// Copyright 2013 Dolphin Emulator Project
// Licensed under GPLv2
// Refer to the license.txt file included.

#include "Common.h"
#include "x64Emitter.h"
#include "x64ABI.h"

using namespace Gen;

// Shared code between Win64 and Unix64

unsigned int XEmitter::ABI_GetAlignedFrameSize(unsigned int frameSize, bool noProlog) {
	// On platforms other than Windows 32-bit: At the beginning of a function,
	// the stack pointer is 4/8 bytes less than a multiple of 16; however, the
	// function prolog immediately subtracts an appropriate amount to align
	// it, so no alignment is required around a call. 
	// In the functions generated by ThunkManager::ProtectFunction, we add the
	// necessary subtraction (and 0x20 bytes shadow space for Win64) into this
	// rather than having a separate prolog.
	// On Windows 32-bit, the required alignment is only 4 bytes, so we just
	// ensure that the frame size isn't misaligned.
#ifdef _M_X64
	// expect frameSize == 0
	frameSize = noProlog ? 0x28 : 0;
#elif defined(_WIN32)
	frameSize = (frameSize + 3) & -4;
#else
	unsigned int existingAlignment = noProlog ? 0xc : 0;
	frameSize -= existingAlignment;
	frameSize = (frameSize + 15) & -16;
	frameSize += existingAlignment;
#endif
	return frameSize;
}

void XEmitter::ABI_AlignStack(unsigned int frameSize, bool noProlog) {
	unsigned int fillSize =
		ABI_GetAlignedFrameSize(frameSize, noProlog) - frameSize;
	if (fillSize != 0) {
#ifdef _M_X64
		SUB(64, R(RSP), Imm8(fillSize));
#else
		SUB(32, R(ESP), Imm8(fillSize));
#endif
	}
}

void XEmitter::ABI_RestoreStack(unsigned int frameSize, bool noProlog) {
	unsigned int alignedSize = ABI_GetAlignedFrameSize(frameSize, noProlog);
	if (alignedSize != 0) {
#ifdef _M_X64
		ADD(64, R(RSP), Imm8(alignedSize));
#else
		ADD(32, R(ESP), Imm8(alignedSize));
#endif
	}
}

#ifdef _M_IX86 // All32

// Shared code between Win32 and Unix32
void XEmitter::ABI_CallFunction(void *func) {
	ABI_AlignStack(0);
	CALL(func);
	ABI_RestoreStack(0);
}

void XEmitter::ABI_CallFunctionC16(void *func, u16 param1) {
	ABI_AlignStack(1 * 2);
	PUSH(16, Imm16(param1));
	CALL(func);
	ABI_RestoreStack(1 * 2);
}

void XEmitter::ABI_CallFunctionCC16(void *func, u32 param1, u16 param2) {
	ABI_AlignStack(1 * 2 + 1 * 4);
	PUSH(16, Imm16(param2));
	PUSH(32, Imm32(param1));
	CALL(func);
	ABI_AlignStack(1 * 2 + 1 * 4);
}

void XEmitter::ABI_CallFunctionC(void *func, u32 param1) {
	ABI_AlignStack(1 * 4);
	PUSH(32, Imm32(param1));
	CALL(func);
	ABI_RestoreStack(1 * 4);
}

void XEmitter::ABI_CallFunctionCC(void *func, u32 param1, u32 param2) {
	ABI_AlignStack(2 * 4);
	PUSH(32, Imm32(param2));
	PUSH(32, Imm32(param1));
	CALL(func);
	ABI_RestoreStack(2 * 4);
}

void XEmitter::ABI_CallFunctionCCC(void *func, u32 param1, u32 param2, u32 param3) {
	ABI_AlignStack(3 * 4);
	PUSH(32, Imm32(param3));
	PUSH(32, Imm32(param2));
	PUSH(32, Imm32(param1));
	CALL(func);
	ABI_RestoreStack(3 * 4);
}

void XEmitter::ABI_CallFunctionCCP(void *func, u32 param1, u32 param2, void *param3) {
	ABI_AlignStack(3 * 4);
	PUSH(32, Imm32((u32)param3));
	PUSH(32, Imm32(param2));
	PUSH(32, Imm32(param1));
	CALL(func);
	ABI_RestoreStack(3 * 4);
}

void XEmitter::ABI_CallFunctionCCCP(void *func, u32 param1, u32 param2,u32 param3, void *param4) {
	ABI_AlignStack(4 * 4);
	PUSH(32, Imm32((u32)param4));
	PUSH(32, Imm32(param3));
	PUSH(32, Imm32(param2));
	PUSH(32, Imm32(param1));
	CALL(func);
	ABI_RestoreStack(4 * 4);
}

void XEmitter::ABI_CallFunctionPPC(void *func, void *param1, void *param2,u32 param3) {
	ABI_AlignStack(3 * 4);
	PUSH(32, Imm32(param3));
	PUSH(32, Imm32((u32)param2));
	PUSH(32, Imm32((u32)param1));
	CALL(func);
	ABI_RestoreStack(3 * 4);
}

