From 78ec0255d9ab184af7799c14d93879e5f21b9007 Mon Sep 17 00:00:00 2001 From: Evan Cheng Date: Wed, 9 Jan 2013 20:56:40 +0000 Subject: Fix a DAG combine bug visitBRCOND() is transforming br(xor(x, y)) to br(x != y). It cahced XOR's operands before calling visitXOR() but failed to update the operands when visitXOR changed the XOR node. rdar://12968664 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171999 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 30 ++++++++++++++++++------------ 1 file changed, 18 insertions(+), 12 deletions(-) (limited to 'lib/CodeGen/SelectionDAG/DAGCombiner.cpp') diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index ff00d0dd16..359c4cf8e4 100644 --- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -6735,18 +6735,24 @@ SDValue DAGCombiner::visitBRCOND(SDNode *N) { if (Op0.getOpcode() == Op1.getOpcode()) { // Avoid missing important xor optimizations. SDValue Tmp = visitXOR(TheXor); - if (Tmp.getNode() && Tmp.getNode() != TheXor) { - DEBUG(dbgs() << "\nReplacing.8 "; - TheXor->dump(&DAG); - dbgs() << "\nWith: "; - Tmp.getNode()->dump(&DAG); - dbgs() << '\n'); - WorkListRemover DeadNodes(*this); - DAG.ReplaceAllUsesOfValueWith(N1, Tmp); - removeFromWorkList(TheXor); - DAG.DeleteNode(TheXor); - return DAG.getNode(ISD::BRCOND, N->getDebugLoc(), - MVT::Other, Chain, Tmp, N2); + if (Tmp.getNode()) { + if (Tmp.getNode() != TheXor) { + DEBUG(dbgs() << "\nReplacing.8 "; + TheXor->dump(&DAG); + dbgs() << "\nWith: "; + Tmp.getNode()->dump(&DAG); + dbgs() << '\n'); + WorkListRemover DeadNodes(*this); + DAG.ReplaceAllUsesOfValueWith(N1, Tmp); + removeFromWorkList(TheXor); + DAG.DeleteNode(TheXor); + return DAG.getNode(ISD::BRCOND, N->getDebugLoc(), + MVT::Other, Chain, Tmp, N2); + } + + // visitXOR has changed XOR's operands. + Op0 = TheXor->getOperand(0); + Op1 = TheXor->getOperand(1); } } -- cgit v1.2.3