Shader: Initial implementation of x86_x64 JIT compiler for Pica vertex shaders.

- Config: Add an option for selecting to use shader JIT or interpreter.
- Qt: Add a menu option for enabling/disabling the shader JIT.

src/video_core/shader/shader_jit.h

@@ -0,0 +1,85 @@
+// Copyright 2015 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <nihstro/shader_bytecode.h>
+
+#if defined(_M_X86_64)
+#include "common/x64_emitter.h"
+#else
+#include "common/fake_emitter.h"
+#endif
+
+#include "video_core/pica.h"
+
+#include "shader.h"
+
+using nihstro::Instruction;
+using nihstro::OpCode;
+using nihstro::SwizzlePattern;
+
+namespace Pica {
+
+namespace Shader {
+
+using CompiledShader = void(void* state);
+
+/**
+ * This class implements the shader JIT compiler. It recompiles a Pica shader program into x86_64
+ * code that can be executed on the host machine directly.
+ */
+class JitCompiler : public Gen::XCodeBlock {
+public:
+    JitCompiler();
+
+    CompiledShader* Compile();
+
+    void Clear();
+
+    void Compile_ADD(Instruction instr);
+    void Compile_DP3(Instruction instr);
+    void Compile_DP4(Instruction instr);
+    void Compile_MUL(Instruction instr);
+    void Compile_FLR(Instruction instr);
+    void Compile_MAX(Instruction instr);
+    void Compile_MIN(Instruction instr);
+    void Compile_RCP(Instruction instr);
+    void Compile_RSQ(Instruction instr);
+    void Compile_MOVA(Instruction instr);
+    void Compile_MOV(Instruction instr);
+    void Compile_SLTI(Instruction instr);
+    void Compile_NOP(Instruction instr);
+    void Compile_END(Instruction instr);
+    void Compile_CALL(Instruction instr);
+    void Compile_CALLC(Instruction instr);
+    void Compile_CALLU(Instruction instr);
+    void Compile_IF(Instruction instr);
+    void Compile_LOOP(Instruction instr);
+    void Compile_JMP(Instruction instr);
+    void Compile_CMP(Instruction instr);
+    void Compile_MAD(Instruction instr);
+
+private:
+    void Compile_Block(unsigned stop);
+    void Compile_NextInstr(unsigned* offset);
+
+#if defined(_M_X86_64)
+    void Compile_SwizzleSrc(Instruction instr, unsigned src_num, SourceRegister src_reg, Gen::X64Reg dest);
+    void Compile_DestEnable(Instruction instr, Gen::X64Reg dest);
+
+    void Compile_EvaluateCondition(Instruction instr);
+    void Compile_UniformCondition(Instruction instr);
+#endif
+
+    /// Pointer to the variable that stores the current Pica code offset. Used to handle nested code blocks.
+    unsigned* offset_ptr = nullptr;
+
+    bool done = false;
+    bool looping = false;
+};
+
+} // Shader
+
+} // Pica