DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Mercurial (5216dd412535)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266
/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 * ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Thebes gfx.
 *
 * The Initial Developer of the Original Code is Oracle Corporation.
 * Portions created by the Initial Developer are Copyright (C) 2010
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#include "mozilla/SSE.h"
#include "gfxAlphaRecovery.h"
#include <emmintrin.h>

// This file should only be compiled on x86 and x64 systems.  Additionally,
// you'll need to compile it with -msse2 if you're using GCC on x86.

#if defined(_MSC_VER) && (defined(_M_IX86) || defined(_M_AMD64))
__declspec(align(16)) static PRUint32 greenMaski[] =
    { 0x0000ff00, 0x0000ff00, 0x0000ff00, 0x0000ff00 };
__declspec(align(16)) static PRUint32 alphaMaski[] =
    { 0xff000000, 0xff000000, 0xff000000, 0xff000000 };
#elif defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__))
static PRUint32 greenMaski[] __attribute__ ((aligned (16))) =
    { 0x0000ff00, 0x0000ff00, 0x0000ff00, 0x0000ff00 };
static PRUint32 alphaMaski[] __attribute__ ((aligned (16))) =
    { 0xff000000, 0xff000000, 0xff000000, 0xff000000 };
#elif defined(__SUNPRO_CC) && (defined(__i386) || defined(__x86_64__))
#pragma align 16 (greenMaski, alphaMaski)
static PRUint32 greenMaski[] = { 0x0000ff00, 0x0000ff00, 0x0000ff00, 0x0000ff00 };
static PRUint32 alphaMaski[] = { 0xff000000, 0xff000000, 0xff000000, 0xff000000 };
#endif

PRBool
gfxAlphaRecovery::RecoverAlphaSSE2(gfxImageSurface* blackSurf,
                                   const gfxImageSurface* whiteSurf)
{
    gfxIntSize size = blackSurf->GetSize();

    if (size != whiteSurf->GetSize() ||
        (blackSurf->Format() != gfxASurface::ImageFormatARGB32 &&
         blackSurf->Format() != gfxASurface::ImageFormatRGB24) ||
        (whiteSurf->Format() != gfxASurface::ImageFormatARGB32 &&
         whiteSurf->Format() != gfxASurface::ImageFormatRGB24))
        return PR_FALSE;

    blackSurf->Flush();
    whiteSurf->Flush();

    unsigned char* blackData = blackSurf->Data();
    unsigned char* whiteData = whiteSurf->Data();

    if ((NS_PTR_TO_UINT32(blackData) & 0xf) != (NS_PTR_TO_UINT32(whiteData) & 0xf) ||
        (blackSurf->Stride() - whiteSurf->Stride()) & 0xf) {
        // Cannot keep these in alignment.
        return PR_FALSE;
    }

    __m128i greenMask = _mm_load_si128((__m128i*)greenMaski);
    __m128i alphaMask = _mm_load_si128((__m128i*)alphaMaski);

    for (PRInt32 i = 0; i < size.height; ++i) {
        PRInt32 j = 0;
        // Loop single pixels until at 4 byte alignment.
        while (NS_PTR_TO_UINT32(blackData) & 0xf && j < size.width) {
            *((PRUint32*)blackData) =
                RecoverPixel(*reinterpret_cast<PRUint32*>(blackData),
                             *reinterpret_cast<PRUint32*>(whiteData));
            blackData += 4;
            whiteData += 4;
            j++;
        }
        // This extra loop allows the compiler to do some more clever registry
        // management and makes it about 5% faster than with only the 4 pixel
        // at a time loop.
        for (; j < size.width - 8; j += 8) {
            __m128i black1 = _mm_load_si128((__m128i*)blackData);
            __m128i white1 = _mm_load_si128((__m128i*)whiteData);
            __m128i black2 = _mm_load_si128((__m128i*)(blackData + 16));
            __m128i white2 = _mm_load_si128((__m128i*)(whiteData + 16));

            // Execute the same instructions as described in RecoverPixel, only
            // using an SSE2 packed saturated subtract.
            white1 = _mm_subs_epu8(white1, black1);
            white2 = _mm_subs_epu8(white2, black2);
            white1 = _mm_subs_epu8(greenMask, white1);
            white2 = _mm_subs_epu8(greenMask, white2);
            // Producing the final black pixel in an XMM register and storing
            // that is actually faster than doing a masked store since that
            // does an unaligned storage. We have the black pixel in a register
            // anyway.
            black1 = _mm_andnot_si128(alphaMask, black1);
            black2 = _mm_andnot_si128(alphaMask, black2);
            white1 = _mm_slli_si128(white1, 2);
            white2 = _mm_slli_si128(white2, 2);
            white1 = _mm_and_si128(alphaMask, white1);
            white2 = _mm_and_si128(alphaMask, white2);
            black1 = _mm_or_si128(white1, black1);
            black2 = _mm_or_si128(white2, black2);

