[pr21886] Change MCJIT/ELF to support MSVC C++ mangled symbol.

[oota-llvm.git] / lib / Analysis / Loads.cpp

diff --git a/lib/Analysis/Loads.cpp b/lib/Analysis/Loads.cpp
index 65a30f2816fbfcbb711dd366cdd374f494d73668..5042eb9777ac9fbb9dd1f550c69cdcb619a9d027 100644 (file)
--- a/lib/Analysis/Loads.cpp
+++ b/lib/Analysis/Loads.cpp
@@ -176,8 +176,13 @@ Value *llvm::FindAvailableLoadedValue(Value *Ptr, BasicBlock *ScanBB,
 
   Type *AccessTy = cast<PointerType>(Ptr->getType())->getElementType();
 
-  // If we're using alias analysis to disambiguate get the size of *Ptr.
-  uint64_t AccessSize = AA ? AA->getTypeStoreSize(AccessTy) : 0;
+  // Try to get the DataLayout for this module. This may be null, in which case
+  // the optimizations will be limited.
+  const DataLayout *DL = ScanBB->getDataLayout();
+
+  // Try to get the store size for the type.
+  uint64_t AccessSize = DL ? DL->getTypeStoreSize(AccessTy)
+                           : AA ? AA->getTypeStoreSize(AccessTy) : 0;
 
   Value *StrippedPtr = Ptr->stripPointerCasts();
 
@@ -202,7 +207,7 @@ Value *llvm::FindAvailableLoadedValue(Value *Ptr, BasicBlock *ScanBB,
     if (LoadInst *LI = dyn_cast<LoadInst>(Inst))
       if (AreEquivalentAddressValues(
               LI->getPointerOperand()->stripPointerCasts(), StrippedPtr) &&
-          CastInst::isBitCastable(LI->getType(), AccessTy)) {
+          CastInst::isBitOrNoopPointerCastable(LI->getType(), AccessTy, DL)) {
         if (AATags)
           LI->getAAMetadata(*AATags);
         return LI;
@@ -214,17 +219,19 @@ Value *llvm::FindAvailableLoadedValue(Value *Ptr, BasicBlock *ScanBB,
       // (This is true even if the store is volatile or atomic, although
       // those cases are unlikely.)
       if (AreEquivalentAddressValues(StorePtr, StrippedPtr) &&
-          CastInst::isBitCastable(SI->getValueOperand()->getType(), AccessTy)) {
+          CastInst::isBitOrNoopPointerCastable(SI->getValueOperand()->getType(),
+                                               AccessTy, DL)) {
         if (AATags)
           SI->getAAMetadata(*AATags);
         return SI->getOperand(0);
       }
 
-      // If Ptr is an alloca and this is a store to a different alloca, ignore
-      // the store.  This is a trivial form of alias analysis that is important
-      // for reg2mem'd code.
+      // If both StrippedPtr and StorePtr reach all the way to an alloca or
+      // global and they are different, ignore the store. This is a trivial form
+      // of alias analysis that is important for reg2mem'd code.
       if ((isa<AllocaInst>(StrippedPtr) || isa<GlobalVariable>(StrippedPtr)) &&
-          (isa<AllocaInst>(StorePtr) || isa<GlobalVariable>(StorePtr)))
+          (isa<AllocaInst>(StorePtr) || isa<GlobalVariable>(StorePtr)) &&
+          StrippedPtr != StorePtr)
         continue;
 
       // If we have alias analysis and it says the store won't modify the loaded