Enhance LICM to promote alias sets whose pointers themselves are stored,

which doesn't affect the memory address being promoted.

llvm-svn: 122172

1 files changed, 4 insertions, 1 deletions

diff --git a/llvm/lib/Transforms/Scalar/LICM.cpp b/llvm/lib/Transforms/Scalar/LICM.cpp
index 46fffccb3ac..6d5b24a01b2 100644
--- a/llvm/lib/Transforms/Scalar/LICM.cpp
+++ b/llvm/lib/Transforms/Scalar/LICM.cpp
@@ -691,7 +691,10 @@ void LICM::PromoteAliasSet(AliasSet &AS) {
       if (isa<LoadInst>(Use))
         assert(!cast<LoadInst>(Use)->isVolatile() && "AST broken");
       else if (isa<StoreInst>(Use)) {
-        if (Use->getOperand(0) == ASIV) return;
+        // Stores *of* the pointer are not interesting, only stores *to* the
+        // pointer.
+        if (Use->getOperand(1) != ASIV)
+          continue;
         assert(!cast<StoreInst>(Use)->isVolatile() && "AST broken");
       } else
         return; // Not a load or store.