[llvm] 45139ab - [SLP][NFC]Improve aliasing support in SLP, NFC.

[Alexey Bataev via llvm-commits]

Author: Alexey Bataev
Date: 2023-11-28T07:24:44-08:00
New Revision: 45139ab6cadcdf3d9a31fc5f04425ce87efeb9d3

URL: https://github.com/llvm/llvm-project/commit/45139ab6cadcdf3d9a31fc5f04425ce87efeb9d3
DIFF: https://github.com/llvm/llvm-project/commit/45139ab6cadcdf3d9a31fc5f04425ce87efeb9d3.diff

LOG: [SLP][NFC]Improve aliasing support in SLP, NFC.

No need to store optional boolean in the map, enough to store boolean
directly. Also, we can do preliminary check for instruction and if they
are not simple, mark as aliased without storing this result in the map.

Added: 
    

Modified: 
    llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp

Removed: 
    


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diff  --git a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
index 8276beb004f22a5..2f34bbd4e0410ec 100644
--- a/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
+++ b/llvm/lib/Transforms/Vectorize/SLPVectorizer.cpp
@@ -2982,25 +2982,25 @@ class BoUpSLP {
   /// is invariant in the calling loop.
   bool isAliased(const MemoryLocation &Loc1, Instruction *Inst1,
                  Instruction *Inst2) {
+    if (!Loc1.Ptr || !isSimple(Inst1) || !isSimple(Inst2))
+      return true;
     // First check if the result is already in the cache.
-    AliasCacheKey key = std::make_pair(Inst1, Inst2);
-    std::optional<bool> &result = AliasCache[key];
-    if (result) {
-      return *result;
-    }
-    bool aliased = true;
-    if (Loc1.Ptr && isSimple(Inst1))
-      aliased = isModOrRefSet(BatchAA.getModRefInfo(Inst2, Loc1));
+    AliasCacheKey Key = std::make_pair(Inst1, Inst2);
+    auto It = AliasCache.find(Key);
+    if (It != AliasCache.end())
+      return It->second;
+    bool Aliased = isModOrRefSet(BatchAA.getModRefInfo(Inst2, Loc1));
     // Store the result in the cache.
-    result = aliased;
-    return aliased;
+    AliasCache.try_emplace(Key, Aliased);
+    AliasCache.try_emplace(std::make_pair(Inst2, Inst1), Aliased);
+    return Aliased;
   }
 
   using AliasCacheKey = std::pair<Instruction *, Instruction *>;
 
   /// Cache for alias results.
   /// TODO: consider moving this to the AliasAnalysis itself.
-  DenseMap<AliasCacheKey, std::optional<bool>> AliasCache;
+  DenseMap<AliasCacheKey, bool> AliasCache;
 
   // Cache for pointerMayBeCaptured calls inside AA.  This is preserved
   // globally through SLP because we don't perform any action which