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
This commit is contained in:
Chris Lattner 2006-09-19 04:51:23 +00:00
parent bc7fa5277f
commit 5c6621c3bc

View File

@ -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); }