From ef72141a75769e7d0111f417b91931a74ec2c1a3 Mon Sep 17 00:00:00 2001 From: Eric Christopher Date: Wed, 16 Feb 2011 01:10:03 +0000 Subject: The change for PR9190 wasn't quite right. We need to avoid making the transformation if we can't legally create a build vector of the correct type. Check that we can make the transformation first, and add a TODO to refactor this code with similar cases. Fixes: PR9223 and rdar://9000350 llvm-svn: 125631 --- llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) (limited to 'llvm/lib/CodeGen/SelectionDAG') diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index f452d6a8420..e213d722eb7 100644 --- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -1532,8 +1532,18 @@ SDValue DAGCombiner::visitSUB(SDNode *N) { } // fold (sub x, x) -> 0 - if (N0 == N1) - return DAG.getConstant(0, N->getValueType(0), LegalTypes); + // FIXME: Refactor this and xor and other similar operations together. + if (N0 == N1) { + if (!VT.isVector()) { + return DAG.getConstant(0, VT); + } else if (!LegalOperations || TLI.isOperationLegal(ISD::BUILD_VECTOR, VT)){ + // Produce a vector of zeros. + SDValue El = DAG.getConstant(0, VT.getVectorElementType()); + std::vector Ops(VT.getVectorNumElements(), El); + return DAG.getNode(ISD::BUILD_VECTOR, N->getDebugLoc(), VT, + &Ops[0], Ops.size()); + } + } // fold (sub c1, c2) -> c1-c2 if (N0C && N1C) return DAG.FoldConstantArithmetic(ISD::SUB, VT, N0C, N1C); -- cgit v1.2.3