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| author | Nikita Popov <npopov@redhat.com> | 2023-01-09 16:29:37 +0100 |
|---|---|---|
| committer | Nikita Popov <npopov@redhat.com> | 2023-01-09 16:34:09 +0100 |
| commit | fd07583ca439494891662d5db58895f63e904cc5 (patch) | |
| tree | 0aafc96e60c11420acf8b7dee36174d00213709c /llvm/lib/IR/ConstantRange.cpp | |
| parent | 835cf3ca6bee4b866488e08db1a2fd158a3ad086 (diff) | |
| download | llvm-fd07583ca439494891662d5db58895f63e904cc5.zip llvm-fd07583ca439494891662d5db58895f63e904cc5.tar.gz llvm-fd07583ca439494891662d5db58895f63e904cc5.tar.bz2 | |
[ConstantRange] Fix single bit abs range (PR59887)
For a full range input, we would produce an empty range instead
of a full range. The change to the SMin.isNonNegative() branch is
an optimality fix, because we should account for the potentially
discarded SMin value in the IntMinIsPoison case.
Change TestUnaryOpExhaustive to test both 4 and 1 bits, to both
cover this specific case in unit tests, and make sure all other
unary operations deal with 1-bit inputs correctly.
Fixes https://github.com/llvm/llvm-project/issues/59887.
Diffstat (limited to 'llvm/lib/IR/ConstantRange.cpp')
| -rw-r--r-- | llvm/lib/IR/ConstantRange.cpp | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/llvm/lib/IR/ConstantRange.cpp b/llvm/lib/IR/ConstantRange.cpp index 2f0d3d1..0dbccaa 100644 --- a/llvm/lib/IR/ConstantRange.cpp +++ b/llvm/lib/IR/ConstantRange.cpp @@ -1656,15 +1656,15 @@ ConstantRange ConstantRange::abs(bool IntMinIsPoison) const { // All non-negative. if (SMin.isNonNegative()) - return *this; + return ConstantRange(SMin, SMax + 1); // All negative. if (SMax.isNegative()) return ConstantRange(-SMax, -SMin + 1); // Range crosses zero. - return ConstantRange(APInt::getZero(getBitWidth()), - APIntOps::umax(-SMin, SMax) + 1); + return ConstantRange::getNonEmpty(APInt::getZero(getBitWidth()), + APIntOps::umax(-SMin, SMax) + 1); } ConstantRange::OverflowResult ConstantRange::unsignedAddMayOverflow( |