SSE2 implementation of S32_D565_Opaque_Dither

Run benchmarks with command line option "--forceDither true". The result
shows that all benchmarks exercised S32_D565_Opaque_Dither benefit from
this SSE2 optimization. Here are the data on i7-3770:
                                                  before    after
constXTile_MM_filter                              900.93   217.75  75.83%
constXTile_CC_filter_scale                        907.59   225.65  75.14%
constXTile_RR_filter                              903.33   219.41  75.71%
constXTile_MM_scale                               902.45   221.46  75.46%
constXTile_CC                                     898.55   218.37  75.70%
constXTile_RR_scale                               902.69   222.35  75.37%
repeatTile_4444_X                                 938.53   240.49  74.38%
gradient_radial2_mirror                         16999.49 11540.39  32.11%
gradient_radial2_clamp_hicolor                  17943.38 12501.71  30.33%
gradient_radial2_clamp                          17816.36 12492.04  29.88%
bitmaprect_FF_filter_trans                         47.81    10.98  77.03%
bitmaprect_FF_nofilter_trans                       47.79    10.91  77.18%
bitmaprect_FF_filter_identity                      47.74    10.89  77.18%
bitmaprect_FF_nofilter_identity                    47.83    10.89  77.24%
bitmap_4444_update_scale_rotate_bilerp            100.45    76.84  23.50%
bitmap_4444_update_volatile_scale_rotate_bilerp   100.80    76.70  23.91%
bitmap_4444_scale_rotate_bilerp                   100.43    77.18  23.15%
bitmap_4444_update_scale_bilerp                    79.00    49.03  37.93%
bitmap_4444_update_volatile_scale_bilerp           78.90    48.87  38.06%
bitmap_4444_scale_bilerp                           78.92    48.81  38.16%
bitmap_4444_update                                 42.19    11.53  72.68%
bitmap_4444_update_volatile                        42.28    11.49  72.82%
bitmap_a8                                          60.37    29.75  50.72%
bitmap_4444                                        42.19    11.52  72.69%

BUG=
R=mtklein@google.com

Author: qiankun.miao@intel.com

Review URL: https://codereview.chromium.org/181293002

git-svn-id: http://skia.googlecode.com/svn/trunk@13698 2bbb7eff-a529-9590-31e7-b0007b416f81
3 files changed