shader_decode: Use BitfieldExtract instead of shift + and

src/video_core/renderer_opengl/gl_shader_decompiler.cpp

@@ -985,6 +985,11 @@ private:
                                   Type::Int);
     }
 
+    template <Type type>
+    std::string BitfieldExtract(Operation operation) {
+        return GenerateTernary(operation, "bitfieldExtract", type, type, Type::Int, Type::Int);
+    }
+
     template <Type type>
     std::string BitCount(Operation operation) {
         return GenerateUnary(operation, "bitCount", type, type, false);
@@ -1369,6 +1374,7 @@ private:
         &GLSLDecompiler::BitwiseXor<Type::Int>,
         &GLSLDecompiler::BitwiseNot<Type::Int>,
         &GLSLDecompiler::BitfieldInsert<Type::Int>,
+        &GLSLDecompiler::BitfieldExtract<Type::Int>,
         &GLSLDecompiler::BitCount<Type::Int>,
 
         &GLSLDecompiler::Add<Type::Uint>,
@@ -1386,6 +1392,7 @@ private:
         &GLSLDecompiler::BitwiseXor<Type::Uint>,
         &GLSLDecompiler::BitwiseNot<Type::Uint>,
         &GLSLDecompiler::BitfieldInsert<Type::Uint>,
+        &GLSLDecompiler::BitfieldExtract<Type::Uint>,
         &GLSLDecompiler::BitCount<Type::Uint>,
 
         &GLSLDecompiler::Add<Type::HalfFloat>,

src/video_core/shader/decode/arithmetic_integer.cpp

@@ -57,10 +57,9 @@ u32 ShaderIR::DecodeArithmeticInteger(BasicBlock& bb, u32 pc) {
             case IAdd3Height::None:
                 return value;
             case IAdd3Height::LowerHalfWord:
-                return Operation(OperationCode::IBitwiseAnd, NO_PRECISE, value, Immediate(0xffff));
+                return BitfieldExtract(value, 0, 16);
             case IAdd3Height::UpperHalfWord:
-                return Operation(OperationCode::ILogicalShiftRight, NO_PRECISE, value,
+                return BitfieldExtract(value, 16, 16);
-                                 Immediate(16));
             default:
                 UNIMPLEMENTED_MSG("Unhandled IADD3 height: {}", static_cast<u32>(height));
                 return Immediate(0);

src/video_core/shader/decode/bfi.cpp

@@ -28,13 +28,8 @@ u32 ShaderIR::DecodeBfi(BasicBlock& bb, u32 pc) {
         }
     }();
     const Node insert = GetRegister(instr.gpr8);
-
+    const Node offset = BitfieldExtract(packed_shift, 0, 8);
-    const Node offset =
+    const Node bits = BitfieldExtract(packed_shift, 8, 8);
-        Operation(OperationCode::UBitwiseAnd, NO_PRECISE, packed_shift, Immediate(0xff));
-
-    Node bits =
-        Operation(OperationCode::ULogicalShiftRight, NO_PRECISE, packed_shift, Immediate(8));
-    bits = Operation(OperationCode::UBitwiseAnd, NO_PRECISE, bits, Immediate(0xff));
 
     const Node value =
         Operation(OperationCode::UBitfieldInsert, PRECISE, base, insert, offset, bits);

src/video_core/shader/decode/register_set_predicate.cpp

@@ -27,20 +27,18 @@ u32 ShaderIR::DecodeRegisterSetPredicate(BasicBlock& bb, u32 pc) {
             return Immediate(static_cast<u32>(instr.r2p.immediate_mask));
         }
     }();
-    const Node mask =
+    const Node mask = GetRegister(instr.gpr8);
-        Operation(OperationCode::ULogicalShiftRight, NO_PRECISE, GetRegister(instr.gpr8),
+    const auto offset = static_cast<u32>(instr.r2p.byte) * 8;
-                  Immediate(static_cast<u32>(instr.r2p.byte)));
 
     constexpr u32 programmable_preds = 7;
     for (u64 pred = 0; pred < programmable_preds; ++pred) {
-        const Node shift = Immediate(1u << static_cast<u32>(pred));
+        const auto shift = static_cast<u32>(pred);
 
