// Copyright (c) 2012- PPSSPP Project.

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, version 2.0 or later versions.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License 2.0 for more details.

// A copy of the GPL 2.0 should have been included with the program.
// If not, see http://www.gnu.org/licenses/

// Official git repository and contact information can be found at
// https://github.com/hrydgard/ppsspp and http://www.ppsspp.org/.

#include "base/logging.h"
#include "Common/ChunkFile.h"
#include "Common/CPUDetect.h"

#include "Core/Reporting.h"
#include "Core/Config.h"
#include "Core/Core.h"
#include "Core/CoreTiming.h"
#include "Core/Debugger/SymbolMap.h"
#include "Core/MemMap.h"

#include "Core/MIPS/MIPS.h"
#include "Core/MIPS/MIPSCodeUtils.h"
#include "Core/MIPS/MIPSInt.h"
#include "Core/MIPS/MIPSTables.h"
#include "Core/HLE/ReplaceTables.h"
#include "Core/MIPS/ARM64/Arm64RegCache.h"
#include "Core/MIPS/ARM64/Arm64RegCacheFPU.h"

#include "Core/MIPS/ARM64/Arm64Jit.h"

#include "ext/disarm.h"

using namespace Arm64JitConstants;

void DisassembleArm64Print(const u8 *data, int size) {
	ILOG("ARM64 TODO");
}

namespace MIPSComp
{
using namespace Arm64Gen;
using namespace Arm64JitConstants;

Arm64Jit::Arm64Jit(MIPSState *mips) : blocks(mips, this), gpr(mips, &js, &jo), fpr(mips, &js, &jo), mips_(mips) { 
	logBlocks = 0;
	dontLogBlocks = 0;
	blocks.Init();
	gpr.SetEmitter(this);
	fpr.SetEmitter(this);
	AllocCodeSpace(1024 * 1024 * 16);  // 32MB is the absolute max because that's what an ARM branch instruction can reach, backwards and forwards.
	GenerateFixedCode();

	js.startDefaultPrefix = mips_->HasDefaultPrefix();
}

Arm64Jit::~Arm64Jit() {
}

void Arm64Jit::DoState(PointerWrap &p)
{
	auto s = p.Section("Jit", 1, 2);
	if (!s)
		return;

	p.Do(js.startDefaultPrefix);
	if (s >= 2) {
		p.Do(js.hasSetRounding);
		js.lastSetRounding = 0;
	} else {
		js.hasSetRounding = 1;
	}
}

// This is here so the savestate matches between jit and non-jit.
void Arm64Jit::DoDummyState(PointerWrap &p)
{
	auto s = p.Section("Jit", 1, 2);
	if (!s)
		return;

	bool dummy = false;
	p.Do(dummy);
	if (s >= 2) {
		dummy = true;
		p.Do(dummy);
	}
}

void Arm64Jit::FlushAll()
{
	gpr.FlushAll();
	fpr.FlushAll();
	FlushPrefixV();
}

void Arm64Jit::FlushPrefixV()
{
	if ((js.prefixSFlag & JitState::PREFIX_DIRTY) != 0) {
		gpr.SetRegImm(SCRATCH1, js.prefixS);
		STR(INDEX_UNSIGNED, SCRATCH1, CTXREG, offsetof(MIPSState, vfpuCtrl[VFPU_CTRL_SPREFIX]));
		js.prefixSFlag = (JitState::PrefixState) (js.prefixSFlag & ~JitState::PREFIX_DIRTY);
	}

	if ((js.prefixTFlag & JitState::PREFIX_DIRTY) != 0) {
		gpr.SetRegImm(SCRATCH1, js.prefixT);
		STR(INDEX_UNSIGNED, SCRATCH1, CTXREG, offsetof(MIPSState, vfpuCtrl[VFPU_CTRL_TPREFIX]));
		js.prefixTFlag = (JitState::PrefixState) (js.prefixTFlag & ~JitState::PREFIX_DIRTY);
	}

	if ((js.prefixDFlag & JitState::PREFIX_DIRTY) != 0) {
		gpr.SetRegImm(SCRATCH1, js.prefixD);
		STR(INDEX_UNSIGNED, SCRATCH1, CTXREG, offsetof(MIPSState, vfpuCtrl[VFPU_CTRL_DPREFIX]));
		js.prefixDFlag = (JitState::PrefixState) (js.prefixDFlag & ~JitState::PREFIX_DIRTY);
	}
}

