diff options
Diffstat (limited to 'llvm/lib/Transforms/InstCombine')
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp index f1a66816c4c..0d56ce5ebe8 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp @@ -1145,6 +1145,14 @@ Instruction *InstCombiner::visitICmpInstWithInstAndIntCst(ICmpInst &ICI, switch (LHSI->getOpcode()) { case Instruction::Trunc: + if (RHS->isOne() && RHSV.getBitWidth() > 1) { + // icmp slt trunc(signum(V)) 1 --> icmp slt V, 1 + Value *V = nullptr; + if (ICI.getPredicate() == ICmpInst::ICMP_SLT && + match(LHSI->getOperand(0), m_Signum(m_Value(V)))) + return new ICmpInst(ICmpInst::ICMP_SLT, V, + ConstantInt::get(V->getType(), 1)); + } if (ICI.isEquality() && LHSI->hasOneUse()) { // Simplify icmp eq (trunc x to i8), 42 -> icmp eq x, 42|highbits if all // of the high bits truncated out of x are known. @@ -1467,6 +1475,15 @@ Instruction *InstCombiner::visitICmpInstWithInstAndIntCst(ICmpInst &ICI, break; case Instruction::Or: { + if (RHS->isOne()) { + // icmp slt signum(V) 1 --> icmp slt V, 1 + Value *V = nullptr; + if (ICI.getPredicate() == ICmpInst::ICMP_SLT && + match(LHSI, m_Signum(m_Value(V)))) + return new ICmpInst(ICmpInst::ICMP_SLT, V, + ConstantInt::get(V->getType(), 1)); + } + if (!ICI.isEquality() || !RHS->isNullValue() || !LHSI->hasOneUse()) break; Value *P, *Q; |
