From 9ee863ecc00ff191bfec3f1421d80b41989f4413 Mon Sep 17 00:00:00 2001 From: Nick Lewycky Date: Wed, 9 Jul 2008 07:29:11 +0000 Subject: Fold (a < 8) && (b < 8) into (a|b) < 8 for unsigned less or greater than. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53282 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/InstructionCombining.cpp | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'lib/Transforms/Scalar/InstructionCombining.cpp') diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp index 27af3c397a..8d35bb5af0 100644 --- a/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/lib/Transforms/Scalar/InstructionCombining.cpp @@ -3594,6 +3594,22 @@ Instruction *InstCombiner::visitAnd(BinaryOperator &I) { } } + + { // (icmp ugt/ult A, C) & (icmp B, C) --> (icmp (A|B), C) + // where C is a power of 2 + Value *A, *B; + ConstantInt *C1, *C2; + ICmpInst::Predicate LHSCC, RHSCC; + if (match(&I, m_And(m_ICmp(LHSCC, m_Value(A), m_ConstantInt(C1)), + m_ICmp(RHSCC, m_Value(B), m_ConstantInt(C2))))) + if (C1 == C2 && LHSCC == RHSCC && C1->getValue().isPowerOf2() && + (LHSCC == ICmpInst::ICMP_ULT || LHSCC == ICmpInst::ICMP_UGT)) { + Instruction *NewOr = BinaryOperator::CreateOr(A, B); + InsertNewInstBefore(NewOr, I); + return new ICmpInst(LHSCC, NewOr, C1); + } + } + if (ICmpInst *RHS = dyn_cast(Op1)) { // (icmp1 A, B) & (icmp2 A, B) --> (icmp3 A, B) if (Instruction *R = AssociativeOpt(I, FoldICmpLogical(*this, RHS))) -- cgit v1.2.3-18-g5258