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path: root/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
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Diffstat (limited to 'lib/CodeGen/SelectionDAG/DAGCombiner.cpp')
-rw-r--r--lib/CodeGen/SelectionDAG/DAGCombiner.cpp8
1 files changed, 5 insertions, 3 deletions
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index f650b4d88a..cb9778bbd6 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -3915,8 +3915,7 @@ SDValue DAGCombiner::visitSRL(SDNode *N) {
DAG.getConstant(~0ULL >> ShAmt, VT));
}
-
- // fold (srl (anyextend x), c) -> (anyextend (srl x, c))
+ // fold (srl (anyextend x), c) -> (and (anyextend (srl x, c)), mask)
if (N1C && N0.getOpcode() == ISD::ANY_EXTEND) {
// Shifting in all undef bits?
EVT SmallVT = N0.getOperand(0).getValueType();
@@ -3929,7 +3928,10 @@ SDValue DAGCombiner::visitSRL(SDNode *N) {
N0.getOperand(0),
DAG.getConstant(ShiftAmt, getShiftAmountTy(SmallVT)));
AddToWorkList(SmallShift.getNode());
- return DAG.getNode(ISD::ANY_EXTEND, SDLoc(N), VT, SmallShift);
+ APInt Mask = APInt::getAllOnesValue(VT.getSizeInBits()).lshr(ShiftAmt);
+ return DAG.getNode(ISD::AND, SDLoc(N), VT,
+ DAG.getNode(ISD::ANY_EXTEND, SDLoc(N), VT, SmallShift),
+ DAG.getConstant(Mask, VT));
}
}