[LSR] Pointers with different address spaces are considered incompatible.
Summary:
Function isCompatibleIVType is already used as a guard before the call to
SE.getMinusSCEV(OperExpr, PrevExpr);
in LSRInstance::ChainInstruction. getMinusSCEV requires the expressions
to be of the same type, so we now consider two pointers with different
address spaces to be incompatible, since it is possible that the pointers
in fact have different sizes.
Reviewers: qcolombet, eli.friedman
Reviewed By: qcolombet
Subscribers: nhaehnle, Ka-Ka, llvm-commits, mzolotukhin
Differential Revision: https://reviews.llvm.org/D29885
llvm-svn: 295033
diff --git a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
index a59d901..baef7b9 100644
--- a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -2559,7 +2559,12 @@
static bool isCompatibleIVType(Value *LVal, Value *RVal) {
Type *LType = LVal->getType();
Type *RType = RVal->getType();
- return (LType == RType) || (LType->isPointerTy() && RType->isPointerTy());
+ return (LType == RType) || (LType->isPointerTy() && RType->isPointerTy() &&
+ // Different address spaces means (possibly)
+ // different types of the pointer implementation,
+ // e.g. i16 vs i32 so disallow that.
+ (LType->getPointerAddressSpace() ==
+ RType->getPointerAddressSpace()));
}
/// Return an approximation of this SCEV expression's "base", or NULL for any