*initHEADmaster

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diff --git a/source/3rd-party/SDL2/src/video/SDL_blit_A.c b/source/3rd-party/SDL2/src/video/SDL_blit_A.c
new file mode 100644
index 0000000..3507932
--- /dev/null
+++ b/source/3rd-party/SDL2/src/video/SDL_blit_A.c
@@ -0,0 +1,1388 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2018 Sam Lantinga <slouken@libsdl.org>
+
+  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_internal.h"
+
+#include "SDL_video.h"
+#include "SDL_blit.h"
+
+/* Functions to perform alpha blended blitting */
+
+/* N->1 blending with per-surface alpha */
+static void
+BlitNto1SurfaceAlpha(SDL_BlitInfo * info)
+{
+    int width = info->dst_w;
+    int height = info->dst_h;
+    Uint8 *src = info->src;
+    int srcskip = info->src_skip;
+    Uint8 *dst = info->dst;
+    int dstskip = info->dst_skip;
+    Uint8 *palmap = info->table;
+    SDL_PixelFormat *srcfmt = info->src_fmt;
+    SDL_PixelFormat *dstfmt = info->dst_fmt;
+    int srcbpp = srcfmt->BytesPerPixel;
+    Uint32 Pixel;
+    unsigned sR, sG, sB;
+    unsigned dR, dG, dB;
+    const unsigned A = info->a;
+
+    while (height--) {
+        /* *INDENT-OFF* */
+        DUFFS_LOOP4(
+        {
+        DISEMBLE_RGB(src, srcbpp, srcfmt, Pixel, sR, sG, sB);
+        dR = dstfmt->palette->colors[*dst].r;
+        dG = dstfmt->palette->colors[*dst].g;
+        dB = dstfmt->palette->colors[*dst].b;
+        ALPHA_BLEND_RGB(sR, sG, sB, A, dR, dG, dB);
+        dR &= 0xff;
+        dG &= 0xff;
+        dB &= 0xff;
+        /* Pack RGB into 8bit pixel */
+        if ( palmap == NULL ) {
+            *dst =((dR>>5)<<(3+2))|((dG>>5)<<(2))|((dB>>6)<<(0));
+        } else {
+            *dst = palmap[((dR>>5)<<(3+2))|((dG>>5)<<(2))|((dB>>6)<<(0))];
+        }
+        dst++;
+        src += srcbpp;
+        },
+        width);
+        /* *INDENT-ON* */
+        src += srcskip;
+        dst += dstskip;
+    }
+}
+
+/* N->1 blending with pixel alpha */
+static void
+BlitNto1PixelAlpha(SDL_BlitInfo * info)
+{
+    int width = info->dst_w;
+    int height = info->dst_h;
+    Uint8 *src = info->src;
+    int srcskip = info->src_skip;
+    Uint8 *dst = info->dst;
+    int dstskip = info->dst_skip;
+    Uint8 *palmap = info->table;
+    SDL_PixelFormat *srcfmt = info->src_fmt;
+    SDL_PixelFormat *dstfmt = info->dst_fmt;
+    int srcbpp = srcfmt->BytesPerPixel;
+    Uint32 Pixel;
+    unsigned sR, sG, sB, sA;
+    unsigned dR, dG, dB;
+
+    while (height--) {
+        /* *INDENT-OFF* */
+        DUFFS_LOOP4(
+        {
+        DISEMBLE_RGBA(src,srcbpp,srcfmt,Pixel,sR,sG,sB,sA);
+        dR = dstfmt->palette->colors[*dst].r;
+        dG = dstfmt->palette->colors[*dst].g;
+        dB = dstfmt->palette->colors[*dst].b;
+        ALPHA_BLEND_RGB(sR, sG, sB, sA, dR, dG, dB);
+        dR &= 0xff;
+        dG &= 0xff;
+        dB &= 0xff;
+        /* Pack RGB into 8bit pixel */
+        if ( palmap == NULL ) {
+            *dst =((dR>>5)<<(3+2))|((dG>>5)<<(2))|((dB>>6)<<(0));
+        } else {
+            *dst = palmap[((dR>>5)<<(3+2))|((dG>>5)<<(2))|((dB>>6)<<(0))];
+        }
+        dst++;
+        src += srcbpp;
+        },
+        width);
+        /* *INDENT-ON* */
+        src += srcskip;
+        dst += dstskip;
+    }
+}
+
+/* colorkeyed N->1 blending with per-surface alpha */
+static void
+BlitNto1SurfaceAlphaKey(SDL_BlitInfo * info)
+{
+    int width = info->dst_w;
+    int height = info->dst_h;
+    Uint8 *src = info->src;
+    int srcskip = info->src_skip;
+    Uint8 *dst = info->dst;
+    int dstskip = info->dst_skip;
+    Uint8 *palmap = info->table;
+    SDL_PixelFormat *srcfmt = info->src_fmt;
+    SDL_PixelFormat *dstfmt = info->dst_fmt;
+    int srcbpp = srcfmt->BytesPerPixel;
+    Uint32 ckey = info->colorkey;
+    Uint32 Pixel;
+    unsigned sR, sG, sB;
+    unsigned dR, dG, dB;
+    const unsigned A = info->a;
+
+    while (height--) {
+        /* *INDENT-OFF* */
+        DUFFS_LOOP(
+        {
+        DISEMBLE_RGB(src, srcbpp, srcfmt, Pixel, sR, sG, sB);
+        if ( Pixel != ckey ) {
+            dR = dstfmt->palette->colors[*dst].r;
+            dG = dstfmt->palette->colors[*dst].g;
+            dB = dstfmt->palette->colors[*dst].b;
+            ALPHA_BLEND_RGB(sR, sG, sB, A, dR, dG, dB);
+            dR &= 0xff;
+            dG &= 0xff;
+            dB &= 0xff;
+            /* Pack RGB into 8bit pixel */
+            if ( palmap == NULL ) {
+                *dst =((dR>>5)<<(3+2))|((dG>>5)<<(2))|((dB>>6)<<(0));
+            } else {
+                *dst = palmap[((dR>>5)<<(3+2))|((dG>>5)<<(2))|((dB>>6)<<(0))];
+            }
+        }
+        dst++;
+        src += srcbpp;
+        },
+        width);
+        /* *INDENT-ON* */
+        src += srcskip;
+        dst += dstskip;
+    }
+}
+
+#ifdef __MMX__
+
+/* fast RGB888->(A)RGB888 blending with surface alpha=128 special case */
+static void
+BlitRGBtoRGBSurfaceAlpha128MMX(SDL_BlitInfo * info)
+{
+    int width = info->dst_w;
+    int height = info->dst_h;
+    Uint32 *srcp = (Uint32 *) info->src;
+    int srcskip = info->src_skip >> 2;
+    Uint32 *dstp = (Uint32 *) info->dst;
+    int dstskip = info->dst_skip >> 2;
+    Uint32 dalpha = info->dst_fmt->Amask;
+
+    __m64 src1, src2, dst1, dst2, lmask, hmask, dsta;
+
+    hmask = _mm_set_pi32(0x00fefefe, 0x00fefefe);       /* alpha128 mask -> hmask */
+    lmask = _mm_set_pi32(0x00010101, 0x00010101);       /* !alpha128 mask -> lmask */
+    dsta = _mm_set_pi32(dalpha, dalpha);        /* dst alpha mask -> dsta */
+
+    while (height--) {
+        int n = width;
+        if (n & 1) {
