andrew@webrtc.org 0e37b898f0 replace inline assembly WebRtcAecm_CalcLinearEnergiesNeon by intrinsics.
The modification only uses the unique part of the CalcLinearEnergies
 function. Pass byte to byte conformance test both on ARMv7 and ARM64,
 and the single function performance is similar with original assembly
 version on different platforms. If not specified, the code is compiled
 by GCC 4.6. The result is the "X version / C version" ratio, and the
 less is better.

| run 100k times             | cortex-a7 | cortex-a9 | cortex-a15 |
| use C as the base on each  |  (1.2Ghz) |  (1.0Ghz) |   (1.7Ghz) |
| CPU target                 |           |           |            |
|----------------------------+-----------+-----------+------------|
| Neon asm                   |    19.48% |    19.26% |     13.68% |
| Neon inline                |    27.90% |    28.87% |     17.79% |
| Neon intrinsics (GCC 4.8)  |    18.69% |    20.18% |     14.69% |
| Neon intrinsics (LLVM 3.4) |    18.52% |    21.15% |     13.56% |

BUG=3580
R=andrew@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/23349004

Patch from Zhongwei Yao <zhongwei.yao@arm.com>.

git-svn-id: http://webrtc.googlecode.com/svn/trunk@7686 4adac7df-926f-26a2-2b94-8c16560cd09d
2014-11-11 19:34:14 +00:00
..