Memory-SSA: strengthen defClobbersUseOrDef interface

As Danny pointed out, defClobbersUseOrDef should use MemoryLocOrCall to make
sure fences are properly handled.

llvm-svn: 284099

1 files changed, 15 insertions, 19 deletions

diff --git a/llvm/lib/Transforms/Utils/MemorySSA.cpp b/llvm/lib/Transforms/Utils/MemorySSA.cpp
index abcfc5a7b51..b02a3f55d03 100644
--- a/llvm/lib/Transforms/Utils/MemorySSA.cpp
+++ b/llvm/lib/Transforms/Utils/MemorySSA.cpp
@@ -105,6 +105,8 @@ public:
   MemoryLocOrCall() : IsCall(false) {}
   MemoryLocOrCall(MemoryUseOrDef *MUD)
       : MemoryLocOrCall(MUD->getMemoryInst()) {}
+  MemoryLocOrCall(const MemoryUseOrDef *MUD)
+      : MemoryLocOrCall(MUD->getMemoryInst()) {}
 
   MemoryLocOrCall(Instruction *Inst) {
     if (ImmutableCallSite(Inst)) {
@@ -254,16 +256,22 @@ static bool instructionClobbersQuery(MemoryDef *MD,
   return AA.getModRefInfo(DefInst, UseLoc) & MRI_Mod;
 }
 
+static bool instructionClobbersQuery(MemoryDef *MD, const MemoryUseOrDef *MU,
+                                     const MemoryLocOrCall &UseMLOC,
+                                     AliasAnalysis &AA) {
+  // FIXME: This is a temporary hack to allow a single instructionClobbersQuery
+  // to exist while MemoryLocOrCall is pushed through places.
+  if (UseMLOC.IsCall)
+    return instructionClobbersQuery(MD, MemoryLocation(), MU->getMemoryInst(),
+                                    AA);
+  return instructionClobbersQuery(MD, UseMLOC.getLoc(), MU->getMemoryInst(),
+                                  AA);
+}
+
 // Return true when MD may alias MU, return false otherwise.
 bool defClobbersUseOrDef(MemoryDef *MD, const MemoryUseOrDef *MU,
                          AliasAnalysis &AA) {
-  Instruction *UseInst = MU->getMemoryInst();
-  MemoryLocation UseLoc;
-  if (ImmutableCallSite(UseInst))
-    UseLoc = MemoryLocation();
-  else
-    UseLoc = MemoryLocation::get(UseInst);
-  return instructionClobbersQuery(MD, UseLoc, UseInst, AA);
+  return instructionClobbersQuery(MD, MU, MemoryLocOrCall(MU), AA);
 }
 }
 
@@ -315,18 +323,6 @@ static bool isUseTriviallyOptimizableToLiveOnEntry(AliasAnalysis &AA,
                               AA.pointsToConstantMemory(I));
 }
 
-static bool instructionClobbersQuery(MemoryDef *MD, MemoryUse *MU,
-                                     const MemoryLocOrCall &UseMLOC,
-                                     AliasAnalysis &AA) {
-  // FIXME: This is a temporary hack to allow a single instructionClobbersQuery
-  // to exist while MemoryLocOrCall is pushed through places.
-  if (UseMLOC.IsCall)
-    return instructionClobbersQuery(MD, MemoryLocation(), MU->getMemoryInst(),
-                                    AA);
-  return instructionClobbersQuery(MD, UseMLOC.getLoc(), MU->getMemoryInst(),
-                                  AA);
-}
-
 /// Cache for our caching MemorySSA walker.
 class WalkerCache {
   DenseMap<ConstMemoryAccessPair, MemoryAccess *> Accesses;