+            Uint32 s = *srcp++;
+            Uint32 d = *dstp;
+            *dstp++ = ((((s & 0x00fefefe) + (d & 0x00fefefe)) >> 1)
+                       + (s & d & 0x00010101)) | dalpha;
+            n--;
+        }
+
+        for (n >>= 1; n > 0; --n) {
+            dst1 = *(__m64 *) dstp;     /* 2 x dst -> dst1(ARGBARGB) */
+            dst2 = dst1;        /* 2 x dst -> dst2(ARGBARGB) */
+
+            src1 = *(__m64 *) srcp;     /* 2 x src -> src1(ARGBARGB) */
+            src2 = src1;        /* 2 x src -> src2(ARGBARGB) */
+
+            dst2 = _mm_and_si64(dst2, hmask);   /* dst & mask -> dst2 */
+            src2 = _mm_and_si64(src2, hmask);   /* src & mask -> src2 */
+            src2 = _mm_add_pi32(src2, dst2);    /* dst2 + src2 -> src2 */
+            src2 = _mm_srli_pi32(src2, 1);      /* src2 >> 1 -> src2 */
+
+            dst1 = _mm_and_si64(dst1, src1);    /* src & dst -> dst1 */
+            dst1 = _mm_and_si64(dst1, lmask);   /* dst1 & !mask -> dst1 */
+            dst1 = _mm_add_pi32(dst1, src2);    /* src2 + dst1 -> dst1 */
+            dst1 = _mm_or_si64(dst1, dsta);     /* dsta(full alpha) | dst1 -> dst1 */
+
+            *(__m64 *) dstp = dst1;     /* dst1 -> 2 x dst pixels */
+            dstp += 2;
+            srcp += 2;
+        }
+
+        srcp += srcskip;
+        dstp += dstskip;
+    }
+    _mm_empty();
+}
+
+/* fast RGB888->(A)RGB888 blending with surface alpha */
+static void
+BlitRGBtoRGBSurfaceAlphaMMX(SDL_BlitInfo * info)
+{
+    SDL_PixelFormat *df = info->dst_fmt;
+    Uint32 chanmask;
+    unsigned alpha = info->a;
+
+    if (alpha == 128 && (df->Rmask | df->Gmask | df->Bmask) == 0x00FFFFFF) {
+        /* only call a128 version when R,G,B occupy lower bits */
+        BlitRGBtoRGBSurfaceAlpha128MMX(info);
+    } else {
+        int width = info->dst_w;
+        int height = info->dst_h;
+        Uint32 *srcp = (Uint32 *) info->src;
+        int srcskip = info->src_skip >> 2;
+        Uint32 *dstp = (Uint32 *) info->dst;
+        int dstskip = info->dst_skip >> 2;
+        Uint32 dalpha = df->Amask;
+        Uint32 amult;
+
+        __m64 src1, src2, dst1, dst2, mm_alpha, mm_zero, dsta;
+
+        mm_zero = _mm_setzero_si64();   /* 0 -> mm_zero */
+        /* form the alpha mult */
+        amult = alpha | (alpha << 8);
+        amult = amult | (amult << 16);
+        chanmask =
+            (0xff << df->Rshift) | (0xff << df->
+                                    Gshift) | (0xff << df->Bshift);
+        mm_alpha = _mm_set_pi32(0, amult & chanmask);   /* 0000AAAA -> mm_alpha, minus 1 chan */
+        mm_alpha = _mm_unpacklo_pi8(mm_alpha, mm_zero); /* 0A0A0A0A -> mm_alpha, minus 1 chan */
+        /* at this point mm_alpha can be 000A0A0A or 0A0A0A00 or another combo */
+        dsta = _mm_set_pi32(dalpha, dalpha);    /* dst alpha mask -> dsta */
+
+        while (height--) {
+            int n = width;
+            if (n & 1) {
+                /* One Pixel Blend */
+                src2 = _mm_cvtsi32_si64(*srcp); /* src(ARGB) -> src2 (0000ARGB) */
+                src2 = _mm_unpacklo_pi8(src2, mm_zero); /* 0A0R0G0B -> src2 */
+
+                dst1 = _mm_cvtsi32_si64(*dstp); /* dst(ARGB) -> dst1 (0000ARGB) */
+                dst1 = _mm_unpacklo_pi8(dst1, mm_zero); /* 0A0R0G0B -> dst1 */
+
+                src2 = _mm_sub_pi16(src2, dst1);        /* src2 - dst2 -> src2 */
+                src2 = _mm_mullo_pi16(src2, mm_alpha);  /* src2 * alpha -> src2 */
+                src2 = _mm_srli_pi16(src2, 8);  /* src2 >> 8 -> src2 */
+                dst1 = _mm_add_pi8(src2, dst1); /* src2 + dst1 -> dst1 */
+
+                dst1 = _mm_packs_pu16(dst1, mm_zero);   /* 0000ARGB -> dst1 */
+                dst1 = _mm_or_si64(dst1, dsta); /* dsta | dst1 -> dst1 */
+                *dstp = _mm_cvtsi64_si32(dst1); /* dst1 -> pixel */
+
+                ++srcp;
+                ++dstp;
+
+                n--;
+            }
+
+            for (n >>= 1; n > 0; --n) {
+                /* Two Pixels Blend */
+                src1 = *(__m64 *) srcp; /* 2 x src -> src1(ARGBARGB) */
+                src2 = src1;    /* 2 x src -> src2(ARGBARGB) */
+                src1 = _mm_unpacklo_pi8(src1, mm_zero); /* low - 0A0R0G0B -> src1 */
+                src2 = _mm_unpackhi_pi8(src2, mm_zero); /* high - 0A0R0G0B -> src2 */
+
+                dst1 = *(__m64 *) dstp; /* 2 x dst -> dst1(ARGBARGB) */
+                dst2 = dst1;    /* 2 x dst -> dst2(ARGBARGB) */
+                dst1 = _mm_unpacklo_pi8(dst1, mm_zero); /* low - 0A0R0G0B -> dst1 */
+                dst2 = _mm_unpackhi_pi8(dst2, mm_zero); /* high - 0A0R0G0B -> dst2 */
+
+                src1 = _mm_sub_pi16(src1, dst1);        /* src1 - dst1 -> src1 */
+                src1 = _mm_mullo_pi16(src1, mm_alpha);  /* src1 * alpha -> src1 */
+                src1 = _mm_srli_pi16(src1, 8);  /* src1 >> 8 -> src1 */
+                dst1 = _mm_add_pi8(src1, dst1); /* src1 + dst1(dst1) -> dst1 */
+
+                src2 = _mm_sub_pi16(src2, dst2);        /* src2 - dst2 -> src2 */
+                src2 = _mm_mullo_pi16(src2, mm_alpha);  /* src2 * alpha -> src2 */
+                src2 = _mm_srli_pi16(src2, 8);  /* src2 >> 8 -> src2 */
+                dst2 = _mm_add_pi8(src2, dst2); /* src2 + dst2(dst2) -> dst2 */
+
+                dst1 = _mm_packs_pu16(dst1, dst2);      /* 0A0R0G0B(res1), 0A0R0G0B(res2) -> dst1(ARGBARGB) */
+                dst1 = _mm_or_si64(dst1, dsta); /* dsta | dst1 -> dst1 */
+
+                *(__m64 *) dstp = dst1; /* dst1 -> 2 x pixel */
+
+                srcp += 2;
+                dstp += 2;
