From f74c794ccfec7f9d7064d5181f7d5788661b2588 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Sun, 10 Apr 2005 04:33:08 +0000 Subject: [PATCH] Fold zext_inreg(zextload), likewise for sext's llvm-svn: 21204 --- llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp index 7cf89144c3b5..6b94adf1d8ed 100644 --- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp @@ -1101,6 +1101,12 @@ SDOperand SelectionDAG::getNode(unsigned Opcode, MVT::ValueType VT,SDOperand N1, return N1; } + // If we are (zero|sign) extending a [zs]extload, return just the load. + if ((N1.getOpcode() == ISD::ZEXTLOAD && Opcode == ISD::ZERO_EXTEND_INREG) || + (N1.getOpcode() == ISD::SEXTLOAD && Opcode == ISD::SIGN_EXTEND_INREG)) + if (cast(N1)->getExtraValueType() <= EVT) + return N1; + // If we are extending the result of a setcc, and we already know the // contents of the top bits, eliminate the extension. if (N1.getOpcode() == ISD::SETCC)