shithub: libvpx

Download patch

ref: 13234d3c433b6379ee1cc0de398dd71cef3f5907
parent: ee5b29ae30d7f7f0b2d9fa7c6a611d840316981c
author: Johann <johannkoenig@google.com>
date: Thu Jan 19 05:07:12 EST 2017

Remove neon assembly for idct 16x16 and 8x8

Tested using test/partial_idct_test.cc:DISABLED_Speed

Both gcc 4.9 and clang 3.8 from the r13 Android NDK offer improvements
using the intrinsics:
<function>    <clang asm> <gcc asm> <clang intrin> <gcc intrin>
idct16x16_256  1720ms      1703ms    1546ms         1554ms
idct16x16_10   1320ms      1247ms     518ms          488ms
idct16x16_1     107ms       108ms      64ms           68ms
idct8x8_64      924ms       931ms     866ms          989ms
idct8x8_12      826ms       824ms     519ms          514ms
idct8x8_1       172ms       166ms     110ms          125ms

idct8x8_64 isn't quite perfect (slight regression with gcc intrinsics)
but as a counter example idct16x16_10 goes from ~1300ms to ~500ms

On a sample clip, clang improved from 48.5 to 49fps and gcc stayed roughly
stable.

BUG=webm:1303

Change-Id: I9d4fd2b41b46ea6174a887b40a82c8e6e4769ed4