+            }
+            srcp += srcskip;
+            dstp += dstskip;
+        }
+        _mm_empty();
+    }
+}
+
+/* fast ARGB888->(A)RGB888 blending with pixel alpha */
+static void
+BlitRGBtoRGBPixelAlphaMMX(SDL_BlitInfo * info)
+{
+    int width = info->dst_w;
+    int height = info->dst_h;
+    Uint32 *srcp = (Uint32 *) info->src;
+    int srcskip = info->src_skip >> 2;
+    Uint32 *dstp = (Uint32 *) info->dst;
+    int dstskip = info->dst_skip >> 2;
+    SDL_PixelFormat *sf = info->src_fmt;
+    Uint32 amask = sf->Amask;
+    Uint32 ashift = sf->Ashift;
+    Uint64 multmask, multmask2;
+
+    __m64 src1, dst1, mm_alpha, mm_zero, mm_alpha2;
+
+    mm_zero = _mm_setzero_si64();       /* 0 -> mm_zero */
+    multmask = 0x00FF;
+    multmask <<= (ashift * 2);
+    multmask2 = 0x00FF00FF00FF00FFULL;
+
+    while (height--) {
+        /* *INDENT-OFF* */
+        DUFFS_LOOP4({
+        Uint32 alpha = *srcp & amask;
+        if (alpha == 0) {
+            /* do nothing */
+        } else if (alpha == amask) {
+            *dstp = *srcp;
+        } else {
+            src1 = _mm_cvtsi32_si64(*srcp); /* src(ARGB) -> src1 (0000ARGB) */
+            src1 = _mm_unpacklo_pi8(src1, mm_zero); /* 0A0R0G0B -> src1 */
+
+            dst1 = _mm_cvtsi32_si64(*dstp); /* dst(ARGB) -> dst1 (0000ARGB) */
+            dst1 = _mm_unpacklo_pi8(dst1, mm_zero); /* 0A0R0G0B -> dst1 */
+
+            mm_alpha = _mm_cvtsi32_si64(alpha); /* alpha -> mm_alpha (0000000A) */
+            mm_alpha = _mm_srli_si64(mm_alpha, ashift); /* mm_alpha >> ashift -> mm_alpha(0000000A) */
+            mm_alpha = _mm_unpacklo_pi16(mm_alpha, mm_alpha); /* 00000A0A -> mm_alpha */
+            mm_alpha2 = _mm_unpacklo_pi32(mm_alpha, mm_alpha); /* 0A0A0A0A -> mm_alpha2 */
+            mm_alpha = _mm_or_si64(mm_alpha2, *(__m64 *) & multmask);    /* 0F0A0A0A -> mm_alpha */
+            mm_alpha2 = _mm_xor_si64(mm_alpha2, *(__m64 *) & multmask2);    /* 255 - mm_alpha -> mm_alpha */
+
+            /* blend */            
+            src1 = _mm_mullo_pi16(src1, mm_alpha);
+            src1 = _mm_srli_pi16(src1, 8);
+            dst1 = _mm_mullo_pi16(dst1, mm_alpha2);
+            dst1 = _mm_srli_pi16(dst1, 8);
+            dst1 = _mm_add_pi16(src1, dst1);
+            dst1 = _mm_packs_pu16(dst1, mm_zero);
+            
+            *dstp = _mm_cvtsi64_si32(dst1); /* dst1 -> pixel */
+        }
+        ++srcp;
+        ++dstp;
+        }, width);
+        /* *INDENT-ON* */
+        srcp += srcskip;
+        dstp += dstskip;
+    }
+    _mm_empty();
+}
+
+#endif /* __MMX__ */
+
+/* fast RGB888->(A)RGB888 blending with surface alpha=128 special case */
+static void
+BlitRGBtoRGBSurfaceAlpha128(SDL_BlitInfo * info)
+{
+    int width = info->dst_w;
+    int height = info->dst_h;
+    Uint32 *srcp = (Uint32 *) info->src;
+    int srcskip = info->src_skip >> 2;
+    Uint32 *dstp = (Uint32 *) info->dst;
+    int dstskip = info->dst_skip >> 2;
+
+    while (height--) {
+        /* *INDENT-OFF* */
+        DUFFS_LOOP4({
+            Uint32 s = *srcp++;
+            Uint32 d = *dstp;
+            *dstp++ = ((((s & 0x00fefefe) + (d & 0x00fefefe)) >> 1)
+                   + (s & d & 0x00010101)) | 0xff000000;
+        }, width);
+        /* *INDENT-ON* */
+        srcp += srcskip;
+        dstp += dstskip;
+    }
+}
+
+/* fast RGB888->(A)RGB888 blending with surface alpha */
+static void
+BlitRGBtoRGBSurfaceAlpha(SDL_BlitInfo * info)
+{
+    unsigned alpha = info->a;
+    if (alpha == 128) {
+        BlitRGBtoRGBSurfaceAlpha128(info);
+    } else {
+        int width = info->dst_w;
+        int height = info->dst_h;
+        Uint32 *srcp = (Uint32 *) info->src;
+        int srcskip = info->src_skip >> 2;
+        Uint32 *dstp = (Uint32 *) info->dst;
+        int dstskip = info->dst_skip >> 2;
+        Uint32 s;
+        Uint32 d;
+        Uint32 s1;
+        Uint32 d1;
+
+        while (height--) {
+            /* *INDENT-OFF* */
+            DUFFS_LOOP4({
+                s = *srcp;
+                d = *dstp;
+                s1 = s & 0xff00ff;
+                d1 = d & 0xff00ff;
+                d1 = (d1 + ((s1 - d1) * alpha >> 8))
+                     & 0xff00ff;
+                s &= 0xff00;
+                d &= 0xff00;
+                d = (d + ((s - d) * alpha >> 8)) & 0xff00;
+                *dstp = d1 | d | 0xff000000;
+                ++srcp;
+                ++dstp;
+            }, width);
+            /* *INDENT-ON* */
+            srcp += srcskip;
+            dstp += dstskip;
+        }
+    }
+}
+
+/* fast ARGB888->(A)RGB888 blending with pixel alpha */
+static void
+BlitRGBtoRGBPixelAlpha(SDL_BlitInfo * info)
+{
+    int width = info->dst_w;
+    int height = info->dst_h;
+    Uint32 *srcp = (Uint32 *) info->src;
+    int srcskip = info->src_skip >> 2;
+    Uint32 *dstp = (Uint32 *) info->dst;
+    int dstskip = info->dst_skip >> 2;
+
+    while (height--) {
+        /* *INDENT-OFF* */
+        DUFFS_LOOP4({
+        Uint32 dalpha;
+        Uint32 d;
+        Uint32 s1;
+        Uint32 d1;
+        Uint32 s = *srcp;
+        Uint32 alpha = s >> 24;
+        /* FIXME: Here we special-case opaque alpha since the
+           compositioning used (>>8 instead of /255) doesn't handle
+           it correctly. Also special-case alpha=0 for speed?
+           Benchmark this! */
+        if (alpha) {
+          if (alpha == SDL_ALPHA_OPAQUE) {
+              *dstp = *srcp;
+          } else {
+            /*
+             * take out the middle component (green), and process
+             * the other two in parallel. One multiply less.
