5 files changed, 35 insertions, 0 deletions

diff --git a/src/video_core/engines/shader_bytecode.h b/src/video_core/engines/shader_bytecode.h
index f8d67e227..16f410538 100644
--- a/src/video_core/engines/shader_bytecode.h
+++ b/src/video_core/engines/shader_bytecode.h
@@ -800,6 +800,12 @@ union Instruction {
     } popc;
 
     union {
+        BitField<41, 1, u64> sh;
+        BitField<40, 1, u64> invert;
+        BitField<48, 1, u64> is_signed;
+    } flo;
+
+    union {
         BitField<39, 3, u64> pred;
         BitField<42, 1, u64> neg_pred;
     } sel;
diff --git a/src/video_core/renderer_opengl/gl_shader_decompiler.cpp b/src/video_core/renderer_opengl/gl_shader_decompiler.cpp
index e56ed51de..b87ee2ae8 100644
--- a/src/video_core/renderer_opengl/gl_shader_decompiler.cpp
+++ b/src/video_core/renderer_opengl/gl_shader_decompiler.cpp
@@ -1472,6 +1472,11 @@ private:
         return GenerateUnary(operation, "bitCount", type, type);
     }
 
+    template <Type type>
+    Expression BitMSB(Operation operation) {
+        return GenerateUnary(operation, "findMSB", type, type);
+    }
+
     Expression HNegate(Operation operation) {
         const auto GetNegate = [&](std::size_t index) {
             return VisitOperand(operation, index).AsBool() + " ? -1 : 1";
@@ -2043,6 +2048,7 @@ private:
         &GLSLDecompiler::BitfieldInsert<Type::Int>,
         &GLSLDecompiler::BitfieldExtract<Type::Int>,
         &GLSLDecompiler::BitCount<Type::Int>,
+        &GLSLDecompiler::BitMSB<Type::Int>,
 
         &GLSLDecompiler::Add<Type::Uint>,
         &GLSLDecompiler::Mul<Type::Uint>,
@@ -2061,6 +2067,7 @@ private:
         &GLSLDecompiler::BitfieldInsert<Type::Uint>,
         &GLSLDecompiler::BitfieldExtract<Type::Uint>,
         &GLSLDecompiler::BitCount<Type::Uint>,
+        &GLSLDecompiler::BitMSB<Type::Uint>,
 
         &GLSLDecompiler::Add<Type::HalfFloat>,
         &GLSLDecompiler::Mul<Type::HalfFloat>,
diff --git a/src/video_core/renderer_vulkan/vk_shader_decompiler.cpp b/src/video_core/renderer_vulkan/vk_shader_decompiler.cpp
index 2850d5b59..8378b35ac 100644
--- a/src/video_core/renderer_vulkan/vk_shader_decompiler.cpp
+++ b/src/video_core/renderer_vulkan/vk_shader_decompiler.cpp
@@ -1390,6 +1390,7 @@ private:
         &SPIRVDecompiler::Quaternary<&Module::OpBitFieldInsert, Type::Int>,
         &SPIRVDecompiler::Ternary<&Module::OpBitFieldSExtract, Type::Int>,
         &SPIRVDecompiler::Unary<&Module::OpBitCount, Type::Int>,
+        &SPIRVDecompiler::Unary<&Module::OpFindSMsb, Type::Int>,
 
         &SPIRVDecompiler::Binary<&Module::OpIAdd, Type::Uint>,
         &SPIRVDecompiler::Binary<&Module::OpIMul, Type::Uint>,
@@ -1408,6 +1409,7 @@ private:
         &SPIRVDecompiler::Quaternary<&Module::OpBitFieldInsert, Type::Uint>,
         &SPIRVDecompiler::Ternary<&Module::OpBitFieldUExtract, Type::Uint>,
         &SPIRVDecompiler::Unary<&Module::OpBitCount, Type::Uint>,
+        &SPIRVDecompiler::Unary<&Module::OpFindUMsb, Type::Uint>,
 
         &SPIRVDecompiler::Binary<&Module::OpFAdd, Type::HalfFloat>,
         &SPIRVDecompiler::Binary<&Module::OpFMul, Type::HalfFloat>,
diff --git a/src/video_core/shader/decode/arithmetic_integer.cpp b/src/video_core/shader/decode/arithmetic_integer.cpp
index a33d242e9..9208b7bef 100644
--- a/src/video_core/shader/decode/arithmetic_integer.cpp
+++ b/src/video_core/shader/decode/arithmetic_integer.cpp
@@ -130,6 +130,24 @@ u32 ShaderIR::DecodeArithmeticInteger(NodeBlock& bb, u32 pc) {
         SetRegister(bb, instr.gpr0, value);
         break;
     }
+    case OpCode::Id::FLO_R:
+    case OpCode::Id::FLO_C:
+    case OpCode::Id::FLO_IMM: {
+        Node value;
+        if (instr.flo.invert) {
+            op_b = Operation(OperationCode::IBitwiseNot, NO_PRECISE, op_b);
+        }
+        if (instr.flo.is_signed) {
+            value = Operation(OperationCode::IBitMSB, NO_PRECISE, op_b);
+        } else {
+            value = Operation(OperationCode::UBitMSB, NO_PRECISE, op_b);
+        }
+        if (instr.flo.sh) {
+            value = Operation(OperationCode::UBitwiseXor, NO_PRECISE, value, Immediate(31));
+        }
+        SetRegister(bb, instr.gpr0, value);
+        break;
+    }
     case OpCode::Id::SEL_C:
     case OpCode::Id::SEL_R:
     case OpCode::Id::SEL_IMM: {
diff --git a/src/video_core/shader/node.h b/src/video_core/shader/node.h
index 54217e6a4..2d11facaf 100644
--- a/src/video_core/shader/node.h
+++ b/src/video_core/shader/node.h
@@ -68,6 +68,7 @@ enum class OperationCode {
     IBitfieldInsert,       /// (MetaArithmetic, int base, int insert, int offset, int bits) -> int
     IBitfieldExtract,      /// (MetaArithmetic, int value, int offset, int offset) -> int
     IBitCount,             /// (MetaArithmetic, int) -> int
+    IBitMSB,               /// (MetaArithmetic, int) -> int
 
     UAdd,                  /// (MetaArithmetic, uint a, uint b) -> uint
     UMul,                  /// (MetaArithmetic, uint a, uint b) -> uint
@@ -86,6 +87,7 @@ enum class OperationCode {
     UBitfieldInsert,  /// (MetaArithmetic, uint base, uint insert, int offset, int bits) -> uint
     UBitfieldExtract, /// (MetaArithmetic, uint value, int offset, int offset) -> uint
     UBitCount,        /// (MetaArithmetic, uint) -> uint
+    UBitMSB,          /// (MetaArithmetic, uint) -> uint
 
     HAdd,       /// (MetaArithmetic, f16vec2 a, f16vec2 b) -> f16vec2
     HMul,       /// (MetaArithmetic, f16vec2 a, f16vec2 b) -> f16vec2