LSR: Don't drop address space when type doesn't match

For targets with different addressing modes in each address space,
if this is dropped querying isLegalAddressingMode later with this
will give a nonsense result, breaking the isLegalUse assertions.

This is a candidate for the 4.0 release branch.

llvm-svn: 293542

1 files changed, 7 insertions, 4 deletions

diff --git a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
index 6e7e135d95a..97e87c5521e 100644
--- a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -158,8 +158,9 @@ struct MemAccessTy {
 
   bool operator!=(MemAccessTy Other) const { return !(*this == Other); }
 
-  static MemAccessTy getUnknown(LLVMContext &Ctx) {
-    return MemAccessTy(Type::getVoidTy(Ctx), UnknownAddressSpace);
+  static MemAccessTy getUnknown(LLVMContext &Ctx,
+                                unsigned AS = UnknownAddressSpace) {
+    return MemAccessTy(Type::getVoidTy(Ctx), AS);
   }
 };
 
@@ -2284,8 +2285,10 @@ bool LSRInstance::reconcileNewOffset(LSRUse &LU, int64_t NewOffset,
   // TODO: Be less conservative when the type is similar and can use the same
   // addressing modes.
   if (Kind == LSRUse::Address) {
-    if (AccessTy != LU.AccessTy)
-      NewAccessTy = MemAccessTy::getUnknown(AccessTy.MemTy->getContext());
+    if (AccessTy.MemTy != LU.AccessTy.MemTy) {
+      NewAccessTy = MemAccessTy::getUnknown(AccessTy.MemTy->getContext(),
+                                            AccessTy.AddrSpace);
+    }
   }
 
   // Conservatively assume HasBaseReg is true for now.