This repository has been archived by the owner on Feb 11, 2021. It is now read-only.
SDL_blit_copy.c
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/*
Simple DirectMedia Layer
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Copyright (C) 1997-2012 Sam Lantinga <slouken@libsdl.org>
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This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:
1. The origin of this software must not be misrepresented; you must not
claim that you wrote the original software. If you use this software
in a product, an acknowledgment in the product documentation would be
appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be
misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.
*/
#include "SDL_config.h"
#include "SDL_video.h"
#include "SDL_blit.h"
#include "SDL_blit_copy.h"
#ifdef __SSE__
/* This assumes 16-byte aligned src and dst */
static __inline__ void
SDL_memcpySSE(Uint8 * dst, const Uint8 * src, int len)
{
int i;
__m128 values[4];
for (i = len / 64; i--;) {
_mm_prefetch(src, _MM_HINT_NTA);
values[0] = *(__m128 *) (src + 0);
values[1] = *(__m128 *) (src + 16);
values[2] = *(__m128 *) (src + 32);
values[3] = *(__m128 *) (src + 48);
_mm_stream_ps((float *) (dst + 0), values[0]);
_mm_stream_ps((float *) (dst + 16), values[1]);
_mm_stream_ps((float *) (dst + 32), values[2]);
_mm_stream_ps((float *) (dst + 48), values[3]);
src += 64;
dst += 64;
}
if (len & 63)
SDL_memcpy(dst, src, len & 63);
}
#endif /* __SSE__ */
#ifdef __MMX__
#ifdef _MSC_VER
#pragma warning(disable:4799)
#endif
static __inline__ void
SDL_memcpyMMX(Uint8 * dst, const Uint8 * src, int len)
{
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const int remain = (len & 63);
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int i;
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__m64* d64 = (__m64*)dst;
__m64* s64 = (__m64*)src;
for(i= len / 64; i--;) {
d64[0] = s64[0];
d64[1] = s64[1];
d64[2] = s64[2];
d64[3] = s64[3];
d64[4] = s64[4];
d64[5] = s64[5];
d64[6] = s64[6];
d64[7] = s64[7];
d64 += 8;
s64 += 8;
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if (remain)
{
const int skip = len - remain;
SDL_memcpy(dst + skip, src + skip, remain);
}
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}
#endif /* __MMX__ */
void
SDL_BlitCopy(SDL_BlitInfo * info)
{
SDL_bool overlap;
Uint8 *src, *dst;
int w, h;
int srcskip, dstskip;
w = info->dst_w * info->dst_fmt->BytesPerPixel;
h = info->dst_h;
src = info->src;
dst = info->dst;
srcskip = info->src_pitch;
dstskip = info->dst_pitch;
/* Properly handle overlapping blits */
if (src < dst) {
overlap = (dst < (src + h*srcskip));
} else {
overlap = (src < (dst + h*dstskip));
}
if (overlap) {
while (h--) {
SDL_memmove(dst, src, w);
src += srcskip;
dst += dstskip;
}
return;
}
#ifdef __SSE__
if (SDL_HasSSE() &&
!((uintptr_t) src & 15) && !(srcskip & 15) &&
!((uintptr_t) dst & 15) && !(dstskip & 15)) {
while (h--) {
SDL_memcpySSE(dst, src, w);
src += srcskip;
dst += dstskip;
}
return;
}
#endif
#ifdef __MMX__
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if (SDL_HasMMX() && !(srcskip & 7) && !(dstskip & 7)) {
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while (h--) {
SDL_memcpyMMX(dst, src, w);
src += srcskip;
dst += dstskip;
}
_mm_empty();
return;
}
#endif
while (h--) {
SDL_memcpy(dst, src, w);
src += srcskip;
dst += dstskip;
}
}
/* vi: set ts=4 sw=4 expandtab: */