view src/video/SDL_blit_copy.c @ 2247:93994f65c74c

Removed hermes since it's LGPL and not compatible with a commercial license. Prepping for using MMX and SSE intrinsics instead of inline assembly. .. except for memcpy equivalents which only get faster if they can exploit the parallelism of loading into multiple SIMD registers. :)
author Sam Lantinga <slouken@libsdl.org>
date Wed, 15 Aug 2007 08:21:10 +0000
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children 5cd2a2293cf0
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/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2006 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library 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
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga
    slouken@libsdl.org
*/
#include "SDL_config.h"

#include "SDL_video.h"
#include "SDL_blit.h"

/* The MMX/SSE intrinsics don't give access to specific registers for
   the most memory parallelism, so we'll use GCC inline assembly here...
*/
#ifndef __GNUC__
#undef __MMX__
#undef __SSE__
#endif

#ifdef __MMX__
static __inline__ void
SDL_memcpyMMX(Uint8 *dst, const Uint8 *src, int len)
{
    int i;

    for (i = len / 64; i--;) {
        __asm__ __volatile__ (
        "prefetchnta (%0)\n"
        "movq (%0), %%mm0\n"
        "movq 8(%0), %%mm1\n"
        "movq 16(%0), %%mm2\n"
        "movq 24(%0), %%mm3\n"
        "movq 32(%0), %%mm4\n"
        "movq 40(%0), %%mm5\n"
        "movq 48(%0), %%mm6\n"
        "movq 56(%0), %%mm7\n"
        "movntq %%mm0, (%1)\n"
        "movntq %%mm1, 8(%1)\n"
        "movntq %%mm2, 16(%1)\n"
        "movntq %%mm3, 24(%1)\n"
        "movntq %%mm4, 32(%1)\n"
        "movntq %%mm5, 40(%1)\n"
        "movntq %%mm6, 48(%1)\n"
        "movntq %%mm7, 56(%1)\n"
        :: "r" (src), "r" (dst) : "memory");
        src += 64;
        dst += 64;
    }
    if (len & 63)
        SDL_memcpy(dst, src, len & 63);
}
#endif /* __MMX__ */

#ifdef __SSE__
static __inline__ void
SDL_memcpySSE(Uint8 *dst, const Uint8 *src, int len)
{
    int i;

    for (i = len / 64; i--;) {
        __asm__ __volatile__ (
        "prefetchnta (%0)\n"
        "movaps (%0), %%xmm0\n"
        "movaps 16(%0), %%xmm1\n"
        "movaps 32(%0), %%xmm2\n"
        "movaps 48(%0), %%xmm3\n"
        "movntps %%xmm0, (%1)\n"
        "movntps %%xmm1, 16(%1)\n"
        "movntps %%xmm2, 32(%1)\n"
        "movntps %%xmm3, 48(%1)\n"
        :: "r" (src), "r" (dst) : "memory");
        src += 64;
        dst += 64;
    }
    if (len & 63)
        SDL_memcpy(dst, src, len & 63);
}
#endif /* __SSE__ */

void
SDL_BlitCopy(SDL_BlitInfo * info)
{
    Uint8 *src, *dst;
    int w, h;
    int srcskip, dstskip;

    w = info->d_width * info->dst->BytesPerPixel;
    h = info->d_height;
    src = info->s_pixels;
    dst = info->d_pixels;
    srcskip = w + info->s_skip;
    dstskip = w + info->d_skip;

#ifdef __SSE__
    if (SDL_HasSSE() && !((uintptr_t)src & 15) && !((uintptr_t)dst & 15)) {
        while (h--) {
            SDL_memcpySSE(dst, src, w);
            src += srcskip;
            dst += dstskip;
        }
        return;
    }
#endif

#ifdef __MMX__
    if (SDL_HasMMX() && !((uintptr_t)src & 7) && !((uintptr_t)dst & 7)) {
        while (h--) {
            SDL_memcpyMMX(dst, src, w);
            src += srcskip;
            dst += dstskip;
        }
        __asm__ __volatile__("	emms\n"::);
        return;
    }
#endif

    while (h--) {
        SDL_memcpy(dst, src, w);
        src += srcskip;
        dst += dstskip;
    }
}

void
SDL_BlitCopyOverlap(SDL_BlitInfo * info)
{
    Uint8 *src, *dst;
    int w, h;
    int skip;

    w = info->d_width * info->dst->BytesPerPixel;
    h = info->d_height;
    src = info->s_pixels;
    dst = info->d_pixels;
    skip = w + info->s_skip;
    if ((dst < src) || (dst >= (src + h*skip))) {
        SDL_BlitCopy(info);
    } else {
        src += ((h - 1) * skip);
        dst += ((h - 1) * skip);
        while (h--) {
            SDL_revcpy(dst, src, w);
            src -= skip;
            dst -= skip;
        }
    }
}

/* vi: set ts=4 sw=4 expandtab: */