Don't look through addrspacecast in GetPointerBaseWithConstantOffset

Pointers in different addrspaces can have different sizes, so it's not valid to look through addrspace cast calculating base and offset for a value.

This is similar to D13008.

Reviewed By: reames

Differential Revision: https://reviews.llvm.org/D24729

llvm-svn: 282612

1 files changed, 7 insertions, 2 deletions

diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index 7983240c3dd..e409edb28fd 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -2848,9 +2848,14 @@ Value *llvm::GetPointerBaseWithConstantOffset(Value *Ptr, int64_t &Offset,
       ByteOffset += GEPOffset;
 
       Ptr = GEP->getPointerOperand();
-    } else if (Operator::getOpcode(Ptr) == Instruction::BitCast ||
-               Operator::getOpcode(Ptr) == Instruction::AddrSpaceCast) {
+    } else if (Operator::getOpcode(Ptr) == Instruction::BitCast) {
       Ptr = cast<Operator>(Ptr)->getOperand(0);
+    } else if (AddrSpaceCastInst *ASCI = dyn_cast<AddrSpaceCastInst>(Ptr)) {
+      Value *SourcePtr = ASCI->getPointerOperand();
+      // Don't look through addrspace cast which changes pointer size
+      if (BitWidth != DL.getPointerTypeSizeInBits(SourcePtr->getType()))
+        break;
+      Ptr = SourcePtr;
     } else if (GlobalAlias *GA = dyn_cast<GlobalAlias>(Ptr)) {
       if (GA->isInterposable())
         break;