+             */
+            d = *dstp;
+            dalpha = d >> 24;
+            s1 = s & 0xff00ff;
+            d1 = d & 0xff00ff;
+            d1 = (d1 + ((s1 - d1) * alpha >> 8)) & 0xff00ff;
+            s &= 0xff00;
+            d &= 0xff00;
+            d = (d + ((s - d) * alpha >> 8)) & 0xff00;
+            dalpha = alpha + (dalpha * (alpha ^ 0xFF) >> 8);
+            *dstp = d1 | d | (dalpha << 24);
+          }
+        }
+        ++srcp;
+        ++dstp;
+        }, width);
+        /* *INDENT-ON* */
+        srcp += srcskip;
+        dstp += dstskip;
+    }
+}
+
+#ifdef __3dNOW__
+/* fast (as in MMX with prefetch) ARGB888->(A)RGB888 blending with pixel alpha */
+static void
+BlitRGBtoRGBPixelAlphaMMX3DNOW(SDL_BlitInfo * info)
+{
+    int width = info->dst_w;
+    int height = info->dst_h;
+    Uint32 *srcp = (Uint32 *) info->src;
+    int srcskip = info->src_skip >> 2;
+    Uint32 *dstp = (Uint32 *) info->dst;
+    int dstskip = info->dst_skip >> 2;
+    SDL_PixelFormat *sf = info->src_fmt;
+    Uint32 amask = sf->Amask;
+    Uint32 ashift = sf->Ashift;
+    Uint64 multmask, multmask2;
+
+    __m64 src1, dst1, mm_alpha, mm_zero, mm_alpha2;
+
+    mm_zero = _mm_setzero_si64();       /* 0 -> mm_zero */
+    multmask = 0x00FF;
+    multmask <<= (ashift * 2);
+    multmask2 = 0x00FF00FF00FF00FFULL;
+
+    while (height--) {
+        /* *INDENT-OFF* */
+        DUFFS_LOOP4({
+        Uint32 alpha;
+
+        _m_prefetch(srcp + 16);
+        _m_prefetch(dstp + 16);
+
+        alpha = *srcp & amask;
+        if (alpha == 0) {
+            /* do nothing */
+        } else if (alpha == amask) {
+            *dstp = *srcp;
+        } else {
+            src1 = _mm_cvtsi32_si64(*srcp); /* src(ARGB) -> src1 (0000ARGB) */
+            src1 = _mm_unpacklo_pi8(src1, mm_zero); /* 0A0R0G0B -> src1 */
+
+            dst1 = _mm_cvtsi32_si64(*dstp); /* dst(ARGB) -> dst1 (0000ARGB) */
+            dst1 = _mm_unpacklo_pi8(dst1, mm_zero); /* 0A0R0G0B -> dst1 */
+
+            mm_alpha = _mm_cvtsi32_si64(alpha); /* alpha -> mm_alpha (0000000A) */
+            mm_alpha = _mm_srli_si64(mm_alpha, ashift); /* mm_alpha >> ashift -> mm_alpha(0000000A) */
+            mm_alpha = _mm_unpacklo_pi16(mm_alpha, mm_alpha); /* 00000A0A -> mm_alpha */
+            mm_alpha2 = _mm_unpacklo_pi32(mm_alpha, mm_alpha); /* 0A0A0A0A -> mm_alpha2 */
+            mm_alpha = _mm_or_si64(mm_alpha2, *(__m64 *) & multmask);    /* 0F0A0A0A -> mm_alpha */
+            mm_alpha2 = _mm_xor_si64(mm_alpha2, *(__m64 *) & multmask2);    /* 255 - mm_alpha -> mm_alpha */
+
+
+            /* blend */            
+            src1 = _mm_mullo_pi16(src1, mm_alpha);
+            src1 = _mm_srli_pi16(src1, 8);
+            dst1 = _mm_mullo_pi16(dst1, mm_alpha2);
+            dst1 = _mm_srli_pi16(dst1, 8);
+            dst1 = _mm_add_pi16(src1, dst1);
+            dst1 = _mm_packs_pu16(dst1, mm_zero);
+            
+            *dstp = _mm_cvtsi64_si32(dst1); /* dst1 -> pixel */
+        }
+        ++srcp;
+        ++dstp;
+        }, width);
+        /* *INDENT-ON* */
+        srcp += srcskip;
+        dstp += dstskip;
+    }
+    _mm_empty();
+}
+
+#endif /* __3dNOW__ */
+
+/* 16bpp special case for per-surface alpha=50%: blend 2 pixels in parallel */
+
+/* blend a single 16 bit pixel at 50% */
+#define BLEND16_50(d, s, mask)                        \
+    ((((s & mask) + (d & mask)) >> 1) + (s & d & (~mask & 0xffff)))
+
+/* blend two 16 bit pixels at 50% */
+#define BLEND2x16_50(d, s, mask)                         \
+    (((s & (mask | mask << 16)) >> 1) + ((d & (mask | mask << 16)) >> 1) \
+     + (s & d & (~(mask | mask << 16))))
+
+static void
+Blit16to16SurfaceAlpha128(SDL_BlitInfo * info, Uint16 mask)
+{
+    int width = info->dst_w;
+    int height = info->dst_h;
+    Uint16 *srcp = (Uint16 *) info->src;
+    int srcskip = info->src_skip >> 1;
+    Uint16 *dstp = (Uint16 *) info->dst;
+    int dstskip = info->dst_skip >> 1;
+
+    while (height--) {
+        if (((uintptr_t) srcp ^ (uintptr_t) dstp) & 2) {
+            /*
+             * Source and destination not aligned, pipeline it.
