[GVNHoist] Move GVNHoist to function simplification part of pipeline.

Summary:
Move GVNHoist to later in the optimization pipeline, specifically, to
the function simplification part of the pipeline.  The new pipeline
location allows GVNHoist to run on a function after its callees have
been inlined but before the function has been considered for inlining
into its callers, exposing more opportunities for hoisting.

Performance results on AArch64 kryo:
Improvements:
  Benchmarks/CoyoteBench/fftbench  -24.952%
  spec2006/bzip2                    -4.071%
  internal bmark                    -3.177%
  Benchmarks/PAQ8p/paq8p            -1.754%
  spec2000/perlbmk                  -1.328%
  spec2006/h264ref                  -1.140%

Regressions:
  internal bmark                    +1.818%
  Benchmarks/mafft/pairlocalalign   +1.084%

Reviewers: sebpop, dberlin, hiraditya

Subscribers: aemerson, mehdi_amini, mcrosier, llvm-commits

Differential Revision: https://reviews.llvm.org/D27722

llvm-svn: 289696

1 files changed, 2 insertions, 2 deletions

diff --git a/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp b/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp
index 254a7461980..5c26c665405 100644
--- a/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp
+++ b/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp
@@ -249,8 +249,6 @@ void PassManagerBuilder::populateFunctionPassManager(
   FPM.add(createCFGSimplificationPass());
   FPM.add(createSROAPass());
   FPM.add(createEarlyCSEPass());
-  if(EnableGVNHoist)
-    FPM.add(createGVNHoistPass());
   FPM.add(createLowerExpectIntrinsicPass());
 }
 
@@ -295,6 +293,8 @@ void PassManagerBuilder::addFunctionSimplificationPasses(
   // Break up aggregate allocas, using SSAUpdater.
   MPM.add(createSROAPass());
   MPM.add(createEarlyCSEPass());              // Catch trivial redundancies
+  if(EnableGVNHoist)
+    MPM.add(createGVNHoistPass());
   // Speculative execution if the target has divergent branches; otherwise nop.
   MPM.add(createSpeculativeExecutionIfHasBranchDivergencePass());
   MPM.add(createJumpThreadingPass());         // Thread jumps.