void Arm64Jit::ClearCache()
{
	blocks.Clear();
	ClearCodeSpace();
	GenerateFixedCode();
}

void Arm64Jit::InvalidateCache()
{
	blocks.Clear();
}

void Arm64Jit::InvalidateCacheAt(u32 em_address, int length)
{
	blocks.InvalidateICache(em_address, length);
}

void Arm64Jit::EatInstruction(MIPSOpcode op) {
	MIPSInfo info = MIPSGetInfo(op);
	if (info & DELAYSLOT) {
		ERROR_LOG_REPORT_ONCE(ateDelaySlot, JIT, "Ate a branch op.");
	}
	if (js.inDelaySlot) {
		ERROR_LOG_REPORT_ONCE(ateInDelaySlot, JIT, "Ate an instruction inside a delay slot.");
	}

	js.numInstructions++;
	js.compilerPC += 4;
	js.downcountAmount += MIPSGetInstructionCycleEstimate(op);
}

void Arm64Jit::CompileDelaySlot(int flags)
{
	// TODO ARM64
}


void Arm64Jit::Compile(u32 em_address) {
	if (GetSpaceLeft() < 0x10000 || blocks.IsFull()) {
		ClearCache();
	}

	int block_num = blocks.AllocateBlock(em_address);
	JitBlock *b = blocks.GetBlock(block_num);
	DoJit(em_address, b);
	blocks.FinalizeBlock(block_num, jo.enableBlocklink);

	bool cleanSlate = false;

	if (js.hasSetRounding && !js.lastSetRounding) {
		WARN_LOG(JIT, "Detected rounding mode usage, rebuilding jit with checks");
		// Won't loop, since hasSetRounding is only ever set to 1.
		js.lastSetRounding = js.hasSetRounding;
		cleanSlate = true;
	}

	// Drat.  The VFPU hit an uneaten prefix at the end of a block.
	if (js.startDefaultPrefix && js.MayHavePrefix()) {
		WARN_LOG(JIT, "An uneaten prefix at end of block: %08x", js.compilerPC - 4);
		js.LogPrefix();

		// Let's try that one more time.  We won't get back here because we toggled the value.
		js.startDefaultPrefix = false;
		cleanSlate = true;
	}

	if (cleanSlate) {
		// Our assumptions are all wrong so it's clean-slate time.
		ClearCache();
		Compile(em_address);
	}
}

void Arm64Jit::RunLoopUntil(u64 globalticks)
{
	((void (*)())enterCode)();
}

const u8 *Arm64Jit::DoJit(u32 em_address, JitBlock *b)
{
	js.cancel = false;
	js.blockStart = js.compilerPC = mips_->pc;
	js.lastContinuedPC = 0;
	js.initialBlockSize = 0;
	js.nextExit = 0;
	js.downcountAmount = 0;
	js.curBlock = b;
	js.compiling = true;
	js.inDelaySlot = false;
	js.PrefixStart();

	// We add a downcount flag check before the block, used when entering from a linked block.
	// The last block decremented downcounter, and the flag should still be available.
	// Got three variants here of where we position the code, needs detailed benchmarking.

	FixupBranch bail;
	/*
	if (jo.useBackJump) {
		// Moves the MOVI2R and B *before* checkedEntry, and just branch backwards there.
		// Speedup seems to be zero unfortunately but I guess it may vary from device to device.
		// Not intrusive so keeping it around here to experiment with, may help on ARMv6 due to
		// large/slow construction of 32-bit immediates?
		JumpTarget backJump = GetCodePtr();
		gpr.SetRegImm(R0, js.blockStart);
		B((const void *)outerLoopPCInR0);
		b->checkedEntry = GetCodePtr();
		SetCC(CC_LT);
		B(backJump);
		SetCC(CC_AL);
	} else if (jo.useForwardJump) {
		b->checkedEntry = GetCodePtr();
		SetCC(CC_LT);
		bail = B();
		SetCC(CC_AL);
	} else {
		b->checkedEntry = GetCodePtr();
		SetCC(CC_LT);
		gpr.SetRegImm(R0, js.blockStart);
		B((const void *)outerLoopPCInR0);
		SetCC(CC_AL);
	}*/
	// TODO ARM64