+             * This is mostly a win for big blits but no loss for
+             * small ones
+             */
+            Uint32 prev_sw;
+            int w = width;
+
+            /* handle odd destination */
+            if ((uintptr_t) dstp & 2) {
+                Uint16 d = *dstp, s = *srcp;
+                *dstp = BLEND16_50(d, s, mask);
+                dstp++;
+                srcp++;
+                w--;
+            }
+            srcp++;             /* srcp is now 32-bit aligned */
+
+            /* bootstrap pipeline with first halfword */
+            prev_sw = ((Uint32 *) srcp)[-1];
+
+            while (w > 1) {
+                Uint32 sw, dw, s;
+                sw = *(Uint32 *) srcp;
+                dw = *(Uint32 *) dstp;
+#if SDL_BYTEORDER == SDL_BIG_ENDIAN
+                s = (prev_sw << 16) + (sw >> 16);
+#else
+                s = (prev_sw >> 16) + (sw << 16);
+#endif
+                prev_sw = sw;
+                *(Uint32 *) dstp = BLEND2x16_50(dw, s, mask);
+                dstp += 2;
+                srcp += 2;
+                w -= 2;
+            }
+
+            /* final pixel if any */
+            if (w) {
+                Uint16 d = *dstp, s;
+#if SDL_BYTEORDER == SDL_BIG_ENDIAN
+                s = (Uint16) prev_sw;
+#else
+                s = (Uint16) (prev_sw >> 16);
+#endif
+                *dstp = BLEND16_50(d, s, mask);
+                srcp++;
+                dstp++;
+            }
+            srcp += srcskip - 1;
+            dstp += dstskip;
+        } else {
+            /* source and destination are aligned */
+            int w = width;
+
+            /* first odd pixel? */
+            if ((uintptr_t) srcp & 2) {
+                Uint16 d = *dstp, s = *srcp;
+                *dstp = BLEND16_50(d, s, mask);
+                srcp++;
+                dstp++;
+                w--;
+            }
+            /* srcp and dstp are now 32-bit aligned */
+
+            while (w > 1) {
+                Uint32 sw = *(Uint32 *) srcp;
+                Uint32 dw = *(Uint32 *) dstp;
+                *(Uint32 *) dstp = BLEND2x16_50(dw, sw, mask);
+                srcp += 2;
+                dstp += 2;
+                w -= 2;
+            }
+
+            /* last odd pixel? */
+            if (w) {
+                Uint16 d = *dstp, s = *srcp;
+                *dstp = BLEND16_50(d, s, mask);
+                srcp++;
+                dstp++;
+            }
+            srcp += srcskip;
+            dstp += dstskip;
+        }
+    }
+}
+
+#ifdef __MMX__
+
+/* fast RGB565->RGB565 blending with surface alpha */
+static void
+Blit565to565SurfaceAlphaMMX(SDL_BlitInfo * info)
+{
+    unsigned alpha = info->a;
+    if (alpha == 128) {
+        Blit16to16SurfaceAlpha128(info, 0xf7de);
+    } else {
+        int width = info->dst_w;
+        int height = info->dst_h;
+        Uint16 *srcp = (Uint16 *) info->src;
+        int srcskip = info->src_skip >> 1;
+        Uint16 *dstp = (Uint16 *) info->dst;
+        int dstskip = info->dst_skip >> 1;
+        Uint32 s, d;
+
+        __m64 src1, dst1, src2, dst2, gmask, bmask, mm_res, mm_alpha;
+
+        alpha &= ~(1 + 2 + 4);  /* cut alpha to get the exact same behaviour */
+        mm_alpha = _mm_set_pi32(0, alpha);      /* 0000000A -> mm_alpha */
+        alpha >>= 3;            /* downscale alpha to 5 bits */
+
+        mm_alpha = _mm_unpacklo_pi16(mm_alpha, mm_alpha);       /* 00000A0A -> mm_alpha */
+        mm_alpha = _mm_unpacklo_pi32(mm_alpha, mm_alpha);       /* 0A0A0A0A -> mm_alpha */
+        /* position alpha to allow for mullo and mulhi on diff channels
+           to reduce the number of operations */
+        mm_alpha = _mm_slli_si64(mm_alpha, 3);
+
+        /* Setup the 565 color channel masks */
+        gmask = _mm_set_pi32(0x07E007E0, 0x07E007E0);   /* MASKGREEN -> gmask */
+        bmask = _mm_set_pi32(0x001F001F, 0x001F001F);   /* MASKBLUE -> bmask */
+
+        while (height--) {
+            /* *INDENT-OFF* */
+            DUFFS_LOOP_124(
+            {
+                s = *srcp++;
+                d = *dstp;
+                /*
+                 * shift out the middle component (green) to
+                 * the high 16 bits, and process all three RGB
+                 * components at the same time.
+                 */
+                s = (s | s << 16) & 0x07e0f81f;
+                d = (d | d << 16) & 0x07e0f81f;
+                d += (s - d) * alpha >> 5;
+                d &= 0x07e0f81f;
+                *dstp++ = (Uint16)(d | d >> 16);
+            },{
+                s = *srcp++;
+                d = *dstp;
+                /*
+                 * shift out the middle component (green) to
+                 * the high 16 bits, and process all three RGB
+                 * components at the same time.
+                 */
+                s = (s | s << 16) & 0x07e0f81f;
+                d = (d | d << 16) & 0x07e0f81f;
+                d += (s - d) * alpha >> 5;
+                d &= 0x07e0f81f;
+                *dstp++ = (Uint16)(d | d >> 16);
+                s = *srcp++;
+                d = *dstp;
+                /*
+                 * shift out the middle component (green) to
+                 * the high 16 bits, and process all three RGB
+                 * components at the same time.
+                 */
+                s = (s | s << 16) & 0x07e0f81f;
+                d = (d | d << 16) & 0x07e0f81f;
+                d += (s - d) * alpha >> 5;
+                d &= 0x07e0f81f;
+                *dstp++ = (Uint16)(d | d >> 16);
+            },{
+                src1 = *(__m64*)srcp; /* 4 src pixels -> src1 */
+                dst1 = *(__m64*)dstp; /* 4 dst pixels -> dst1 */
+
+                /* red */
+                src2 = src1;
+                src2 = _mm_srli_pi16(src2, 11); /* src2 >> 11 -> src2 [000r 000r 000r 000r] */
+
+                dst2 = dst1;
+                dst2 = _mm_srli_pi16(dst2, 11); /* dst2 >> 11 -> dst2 [000r 000r 000r 000r] */
+
+                /* blend */
+                src2 = _mm_sub_pi16(src2, dst2);/* src - dst -> src2 */
+                src2 = _mm_mullo_pi16(src2, mm_alpha); /* src2 * alpha -> src2 */
+                src2 = _mm_srli_pi16(src2, 11); /* src2 >> 11 -> src2 */
+                dst2 = _mm_add_pi16(src2, dst2); /* src2 + dst2 -> dst2 */
+                dst2 = _mm_slli_pi16(dst2, 11); /* dst2 << 11 -> dst2 */
+
+                mm_res = dst2; /* RED -> mm_res */
+
+                /* green -- process the bits in place */
+                src2 = src1;
+                src2 = _mm_and_si64(src2, gmask); /* src & MASKGREEN -> src2 */
+
+                dst2 = dst1;
+                dst2 = _mm_and_si64(dst2, gmask); /* dst & MASKGREEN -> dst2 */
+
+                /* blend */
+                src2 = _mm_sub_pi16(src2, dst2);/* src - dst -> src2 */
+                src2 = _mm_mulhi_pi16(src2, mm_alpha); /* src2 * alpha -> src2 */
+                src2 = _mm_slli_pi16(src2, 5); /* src2 << 5 -> src2 */
+                dst2 = _mm_add_pi16(src2, dst2); /* src2 + dst2 -> dst2 */
+
+                mm_res = _mm_or_si64(mm_res, dst2); /* RED | GREEN -> mm_res */
+
+                /* blue */
+                src2 = src1;
+                src2 = _mm_and_si64(src2, bmask); /* src & MASKBLUE -> src2[000b 000b 000b 000b] */
+
+                dst2 = dst1;
+                dst2 = _mm_and_si64(dst2, bmask); /* dst & MASKBLUE -> dst2[000b 000b 000b 000b] */
+
+                /* blend */
+                src2 = _mm_sub_pi16(src2, dst2);/* src - dst -> src2 */
+                src2 = _mm_mullo_pi16(src2, mm_alpha); /* src2 * alpha -> src2 */
+                src2 = _mm_srli_pi16(src2, 11); /* src2 >> 11 -> src2 */
+                dst2 = _mm_add_pi16(src2, dst2); /* src2 + dst2 -> dst2 */
+                dst2 = _mm_and_si64(dst2, bmask); /* dst2 & MASKBLUE -> dst2 */
+
+                mm_res = _mm_or_si64(mm_res, dst2); /* RED | GREEN | BLUE -> mm_res */
+
+                *(__m64*)dstp = mm_res; /* mm_res -> 4 dst pixels */
+
+                srcp += 4;
+                dstp += 4;
+            }, width);
+            /* *INDENT-ON* */
+            srcp += srcskip;
+            dstp += dstskip;
+        }
+        _mm_empty();
+    }
+}
+
+/* fast RGB555->RGB555 blending with surface alpha */
+static void
+Blit555to555SurfaceAlphaMMX(SDL_BlitInfo * info)
+{
+    unsigned alpha = info->a;
+    if (alpha == 128) {
+        Blit16to16SurfaceAlpha128(info, 0xfbde);
+    } else {
+        int width = info->dst_w;
+        int height = info->dst_h;
+        Uint16 *srcp = (Uint16 *) info->src;
+        int srcskip = info->src_skip >> 1;
+        Uint16 *dstp = (Uint16 *) info->dst;
+        int dstskip = info->dst_skip >> 1;
+        Uint32 s, d;
+
+        __m64 src1, dst1, src2, dst2, rmask, gmask, bmask, mm_res, mm_alpha;
+
+        alpha &= ~(1 + 2 + 4);  /* cut alpha to get the exact same behaviour */
+        mm_alpha = _mm_set_pi32(0, alpha);      /* 0000000A -> mm_alpha */
+        alpha >>= 3;            /* downscale alpha to 5 bits */
+
+        mm_alpha = _mm_unpacklo_pi16(mm_alpha, mm_alpha);       /* 00000A0A -> mm_alpha */
+        mm_alpha = _mm_unpacklo_pi32(mm_alpha, mm_alpha);       /* 0A0A0A0A -> mm_alpha */
+        /* position alpha to allow for mullo and mulhi on diff channels
+           to reduce the number of operations */
+        mm_alpha = _mm_slli_si64(mm_alpha, 3);
+
+        /* Setup the 555 color channel masks */
+        rmask = _mm_set_pi32(0x7C007C00, 0x7C007C00);   /* MASKRED -> rmask */
+        gmask = _mm_set_pi32(0x03E003E0, 0x03E003E0);   /* MASKGREEN -> gmask */
+        bmask = _mm_set_pi32(0x001F001F, 0x001F001F);   /* MASKBLUE -> bmask */
+
+        while (height--) {
+            /* *INDENT-OFF* */
+            DUFFS_LOOP_124(
+            {
+                s = *srcp++;
+                d = *dstp;
+                /*
+                 * shift out the middle component (green) to
+                 * the high 16 bits, and process all three RGB
+                 * components at the same time.