// Pass a register as a parameter.
void XEmitter::ABI_CallFunctionR(void *func, X64Reg reg1) {
	ABI_AlignStack(1 * 4);
	PUSH(32, R(reg1));
	CALL(func);
	ABI_RestoreStack(1 * 4);
}

// Pass two registers as parameters.
void XEmitter::ABI_CallFunctionRR(void *func, Gen::X64Reg reg1, Gen::X64Reg reg2)
{
	ABI_AlignStack(2 * 4);
	PUSH(32, R(reg2));
	PUSH(32, R(reg1));
	CALL(func);
	ABI_RestoreStack(2 * 4);
}

void XEmitter::ABI_CallFunctionAC(void *func, const Gen::OpArg &arg1, u32 param2)
{
	ABI_AlignStack(2 * 4);
	PUSH(32, Imm32(param2));
	PUSH(32, arg1);
	CALL(func);
	ABI_RestoreStack(2 * 4);
}

void XEmitter::ABI_CallFunctionA(void *func, const Gen::OpArg &arg1)
{
	ABI_AlignStack(1 * 4);
	PUSH(32, arg1);
	CALL(func);
	ABI_RestoreStack(1 * 4);
}

void XEmitter::ABI_PushAllCalleeSavedRegsAndAdjustStack() {
	PUSH(EBP);
	MOV(32, R(EBP), R(ESP));
	PUSH(EBX);
	PUSH(ESI);
	PUSH(EDI);
	SUB(32, R(ESP), Imm8(0xc));
}

void XEmitter::ABI_PopAllCalleeSavedRegsAndAdjustStack() {
	ADD(32, R(ESP), Imm8(0xc));
	POP(EDI);
	POP(ESI);
	POP(EBX);
	POP(EBP);
}

#else //64bit

// Common functions
void XEmitter::ABI_CallFunction(void *func) {
	ABI_AlignStack(0);
	u64 distance = u64(func) - (u64(code) + 5);
	if (distance >= 0x0000000080000000ULL
	 && distance <  0xFFFFFFFF80000000ULL) {
		// Far call
		MOV(64, R(RAX), Imm64((u64)func));
		CALLptr(R(RAX));
	} else {
		CALL(func);
	}
	ABI_RestoreStack(0);
}

void XEmitter::ABI_CallFunctionC16(void *func, u16 param1) {
	ABI_AlignStack(0);
	MOV(32, R(ABI_PARAM1), Imm32((u32)param1));
	u64 distance = u64(func) - (u64(code) + 5);
	if (distance >= 0x0000000080000000ULL
	 && distance <  0xFFFFFFFF80000000ULL) {
		// Far call
		MOV(64, R(RAX), Imm64((u64)func));
		CALLptr(R(RAX));
	} else {
		CALL(func);
	}
	ABI_RestoreStack(0);
}

void XEmitter::ABI_CallFunctionCC16(void *func, u32 param1, u16 param2) {
	ABI_AlignStack(0);
	MOV(32, R(ABI_PARAM1), Imm32(param1));
	MOV(32, R(ABI_PARAM2), Imm32((u32)param2));
	u64 distance = u64(func) - (u64(code) + 5);
	if (distance >= 0x0000000080000000ULL
		&& distance <  0xFFFFFFFF80000000ULL) {
			// Far call
			MOV(64, R(RAX), Imm64((u64)func));
			CALLptr(R(RAX));
	} else {
		CALL(func);
	}
	ABI_RestoreStack(0);
}

void XEmitter::ABI_CallFunctionC(void *func, u32 param1) {
	ABI_AlignStack(0);
	MOV(32, R(ABI_PARAM1), Imm32(param1));
	u64 distance = u64(func) - (u64(code) + 5);
	if (distance >= 0x0000000080000000ULL
	 && distance <  0xFFFFFFFF80000000ULL) {
		// Far call
		MOV(64, R(RAX), Imm64((u64)func));
		CALLptr(R(RAX));
	} else {
		CALL(func);
	}
	ABI_RestoreStack(0);
}

