[llvm] [LV] Extend FindFirstIV to unsigned case (PR #146386)
Florian Hahn via llvm-commits
llvm-commits at lists.llvm.org
Tue Jul 8 04:40:34 PDT 2025
================
@@ -741,10 +739,9 @@ RecurrenceDescriptor::isFindIVPattern(RecurKind Kind, Loop *TheLoop,
: APInt::getMinValue(NumBits);
ValidRange = ConstantRange::getNonEmpty(Sentinel + 1, Sentinel);
} else {
- assert(IsSigned && "Only FindFirstIV with SMax is supported currently");
- ValidRange =
- ConstantRange::getNonEmpty(APInt::getSignedMinValue(NumBits),
- APInt::getSignedMaxValue(NumBits) - 1);
+ APInt Sentinel = IsSigned ? APInt::getSignedMaxValue(NumBits)
+ : APInt::getMaxValue(NumBits);
+ ValidRange = ConstantRange::getNonEmpty(Sentinel + 1, Sentinel);
----------------
fhahn wrote:
On second thought, I think the wrapped range isn't sufficient and this will need to initialize the range with min & max - 1 explicitly as suggested earlier (and also clearer)
Currently test coverage is missing for the case where the IV range includes both signed and unsigned sentinel values.
https://github.com/llvm/llvm-project/pull/146386
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