+                 */
+                s = (s | s << 16) & 0x03e07c1f;
+                d = (d | d << 16) & 0x03e07c1f;
+                d += (s - d) * alpha >> 5;
+                d &= 0x03e07c1f;
+                *dstp++ = (Uint16)(d | d >> 16);
+            },{
+                s = *srcp++;
+                d = *dstp;
+                /*
+                 * shift out the middle component (green) to
+                 * the high 16 bits, and process all three RGB
+                 * components at the same time.
+                 */
+                s = (s | s << 16) & 0x03e07c1f;
+                d = (d | d << 16) & 0x03e07c1f;
+                d += (s - d) * alpha >> 5;
+                d &= 0x03e07c1f;
+                *dstp++ = (Uint16)(d | d >> 16);
+                    s = *srcp++;
+                d = *dstp;
+                /*
+                 * shift out the middle component (green) to
+                 * the high 16 bits, and process all three RGB
+                 * components at the same time.
+                 */
+                s = (s | s << 16) & 0x03e07c1f;
+                d = (d | d << 16) & 0x03e07c1f;
+                d += (s - d) * alpha >> 5;
+                d &= 0x03e07c1f;
+                *dstp++ = (Uint16)(d | d >> 16);
+            },{
+                src1 = *(__m64*)srcp; /* 4 src pixels -> src1 */
+                dst1 = *(__m64*)dstp; /* 4 dst pixels -> dst1 */
+
+                /* red -- process the bits in place */
+                src2 = src1;
+                src2 = _mm_and_si64(src2, rmask); /* src & MASKRED -> src2 */
+
+                dst2 = dst1;
+                dst2 = _mm_and_si64(dst2, rmask); /* dst & MASKRED -> dst2 */
+
+                /* blend */
+                src2 = _mm_sub_pi16(src2, dst2);/* src - dst -> src2 */
+                src2 = _mm_mulhi_pi16(src2, mm_alpha); /* src2 * alpha -> src2 */
+                src2 = _mm_slli_pi16(src2, 5); /* src2 << 5 -> src2 */
+                dst2 = _mm_add_pi16(src2, dst2); /* src2 + dst2 -> dst2 */
+                dst2 = _mm_and_si64(dst2, rmask); /* dst2 & MASKRED -> dst2 */
+
+                mm_res = dst2; /* RED -> mm_res */
+                
+                /* green -- process the bits in place */
+                src2 = src1;
+                src2 = _mm_and_si64(src2, gmask); /* src & MASKGREEN -> src2 */
+
+                dst2 = dst1;
+                dst2 = _mm_and_si64(dst2, gmask); /* dst & MASKGREEN -> dst2 */
+
+                /* blend */
+                src2 = _mm_sub_pi16(src2, dst2);/* src - dst -> src2 */
+                src2 = _mm_mulhi_pi16(src2, mm_alpha); /* src2 * alpha -> src2 */
+                src2 = _mm_slli_pi16(src2, 5); /* src2 << 5 -> src2 */
+                dst2 = _mm_add_pi16(src2, dst2); /* src2 + dst2 -> dst2 */
+
+                mm_res = _mm_or_si64(mm_res, dst2); /* RED | GREEN -> mm_res */
+
+                /* blue */
+                src2 = src1; /* src -> src2 */
+                src2 = _mm_and_si64(src2, bmask); /* src & MASKBLUE -> src2[000b 000b 000b 000b] */
+
+                dst2 = dst1; /* dst -> dst2 */
+                dst2 = _mm_and_si64(dst2, bmask); /* dst & MASKBLUE -> dst2[000b 000b 000b 000b] */
+
+                /* blend */
+                src2 = _mm_sub_pi16(src2, dst2);/* src - dst -> src2 */
+                src2 = _mm_mullo_pi16(src2, mm_alpha); /* src2 * alpha -> src2 */
+                src2 = _mm_srli_pi16(src2, 11); /* src2 >> 11 -> src2 */
+                dst2 = _mm_add_pi16(src2, dst2); /* src2 + dst2 -> dst2 */
+                dst2 = _mm_and_si64(dst2, bmask); /* dst2 & MASKBLUE -> dst2 */
+
+                mm_res = _mm_or_si64(mm_res, dst2); /* RED | GREEN | BLUE -> mm_res */
+
+                *(__m64*)dstp = mm_res; /* mm_res -> 4 dst pixels */
+
+                srcp += 4;
+                dstp += 4;
+            }, width);
+            /* *INDENT-ON* */
+            srcp += srcskip;
+            dstp += dstskip;
+        }
+        _mm_empty();
+    }
+}
+
+#endif /* __MMX__ */
+
+/* fast RGB565->RGB565 blending with surface alpha */
+static void
+Blit565to565SurfaceAlpha(SDL_BlitInfo * info)
+{
+    unsigned alpha = info->a;
+    if (alpha == 128) {
+        Blit16to16SurfaceAlpha128(info, 0xf7de);
+    } else {
+        int width = info->dst_w;
+        int height = info->dst_h;
+        Uint16 *srcp = (Uint16 *) info->src;
+        int srcskip = info->src_skip >> 1;
+        Uint16 *dstp = (Uint16 *) info->dst;
+        int dstskip = info->dst_skip >> 1;
+        alpha >>= 3;            /* downscale alpha to 5 bits */
+
+        while (height--) {
+            /* *INDENT-OFF* */
+            DUFFS_LOOP4({
+                Uint32 s = *srcp++;
+                Uint32 d = *dstp;
+                /*
+                 * shift out the middle component (green) to
+                 * the high 16 bits, and process all three RGB
+                 * components at the same time.
