commit 10d6870ae4d0a52579fd520e8ee0fdcb4dfcd25a
author Santiago Aboy Solanes <solanes@google.com> Tue Jan 24 18:05:10 2023 +0000
committer Santiago Aboy Solanes <solanes@google.com> Tue Jan 31 13:19:08 2023 +0000
tree e9958cfeb1694c325452b450caad1bbc367424cb
parent fa26b96f2f56ea2380d96922f3c859a2c3b417e8

Add phis in SimplifyIfs to enable branch redirection

For example it turns:
if(cond)
  /  \
 B1  B2
  \ /
if(cond)
  /  \
 B3  B4

into:
if(cond)
  /  \
 B1  B2
  \ /
if(Phi(1, 0))
  /  \
 B3  B4

Following this, SimplifyIfs is able to connect B1->B3
and B2->B4 effectively skipping an if.

Locally, speed compiling on a Pixel 5:
 * system server: -4.0KB (-0.01%)
 * SystemUIGoogle: -8.0KB (-0.03%)
 * AGSA: -17.75KB (-0.01%)

Test: art/test/testrunner/testrunner.py --host --64 --optimizing -b
Change-Id: I3b2e6a986b4d5e162bec28d72e9b0e2a3de1a4c3

compiler/optimizing/optimizing_compiler_stats.h

diff --git a/compiler/optimizing/optimizing_compiler_stats.h b/compiler/optimizing/optimizing_compiler_stats.h
index 866c883..a1d0a5a 100644
--- a/compiler/optimizing/optimizing_compiler_stats.h
+++ b/compiler/optimizing/optimizing_compiler_stats.h
@@ -82,6 +82,7 @@
   kImplicitNullCheckGenerated,
   kExplicitNullCheckGenerated,
   kSimplifyIf,
+  kSimplifyIfAddedPhi,
   kSimplifyThrowingInvoke,
   kInstructionSunk,
   kNotInlinedUnresolvedEntrypoint,