From 5c6621c3bc7e53e0754cb74062d27a6e8b7275e8 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Tue, 19 Sep 2006 04:51:23 +0000 Subject: [PATCH] Minor speedup for legalize by avoiding some malloc traffic git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@30477 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/SelectionDAG/SelectionDAG.cpp | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp index df6d604bd18..55b128f515d 100644 --- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp +++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp @@ -1329,6 +1329,15 @@ SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT, if (EVT == VT) return N1; // Not actually extending break; } + case ISD::EXTRACT_ELEMENT: + // EXTRACT_ELEMENT of BUILD_PAIR is often formed while legalize is expanding + // 64-bit integers into 32-bit parts. Instead of building the extract of + // the BUILD_PAIR, only to have legalize rip it apart, just do it now. + if (N2C && N1.getOpcode() == ISD::BUILD_PAIR) { + assert((unsigned)N2C->getValue() < 2 && "Bad EXTRACT_ELEMENT!"); + return N1.getOperand(N2C->getValue()); + } + break; // FIXME: figure out how to safely handle things like // int foo(int x) { return 1 << (x & 255); }