[llvm] 06ebed3 - [SCEVNormalization] Short circuit case with no loops (NFC)

[Nikita Popov via llvm-commits]

Author: Nikita Popov
Date: 2023-06-20T10:48:16+02:00
New Revision: 06ebed3e55759ab503c9bbcae5e47fcce9f26928

URL: https://github.com/llvm/llvm-project/commit/06ebed3e55759ab503c9bbcae5e47fcce9f26928
DIFF: https://github.com/llvm/llvm-project/commit/06ebed3e55759ab503c9bbcae5e47fcce9f26928.diff

LOG: [SCEVNormalization] Short circuit case with no loops (NFC)

If there are no post-inc loops, normalization is a no-op. Don't
bother rewriting the SCEV in that case.

Added: 
    

Modified: 
    llvm/lib/Analysis/ScalarEvolutionNormalization.cpp

Removed: 
    


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diff  --git a/llvm/lib/Analysis/ScalarEvolutionNormalization.cpp b/llvm/lib/Analysis/ScalarEvolutionNormalization.cpp
index 22dff5efec5c8..bc0fbffee61b0 100644
--- a/llvm/lib/Analysis/ScalarEvolutionNormalization.cpp
+++ b/llvm/lib/Analysis/ScalarEvolutionNormalization.cpp
@@ -97,6 +97,8 @@ NormalizeDenormalizeRewriter::visitAddRecExpr(const SCEVAddRecExpr *AR) {
 const SCEV *llvm::normalizeForPostIncUse(const SCEV *S,
                                          const PostIncLoopSet &Loops,
                                          ScalarEvolution &SE) {
+  if (Loops.empty())
+    return S;
   auto Pred = [&](const SCEVAddRecExpr *AR) {
     return Loops.count(AR->getLoop());
   };
@@ -111,6 +113,8 @@ const SCEV *llvm::normalizeForPostIncUseIf(const SCEV *S, NormalizePredTy Pred,
 const SCEV *llvm::denormalizeForPostIncUse(const SCEV *S,
                                            const PostIncLoopSet &Loops,
                                            ScalarEvolution &SE) {
+  if (Loops.empty())
+    return S;
   auto Pred = [&](const SCEVAddRecExpr *AR) {
     return Loops.count(AR->getLoop());
   };