LookingGlass/common/memcpySSE.h
2017-12-12 04:30:47 +11:00

124 lines
3.6 KiB
C

/*
KVMGFX Client - A KVM Client for VGA Passthrough
Copyright (C) 2017 Geoffrey McRae <geoff@hostfission.com>
https://looking-glass.hostfission.com
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; either version 2 of the License, or (at your option) any later
version.
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 for more details.
You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 59 Temple
Place, Suite 330, Boston, MA 02111-1307 USA
*/
#pragma once
#include <stdbool.h>
#include <stdint.h>
#include <string.h>
#include <tmmintrin.h>
#include <immintrin.h>
#include "debug.h"
static inline void memcpySSE(void * dst, const void * src, size_t length)
{
// check if we can't perform an aligned copy
if (((uintptr_t)src & 0xF) != ((uintptr_t)dst & 0xF))
{
static bool unalignedDstWarn = false;
if (!unalignedDstWarn)
{
DEBUG_WARN("Memcpy64 unable to perform aligned copy, performance will suffer");
unalignedDstWarn = true;
}
// fallback to system memcpy
memcpy(dst, src, length);
return;
}
// check if the source needs alignment
{
uint8_t * _src = (uint8_t *)src;
unsigned int count = (16 - ((uintptr_t)src & 0xF)) & 0xF;
static bool unalignedSrcWarn = false;
if (count > 0)
{
if (!unalignedSrcWarn)
{
DEBUG_WARN("Memcpy64 unaligned source, performance will suffer");
unalignedSrcWarn = true;
}
uint8_t * _dst = (uint8_t *)dst;
for (unsigned int i = count; i > 0; --i)
*_dst++ = *_src++;
src = _src;
dst = _dst;
length -= count;
}
}
__m128i * _src = (__m128i *)src;
__m128i * _dst = (__m128i *)dst;
__m128i v0, v1, v2, v3, v4, v5, v6, v7;
const size_t sselen = length & ~0x7F;
const __m128i * _end = (__m128i *)((uintptr_t)src + sselen);
for (; _src != _end; _src += 8, _dst += 8)
{
_mm_prefetch(((char *)(_src + 8 )), _MM_HINT_NTA);
_mm_prefetch(((char *)(_src + 9 )), _MM_HINT_NTA);
_mm_prefetch(((char *)(_src + 10)), _MM_HINT_NTA);
_mm_prefetch(((char *)(_src + 11)), _MM_HINT_NTA);
v0 = _mm_load_si128(_src + 0);
v1 = _mm_load_si128(_src + 1);
v2 = _mm_load_si128(_src + 2);
v3 = _mm_load_si128(_src + 3);
v4 = _mm_load_si128(_src + 4);
v5 = _mm_load_si128(_src + 5);
v6 = _mm_load_si128(_src + 6);
v7 = _mm_load_si128(_src + 7);
_mm_stream_si128(_dst + 0, v0);
_mm_stream_si128(_dst + 1, v1);
_mm_stream_si128(_dst + 2, v2);
_mm_stream_si128(_dst + 3, v3);
_mm_stream_si128(_dst + 4, v4);
_mm_stream_si128(_dst + 5, v5);
_mm_stream_si128(_dst + 6, v6);
_mm_stream_si128(_dst + 7, v7);
}
const size_t remain = ((length - sselen) & ~0xF) >> 4;
switch (remain)
{
case 7: v0 = _mm_load_si128(_src++);
case 6: v1 = _mm_load_si128(_src++);
case 5: v2 = _mm_load_si128(_src++);
case 4: v3 = _mm_load_si128(_src++);
case 3: v4 = _mm_load_si128(_src++);
case 2: v5 = _mm_load_si128(_src++);
case 1: v6 = _mm_load_si128(_src++);
}
switch (remain)
{
case 7: _mm_stream_si128(_dst++, v0);
case 6: _mm_stream_si128(_dst++, v1);
case 5: _mm_stream_si128(_dst++, v2);
case 4: _mm_stream_si128(_dst++, v3);
case 3: _mm_stream_si128(_dst++, v4);
case 2: _mm_stream_si128(_dst++, v5);
case 1: _mm_stream_si128(_dst++, v6);
}
}