Canonicalize addrspacecast ConstExpr between different pointer types

[oota-llvm.git] / lib / IR / ConstantFold.cpp

diff --git a/lib/IR/ConstantFold.cpp b/lib/IR/ConstantFold.cpp
index 706e66fb422eac96f140cb0442943bd5d99b5aec..c23ab71eaf3ac121d8ac764716ef3a38d9b26b72 100644 (file)
--- a/lib/IR/ConstantFold.cpp
+++ b/lib/IR/ConstantFold.cpp
@@ -529,7 +529,10 @@ Constant *llvm::ConstantFoldCastInstruction(unsigned opc, Constant *V,
       // Try hard to fold cast of cast because they are often eliminable.
       if (unsigned newOpc = foldConstantCastPair(opc, CE, DestTy))
         return ConstantExpr::getCast(newOpc, CE->getOperand(0), DestTy);
-    } else if (CE->getOpcode() == Instruction::GetElementPtr) {
+    } else if (CE->getOpcode() == Instruction::GetElementPtr &&
+               // Do not fold addrspacecast (gep 0, .., 0). It might make the
+               // addrspacecast uncanonicalized.
+               opc != Instruction::AddrSpaceCast) {
       // If all of the indexes in the GEP are null values, there is no pointer
       // adjustment going on.  We might as well cast the source pointer.
       bool isAllNull = true;