[llvm-branch-commits] [llvm] e3bdfcf - Tweak ADCE postition

[Florian Hahn via llvm-branch-commits]

Author: Florian Hahn
Date: 2020-09-08T13:57:14+01:00
New Revision: e3bdfcf94a9eeae6e006d010464f0c1b3550577d

URL: https://github.com/llvm/llvm-project/commit/e3bdfcf94a9eeae6e006d010464f0c1b3550577d
DIFF: https://github.com/llvm/llvm-project/commit/e3bdfcf94a9eeae6e006d010464f0c1b3550577d.diff

LOG: Tweak ADCE postition

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 9a2e895d7b71..5f6d39ba0ed6 100644
--- a/llvm/lib/Passes/PassBuilder.cpp
+++ b/llvm/lib/Passes/PassBuilder.cpp
@@ -717,6 +717,7 @@ PassBuilder::buildFunctionSimplificationPipeline(OptimizationLevel Level,
   // redo DCE, etc.
   FPM.addPass(JumpThreadingPass());
   FPM.addPass(CorrelatedValuePropagationPass());
+  FPM.addPass(ADCEPass());
   FPM.addPass(DSEPass());
   FPM.addPass(createFunctionToLoopPassAdaptor(
       LICMPass(PTO.LicmMssaOptCap, PTO.LicmMssaNoAccForPromotionCap),
@@ -731,7 +732,6 @@ PassBuilder::buildFunctionSimplificationPipeline(OptimizationLevel Level,
   // Finally, do an expensive DCE pass to catch all the dead code exposed by
   // the simplifications and basic cleanup after all the simplifications.
   // TODO: Investigate if this is too expensive.
-  FPM.addPass(ADCEPass());
   FPM.addPass(SimplifyCFGPass());
   FPM.addPass(InstCombinePass());
   invokePeepholeEPCallbacks(FPM, Level);

diff  --git a/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp b/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp
index caa9a98ecb07..9909f7437147 100644
--- a/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp
+++ b/llvm/lib/Transforms/IPO/PassManagerBuilder.cpp
@@ -463,6 +463,11 @@ void PassManagerBuilder::addFunctionSimplificationPasses(
   if (OptLevel > 1) {
     MPM.add(createJumpThreadingPass());         // Thread jumps
     MPM.add(createCorrelatedValuePropagationPass());
+  }
+  MPM.add(createAggressiveDCEPass());         // Delete dead instructions
+  
+  // TODO: Investigate if this is too expensive at O1.
+  if (OptLevel > 1) {
     MPM.add(createDeadStoreEliminationPass());  // Delete dead stores
     MPM.add(createLICMPass(LicmMssaOptCap, LicmMssaNoAccForPromotionCap));
   }
@@ -472,8 +477,6 @@ void PassManagerBuilder::addFunctionSimplificationPasses(
   if (RerollLoops)
     MPM.add(createLoopRerollPass());
 
-  // TODO: Investigate if this is too expensive at O1.
-  MPM.add(createAggressiveDCEPass());         // Delete dead instructions
   MPM.add(createCFGSimplificationPass()); // Merge & remove BBs
   // Clean up after everything.
   MPM.add(createInstructionCombiningPass());