From 59f1e97ef3940840e023ae1d6226c9b416222d2d Mon Sep 17 00:00:00 2001 From: Dale Johannesen Date: Thu, 6 Dec 2007 01:43:46 +0000 Subject: [PATCH] Fix PR1842. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44649 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index 3be1fdd0c7f..27709b39fd6 100644 --- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -2396,6 +2396,10 @@ SDOperand DAGCombiner::visitSELECT(SDNode *N) { MVT::ValueType VT = N->getValueType(0); MVT::ValueType VT0 = N0.getValueType(); + + // Some targets have SETCC types bigger than 1 bit, but do not set all the + // bits to 1; identified by getSetCCResultContents. Watch out for these. + // fold select C, X, X -> X if (N1 == N2) return N1; @@ -2420,14 +2424,22 @@ SDOperand DAGCombiner::visitSELECT(SDNode *N) { return DAG.getNode(ISD::TRUNCATE, VT, XORNode); } // fold select C, 0, X -> ~C & X - if (VT == VT0 && N1C && N1C->isNullValue()) { - SDOperand XORNode = DAG.getNode(ISD::XOR, VT, N0, DAG.getConstant(1, VT)); + if (VT == VT0 && N1C && N1C->isNullValue() && + (N0.Val->getOpcode()!=ISD::SETCC || VT==MVT::i1 || + TLI.getSetCCResultContents()== + TargetLowering::ZeroOrNegativeOneSetCCResult)) { + SDOperand XORNode; + XORNode = DAG.getNode(ISD::XOR, VT, N0, DAG.getConstant(~0UL, VT)); AddToWorkList(XORNode.Val); return DAG.getNode(ISD::AND, VT, XORNode, N2); } // fold select C, X, 1 -> ~C | X - if (VT == VT0 && N2C && N2C->getValue() == 1) { - SDOperand XORNode = DAG.getNode(ISD::XOR, VT, N0, DAG.getConstant(1, VT)); + if (VT == VT0 && N2C && N2C->getValue() == 1 && + (N0.Val->getOpcode()!=ISD::SETCC || VT==MVT::i1 || + TLI.getSetCCResultContents()== + TargetLowering::ZeroOrNegativeOneSetCCResult)) { + SDOperand XORNode; + XORNode = DAG.getNode(ISD::XOR, VT, N0, DAG.getConstant(~0UL, VT)); AddToWorkList(XORNode.Val); return DAG.getNode(ISD::OR, VT, XORNode, N1); }