From 2974e49019b05ee4bec175a8d9cc736a512e3254 Mon Sep 17 00:00:00 2001 From: Bill Wendling Date: Tue, 18 Mar 2008 22:29:51 +0000 Subject: Temporarily revert r48491. It's breaking test/CodeGen/X86/xorl.ll. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48510 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 26 -------------------------- 1 file changed, 26 deletions(-) (limited to 'lib/CodeGen') diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index 737d9661fd..acc00fd58b 100644 --- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -2374,32 +2374,6 @@ SDOperand DAGCombiner::visitSRA(SDNode *N) { DAG.getValueType(EVT)); } - // fold sra (shl X, m), result_size - n - // -> (sign_extend (trunc (shl X, result_size - n - m))) for - // result_size - n != m. If truncate is free for the target sext(shl) is - // likely to result in better code. - if (N0.getOpcode() == ISD::SHL) { - // Get the two constanst of the shifts, CN0 = m, CN = n. - const ConstantSDNode *N01C = dyn_cast(N0.getOperand(1)); - if (N01C && N1C) { - // Determine if the truncate type's bitsize would correspond to - // an integer type for this target. - unsigned VTValSize = MVT::getSizeInBits(VT); - MVT::ValueType TruncVT = MVT::getIntegerType(VTValSize - N1C->getValue()); - unsigned ShiftAmt = N1C->getValue() - N01C->getValue(); - - // If the shift wouldn't be a noop, the truncated type is an actual type, - // and the truncate is free, then proceed with the transform. - if (ShiftAmt != 0 && - !MVT::isExtendedVT(TruncVT) && TLI.isTruncateFree(VT, TruncVT)) { - SDOperand Amt = DAG.getConstant(ShiftAmt, TLI.getShiftAmountTy()); - SDOperand Shift = DAG.getNode(ISD::SRL, VT, N0.getOperand(0), Amt); - SDOperand Trunc = DAG.getNode(ISD::TRUNCATE, TruncVT, Shift); - return DAG.getNode(ISD::SIGN_EXTEND, N->getValueType(0), Trunc); - } - } - } - // fold (sra (sra x, c1), c2) -> (sra x, c1+c2) if (N1C && N0.getOpcode() == ISD::SRA) { if (ConstantSDNode *C1 = dyn_cast(N0.getOperand(1))) { -- cgit v1.2.3-70-g09d2