view src/video/SDL_blit_copy.c @ 4525:3abf0b9cafad

pelya 2010-07-12 03:53:48 PDT In function GLES_RenderCopy() in SDL_renderer_gles.c:819 there is one memcpy() that can be avoided if we're updating whole texture. Because of that the SDL 1.3 in compatibility mode is working even slower than software rendering in SDL 1.2.
author Sam Lantinga <slouken@libsdl.org>
date Wed, 14 Jul 2010 07:31:35 -0700
parents f7b03b6838cb
children b530ef003506
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/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2010 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"
#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
/* This assumes 8-byte aligned src and dst */
static __inline__ void
SDL_memcpyMMX(Uint8 * dst, const Uint8 * src, int len)
{
    int i;

    __m64 values[8];
    for (i = len / 64; i--;) {
#ifdef __SSE__
        _mm_prefetch(src, _MM_HINT_NTA);
#endif
        values[0] = *(__m64 *) (src + 0);
        values[1] = *(__m64 *) (src + 8);
        values[2] = *(__m64 *) (src + 16);
        values[3] = *(__m64 *) (src + 24);
        values[4] = *(__m64 *) (src + 32);
        values[5] = *(__m64 *) (src + 40);
        values[6] = *(__m64 *) (src + 48);
        values[7] = *(__m64 *) (src + 56);
        _mm_stream_pi((__m64 *) (dst + 0), values[0]);
        _mm_stream_pi((__m64 *) (dst + 8), values[1]);
        _mm_stream_pi((__m64 *) (dst + 16), values[2]);
        _mm_stream_pi((__m64 *) (dst + 24), values[3]);
        _mm_stream_pi((__m64 *) (dst + 32), values[4]);
        _mm_stream_pi((__m64 *) (dst + 40), values[5]);
        _mm_stream_pi((__m64 *) (dst + 48), values[6]);
        _mm_stream_pi((__m64 *) (dst + 56), values[7]);
        src += 64;
        dst += 64;
    }

    if (len & 63)
        SDL_memcpy(dst, src, len & 63);
}
#endif /* __MMX__ */

void
SDL_BlitCopy(SDL_BlitInfo * info)
{
    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;

#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__
    if (SDL_HasMMX() &&
        !((uintptr_t) src & 7) && !(srcskip & 7) &&
        !((uintptr_t) dst & 7) && !(dstskip & 7)) {
        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;
    }
}

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

    w = info->dst_w * info->dst_fmt->BytesPerPixel;
    h = info->dst_h;
    src = info->src;
    dst = info->dst;
    skip = info->src_pitch;
    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;
        }
    }
}

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