diff options
| author | Nate Begeman <natebegeman@mac.com> | 2006-02-05 08:07:24 +0000 |
|---|---|---|
| committer | Nate Begeman <natebegeman@mac.com> | 2006-02-05 08:07:24 +0000 |
| commit | bab9239d0572d35a08423782eb964e532c3c6524 (patch) | |
| tree | d833cbadff3ba21527630b244a654b4441abfa2d /lib/CodeGen | |
| parent | 176f0416d103f5ce34ae0899f053890ee2aa016f (diff) | |
fold c1 << (x + c2) into (c1 << c2) << x. fix a warning.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26005 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/CodeGen')
| -rw-r--r-- | lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index 533fd70de0..e853db3310 100644 --- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -838,7 +838,7 @@ SDOperand DAGCombiner::visitUREM(SDNode *N) { if (N1.getOpcode() == ISD::SHL) { if (ConstantSDNode *SHC = dyn_cast<ConstantSDNode>(N1.getOperand(0))) { if (isPowerOf2_64(SHC->getValue())) { - SDOperand Add = DAG.getNode(ISD::ADD, VT, N1, DAG.getConstant(-1, VT)); + SDOperand Add = DAG.getNode(ISD::ADD, VT, N1,DAG.getConstant(~0ULL,VT)); WorkList.push_back(Add.Val); return DAG.getNode(ISD::AND, VT, N0, Add); } @@ -1288,6 +1288,12 @@ SDOperand DAGCombiner::visitSHL(SDNode *N) { // fold (shl 0, x) -> 0 if (N0C && N0C->isNullValue()) return N0; + // fold (shl c1, (add x, c2)) -> (shl c1 << c2, x) + if (N0C && N1.getOpcode() == ISD::ADD && + N1.getOperand(1).getOpcode() == ISD::Constant) { + SDOperand LHS = DAG.getNode(ISD::SHL, VT, N0, N1.getOperand(1)); + return DAG.getNode(ISD::SHL, VT, LHS, N1.getOperand(0)); + } // fold (shl x, c >= size(x)) -> undef if (N1C && N1C->getValue() >= OpSizeInBits) return DAG.getNode(ISD::UNDEF, VT); |