            _mm_store_si128((__m128i*)blackData, black1);
            _mm_store_si128((__m128i*)(blackData + 16), black2);
            blackData += 32;
            whiteData += 32;
        }
        for (; j < size.width - 4; j += 4) {
            __m128i black = _mm_load_si128((__m128i*)blackData);
            __m128i white = _mm_load_si128((__m128i*)whiteData);

            white = _mm_subs_epu8(white, black);
            white = _mm_subs_epu8(greenMask, white);
            black = _mm_andnot_si128(alphaMask, black);
            white = _mm_slli_si128(white, 2);
            white = _mm_and_si128(alphaMask, white);
            black = _mm_or_si128(white, black);
            _mm_store_si128((__m128i*)blackData, black);
            blackData += 16;
            whiteData += 16;
        }
        // Loop single pixels until we're done.
        while (j < size.width) {
            *((PRUint32*)blackData) =
                RecoverPixel(*reinterpret_cast<PRUint32*>(blackData),
                             *reinterpret_cast<PRUint32*>(whiteData));
            blackData += 4;
            whiteData += 4;
            j++;
        }
        blackData += blackSurf->Stride() - j * 4;
        whiteData += whiteSurf->Stride() - j * 4;
    }

    blackSurf->MarkDirty();

    return PR_TRUE;
}

static PRInt32
ByteAlignment(PRInt32 aAlignToLog2, PRInt32 aX, PRInt32 aY=0, PRInt32 aStride=1)
{
    return (aX + aStride * aY) & ((1 << aAlignToLog2) - 1);
}

/*static*/ nsIntRect
gfxAlphaRecovery::AlignRectForSubimageRecovery(const nsIntRect& aRect,
                                               gfxImageSurface* aSurface)
{
    NS_ASSERTION(gfxASurface::ImageFormatARGB32 == aSurface->Format(),
                 "Thebes grew support for non-ARGB32 COLOR_ALPHA?");
    static const PRInt32 kByteAlignLog2 = GoodAlignmentLog2();
    static const PRInt32 bpp = 4;
    static const PRInt32 pixPerAlign = (1 << kByteAlignLog2) / bpp;
    //
    // We're going to create a subimage of the surface with size
    // <sw,sh> for alpha recovery, and want a SIMD fast-path.  The
    // rect <x,y, w,h> /needs/ to be redrawn, but it might not be
    // properly aligned for SIMD.  So we want to find a rect <x',y',
    // w',h'> that's a superset of what needs to be redrawn but is
    // properly aligned.  Proper alignment is
    //
    //   BPP * (x' + y' * sw) \cong 0         (mod ALIGN)
    //   BPP * w'             \cong BPP * sw  (mod ALIGN)
    //
    // (We assume the pixel at surface <0,0> is already ALIGN'd.)
    // That rect (obviously) has to fit within the surface bounds, and
    // we should also minimize the extra pixels redrawn only for
    // alignment's sake.  So we also want
    //
    //  minimize <x',y', w',h'>
    //   0 <= x' <= x
    //   0 <= y' <= y
    //   w <= w' <= sw
    //   h <= h' <= sh
    //
    // This is a messy integer non-linear programming problem, except
    // ... we can assume that ALIGN/BPP is a very small constant.  So,
    // brute force is viable.  The algorithm below will find a
    // solution if one exists, but isn't guaranteed to find the
    // minimum solution.  (For SSE2, ALIGN/BPP = 4, so it'll do at
    // most 64 iterations below).  In what's likely the common case,
    // an already-aligned rectangle, it only needs 1 iteration.
    //
    // Is this alignment worth doing?  Recovering alpha will take work
    // proportional to w*h (assuming alpha recovery computation isn't
    // memory bound).  This analysis can lead to O(w+h) extra work
    // (with small constants).  In exchange, we expect to shave off a
    // ALIGN/BPP constant by using SIMD-ized alpha recovery.  So as
    // w*h diverges from w+h, the win factor approaches ALIGN/BPP.  We
    // only really care about the w*h >> w+h case anyway; others
    // should be fast enough even with the overhead.  (Unless the cost
    // of repainting the expanded rect is high, but in that case
    // SIMD-ized alpha recovery won't make a difference so this code
    // shouldn't be called.)
    //
    gfxIntSize surfaceSize = aSurface->GetSize();
    const PRInt32 stride = bpp * surfaceSize.width;
    if (stride != aSurface->Stride()) {
        NS_WARNING("Unexpected stride, falling back on slow alpha recovery");
        return aRect;
    }

    const PRInt32 x = aRect.x, y = aRect.y, w = aRect.width, h = aRect.height;
    const PRInt32 r = x + w;
    const PRInt32 sw = surfaceSize.width, sh = surfaceSize.height;
    const PRInt32 strideAlign = ByteAlignment(kByteAlignLog2, stride);

    // The outer two loops below keep the rightmost (|r| above) and
    // bottommost pixels in |aRect| fixed wrt <x,y>, to ensure that we
    // return only a superset of the original rect.  These loops
    // search for an aligned top-left pixel by trying to expand <x,y>
    // left and up by <dx,dy> pixels, respectively.
    //
    // Then if a properly-aligned top-left pixel is found, the
    // innermost loop tries to find an aligned stride by moving the
    // rightmost pixel rightward by dr.
    PRInt32 dx, dy, dr;
    for (dy = 0; (dy < pixPerAlign) && (y - dy >= 0); ++dy) {
        for (dx = 0; (dx < pixPerAlign) && (x - dx >= 0); ++dx) {
            if (0 != ByteAlignment(kByteAlignLog2,
                                   bpp * (x - dx), y - dy, stride)) {
                continue;
            }
            for (dr = 0; (dr < pixPerAlign) && (r + dr <= sw); ++dr) {
                if (strideAlign == ByteAlignment(kByteAlignLog2,
                                                 bpp * (w + dr + dx))) {
                    goto FOUND_SOLUTION;
                }
            }
        }
    }

    // Didn't find a solution.
    return aRect;

FOUND_SOLUTION:
    nsIntRect solution = nsIntRect(x - dx, y - dy, w + dr + dx, h + dy);
    NS_ABORT_IF_FALSE(nsIntRect(0,0, sw,sh).Contains(solution),
                      "'Solution' extends outside surface bounds!");
    return solution;
}