Disable null pointer folding transforms for non-generic address spaces. This should probably be a target-specific predicate based on address space. That way for targets where this isn't applicable the predicate can be optimized away.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45403 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index de528d9..6502bb3 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -9338,8 +9338,11 @@
return ReplaceInstUsesWith(LI, LIB);
}
- if (GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(Op))
- if (isa<ConstantPointerNull>(GEPI->getOperand(0))) {
+ if (GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(Op)) {
+ const Value *GEPI0 = GEPI->getOperand(0);
+ // TODO: Consider a target hook for valid address spaces for this xform.
+ if (isa<ConstantPointerNull>(GEPI0) &&
+ cast<PointerType>(GEPI0->getType())->getAddressSpace() == 0) {
// Insert a new store to null instruction before the load to indicate
// that this code is not reachable. We do this instead of inserting
// an unreachable instruction directly because we cannot modify the
@@ -9348,10 +9351,13 @@
Constant::getNullValue(Op->getType()), &LI);
return ReplaceInstUsesWith(LI, UndefValue::get(LI.getType()));
}
+ }
if (Constant *C = dyn_cast<Constant>(Op)) {
// load null/undef -> undef
- if ((C->isNullValue() || isa<UndefValue>(C))) {
+ // TODO: Consider a target hook for valid address spaces for this xform.
+ if (isa<UndefValue>(C) || (C->isNullValue() &&
+ cast<PointerType>(Op->getType())->getAddressSpace() == 0)) {
// Insert a new store to null instruction before the load to indicate that
// this code is not reachable. We do this instead of inserting an
// unreachable instruction directly because we cannot modify the CFG.
diff --git a/lib/Transforms/Scalar/SCCP.cpp b/lib/Transforms/Scalar/SCCP.cpp
index d236039..3a607cb 100644
--- a/lib/Transforms/Scalar/SCCP.cpp
+++ b/lib/Transforms/Scalar/SCCP.cpp
@@ -1015,7 +1015,9 @@
if (PtrVal.isUndefined()) return; // The pointer is not resolved yet!
if (PtrVal.isConstant() && !I.isVolatile()) {
Value *Ptr = PtrVal.getConstant();
- if (isa<ConstantPointerNull>(Ptr)) {
+ // TODO: Consider a target hook for valid address spaces for this xform.
+ if (isa<ConstantPointerNull>(Ptr) &&
+ cast<PointerType>(Ptr->getType())->getAddressSpace() == 0) {
// load null -> null
markConstant(IV, &I, Constant::getNullValue(I.getType()));
return;