+                 */
+                s = (s | s << 16) & 0x07e0f81f;
+                d = (d | d << 16) & 0x07e0f81f;
+                d += (s - d) * alpha >> 5;
+                d &= 0x07e0f81f;
+                *dstp++ = (Uint16)(d | d >> 16);
+            }, width);
+            /* *INDENT-ON* */
+            srcp += srcskip;
+            dstp += dstskip;
+        }
+    }
+}
+
+/* fast RGB555->RGB555 blending with surface alpha */
+static void
+Blit555to555SurfaceAlpha(SDL_BlitInfo * info)
+{
+    unsigned alpha = info->a;   /* downscale alpha to 5 bits */
+    if (alpha == 128) {
+        Blit16to16SurfaceAlpha128(info, 0xfbde);
+    } else {
+        int width = info->dst_w;
+        int height = info->dst_h;
+        Uint16 *srcp = (Uint16 *) info->src;
+        int srcskip = info->src_skip >> 1;
+        Uint16 *dstp = (Uint16 *) info->dst;
+        int dstskip = info->dst_skip >> 1;
+        alpha >>= 3;            /* downscale alpha to 5 bits */
+
+        while (height--) {
+            /* *INDENT-OFF* */
+            DUFFS_LOOP4({
+                Uint32 s = *srcp++;
+                Uint32 d = *dstp;
+                /*
+                 * shift out the middle component (green) to
+                 * the high 16 bits, and process all three RGB
+                 * components at the same time.
+                 */
+                s = (s | s << 16) & 0x03e07c1f;
+                d = (d | d << 16) & 0x03e07c1f;
+                d += (s - d) * alpha >> 5;
+                d &= 0x03e07c1f;
+                *dstp++ = (Uint16)(d | d >> 16);
+            }, width);
+            /* *INDENT-ON* */
+            srcp += srcskip;
+            dstp += dstskip;
+        }
+    }
+}
+
+/* fast ARGB8888->RGB565 blending with pixel alpha */
+static void
+BlitARGBto565PixelAlpha(SDL_BlitInfo * info)
+{
+    int width = info->dst_w;
+    int height = info->dst_h;
+    Uint32 *srcp = (Uint32 *) info->src;
+    int srcskip = info->src_skip >> 2;
+    Uint16 *dstp = (Uint16 *) info->dst;
+    int dstskip = info->dst_skip >> 1;
+
+    while (height--) {
+        /* *INDENT-OFF* */
+        DUFFS_LOOP4({
+        Uint32 s = *srcp;
+        unsigned alpha = s >> 27; /* downscale alpha to 5 bits */
+        /* FIXME: Here we special-case opaque alpha since the
+           compositioning used (>>8 instead of /255) doesn't handle
+           it correctly. Also special-case alpha=0 for speed?
+           Benchmark this! */
+        if(alpha) {   
+          if(alpha == (SDL_ALPHA_OPAQUE >> 3)) {
+            *dstp = (Uint16)((s >> 8 & 0xf800) + (s >> 5 & 0x7e0) + (s >> 3  & 0x1f));
+          } else {
+            Uint32 d = *dstp;
+            /*
+             * convert source and destination to G0RAB65565
+             * and blend all components at the same time
+             */
+            s = ((s & 0xfc00) << 11) + (s >> 8 & 0xf800)
+              + (s >> 3 & 0x1f);
+            d = (d | d << 16) & 0x07e0f81f;
+            d += (s - d) * alpha >> 5;
+            d &= 0x07e0f81f;
+            *dstp = (Uint16)(d | d >> 16);
+          }
+        }
+        srcp++;
+        dstp++;
+        }, width);
+        /* *INDENT-ON* */
+        srcp += srcskip;
+        dstp += dstskip;
+    }
+}
+
+/* fast ARGB8888->RGB555 blending with pixel alpha */
+static void
+BlitARGBto555PixelAlpha(SDL_BlitInfo * info)
+{
+    int width = info->dst_w;
+    int height = info->dst_h;
+    Uint32 *srcp = (Uint32 *) info->src;
+    int srcskip = info->src_skip >> 2;
+    Uint16 *dstp = (Uint16 *) info->dst;
+    int dstskip = info->dst_skip >> 1;
+
+    while (height--) {
+        /* *INDENT-OFF* */
+        DUFFS_LOOP4({
+        unsigned alpha;
+        Uint32 s = *srcp;
+        alpha = s >> 27; /* downscale alpha to 5 bits */
+        /* FIXME: Here we special-case opaque alpha since the
+           compositioning used (>>8 instead of /255) doesn't handle
+           it correctly. Also special-case alpha=0 for speed?
+           Benchmark this! */
+        if(alpha) {   
+          if(alpha == (SDL_ALPHA_OPAQUE >> 3)) {
+            *dstp = (Uint16)((s >> 9 & 0x7c00) + (s >> 6 & 0x3e0) + (s >> 3  & 0x1f));
+          } else {
+            Uint32 d = *dstp;
+            /*
+             * convert source and destination to G0RAB65565
+             * and blend all components at the same time
+             */
+            s = ((s & 0xf800) << 10) + (s >> 9 & 0x7c00)
+              + (s >> 3 & 0x1f);
+            d = (d | d << 16) & 0x03e07c1f;
+            d += (s - d) * alpha >> 5;
+            d &= 0x03e07c1f;
+            *dstp = (Uint16)(d | d >> 16);
+          }
+        }
+        srcp++;
+        dstp++;
+        }, width);
+        /* *INDENT-ON* */
+        srcp += srcskip;
+        dstp += dstskip;
+    }
+}
+
+/* General (slow) N->N blending with per-surface alpha */
+static void
+BlitNtoNSurfaceAlpha(SDL_BlitInfo * info)
+{
+    int width = info->dst_w;
+    int height = info->dst_h;
+    Uint8 *src = info->src;
+    int srcskip = info->src_skip;
+    Uint8 *dst = info->dst;
+    int dstskip = info->dst_skip;
+    SDL_PixelFormat *srcfmt = info->src_fmt;
+    SDL_PixelFormat *dstfmt = info->dst_fmt;
+    int srcbpp = srcfmt->BytesPerPixel;
+    int dstbpp = dstfmt->BytesPerPixel;
+    Uint32 Pixel;
+    unsigned sR, sG, sB;
+    unsigned dR, dG, dB, dA;
+    const unsigned sA = info->a;
+
+    if (sA) {
+        while (height--) {
+        /* *INDENT-OFF* */
+        DUFFS_LOOP4(
+        {
+        DISEMBLE_RGB(src, srcbpp, srcfmt, Pixel, sR, sG, sB);
+        DISEMBLE_RGBA(dst, dstbpp, dstfmt, Pixel, dR, dG, dB, dA);
+        ALPHA_BLEND_RGBA(sR, sG, sB, sA, dR, dG, dB, dA);
+        ASSEMBLE_RGBA(dst, dstbpp, dstfmt, dR, dG, dB, dA);
+        src += srcbpp;
+        dst += dstbpp;
+        },
+        width);
+        /* *INDENT-ON* */
+            src += srcskip;
+            dst += dstskip;
+        }
+    }
+}
+
+/* General (slow) colorkeyed N->N blending with per-surface alpha */
+static void
+BlitNtoNSurfaceAlphaKey(SDL_BlitInfo * info)
+{
+    int width = info->dst_w;
+    int height = info->dst_h;
+    Uint8 *src = info->src;
+    int srcskip = info->src_skip;
