src/video/SDL_blit_copy.c
author Sam Lantinga <slouken@libsdl.org>
Sun, 14 Jul 2013 11:28:44 -0700
changeset 7776 d4a39491577f
parent 6885 700f1b25f77f
child 7860 2b0bcdea3a79
permissions -rw-r--r--
Added the platform specific messagebox function to the video function list
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2013 Sam Lantinga <slouken@libsdl.org>
     4 
     5   This software is provided 'as-is', without any express or implied
     6   warranty.  In no event will the authors be held liable for any damages
     7   arising from the use of this software.
     8 
     9   Permission is granted to anyone to use this software for any purpose,
    10   including commercial applications, and to alter it and redistribute it
    11   freely, subject to the following restrictions:
    12 
    13   1. The origin of this software must not be misrepresented; you must not
    14      claim that you wrote the original software. If you use this software
    15      in a product, an acknowledgment in the product documentation would be
    16      appreciated but is not required.
    17   2. Altered source versions must be plainly marked as such, and must not be
    18      misrepresented as being the original software.
    19   3. This notice may not be removed or altered from any source distribution.
    20 */
    21 #include "SDL_config.h"
    22 
    23 #include "SDL_video.h"
    24 #include "SDL_blit.h"
    25 #include "SDL_blit_copy.h"
    26 
    27 
    28 #ifdef __SSE__
    29 /* This assumes 16-byte aligned src and dst */
    30 static __inline__ void
    31 SDL_memcpySSE(Uint8 * dst, const Uint8 * src, int len)
    32 {
    33     int i;
    34 
    35     __m128 values[4];
    36     for (i = len / 64; i--;) {
    37         _mm_prefetch(src, _MM_HINT_NTA);
    38         values[0] = *(__m128 *) (src + 0);
    39         values[1] = *(__m128 *) (src + 16);
    40         values[2] = *(__m128 *) (src + 32);
    41         values[3] = *(__m128 *) (src + 48);
    42         _mm_stream_ps((float *) (dst + 0), values[0]);
    43         _mm_stream_ps((float *) (dst + 16), values[1]);
    44         _mm_stream_ps((float *) (dst + 32), values[2]);
    45         _mm_stream_ps((float *) (dst + 48), values[3]);
    46         src += 64;
    47         dst += 64;
    48     }
    49 
    50     if (len & 63)
    51         SDL_memcpy(dst, src, len & 63);
    52 }
    53 #endif /* __SSE__ */
    54 
    55 #ifdef __MMX__
    56 #ifdef _MSC_VER
    57 #pragma warning(disable:4799)
    58 #endif
    59 static __inline__ void
    60 SDL_memcpyMMX(Uint8 * dst, const Uint8 * src, int len)
    61 {
    62     const int remain = (len & 63);
    63     int i;
    64 
    65     __m64* d64 = (__m64*)dst;
    66     __m64* s64 = (__m64*)src;
    67 
    68     for(i= len / 64; i--;) {
    69         d64[0] = s64[0];
    70         d64[1] = s64[1];
    71         d64[2] = s64[2];
    72         d64[3] = s64[3];
    73         d64[4] = s64[4];
    74         d64[5] = s64[5];
    75         d64[6] = s64[6];
    76         d64[7] = s64[7];
    77 
    78         d64 += 8;
    79         s64 += 8;
    80     }
    81 
    82     if (remain)
    83     {
    84         const int skip = len - remain;
    85         SDL_memcpy(dst + skip, src + skip, remain);
    86     }
    87 }
    88 #endif /* __MMX__ */
    89 
    90 void
    91 SDL_BlitCopy(SDL_BlitInfo * info)
    92 {
    93     SDL_bool overlap;
    94     Uint8 *src, *dst;
    95     int w, h;
    96     int srcskip, dstskip;
    97 
    98     w = info->dst_w * info->dst_fmt->BytesPerPixel;
    99     h = info->dst_h;
   100     src = info->src;
   101     dst = info->dst;
   102     srcskip = info->src_pitch;
   103     dstskip = info->dst_pitch;
   104 
   105     /* Properly handle overlapping blits */
   106     if (src < dst) {
   107         overlap = (dst < (src + h*srcskip));
   108     } else {
   109         overlap = (src < (dst + h*dstskip));
   110     }
   111     if (overlap) {
   112         while (h--) {
   113             SDL_memmove(dst, src, w);
   114             src += srcskip;
   115             dst += dstskip;
   116         }
   117         return;
   118     }
   119 
   120 #ifdef __SSE__
   121     if (SDL_HasSSE() &&
   122         !((uintptr_t) src & 15) && !(srcskip & 15) &&
   123         !((uintptr_t) dst & 15) && !(dstskip & 15)) {
   124         while (h--) {
   125             SDL_memcpySSE(dst, src, w);
   126             src += srcskip;
   127             dst += dstskip;
   128         }
   129         return;
   130     }
   131 #endif
   132 
   133 #ifdef __MMX__
   134     if (SDL_HasMMX() && !(srcskip & 7) && !(dstskip & 7)) {
   135         while (h--) {
   136             SDL_memcpyMMX(dst, src, w);
   137             src += srcskip;
   138             dst += dstskip;
   139         }
   140         _mm_empty();
   141         return;
   142     }
   143 #endif
   144 
   145     while (h--) {
   146         SDL_memcpy(dst, src, w);
   147         src += srcskip;
   148         dst += dstskip;
   149     }
   150 }
   151 
   152 /* vi: set ts=4 sw=4 expandtab: */