void XEmitter::ABI_CallFunctionCC(void *func, u32 param1, u32 param2) {
	ABI_AlignStack(0);
	MOV(32, R(ABI_PARAM1), Imm32(param1));
	MOV(32, R(ABI_PARAM2), Imm32(param2));
	u64 distance = u64(func) - (u64(code) + 5);
	if (distance >= 0x0000000080000000ULL
	 && distance <  0xFFFFFFFF80000000ULL) {
		// Far call
		MOV(64, R(RAX), Imm64((u64)func));
		CALLptr(R(RAX));
	} else {
		CALL(func);
	}
	ABI_RestoreStack(0);
}

void XEmitter::ABI_CallFunctionCCC(void *func, u32 param1, u32 param2, u32 param3) {
	ABI_AlignStack(0);
	MOV(32, R(ABI_PARAM1), Imm32(param1));
	MOV(32, R(ABI_PARAM2), Imm32(param2));
	MOV(32, R(ABI_PARAM3), Imm32(param3));
	u64 distance = u64(func) - (u64(code) + 5);
	if (distance >= 0x0000000080000000ULL
	 && distance <  0xFFFFFFFF80000000ULL) {
		// Far call
		MOV(64, R(RAX), Imm64((u64)func));
		CALLptr(R(RAX));
	} else {
		CALL(func);
	}
	ABI_RestoreStack(0);
}

void XEmitter::ABI_CallFunctionCCP(void *func, u32 param1, u32 param2, void *param3) {
	ABI_AlignStack(0);
	MOV(32, R(ABI_PARAM1), Imm32(param1));
	MOV(32, R(ABI_PARAM2), Imm32(param2));
	MOV(64, R(ABI_PARAM3), Imm64((u64)param3));
	u64 distance = u64(func) - (u64(code) + 5);
	if (distance >= 0x0000000080000000ULL
	 && distance <  0xFFFFFFFF80000000ULL) {
		// Far call
		MOV(64, R(RAX), Imm64((u64)func));
		CALLptr(R(RAX));
	} else {
		CALL(func);
	}
	ABI_RestoreStack(0);
}

void XEmitter::ABI_CallFunctionCCCP(void *func, u32 param1, u32 param2, u32 param3, void *param4) {
	ABI_AlignStack(0);
	MOV(32, R(ABI_PARAM1), Imm32(param1));
	MOV(32, R(ABI_PARAM2), Imm32(param2));
	MOV(32, R(ABI_PARAM3), Imm32(param3));
	MOV(64, R(ABI_PARAM4), Imm64((u64)param4));
	u64 distance = u64(func) - (u64(code) + 5);
	if (distance >= 0x0000000080000000ULL
	 && distance <  0xFFFFFFFF80000000ULL) {
		// Far call
		MOV(64, R(RAX), Imm64((u64)func));
		CALLptr(R(RAX));
	} else {
		CALL(func);
	}
	ABI_RestoreStack(0);
}

void XEmitter::ABI_CallFunctionPPC(void *func, void *param1, void *param2, u32 param3) {
	ABI_AlignStack(0);
	MOV(64, R(ABI_PARAM1), Imm64((u64)param1));
	MOV(64, R(ABI_PARAM2), Imm64((u64)param2));
	MOV(32, R(ABI_PARAM3), Imm32(param3));
	u64 distance = u64(func) - (u64(code) + 5);
	if (distance >= 0x0000000080000000ULL
	 && distance <  0xFFFFFFFF80000000ULL) {
		// Far call
		MOV(64, R(RAX), Imm64((u64)func));
		CALLptr(R(RAX));
	} else {
		CALL(func);
	}
	ABI_RestoreStack(0);
}

// Pass a register as a parameter.
void XEmitter::ABI_CallFunctionR(void *func, X64Reg reg1) {
	ABI_AlignStack(0);
	if (reg1 != ABI_PARAM1)
		MOV(32, R(ABI_PARAM1), R(reg1));
	u64 distance = u64(func) - (u64(code) + 5);
	if (distance >= 0x0000000080000000ULL
	 && distance <  0xFFFFFFFF80000000ULL) {
		// Far call
		MOV(64, R(RAX), Imm64((u64)func));
		CALLptr(R(RAX));
	} else {
		CALL(func);
	}
	ABI_RestoreStack(0);
}

