dolphin/Source/Core/Core/HW/GPFifo.cpp

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

#include "Common/ChunkFile.h"
#include "Common/CommonFuncs.h"
#include "Common/CommonTypes.h"

#include "Core/HW/GPFifo.h"
#include "Core/HW/Memmap.h"
#include "Core/HW/ProcessorInterface.h"
#include "Core/PowerPC/JitInterface.h"
#include "Core/PowerPC/PowerPC.h"

#include "VideoCommon/VideoBackendBase.h"

namespace GPFifo
{

// 32 Byte gather pipe with extra space
// Overfilling is no problem (up to the real limit), CheckGatherPipe will blast the
// contents in nicely sized chunks

// Other optimizations to think about:

// If the gp is NOT linked to the fifo, just blast to memory byte by word
// If the gp IS linked to the fifo, use a fast wrapping buffer and skip writing to memory

// Both of these should actually work! Only problem is that we have to decide at run time,
// the same function could use both methods. Compile 2 different versions of each such block?

u8 GC_ALIGNED32(m_gatherPipe[GATHER_PIPE_SIZE*16]); //more room, for the fastmodes

// pipe counter
u32 m_gatherPipeCount = 0;

void DoState(PointerWrap &p)
{
	p.Do(m_gatherPipe);
	p.Do(m_gatherPipeCount);
}

void Init()
{
	ResetGatherPipe();
	memset(m_gatherPipe, 0, sizeof(m_gatherPipe));
}

bool IsEmpty()
{
	return m_gatherPipeCount == 0;
}

void ResetGatherPipe()
{
	m_gatherPipeCount = 0;
}

static void UpdateGatherPipe()
{
	u32 cnt;
	u8* curMem = Memory::GetPointer(ProcessorInterface::Fifo_CPUWritePointer);
	for (cnt = 0; m_gatherPipeCount >= GATHER_PIPE_SIZE; cnt += GATHER_PIPE_SIZE)
	{
		// copy the GatherPipe
		memcpy(curMem, m_gatherPipe + cnt, GATHER_PIPE_SIZE);
		m_gatherPipeCount -= GATHER_PIPE_SIZE;

		// increase the CPUWritePointer
		if (ProcessorInterface::Fifo_CPUWritePointer == ProcessorInterface::Fifo_CPUEnd)
		{
			ProcessorInterface::Fifo_CPUWritePointer = ProcessorInterface::Fifo_CPUBase;
			curMem = Memory::GetPointer(ProcessorInterface::Fifo_CPUWritePointer);
		}
		else
		{
			curMem += GATHER_PIPE_SIZE;
			ProcessorInterface::Fifo_CPUWritePointer += GATHER_PIPE_SIZE;
		}

		g_video_backend->Video_GatherPipeBursted();
	}

	// move back the spill bytes
	memmove(m_gatherPipe, m_gatherPipe + cnt, m_gatherPipeCount);
}

void FastCheckGatherPipe()
{
	if (m_gatherPipeCount >= GATHER_PIPE_SIZE)
	{
		UpdateGatherPipe();
	}
}

void CheckGatherPipe()
{
	if (m_gatherPipeCount >= GATHER_PIPE_SIZE)
	{
		UpdateGatherPipe();

		// Profile where slow FIFO writes are occurring.
		JitInterface::CompileExceptionCheck(JitInterface::ExceptionType::EXCEPTIONS_FIFO_WRITE);
	}
}

void Write8(const u8 _iValue)
{
//	LOG(GPFIFO, "GPFIFO #%x: 0x%02x",ProcessorInterface::Fifo_CPUWritePointer+m_gatherPipeCount, _iValue);
	FastWrite8(_iValue);
	CheckGatherPipe();
}

void Write16(const u16 _iValue)
{
//	LOG(GPFIFO, "GPFIFO #%x: 0x%04x",ProcessorInterface::Fifo_CPUWritePointer+m_gatherPipeCount, _iValue);
	FastWrite16(_iValue);
	CheckGatherPipe();
}

void Write32(const u32 _iValue)
{
//#ifdef _DEBUG
//	float floatvalue = *(float*)&_iValue;
//	LOG(GPFIFO, "GPFIFO #%x: 0x%08x / %f",ProcessorInterface::Fifo_CPUWritePointer+m_gatherPipeCount, _iValue, floatvalue);
//#endif
	FastWrite32(_iValue);
	CheckGatherPipe();
}

void Write64(const u64 _iValue)
{
	FastWrite64(_iValue);
	CheckGatherPipe();
}

void FastWrite8(const u8 _iValue)
{
	m_gatherPipe[m_gatherPipeCount] = _iValue;
	++m_gatherPipeCount;
}

void FastWrite16(const u16 _iValue)
{
	*(u16*)(&m_gatherPipe[m_gatherPipeCount]) = Common::swap16(_iValue);
	m_gatherPipeCount += 2;
}

void FastWrite32(const u32 _iValue)
{
	*(u32*)(&m_gatherPipe[m_gatherPipeCount]) = Common::swap32(_iValue);
	m_gatherPipeCount += 4;
}

void FastWrite64(const u64 _iValue)
{
	*(u64*)(&m_gatherPipe[m_gatherPipeCount]) = Common::swap64(_iValue);
	m_gatherPipeCount += 8;
}

} // end of namespace GPFifo