-        const Node apply_compare =
+        const Node apply_compare = BitfieldExtract(apply_mask, shift, 1);
-            Operation(OperationCode::UBitwiseAnd, NO_PRECISE, apply_mask, shift);
         const Node condition =
             Operation(OperationCode::LogicalUNotEqual, apply_compare, Immediate(0));
 
-        const Node value_compare = Operation(OperationCode::UBitwiseAnd, NO_PRECISE, mask, shift);
+        const Node value_compare = BitfieldExtract(mask, offset + shift, 1);
         const Node value = Operation(OperationCode::LogicalUNotEqual, value_compare, Immediate(0));
 
         const Node code = Operation(OperationCode::LogicalAssign, GetPredicate(pred), value);

src/video_core/shader/decode/video.cpp

@@ -88,21 +88,15 @@ u32 ShaderIR::DecodeVideo(BasicBlock& bb, u32 pc) {
 Node ShaderIR::GetVideoOperand(Node op, bool is_chunk, bool is_signed,
                                Tegra::Shader::VideoType type, u64 byte_height) {
     if (!is_chunk) {
-        const auto offset = static_cast<u32>(byte_height * 8);
+        return BitfieldExtract(op, static_cast<u32>(byte_height * 8), 8);
-        const Node shift = SignedOperation(OperationCode::ILogicalShiftRight, is_signed, NO_PRECISE,
-                                           op, Immediate(offset));
-        return SignedOperation(OperationCode::IBitwiseAnd, is_signed, NO_PRECISE, shift,
-                               Immediate(0xff));
     }
     const Node zero = Immediate(0);
 
     switch (type) {
     case Tegra::Shader::VideoType::Size16_Low:
-        return SignedOperation(OperationCode::IBitwiseAnd, is_signed, NO_PRECISE, op,
+        return BitfieldExtract(op, 0, 16);
-                               Immediate(0xffff));
     case Tegra::Shader::VideoType::Size16_High:
-        return SignedOperation(OperationCode::ILogicalShiftRight, is_signed, NO_PRECISE, op,
+        return BitfieldExtract(op, 16, 16);
-                               Immediate(16));
     case Tegra::Shader::VideoType::Size32:
         // TODO(Rodrigo): From my hardware tests it becomes a bit "mad" when this type is used
         // (1 * 1 + 0 == 0x5b800000). Until a better explanation is found: abort.

src/video_core/shader/decode/xmad.cpp

@@ -47,22 +47,10 @@ u32 ShaderIR::DecodeXmad(BasicBlock& bb, u32 pc) {
         return {false, Immediate(0), Immediate(0)};
     }();
 
-    if (instr.xmad.high_a) {
+    op_a = BitfieldExtract(op_a, instr.xmad.high_a ? 16 : 0, 16);
-        op_a = SignedOperation(OperationCode::ILogicalShiftRight, is_signed_a, NO_PRECISE, op_a,
-                               Immediate(16));
-    } else {
-        op_a = SignedOperation(OperationCode::IBitwiseAnd, is_signed_a, NO_PRECISE, op_a,
-                               Immediate(0xffff));
-    }
 
     const Node original_b = op_b;
-    if (instr.xmad.high_b) {
+    op_b = BitfieldExtract(op_b, instr.xmad.high_b ? 16 : 0, 16);
-        op_b = SignedOperation(OperationCode::ILogicalShiftRight, is_signed_b, NO_PRECISE, op_a,
-                               Immediate(16));
-    } else {
-        op_b = SignedOperation(OperationCode::IBitwiseAnd, is_signed_b, NO_PRECISE, op_b,
-                               Immediate(0xffff));
-    }
 
