diff options
| author | Dimitry Andric <dim@FreeBSD.org> | 2021-12-25 22:30:44 +0000 |
|---|---|---|
| committer | Dimitry Andric <dim@FreeBSD.org> | 2021-12-25 22:30:44 +0000 |
| commit | 77fc4c146f0870ffb09c1afb823ccbe742c5e6ff (patch) | |
| tree | 5c0eb39553003b9c75a901af6bc4ddabd6f2f28c /llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp | |
| parent | f65dcba83ce5035ab88a85fe17628b447eb56e1b (diff) | |
Diffstat (limited to 'llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp')
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp index 518d3952dce5..a6d6b5199105 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp @@ -1482,7 +1482,12 @@ tryToReuseConstantFromSelectInComparison(SelectInst &Sel, ICmpInst &Cmp, if (C0->getType() != Sel.getType()) return nullptr; - // FIXME: are there any magic icmp predicate+constant pairs we must not touch? + // ULT with 'add' of a constant is canonical. See foldICmpAddConstant(). + // FIXME: Are there more magic icmp predicate+constant pairs we must avoid? + // Or should we just abandon this transform entirely? + if (Pred == CmpInst::ICMP_ULT && match(X, m_Add(m_Value(), m_Constant()))) + return nullptr; + Value *SelVal0, *SelVal1; // We do not care which one is from where. match(&Sel, m_Select(m_Value(), m_Value(SelVal0), m_Value(SelVal1))); |