diff options
Diffstat (limited to 'llvm/lib/Transforms')
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp index a295f65f387..5f8bf84092c 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp @@ -4624,8 +4624,8 @@ static Instruction *canonicalizeICmpBool(ICmpInst &I, } // Transform pattern like: -// (1 << Y) u<= X or ~(-1 << Y) u< X -// (1 << Y) u> X or ~(-1 << Y) u>= X +// (1 << Y) u<= X or ~(-1 << Y) u< X or ((1 << Y)+(-1)) u< X +// (1 << Y) u> X or ~(-1 << Y) u>= X or ((1 << Y)+(-1)) u>= X // Into: // (X l>> Y) != 0 // (X l>> Y) == 0 @@ -4649,10 +4649,15 @@ static Instruction *foldICmpWithHighBitMask(ICmpInst &Cmp, default: return nullptr; } - } else if (match(&Cmp, - m_c_ICmp(Pred, - m_OneUse(m_Not(m_Shl(m_AllOnes(), m_Value(Y)))), - m_Value(X)))) { + } else if (match(&Cmp, m_c_ICmp(Pred, + m_OneUse(m_CombineOr( + m_Not(m_Shl(m_AllOnes(), m_Value(Y))), + m_Add(m_Shl(m_One(), m_Value(Y)), + m_AllOnes()))), + m_Value(X)))) { + // The variant with 'add' is not canonical, (the variant with 'not' is) + // we only get it because it has extra uses, and can't be canonicalized, + // We want X to be the icmp's second operand, so swap predicate if it isn't. if (Cmp.getOperand(0) == X) Pred = Cmp.getSwappedPredicate(); |
