[PATCH] D134161: [MemorySSA] Reset location size if IsGuaranteedLoopInvariant after phi tranlation

[luxufan via Phabricator via llvm-commits]

StephenFan updated this revision to Diff 461474.
StephenFan added a comment.

Rebase.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D134161/new/

https://reviews.llvm.org/D134161

Files:
  llvm/include/llvm/Analysis/MemorySSA.h
  llvm/test/Analysis/MemorySSA/phi-translation.ll


Index: llvm/test/Analysis/MemorySSA/phi-translation.ll
===================================================================
--- llvm/test/Analysis/MemorySSA/phi-translation.ll
+++ llvm/test/Analysis/MemorySSA/phi-translation.ll
@@ -437,10 +437,10 @@
 ; CHECK-LABEL: merge:
 ; CHECK:       ; 3 = MemoryPhi({lhs,1},{rhs,2})
 ; CHECK-NEXT   %storemerge2 = phi i32 [ 2, %lhs ], [ 3, %rhs ]
-; TODO: Here the defining access could be liveOnEntry. Since all incoming
-; values of phi node can be phi translated.
-; CHECK:       ; MemoryUse(3)
-; CHECK-NEXT:    %lv = load i16, i16* %arrayidx, align 2
+; LIMIT:       ; MemoryUse(3)
+; LIMIT-NEXT:  %lv = load i16, i16* %arrayidx, align 2
+; NOLIMIT:     ; MemoryUse(liveOnEntry)
+; NOLIMIT-NEXT: %lv = load i16, i16* %arrayidx, align 2
 
 entry:
   br i1 %cmp, label %lhs, label %rhs
Index: llvm/include/llvm/Analysis/MemorySSA.h
===================================================================
--- llvm/include/llvm/Analysis/MemorySSA.h
+++ llvm/include/llvm/Analysis/MemorySSA.h
@@ -1252,7 +1252,9 @@
       // to unknown guarantees that any memory accesses that access locations
       // after the pointer are considered as clobbers, which is important to
       // catch loop carried dependences.
-      if (!IsGuaranteedLoopInvariant(Location.Ptr))
+      bool GuaranteedLoopInvariant =
+          IsGuaranteedLoopInvariant(Location.Ptr);
+      if (!GuaranteedLoopInvariant)
         CurrentPair.second =
             Location.getWithNewSize(LocationSize::beforeOrAfterPointer());
       PHITransAddr Translator(
@@ -1266,6 +1268,10 @@
         if (TransAddr != Location.Ptr) {
           CurrentPair.second = CurrentPair.second.getWithNewPtr(TransAddr);
 
+          if (!GuaranteedLoopInvariant && IsGuaranteedLoopInvariant(TransAddr))
+            CurrentPair.second =
+                CurrentPair.second.getWithNewSize(Location.Size);
+
           if (TransAddr &&
               !IsGuaranteedLoopInvariant(TransAddr))
             CurrentPair.second = CurrentPair.second.getWithNewSize(


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