	b->normalEntry = GetCodePtr();
	// TODO: this needs work
	MIPSAnalyst::AnalysisResults analysis; // = MIPSAnalyst::Analyze(em_address);

	gpr.Start(analysis);
	fpr.Start(analysis);

	int partialFlushOffset = 0;

	js.numInstructions = 0;
	while (js.compiling)
	{
		gpr.SetCompilerPC(js.compilerPC);  // Let it know for log messages
		MIPSOpcode inst = Memory::Read_Opcode_JIT(js.compilerPC);
		//MIPSInfo info = MIPSGetInfo(inst);
		//if (info & IS_VFPU) {
		//	logBlocks = 1;
		//}

		js.downcountAmount += MIPSGetInstructionCycleEstimate(inst);

		MIPSCompileOp(inst);
	
		js.compilerPC += 4;
		js.numInstructions++;

		// Safety check, in case we get a bunch of really large jit ops without a lot of branching.
		if (GetSpaceLeft() < 0x800 || js.numInstructions >= JitBlockCache::MAX_BLOCK_INSTRUCTIONS)
		{
			FlushAll();
			WriteExit(js.compilerPC, js.nextExit++);
			js.compiling = false;
		}
	}

	if (jo.useForwardJump) {
		//SetJumpTarget(bail);
		//gpr.SetRegImm(R0, js.blockStart);
		//B((const void *)outerLoopPCInR0);
	}

	char temp[256];
	if (logBlocks > 0 && dontLogBlocks == 0) {
		INFO_LOG(JIT, "=============== mips ===============");
		for (u32 cpc = em_address; cpc != js.compilerPC + 4; cpc += 4) {
			MIPSDisAsm(Memory::Read_Opcode_JIT(cpc), cpc, temp, true);
			INFO_LOG(JIT, "M: %08x   %s", cpc, temp);
		}
	}

	b->codeSize = GetCodePtr() - b->normalEntry;

	if (logBlocks > 0 && dontLogBlocks == 0) {
		INFO_LOG(JIT, "=============== ARM ===============");
		DisassembleArm64Print(b->normalEntry, GetCodePtr() - b->normalEntry);
	}
	if (logBlocks > 0)
		logBlocks--;
	if (dontLogBlocks > 0)
		dontLogBlocks--;

	// Don't forget to zap the newly written instructions in the instruction cache!
	FlushIcache();

	if (js.lastContinuedPC == 0)
		b->originalSize = js.numInstructions;
	else
	{
		// We continued at least once.  Add the last proxy and set the originalSize correctly.
		blocks.ProxyBlock(js.blockStart, js.lastContinuedPC, (js.compilerPC - js.lastContinuedPC) / sizeof(u32), GetCodePtr());
		b->originalSize = js.initialBlockSize;
	}
	return b->normalEntry;
}

void Arm64Jit::AddContinuedBlock(u32 dest)
{
	// The first block is the root block.  When we continue, we create proxy blocks after that.
	if (js.lastContinuedPC == 0)
		js.initialBlockSize = js.numInstructions;
	else
		blocks.ProxyBlock(js.blockStart, js.lastContinuedPC, (js.compilerPC - js.lastContinuedPC) / sizeof(u32), GetCodePtr());
	js.lastContinuedPC = dest;
}

bool Arm64Jit::DescribeCodePtr(const u8 *ptr, std::string &name)
{
	// TODO: Not used by anything yet.
	return false;
}

void Arm64Jit::Comp_RunBlock(MIPSOpcode op)
{
	// This shouldn't be necessary, the dispatcher should catch us before we get here.
	ERROR_LOG(JIT, "Comp_RunBlock should never be reached!");
}

bool Arm64Jit::ReplaceJalTo(u32 dest) {
	return false;
}

void Arm64Jit::Comp_ReplacementFunc(MIPSOpcode op)
{
	// TODO ARM64
}

void Arm64Jit::Comp_Generic(MIPSOpcode op)
{
	FlushAll();
	MIPSInterpretFunc func = MIPSGetInterpretFunc(op);
	if (func) {
		SaveDowncount();
		// TODO: Perhaps keep the rounding mode for interp?
		RestoreRoundingMode();
		// gpr.SetRegImm(SCRATCHREG1, js.compilerPC);
		// MovToPC(SCRATCHREG1);
		//gpr.SetRegImm(R0, op.encoding);
		//QuickCallFunction(R1, (void *)func);
		// TODO ARM64
		ApplyRoundingMode();
		RestoreDowncount();
	}

