From 02a78cf7eacf97f2c9584e29d02f77612aead35f Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Fri, 25 Apr 2003 23:14:19 +0000 Subject: [PATCH] Fix a bug that occurred when removing the last predecessor INTO an infinite loop git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@5953 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/VMCore/BasicBlock.cpp | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/lib/VMCore/BasicBlock.cpp b/lib/VMCore/BasicBlock.cpp index 04f4e1cfc0d..d04e5546162 100644 --- a/lib/VMCore/BasicBlock.cpp +++ b/lib/VMCore/BasicBlock.cpp @@ -186,7 +186,11 @@ void BasicBlock::removePredecessor(BasicBlock *Pred) { // If the PHI _HAD_ two uses, replace PHI node with its now *single* value if (max_idx == 2) { - PN->replaceAllUsesWith(PN->getOperand(0)); + if (PN->getOperand(0) != PN) + PN->replaceAllUsesWith(PN->getOperand(0)); + else + // We are left with an infinite loop with no entries: kill the PHI. + PN->replaceAllUsesWith(Constant::getNullValue(PN->getType())); getInstList().pop_front(); // Remove the PHI node }