     // TODO(Rodrigo): Use an appropiate sign for this operation
     Node product = Operation(OperationCode::IMul, NO_PRECISE, op_a, op_b);
@@ -75,11 +63,9 @@ u32 ShaderIR::DecodeXmad(BasicBlock& bb, u32 pc) {
         case Tegra::Shader::XmadMode::None:
             return op_c;
         case Tegra::Shader::XmadMode::CLo:
-            return SignedOperation(OperationCode::IBitwiseAnd, is_signed_c, NO_PRECISE, op_c,
+            return BitfieldExtract(op_c, 0, 16);
-                                   Immediate(0xffff));
         case Tegra::Shader::XmadMode::CHi:
-            return SignedOperation(OperationCode::ILogicalShiftRight, is_signed_c, NO_PRECISE, op_c,
+            return BitfieldExtract(op_c, 16, 16);
-                                   Immediate(16));
         case Tegra::Shader::XmadMode::CBcc: {
             const Node shifted_b = SignedOperation(OperationCode::ILogicalShiftLeft, is_signed_b,
                                                    NO_PRECISE, original_b, Immediate(16));
@@ -94,9 +80,9 @@ u32 ShaderIR::DecodeXmad(BasicBlock& bb, u32 pc) {
     // TODO(Rodrigo): Use an appropiate sign for this operation
     Node sum = Operation(OperationCode::IAdd, product, op_c);
     if (is_merge) {
-        const Node a = Operation(OperationCode::IBitwiseAnd, NO_PRECISE, sum, Immediate(0xffff));
+        const Node a = BitfieldExtract(sum, 0, 16);
         const Node b =
-            Operation(OperationCode::ILogicalShiftLeft, NO_PRECISE, original_b, Immediate(0xffff));
+            Operation(OperationCode::ILogicalShiftLeft, NO_PRECISE, original_b, Immediate(16));
         sum = Operation(OperationCode::IBitwiseOr, NO_PRECISE, a, b);
     }
 

src/video_core/shader/shader_ir.cpp

@@ -348,6 +348,11 @@ void ShaderIR::SetLocalMemory(BasicBlock& bb, Node address, Node value) {
     bb.push_back(Operation(OperationCode::Assign, GetLocalMemory(address), value));
 }
 
+Node ShaderIR::BitfieldExtract(Node value, u32 offset, u32 bits) {
+    return Operation(OperationCode::UBitfieldExtract, NO_PRECISE, value, Immediate(offset),
+                     Immediate(bits));
+}
+
 /*static*/ OperationCode ShaderIR::SignedToUnsignedCode(OperationCode operation_code,
                                                         bool is_signed) {
     if (is_signed) {

src/video_core/shader/shader_ir.h

@@ -88,6 +88,7 @@ enum class OperationCode {
     IBitwiseXor,           /// (MetaArithmetic, int a, int b) -> int
     IBitwiseNot,           /// (MetaArithmetic, int a) -> int
     IBitfieldInsert,       /// (MetaArithmetic, int base, int insert, int offset, int bits) -> int
+    IBitfieldExtract,      /// (MetaArithmetic, int value, int offset, int offset) -> int
     IBitCount,             /// (MetaArithmetic, int) -> int
 
     UAdd,                  /// (MetaArithmetic, uint a, uint b) -> uint
@@ -104,8 +105,9 @@ enum class OperationCode {
     UBitwiseOr,            /// (MetaArithmetic, uint a, uint b) -> uint
     UBitwiseXor,           /// (MetaArithmetic, uint a, uint b) -> uint
     UBitwiseNot,           /// (MetaArithmetic, uint a) -> uint
-    UBitfieldInsert, /// (MetaArithmetic, uint base, uint insert, int offset, int bits) -> uint
+    UBitfieldInsert,  /// (MetaArithmetic, uint base, uint insert, int offset, int bits) -> uint
-    UBitCount,       /// (MetaArithmetic, uint) -> uint
+    UBitfieldExtract, /// (MetaArithmetic, uint value, int offset, int offset) -> uint
+    UBitCount,        /// (MetaArithmetic, uint) -> uint
 
     HAdd,      /// (MetaHalfArithmetic, f16vec2 a, f16vec2 b) -> f16vec2
     HMul,      /// (MetaHalfArithmetic, f16vec2 a, f16vec2 b) -> f16vec2
@@ -689,6 +691,9 @@ private:
     const Sampler& GetSampler(const Tegra::Shader::Sampler& sampler,
                               Tegra::Shader::TextureType type, bool is_array, bool is_shadow);
 
+    /// Extracts a sequence of bits from a node
+    Node BitfieldExtract(Node value, u32 offset, u32 bits);
+
     void WriteTexsInstructionFloat(BasicBlock& bb, Tegra::Shader::Instruction instr, Node texture);
     void WriteTexsInstructionHalfFloat(BasicBlock& bb, Tegra::Shader::Instruction instr,
                                        Node texture);