All graphs for this bug:
  https://chromeperf.appspot.com/group_report?bug_id=737061

Original alerts at time of bug-filing:
  https://chromeperf.appspot.com/group_report?keys=agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDgtqWatgoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDgtvCpuAsM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDg1ovO_QkM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDg1s__6wkM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDg1rb87wgM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDglvqLzwoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDg1vaK9QoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDg1veC4ggM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDg1t23qAsM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDgtpbpqwoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDg1qmb9QkM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDglq_pggoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDg1vmppAkM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDg1uK0iQgM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDg1oGF6AoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDglpvN5woM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDglq_p_AgM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDglvPBmwkM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDg1qzeogoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDglunE4AsM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDglr2fuAoM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDg1szCoAkM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDglr7A6ggM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDg1oj3tAkM,agxzfmNocm9tZXBlcmZyFAsSB0Fub21hbHkYgIDg1u6E7wgM


Bot(s) for this bug's original alert(s):

webrtc-android-tests-nexus4-lollipop
webrtc-android-tests-nexus5
webrtc-android-tests-nexus6-nougat
webrtc-android-tests-nexus72

Yes, this has been observed in other bugs as well, the GCC->Clang switch causes this. 
We could proceed with GCC short term by explicitly setting is_clang=false in our GN builds. Long term, I think we have to move to Clang, since GCC is deprecated in the NDK and will be removed in the future.

I'm leaving it to marpan@ / holmer@ to decide what to do.

Marco, I just found this in my backlog, it must have slipped. Can you look into why this is the case, and if there's something we can do to improve the quality with clang?

 Issue 733604  has been merged into this issue.

Tested on Pixel, built with gcc vs clang in NDK.

The clang one runs 6-10% faster than the one built with gcc, depending on resolution and number of threads. I didn't see any regression across several HD and VGA clips on both 1 and 2 threads.
And the results of gcc and clang are bit-exact.

Close this for now.

The test I ran above is standalone libvpx.

The clang I used is Android clang version 3.8.256229  (based on LLVM 3.8.256229).
The gcc I used is aarch64-linux-android-gcc (GCC) 4.9.x 20150123 (prerelease).