From 419a50ed9c885b08904a79c74f518c276cfa2b68 Mon Sep 17 00:00:00 2001 From: Sanjay Patel Date: Mon, 5 Jun 2017 17:01:10 +0000 Subject: [PATCH] [DAGCombine] Fix unchecked calls to DAGCombiner::*ExtPromoteOperand Other calls to DAGCombiner::*PromoteOperand check the result, but here it could cause an assertion in getNode. Falling back to any extend in this case instead of failing outright seems correct to me. No test case because: The failure was triggered by an out of tree backend. In order to trigger it, a backend would need to overload TargetLowering::IsDesirableToPromoteOp to return true for a type for which ISD::SIGN_EXTEND_INREG is marked illegal. In tree, only X86 overloads and sometimes returns true for MVT::i16 yet it marks setOperationAction(ISD::SIGN_EXTEND_INREG, MVT::i16 , Legal);. Patch by Jacob Young! Differential Revision: https://reviews.llvm.org/D33633 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@304723 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index fb51a4eb142..5e872f522d8 100644 --- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -1028,13 +1028,13 @@ SDValue DAGCombiner::PromoteOperand(SDValue Op, EVT PVT, bool &Replace) { switch (Opc) { default: break; case ISD::AssertSext: - return DAG.getNode(ISD::AssertSext, DL, PVT, - SExtPromoteOperand(Op.getOperand(0), PVT), - Op.getOperand(1)); + if (SDValue Op0 = SExtPromoteOperand(Op.getOperand(0), PVT)) + return DAG.getNode(ISD::AssertSext, DL, PVT, Op0, Op.getOperand(1)); + break; case ISD::AssertZext: - return DAG.getNode(ISD::AssertZext, DL, PVT, - ZExtPromoteOperand(Op.getOperand(0), PVT), - Op.getOperand(1)); + if (SDValue Op0 = ZExtPromoteOperand(Op.getOperand(0), PVT)) + return DAG.getNode(ISD::AssertZext, DL, PVT, Op0, Op.getOperand(1)); + break; case ISD::Constant: { unsigned ExtOpc = Op.getValueType().isByteSized() ? ISD::SIGN_EXTEND : ISD::ZERO_EXTEND; -- 2.50.1