	const MIPSInfo info = MIPSGetInfo(op);
	if ((info & IS_VFPU) != 0 && (info & VFPU_NO_PREFIX) == 0)
	{
		// If it does eat them, it'll happen in MIPSCompileOp().
		if ((info & OUT_EAT_PREFIX) == 0)
			js.PrefixUnknown();
	}
}

void Arm64Jit::MovFromPC(ARM64Reg r) {
	LDR(INDEX_UNSIGNED, r, CTXREG, offsetof(MIPSState, pc));
}

void Arm64Jit::MovToPC(ARM64Reg r) {
	STR(INDEX_UNSIGNED, r, CTXREG, offsetof(MIPSState, pc));
}

void Arm64Jit::SaveDowncount() {
	if (jo.downcountInRegister)
		STR(INDEX_UNSIGNED, DOWNCOUNTREG, CTXREG, offsetof(MIPSState, downcount));
}

void Arm64Jit::RestoreDowncount() {
	if (jo.downcountInRegister)
		LDR(INDEX_UNSIGNED, DOWNCOUNTREG, CTXREG, offsetof(MIPSState, downcount));
}

void Arm64Jit::WriteDownCount(int offset) {
	// TODO ARM64
}

// Abuses R2
void Arm64Jit::WriteDownCountR(ARM64Reg reg) {
	if (jo.downcountInRegister) {
		SUBS(DOWNCOUNTREG, DOWNCOUNTREG, reg);
	} else {
		LDR(INDEX_UNSIGNED, X2, CTXREG, offsetof(MIPSState, downcount));
		SUBS(X2, X2, reg);
		STR(INDEX_UNSIGNED, X2, CTXREG, offsetof(MIPSState, downcount));
	}
}

void Arm64Jit::RestoreRoundingMode(bool force) {
	// TODO ARM64
}

void Arm64Jit::ApplyRoundingMode(bool force) {
	// TODO ARM64
}

void Arm64Jit::UpdateRoundingMode() {
	// TODO ARM64
}

// IDEA - could have a WriteDualExit that takes two destinations and two condition flags,
// and just have conditional that set PC "twice". This only works when we fall back to dispatcher
// though, as we need to have the SUBS flag set in the end. So with block linking in the mix,
// I don't think this gives us that much benefit.
void Arm64Jit::WriteExit(u32 destination, int exit_num)
{
	WriteDownCount(); 
	//If nobody has taken care of this yet (this can be removed when all branches are done)
	JitBlock *b = js.curBlock;
	b->exitAddress[exit_num] = destination;
	b->exitPtrs[exit_num] = GetWritableCodePtr();

	// Link opportunity!
	int block = blocks.GetBlockNumberFromStartAddress(destination);
	if (block >= 0 && jo.enableBlocklink) {
		// It exists! Joy of joy!
		B(blocks.GetBlock(block)->checkedEntry);
		b->linkStatus[exit_num] = true;
	} else {
		gpr.SetRegImm(X0, destination);
		B((const void *)dispatcherPCInSCRATCH1);	
	}
}

void Arm64Jit::WriteExitDestInR(ARM64Reg Reg) 
{
	MovToPC(Reg);
	WriteDownCount();
	// TODO: shouldn't need an indirect branch here...
	B((const void *)dispatcher);
}

void Arm64Jit::WriteSyscallExit()
{
	WriteDownCount();
	B((const void *)dispatcherCheckCoreState);
}

void Arm64Jit::Comp_DoNothing(MIPSOpcode op) { }

#define _RS ((op>>21) & 0x1F)
#define _RT ((op>>16) & 0x1F)
#define _RD ((op>>11) & 0x1F)
#define _FS ((op>>11) & 0x1F)
#define _FT ((op>>16) & 0x1F)
#define _FD ((op>>6) & 0x1F)
#define _POS ((op>>6) & 0x1F)
#define _SIZE ((op>>11) & 0x1F)

//memory regions:
//
// 08-0A
// 48-4A
// 04-05
// 44-45
// mov eax, addrreg
	// shr eax, 28
// mov eax, [table+eax]
// mov dreg, [eax+offreg]
	
}