& program) {
+    for (IR::Block* const block : program.blocks) {
+        for (IR::Inst& inst : block->Instructions()) {
+            Lower(*block, inst);
+        }
+    }
+}
+
+} // namespace Shader::Optimization
diff --git a/src/shader_recompiler/ir_opt/passes.h b/src/shader_recompiler/ir_opt/passes.h
index 1f8f2ba95..53606b78d 100644
--- a/src/shader_recompiler/ir_opt/passes.h
+++ b/src/shader_recompiler/ir_opt/passes.h
@@ -17,6 +17,7 @@ void ConstantPropagationPass(Environment& env, IR::Program& program);
 void DeadCodeEliminationPass(IR::Program& program);
 void GlobalMemoryToStorageBufferPass(IR::Program& program);
 void IdentityRemovalPass(IR::Program& program);
+void LowerFp64ToFp32(IR::Program& program);
 void LowerFp16ToFp32(IR::Program& program);
 void LowerInt64ToInt32(IR::Program& program);
 void RescalingPass(IR::Program& program);