[llvm] c367258 - [SimplifyCFG] Enabled hoisting late in LTO pipeline.

[Florian Hahn via llvm-commits]

Author: Florian Hahn
Date: 2021-01-04T16:26:58Z
New Revision: c367258b5cc257973f49508c1ac5763cb077428e

URL: https://github.com/llvm/llvm-project/commit/c367258b5cc257973f49508c1ac5763cb077428e
DIFF: https://github.com/llvm/llvm-project/commit/c367258b5cc257973f49508c1ac5763cb077428e.diff

LOG: [SimplifyCFG] Enabled hoisting late in LTO pipeline.

bb7d3af1139c disabled hoisting in SimplifyCFG by default, but enabled it
late in the pipeline. But it appears as if the LTO pipelines got missed.

This patch adjusts the LTO pipelines to also enable hoisting in the
later stages.

Unfortunately there's no easy way to add a test for the change I think.

Reviewed By: lebedev.ri

Differential Revision: https://reviews.llvm.org/D93684

Added: 
    

Modified: 
    llvm/lib/Passes/PassBuilder.cpp
    llvm/lib/Transforms/IPO/PassManagerBuilder.cpp

Removed: 
    


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diff  --git a/llvm/lib/Passes/PassBuilder.cpp b/llvm/lib/Passes/PassBuilder.cpp
index 95f58d9e3f73..96d96d43b432 100644
--- a/llvm/lib/Passes/PassBuilder.cpp
+++ b/llvm/lib/Passes/PassBuilder.cpp
@@ -1715,7 +1715,7 @@ PassBuilder::buildLTODefaultPipeline(OptimizationLevel Level,
   // are sorted out.
 
   MainFPM.addPass(InstCombinePass());
-  MainFPM.addPass(SimplifyCFGPass());
+  MainFPM.addPass(SimplifyCFGPass(SimplifyCFGOptions().hoistCommonInsts(true)));
   MainFPM.addPass(SCCPPass());
   MainFPM.addPass(InstCombinePass());
   MainFPM.addPass(BDCEPass());
@@ -1755,7 +1755,8 @@ PassBuilder::buildLTODefaultPipeline(OptimizationLevel Level,
 
   // Add late LTO optimization passes.
   // Delete basic blocks, which optimization passes may have killed.
-  MPM.addPass(createModuleToFunctionPassAdaptor(SimplifyCFGPass()));
+  MPM.addPass(createModuleToFunctionPassAdaptor(
+      SimplifyCFGPass(SimplifyCFGOptions().hoistCommonInsts(true))));
 
   // Drop bodies of available eternally objects to improve GlobalDCE.
   MPM.addPass(EliminateAvailableExternallyPass());

diff  --git a/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp b/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp
index e7b5414a3841..33fa158e70ca 100644
--- a/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp
+++ b/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp
@@ -1087,7 +1087,8 @@ void PassManagerBuilder::addLTOOptimizationPasses(legacy::PassManagerBase &PM) {
   // we may have exposed more scalar opportunities. Run parts of the scalar
   // optimizer again at this point.
   PM.add(createInstructionCombiningPass()); // Initial cleanup
-  PM.add(createCFGSimplificationPass()); // if-convert
+  PM.add(createCFGSimplificationPass(SimplifyCFGOptions() // if-convert
+                                         .hoistCommonInsts(true)));
   PM.add(createSCCPPass()); // Propagate exposed constants
   PM.add(createInstructionCombiningPass()); // Clean up again
   PM.add(createBitTrackingDCEPass());
@@ -1117,7 +1118,8 @@ void PassManagerBuilder::addLateLTOOptimizationPasses(
     PM.add(createHotColdSplittingPass());
 
   // Delete basic blocks, which optimization passes may have killed.
-  PM.add(createCFGSimplificationPass());
+  PM.add(
+      createCFGSimplificationPass(SimplifyCFGOptions().hoistCommonInsts(true)));
 
   // Drop bodies of available externally objects to improve GlobalDCE.
   PM.add(createEliminateAvailableExternallyPass());