From 86e8a700f516e8993417fb57d5386614b35c775d Mon Sep 17 00:00:00 2001 From: Owen Anderson Date: Wed, 15 Dec 2010 00:55:35 +0000 Subject: Fix PR8790, another instance where unreachable code can cause instruction simplification to fail, this case involve a select that simplifies to itself. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121817 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/CorrelatedValuePropagation.cpp | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'lib') diff --git a/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp b/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp index f364375..be12973 100644 --- a/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp +++ b/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp @@ -73,7 +73,12 @@ bool CorrelatedValuePropagation::processSelect(SelectInst *S) { ConstantInt *CI = dyn_cast(C); if (!CI) return false; - S->replaceAllUsesWith(S->getOperand(CI->isOne() ? 1 : 2)); + Value *ReplaceWith = S->getOperand(1); + Value *Other = S->getOperand(2); + if (!CI->isOne()) std::swap(ReplaceWith, Other); + if (ReplaceWith == S) ReplaceWith = UndefValue::get(S->getType()); + + S->replaceAllUsesWith(ReplaceWith); S->eraseFromParent(); ++NumSelects; -- cgit v1.1