From 9d86a4a3b636abc9871108d0ffecb990b824f3dd Mon Sep 17 00:00:00 2001 From: Paul Redmond Date: Mon, 21 Jan 2013 21:57:20 +0000 Subject: Transform (sub 0, (zext bool to A)) to (sext bool to A) and (sub 0, (sext bool to A)) to (zext bool to A). Patch by Muhammad Ahmad Reviewed by Duncan Sands llvm-svn: 173093 --- llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp') diff --git a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp index 03be8ef6fb7..c6d60d6f008 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineAddSub.cpp @@ -1250,6 +1250,16 @@ Instruction *InstCombiner::visitSub(BinaryOperator &I) { if (SimplifyDemandedInstructionBits(I)) return &I; + + // Fold (sub 0, (zext bool to B)) --> (sext bool to B) + if (C->isZero() && match(Op1, m_ZExt(m_Value(X)))) + if (X->getType()->isIntegerTy(1)) + return CastInst::CreateSExtOrBitCast(X, Op1->getType()); + + // Fold (sub 0, (sext bool to B)) --> (zext bool to B) + if (C->isZero() && match(Op1, m_SExt(m_Value(X)))) + if (X->getType()->isIntegerTy(1)) + return CastInst::CreateZExtOrBitCast(X, Op1->getType()); } -- cgit v1.2.3