Canonicalize addrspacecast ConstExpr between different pointer types

As a follow-up to r210375 which canonicalizes addrspacecast
instructions, this patch canonicalizes addrspacecast constant
expressions.

Given clang uses ConstantExpr::getAddrSpaceCast to emit addrspacecast
cosntant expressions, this patch is also a step towards having the
frontend emit canonicalized addrspacecasts.

Piggyback a minor refactor in InstCombineCasts.cpp

Update three affected tests in addrspacecast-alias.ll,
access-non-generic.ll and constant-fold-gep.ll and added one new test in
constant-fold-address-space-pointer.ll


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@211004 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 4 insertions, 2 deletions

diff --git a/lib/Transforms/InstCombine/InstCombineCasts.cpp b/lib/Transforms/InstCombine/InstCombineCasts.cpp
index 1b331d118f..ff083d7926 100644
--- a/lib/Transforms/InstCombine/InstCombineCasts.cpp
+++ b/lib/Transforms/InstCombine/InstCombineCasts.cpp
@@ -1919,8 +1919,10 @@ Instruction *InstCombiner::visitAddrSpaceCast(AddrSpaceCastInst &CI) {
   Type *DestElemTy = DestTy->getElementType();
   if (SrcTy->getElementType() != DestElemTy) {
     Type *MidTy = PointerType::get(DestElemTy, SrcTy->getAddressSpace());
-    if (CI.getType()->isVectorTy()) // Handle vectors of pointers.
-      MidTy = VectorType::get(MidTy, CI.getType()->getVectorNumElements());
+    if (VectorType *VT = dyn_cast<VectorType>(CI.getType())) {
+      // Handle vectors of pointers.
+      MidTy = VectorType::get(MidTy, VT->getNumElements());
+    }
 
     Value *NewBitCast = Builder->CreateBitCast(Src, MidTy);
     return new AddrSpaceCastInst(NewBitCast, CI.getType());