+    Uint8 *dst = info->dst;
+    int dstskip = info->dst_skip;
+    SDL_PixelFormat *srcfmt = info->src_fmt;
+    SDL_PixelFormat *dstfmt = info->dst_fmt;
+    Uint32 ckey = info->colorkey;
+    int srcbpp = srcfmt->BytesPerPixel;
+    int dstbpp = dstfmt->BytesPerPixel;
+    Uint32 Pixel;
+    unsigned sR, sG, sB;
+    unsigned dR, dG, dB, dA;
+    const unsigned sA = info->a;
+
+    while (height--) {
+        /* *INDENT-OFF* */
+        DUFFS_LOOP4(
+        {
+        RETRIEVE_RGB_PIXEL(src, srcbpp, Pixel);
+        if(sA && Pixel != ckey) {
+            RGB_FROM_PIXEL(Pixel, srcfmt, sR, sG, sB);
+            DISEMBLE_RGBA(dst, dstbpp, dstfmt, Pixel, dR, dG, dB, dA);
+            ALPHA_BLEND_RGBA(sR, sG, sB, sA, dR, dG, dB, dA);
+            ASSEMBLE_RGBA(dst, dstbpp, dstfmt, dR, dG, dB, dA);
+        }
+        src += srcbpp;
+        dst += dstbpp;
+        },
+        width);
+        /* *INDENT-ON* */
+        src += srcskip;
+        dst += dstskip;
+    }
+}
+
+/* General (slow) N->N blending with pixel alpha */
+static void
+BlitNtoNPixelAlpha(SDL_BlitInfo * info)
+{
+    int width = info->dst_w;
+    int height = info->dst_h;
+    Uint8 *src = info->src;
+    int srcskip = info->src_skip;
+    Uint8 *dst = info->dst;
+    int dstskip = info->dst_skip;
+    SDL_PixelFormat *srcfmt = info->src_fmt;
+    SDL_PixelFormat *dstfmt = info->dst_fmt;
+    int srcbpp;
+    int dstbpp;
+    Uint32 Pixel;
+    unsigned sR, sG, sB, sA;
+    unsigned dR, dG, dB, dA;
+
+    /* Set up some basic variables */
+    srcbpp = srcfmt->BytesPerPixel;
+    dstbpp = dstfmt->BytesPerPixel;
+
+    while (height--) {
+        /* *INDENT-OFF* */
+        DUFFS_LOOP4(
+        {
+        DISEMBLE_RGBA(src, srcbpp, srcfmt, Pixel, sR, sG, sB, sA);
+        if(sA) {
+            DISEMBLE_RGBA(dst, dstbpp, dstfmt, Pixel, dR, dG, dB, dA);
+            ALPHA_BLEND_RGBA(sR, sG, sB, sA, dR, dG, dB, dA);
+            ASSEMBLE_RGBA(dst, dstbpp, dstfmt, dR, dG, dB, dA);
+        }
+        src += srcbpp;
+        dst += dstbpp;
+        },
+        width);
+        /* *INDENT-ON* */
+        src += srcskip;
+        dst += dstskip;
+    }
+}
+
+
+SDL_BlitFunc
+SDL_CalculateBlitA(SDL_Surface * surface)
+{
+    SDL_PixelFormat *sf = surface->format;
+    SDL_PixelFormat *df = surface->map->dst->format;
+
+    switch (surface->map->info.flags & ~SDL_COPY_RLE_MASK) {
+    case SDL_COPY_BLEND:
+        /* Per-pixel alpha blits */
+        switch (df->BytesPerPixel) {
+        case 1:
+            return BlitNto1PixelAlpha;
+
+        case 2:
+                if (sf->BytesPerPixel == 4 && sf->Amask == 0xff000000
+                    && sf->Gmask == 0xff00
+                    && ((sf->Rmask == 0xff && df->Rmask == 0x1f)
+                        || (sf->Bmask == 0xff && df->Bmask == 0x1f))) {
+                if (df->Gmask == 0x7e0)
+                    return BlitARGBto565PixelAlpha;
+                else if (df->Gmask == 0x3e0)
+                    return BlitARGBto555PixelAlpha;
+            }
+            return BlitNtoNPixelAlpha;
+
+        case 4:
+            if (sf->Rmask == df->Rmask
+                && sf->Gmask == df->Gmask
+                && sf->Bmask == df->Bmask && sf->BytesPerPixel == 4) {
+#if defined(__MMX__) || defined(__3dNOW__)
+                if (sf->Rshift % 8 == 0
+                    && sf->Gshift % 8 == 0
+                    && sf->Bshift % 8 == 0
+                    && sf->Ashift % 8 == 0 && sf->Aloss == 0) {
+#ifdef __3dNOW__
+                    if (SDL_Has3DNow())
+                        return BlitRGBtoRGBPixelAlphaMMX3DNOW;
+#endif
+#ifdef __MMX__
+                    if (SDL_HasMMX())
+                        return BlitRGBtoRGBPixelAlphaMMX;
+#endif
+                }
+#endif /* __MMX__ || __3dNOW__ */
+                if (sf->Amask == 0xff000000) {
+                    return BlitRGBtoRGBPixelAlpha;
+                }
+            }
+            return BlitNtoNPixelAlpha;
+
+        case 3:
+        default:
+            break;
+        }
+        return BlitNtoNPixelAlpha;
+
+    case SDL_COPY_MODULATE_ALPHA | SDL_COPY_BLEND:
+        if (sf->Amask == 0) {
+            /* Per-surface alpha blits */
+            switch (df->BytesPerPixel) {
+            case 1:
+                return BlitNto1SurfaceAlpha;
+
+            case 2:
+                if (surface->map->identity) {
+                    if (df->Gmask == 0x7e0) {
+#ifdef __MMX__
+                        if (SDL_HasMMX())
+                            return Blit565to565SurfaceAlphaMMX;
+                        else
+#endif
+                            return Blit565to565SurfaceAlpha;
+                    } else if (df->Gmask == 0x3e0) {
+#ifdef __MMX__
+                        if (SDL_HasMMX())
+                            return Blit555to555SurfaceAlphaMMX;
+                        else
+#endif
+                            return Blit555to555SurfaceAlpha;
+                    }
+                }
+                return BlitNtoNSurfaceAlpha;
+
+            case 4:
+                if (sf->Rmask == df->Rmask
+                    && sf->Gmask == df->Gmask
+                    && sf->Bmask == df->Bmask && sf->BytesPerPixel == 4) {
+#ifdef __MMX__
+                    if (sf->Rshift % 8 == 0
+                        && sf->Gshift % 8 == 0
+                        && sf->Bshift % 8 == 0 && SDL_HasMMX())
+                        return BlitRGBtoRGBSurfaceAlphaMMX;
+#endif
+                    if ((sf->Rmask | sf->Gmask | sf->Bmask) == 0xffffff) {
+                        return BlitRGBtoRGBSurfaceAlpha;
+                    }
+                }
+                return BlitNtoNSurfaceAlpha;
+
+            case 3:
+            default:
+                return BlitNtoNSurfaceAlpha;
+            }
+        }
+        break;
+
+    case SDL_COPY_COLORKEY | SDL_COPY_MODULATE_ALPHA | SDL_COPY_BLEND:
+        if (sf->Amask == 0) {
+            if (df->BytesPerPixel == 1) {
+                return BlitNto1SurfaceAlphaKey;
+            } else {
+                return BlitNtoNSurfaceAlphaKey;
+            }
+        }
+        break;
+    }
+
+    return NULL;
+}
+
+/* vi: set ts=4 sw=4 expandtab: */