tree f66c1ce42213596ee247832e5e9f1f5399676f83
parent dfd79b8ebfa6dbf1e438c3647be593b7dc702580
author David Turner <david.turner@argondesign.com> 1540813775 +0000
committer Debargha Mukherjee <debargha@google.com> 1540920696 +0000

Fix issues with SIMD horver_correlation_full

On x86/x64 SIMD registers are shared with the FPU, so we need to clear
state before doing FPU ops after using SIMD instructions, otherwise
results may be unpredictable.

Also, a zero-extend was erroneously used instead of a sign-extend on
signed data.  This wasn't caught by the unit tests because the test
stimulus only generated unsigned data.  I have updated the unit test so
that it catches this issue, and changed the zero-extend to a
sign-extend.

This should fix the issue observed in
https://aomedia-review.googlesource.com/c/aom/+/73884
so at the same time, reinstitute the SIMD optimised horver_correlation

Change-Id: I8db61146e46f36c23119bd1abdbb466ab3dd50bc