From cc2210b4fa9debfaafa2d385549b0c30448e9c12 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Wed, 7 Dec 2005 18:02:05 +0000 Subject: [PATCH] Only transform (sext (truncate x)) -> (sextinreg x) if before legalize or if the target supports the resultant sextinreg git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@24632 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index b7f6853f74c..7adfecb2220 100644 --- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -1547,7 +1547,9 @@ SDOperand DAGCombiner::visitSIGN_EXTEND(SDNode *N) { if (N0.getOpcode() == ISD::SEXTLOAD && VT == N0.getValueType()) return N0; // fold (sext (truncate x)) -> (sextinreg x) iff x size == sext size. - if (N0.getOpcode() == ISD::TRUNCATE && N0.getOperand(0).getValueType() == VT) + if (N0.getOpcode() == ISD::TRUNCATE && N0.getOperand(0).getValueType() == VT&& + (!AfterLegalize || + TLI.isOperationLegal(ISD::SIGN_EXTEND_INREG, N0.getValueType()))) return DAG.getNode(ISD::SIGN_EXTEND_INREG, VT, N0.getOperand(0), DAG.getValueType(N0.getValueType())); // fold (sext (load x)) -> (sextload x) -- 2.34.1