Panda3DS/include/PICA/dynapica/shader_rec_emitter_x64.hpp
2023-06-08 22:48:37 +03:00

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2.5 KiB
C++

#pragma once
// Only do anything if we're on an x64 target with JIT support enabled
#if defined(PANDA3DS_DYNAPICA_SUPPORTED) && defined(PANDA3DS_X64_HOST)
#include "helpers.hpp"
#include "PICA/shader.hpp"
#include "xbyak/xbyak.h"
#include "x64_regs.hpp"
#include <vector>
class ShaderEmitter : public Xbyak::CodeGenerator {
static constexpr size_t executableMemorySize = PICAShader::maxInstructionCount * 96; // How much executable memory to alloc for each shader
// Allocate some extra space as padding for security purposes in the extremely unlikely occasion we manage to overflow the above size
static constexpr size_t allocSize = executableMemorySize + 0x1000;
// An array of labels (incl pointers) to each compiled (to x64) PICA instruction
std::array<Xbyak::Label, PICAShader::maxInstructionCount> instructionLabels;
// A vector of PCs that can potentially return based on the state of the PICA callstack.
// Filled before compiling a shader by scanning the code for call instructions
std::vector<u32> returnPCs;
u32 recompilerPC; // PC the recompiler is currently recompiling @
// Compile all instructions from [current recompiler PC, end)
void compileUntil(const PICAShader& shaderUnit, u32 endPC);
// Compile instruction "instr"
void compileInstruction(const PICAShader& shaderUnit);
bool isCall(u32 instruction) {
const u32 opcode = instruction >> 26;
return (opcode == ShaderOpcodes::CALL) || (opcode == ShaderOpcodes::CALLC) || (opcode == ShaderOpcodes::CALLU);
}
// Scan the shader code for call instructions to fill up the returnPCs vector before starting compilation
void scanForCalls(const PICAShader& shader);
public:
using InstructionCallback = const void(*)(PICAShader& shaderUnit); // Callback type used for instructions
// Callback type used for the JIT prologue. This is what the caller will call
using PrologueCallback = const void(*)(PICAShader& shaderUnit, InstructionCallback cb);
PrologueCallback prologueCb;
// Initialize our emitter with "allocSize" bytes of RWX memory
ShaderEmitter() : Xbyak::CodeGenerator(allocSize) {}
void compile(const PICAShader& shaderUnit);
// PC must be a valid entrypoint here. It doesn't have that much overhead in this case, so we use std::array<>::at() to assert it does
InstructionCallback getInstructionCallback(u32 pc) {
return reinterpret_cast<InstructionCallback>(instructionLabels.at(pc).getAddress());
}
PrologueCallback getPrologueCallback() {
return prologueCb;
}
};
#endif // x64 recompiler check