================
@@ -4386,34 +4386,59 @@ void SelectionDAGBuilder::visitGetElementPtr(const User
&I) {
// it.
IdxN = DAG.getSExtOrTrunc(IdxN, dl, N.getValueType());
+ SDNodeFlags ScaleFlags;
+ // The multiplication of an index by the type size does not wrap the
+ // pointer index type in a signed sense (mul nsw).
+ if (NW.hasNoUnsignedSignedWrap())
+ ScaleFlags.setNoSignedWrap(true);
+
+ // The multiplication of an index by the type size does not wrap the
+ // pointer index type in an unsigned sense (mul nuw).
+ if (NW.hasNoUnsignedWrap())
+ ScaleFlags.setNoUnsignedWrap(true);
+
if (ElementScalable) {
EVT VScaleTy = N.getValueType().getScalarType();
SDValue VScale = DAG.getNode(
ISD::VSCALE, dl, VScaleTy,
DAG.getConstant(ElementMul.getZExtValue(), dl, VScaleTy));
if (IsVectorGEP)
VScale = DAG.getSplatVector(N.getValueType(), dl, VScale);
- IdxN = DAG.getNode(ISD::MUL, dl, N.getValueType(), IdxN, VScale);
+ IdxN = DAG.getNode(ISD::MUL, dl, N.getValueType(), IdxN, VScale,
+ ScaleFlags);
} else {
// If this is a multiply by a power of two, turn it into a shl
// immediately. This is a very common case.
if (ElementMul != 1) {
if (ElementMul.isPowerOf2()) {
unsigned Amt = ElementMul.logBase2();
- IdxN = DAG.getNode(ISD::SHL, dl,
- N.getValueType(), IdxN,
- DAG.getConstant(Amt, dl, IdxN.getValueType()));
+ IdxN = DAG.getNode(ISD::SHL, dl, N.getValueType(), IdxN,
+ DAG.getConstant(Amt, dl, IdxN.getValueType()),
+ ScaleFlags);
} else {
SDValue Scale = DAG.getConstant(ElementMul.getZExtValue(), dl,
IdxN.getValueType());
- IdxN = DAG.getNode(ISD::MUL, dl,
- N.getValueType(), IdxN, Scale);
+ IdxN = DAG.getNode(ISD::MUL, dl, N.getValueType(), IdxN, Scale,
+ ScaleFlags);
}
}
}
- N = DAG.getNode(ISD::ADD, dl,
- N.getValueType(), N, IdxN);
+ SDNodeFlags AddFlags;
+
+ // The successive addition of each offset (without adding the base
+ // address) does not wrap the pointer index type in a signed sense (add
+ // nsw).
+ if (NW.hasNoUnsignedSignedWrap())
+ AddFlags.setNoSignedWrap(true);
----------------
arsenm wrote:
Loses the test benefit though
https://github.com/llvm/llvm-project/pull/110815
_______________________________________________
llvm-branch-commits mailing list
llvm-branch-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
