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| author | Simon Pilgrim <llvm-dev@redking.me.uk> | 2018-12-16 13:33:37 +0000 |
|---|---|---|
| committer | Simon Pilgrim <llvm-dev@redking.me.uk> | 2018-12-16 13:33:37 +0000 |
| commit | 0ef977b83dae860f0c00a1f23eaaefeb82913b7e (patch) | |
| tree | 34fa58c997877dd3c62ec2880154289cad749bab /llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp | |
| parent | 780b3ca775852acacc4313e8d7ff9238184d7df2 (diff) | |
| download | bcm5719-llvm-0ef977b83dae860f0c00a1f23eaaefeb82913b7e.tar.gz bcm5719-llvm-0ef977b83dae860f0c00a1f23eaaefeb82913b7e.zip | |
[SelectionDAG] Add FSHL/FSHR support to computeKnownBits
Also exposes an issue in DAGCombiner::visitFunnelShift where we were assuming the shift amount had the result type (after legalization it'll have the targets shift amount type).
llvm-svn: 349298
Diffstat (limited to 'llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index cad130ecea6..93a1ab1dcff 100644 --- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -6966,8 +6966,10 @@ SDValue DAGCombiner::visitFunnelShift(SDNode *N) { // fold (fshl N0, N1, 0) -> N0 // fold (fshr N0, N1, 0) -> N1 - if (DAG.MaskedValueIsZero(N2, APInt::getAllOnesValue(BitWidth))) - return IsFSHL ? N0 : N1; + if (isPowerOf2_32(BitWidth)) + if (DAG.MaskedValueIsZero( + N2, APInt(N2.getScalarValueSizeInBits(), BitWidth - 1))) + return IsFSHL ? N0 : N1; // fold (fsh* N0, N1, c) -> (fsh* N0, N1, c % BitWidth) if (ConstantSDNode *Cst = isConstOrConstSplat(N2)) { |