// Pass two registers as parameters.
void XEmitter::ABI_CallFunctionRR(void *func, X64Reg reg1, X64Reg reg2) {
	ABI_AlignStack(0);
	if (reg2 != ABI_PARAM1) {
		if (reg1 != ABI_PARAM1)
			MOV(64, R(ABI_PARAM1), R(reg1));
		if (reg2 != ABI_PARAM2)
			MOV(64, R(ABI_PARAM2), R(reg2));
	} else {
		if (reg2 != ABI_PARAM2)
			MOV(64, R(ABI_PARAM2), R(reg2));
		if (reg1 != ABI_PARAM1)
			MOV(64, R(ABI_PARAM1), R(reg1));
	}
	u64 distance = u64(func) - (u64(code) + 5);
	if (distance >= 0x0000000080000000ULL
	 && distance <  0xFFFFFFFF80000000ULL) {
		// Far call
		MOV(64, R(RAX), Imm64((u64)func));
		CALLptr(R(RAX));
	} else {
		CALL(func);
	}
	ABI_RestoreStack(0);
}

void XEmitter::ABI_CallFunctionAC(void *func, const Gen::OpArg &arg1, u32 param2)
{
	ABI_AlignStack(0);
	if (!arg1.IsSimpleReg(ABI_PARAM1))
		MOV(32, R(ABI_PARAM1), arg1);
	MOV(32, R(ABI_PARAM2), Imm32(param2));
	u64 distance = u64(func) - (u64(code) + 5);
	if (distance >= 0x0000000080000000ULL
	 && distance <  0xFFFFFFFF80000000ULL) {
		// Far call
		MOV(64, R(RAX), Imm64((u64)func));
		CALLptr(R(RAX));
	} else {
		CALL(func);
	}
	ABI_RestoreStack(0);
}

void XEmitter::ABI_CallFunctionA(void *func, const Gen::OpArg &arg1)
{
	ABI_AlignStack(0);
	if (!arg1.IsSimpleReg(ABI_PARAM1))
		MOV(32, R(ABI_PARAM1), arg1);
	u64 distance = u64(func) - (u64(code) + 5);
	if (distance >= 0x0000000080000000ULL
	 && distance <  0xFFFFFFFF80000000ULL) {
		// Far call
		MOV(64, R(RAX), Imm64((u64)func));
		CALLptr(R(RAX));
	} else {
		CALL(func);
	}
	ABI_RestoreStack(0);
}

void XEmitter::ABI_PushAllCallerSavedRegsAndAdjustStack() {
	PUSH(RCX);
	PUSH(RDX);
	PUSH(RSI); 
	PUSH(RDI);
	PUSH(R8);
	PUSH(R9);
	PUSH(R10);
	PUSH(R11);
	PUSH(R11);
}

void XEmitter::ABI_PopAllCallerSavedRegsAndAdjustStack() {
	POP(R11);
	POP(R11);
	POP(R10);
	POP(R9);
	POP(R8);
	POP(RDI); 
	POP(RSI); 
	POP(RDX);
	POP(RCX);
}


#ifdef _WIN32
// Win64 Specific Code

void XEmitter::ABI_PushAllCalleeSavedRegsAndAdjustStack() {
	//we only want to do this once
	PUSH(RBP);
	MOV(64, R(RBP), R(RSP));
	PUSH(RBX); 
	PUSH(RSI); 
	PUSH(RDI);
	PUSH(R12); 
	PUSH(R13); 
	PUSH(R14); 
	PUSH(R15);
	SUB(64, R(RSP), Imm8(0x28));
	//TODO: Also preserve XMM0-3?
}

void XEmitter::ABI_PopAllCalleeSavedRegsAndAdjustStack() {
	ADD(64, R(RSP), Imm8(0x28));
	POP(R15);
	POP(R14); 
	POP(R13); 
	POP(R12);
	POP(RDI);
	POP(RSI); 
	POP(RBX); 
	POP(RBP);
}

#else
// Unix64 Specific Code

void XEmitter::ABI_PushAllCalleeSavedRegsAndAdjustStack() {
	PUSH(RBP);
	MOV(64, R(RBP), R(RSP));
	PUSH(RBX); 
	PUSH(R12); 
	PUSH(R13); 
	PUSH(R14); 
	PUSH(R15);
	SUB(64, R(RSP), Imm8(8));
}

void XEmitter::ABI_PopAllCalleeSavedRegsAndAdjustStack() {
	ADD(64, R(RSP), Imm8(8));
	POP(R15);
	POP(R14); 
	POP(R13); 
	POP(R12);
	POP(RBX); 
	POP(RBP);
}

#endif // WIN32

#endif // 32bit


