commit c269a16
Author: Jeff Muizelaar <jmuizelaar@mozilla.com>
Date:   Fri Sep 14 15:54:55 2012 -0400

    Bug 791305. Use libjpeg's color conversion code instead of our own. r=joe,r=khuey
    
    libjpeg-turbo supports converting directly to a format compatible with cairo's
    FORMAT_RGB24. Use that instead of our own handcoded function. This also gives
    us SSE2 and NEON version of this function.
    
    --HG--
    extra : rebase_source : 18f48925f023a33ec2a097d4f4e5cc2ab40be1e9
---
 configure.in                     |   6 +-
 image/decoders/nsJPEGDecoder.cpp | 311 ++-------------------------------------
 2 files changed, 20 insertions(+), 297 deletions(-)

diff --git image/decoders/nsJPEGDecoder.cpp image/decoders/nsJPEGDecoder.cpp
index c1fb515..1d2a259 100644
--- image/decoders/nsJPEGDecoder.cpp
+++ image/decoders/nsJPEGDecoder.cpp
@@ -22,6 +22,13 @@
 extern "C" {
 #include "iccjpeg.h"
 
+#ifdef JCS_EXTENSIONS
+#if defined(IS_BIG_ENDIAN)
+#define MOZ_JCS_EXT_NATIVE_ENDIAN_XRGB JCS_EXT_XRGB
+#else
+#define MOZ_JCS_EXT_NATIVE_ENDIAN_XRGB JCS_EXT_BGRX
+#endif
+#else
 /* Colorspace conversion (copied from jpegint.h) */
 struct jpeg_color_deconverter {
   JMETHOD(void, start_pass, (j_decompress_ptr cinfo));
@@ -34,6 +41,7 @@ METHODDEF(void)
 ycc_rgb_convert_argb (j_decompress_ptr cinfo,
                  JSAMPIMAGE input_buf, JDIMENSION input_row,
                  JSAMPARRAY output_buf, int num_rows);
+#endif
 }
 
 static void cmyk_convert_rgb(JSAMPROW row, JDIMENSION width);
@@ -329,7 +340,18 @@ nsJPEGDecoder::WriteInternal(const char *aBuffer, PRUint32 aCount)
       case JCS_GRAYSCALE:
       case JCS_RGB:
       case JCS_YCbCr:
+#ifdef JCS_EXTENSIONS
+        // if we're not color managing we can decode directly to
+        // MOZ_JCS_EXT_NATIVE_ENDIAN_XRGB
+        if (mCMSMode != eCMSMode_All) {
+            mInfo.out_color_space = MOZ_JCS_EXT_NATIVE_ENDIAN_XRGB;
+            mInfo.out_color_components = 4;
+        } else {
+            mInfo.out_color_space = JCS_RGB;
+        }
+#else
         mInfo.out_color_space = JCS_RGB;
+#endif
         break;
       case JCS_CMYK:
       case JCS_YCCK:
@@ -397,6 +419,7 @@ nsJPEGDecoder::WriteInternal(const char *aBuffer, PRUint32 aCount)
       return; /* I/O suspension */
     }
 
+#ifndef JCS_EXTENSIONS
     /* Force to use our YCbCr to Packed RGB converter when possible */
     if (!mTransform && (mCMSMode != eCMSMode_All) &&
         mInfo.jpeg_color_space == JCS_YCbCr && mInfo.out_color_space == JCS_RGB) {
@@ -404,6 +427,7 @@ nsJPEGDecoder::WriteInternal(const char *aBuffer, PRUint32 aCount)
       mInfo.out_color_components = 4; /* Packed ARGB pixels are always 4 bytes...*/
       mInfo.cconvert->color_convert = ycc_rgb_convert_argb;
     }
+#endif
 
     /* If this is a progressive JPEG ... */
     mState = mInfo.buffered_image ? JPEG_DECOMPRESS_PROGRESSIVE : JPEG_DECOMPRESS_SEQUENTIAL;
@@ -542,7 +566,11 @@ nsJPEGDecoder::OutputScanlines(bool* suspend)
       PRUint32 *imageRow = ((PRUint32*)mImageData) +
                            (mInfo.output_scanline * mInfo.output_width);
 
+#ifdef JCS_EXTENSIONS
+      if (mInfo.out_color_space == MOZ_JCS_EXT_NATIVE_ENDIAN_XRGB) {
+#else
       if (mInfo.cconvert->color_convert == ycc_rgb_convert_argb) {
+#endif
         /* Special case: scanline will be directly converted into packed ARGB */
         if (jpeg_read_scanlines(&mInfo, (JSAMPARRAY)&imageRow, 1) != 1) {
           *suspend = true; /* suspend */
@@ -858,6 +887,7 @@ term_source (j_decompress_ptr jd)
 } // namespace mozilla
 
 
+#ifndef JCS_EXTENSIONS
 /**************** YCbCr -> Cairo's RGB24/ARGB32 conversion: most common case **************/
 
 /*
@@ -1130,7 +1160,8 @@ ycc_rgb_convert_argb (j_decompress_ptr cinfo,
     }
   }
 }
+#endif
 
 
 /**************** Inverted CMYK -> RGB conversion **************/
 /*