Do not fold (zero_ext (sign_ext V)) -> (sign_ext V), they are not the same.

This fixes llvm-test/SingleSource/Regression/C/casts.c

llvm-svn: 19519
This commit is contained in:
Chris Lattner 2005-01-12 18:51:15 +00:00
parent 7b1dae8032
commit 4dfd2cfc0c
1 changed files with 2 additions and 2 deletions

View File

@ -511,8 +511,8 @@ SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT,
break;
case ISD::ZERO_EXTEND:
if (Operand.getValueType() == VT) return Operand; // noop extension
if (OpOpcode == ISD::SIGN_EXTEND || OpOpcode == ISD::ZERO_EXTEND)
return getNode(OpOpcode, VT, Operand.Val->getOperand(0));
if (OpOpcode == ISD::ZERO_EXTEND)
return getNode(ISD::ZERO_EXTEND, VT, Operand.Val->getOperand(0));
break;
case ISD::TRUNCATE:
if (Operand.getValueType() == VT) return Operand; // noop truncate