From d2f3b0179763f9c169fe74b7dd19498ac66af1a0 Mon Sep 17 00:00:00 2001 From: Evan Cheng Date: Mon, 14 Mar 2011 18:15:55 +0000 Subject: Minor optimization. sign-ext/anyext of undef is still undef. llvm-svn: 127598 --- llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'llvm/lib/CodeGen/SelectionDAG') diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp index 8deaae935a6..2c97d35618d 100644 --- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp @@ -2482,6 +2482,8 @@ SDValue SelectionDAG::getNode(unsigned Opcode, DebugLoc DL, "Vector element count mismatch!"); if (OpOpcode == ISD::SIGN_EXTEND || OpOpcode == ISD::ZERO_EXTEND) return getNode(OpOpcode, DL, VT, Operand.getNode()->getOperand(0)); + else if (OpOpcode == ISD::UNDEF) + return getUNDEF(VT); break; case ISD::ZERO_EXTEND: assert(VT.isInteger() && Operand.getValueType().isInteger() && @@ -2512,6 +2514,8 @@ SDValue SelectionDAG::getNode(unsigned Opcode, DebugLoc DL, OpOpcode == ISD::ANY_EXTEND) // (ext (zext x)) -> (zext x) and (ext (sext x)) -> (sext x) return getNode(OpOpcode, DL, VT, Operand.getNode()->getOperand(0)); + else if (OpOpcode == ISD::UNDEF) + return getUNDEF(VT); // (ext (trunx x)) -> x if (OpOpcode == ISD::TRUNCATE) { -- cgit v1.2.3