commit 36b541544666c34b3c54a6408339daa7ae7c3e98
author Yi Kong <yikong@google.com> Thu Mar 08 03:19:06 2018 +0000
committer Yi Kong <yikong@google.com> Thu Mar 08 04:08:44 2018 +0000
tree cb984e6d4f69a732e9b663dde1367b5855935f9d
parent df29be4d63c4187a7eb35b8f473ad9fad1fc439a

Enable ThinLTO for dex2oat

This helps reducing binary size as well as improve performance of
dex2oat.

On Marlin (lower clocked cores)
  With PGO
  dex2oat binary + libraries size:
   - no-lto:   9.90MB
   - thin-lto: 9.81MB

  dex2oat run time for top 25 apps (with speed filter):
    Average case: -2.83%
    Best case   : -4.65%
    Worst case  :  0.25%, likely noise

  Without PGO
  dex2oat binary + libraries size:
   - no-lto:   9.67MB
   - thin-lto: 9.60MB

  dex2oat run time for top 25 apps (with speed filter):
    Average case : -0.96%
    Best case    : -2.30%
    Worst case   :  0.52%, likely noise

Test: Benchmark on Marlin (low-clock cores)
Bug: 62839002
Change-Id: I051d020fd9a0e23b249da2d58295e81594b35601
Merged-in: I051d020fd9a0e23b249da2d58295e81594b35601
(cherry picked from commit 4d07397a2443cf7c870fdc484553452f40241f0e)