Commit 3d82e875 authored by Committed by Fiona GlaserBrowse files
SSSE3/SSE4 9-way fully merged i4x4 analysis (sad/satd_x9)
i4x4 analysis cycles (per partition): penryn sandybridge 184-> 75 157-> 54 preset=superfast (sad) 281->165 225->124 preset=faster (satd with early termination) 332->165 263->124 preset=medium 379->165 297->124 preset=slower (satd without early termination) This is the first code in x264 that intentionally produces different behavior on different cpus: satd_x9 is implemented only on ssse3+ and checks all intra directions, whereas the old code (on fast presets) may early terminate after checking only some of them. There is no systematic difference on slow presets, though they still occasionally disagree about tiebreaks. For ease of debugging, add an option "--cpu-independent" to disable satd_x9 and any analogous future code.