[llvm] e6cf796 - Preserve GlobalsAA analysis result in LowerConstantIntrinsics

[Florian Hahn via llvm-commits]

Author: Ryan Santhiraraja
Date: 2020-07-02T15:40:41+01:00
New Revision: e6cf796bab7e02d2b8ac7fd495f14f5e21494270

URL: https://github.com/llvm/llvm-project/commit/e6cf796bab7e02d2b8ac7fd495f14f5e21494270
DIFF: https://github.com/llvm/llvm-project/commit/e6cf796bab7e02d2b8ac7fd495f14f5e21494270.diff

LOG: Preserve GlobalsAA analysis result in LowerConstantIntrinsics

LowerConstantIntrinsics fails to preserve the analysis result of
GlobalsAA. Not preserving the analysis might affect benchmark
performance. This change fixes this issue.

Patch by Ryan Santhiraraja <rsanthir at quicinc.com>

Reviewers: fpetrogalli, joerg, fhahn

Reviewed By: fhahn

Differential Revision: https://reviews.llvm.org/D82342

Added: 
    

Modified: 
    llvm/lib/Transforms/Scalar/LowerConstantIntrinsics.cpp

Removed: 
    


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diff  --git a/llvm/lib/Transforms/Scalar/LowerConstantIntrinsics.cpp b/llvm/lib/Transforms/Scalar/LowerConstantIntrinsics.cpp
index f59280b60d8d..fddf28c281fc 100644
--- a/llvm/lib/Transforms/Scalar/LowerConstantIntrinsics.cpp
+++ b/llvm/lib/Transforms/Scalar/LowerConstantIntrinsics.cpp
@@ -15,6 +15,7 @@
 #include "llvm/ADT/PostOrderIterator.h"
 #include "llvm/ADT/SetVector.h"
 #include "llvm/ADT/Statistic.h"
+#include "llvm/Analysis/GlobalsModRef.h"
 #include "llvm/Analysis/InstructionSimplify.h"
 #include "llvm/Analysis/MemoryBuiltins.h"
 #include "llvm/Analysis/TargetLibraryInfo.h"
@@ -136,8 +137,12 @@ static bool lowerConstantIntrinsics(Function &F, const TargetLibraryInfo *TLI) {
 
 PreservedAnalyses
 LowerConstantIntrinsicsPass::run(Function &F, FunctionAnalysisManager &AM) {
-  if (lowerConstantIntrinsics(F, AM.getCachedResult<TargetLibraryAnalysis>(F)))
-    return PreservedAnalyses::none();
+  if (lowerConstantIntrinsics(F,
+                              AM.getCachedResult<TargetLibraryAnalysis>(F))) {
+    PreservedAnalyses PA;
+    PA.preserve<GlobalsAA>();
+    return PA;
+  }
 
   return PreservedAnalyses::all();
 }
@@ -160,6 +165,10 @@ class LowerConstantIntrinsics : public FunctionPass {
     const TargetLibraryInfo *TLI = TLIP ? &TLIP->getTLI(F) : nullptr;
     return lowerConstantIntrinsics(F, TLI);
   }
+
+  void getAnalysisUsage(AnalysisUsage &AU) const override {
+    AU.addPreserved<GlobalsAAWrapperPass>();
+  }
 };
 } // namespace