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| author | Simon Pilgrim <llvm-dev@redking.me.uk> | 2019-05-13 12:44:03 +0000 |
|---|---|---|
| committer | Simon Pilgrim <llvm-dev@redking.me.uk> | 2019-05-13 12:44:03 +0000 |
| commit | d845bc3d0c7f309e932a4d59d703d007787ac49b (patch) | |
| tree | a27094cd6d7dc9457040a6f74ebc84829522f2af /llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp | |
| parent | e47362c1ec1ea31b626336cc05822035601c3e57 (diff) | |
| download | bcm5719-llvm-d845bc3d0c7f309e932a4d59d703d007787ac49b.tar.gz bcm5719-llvm-d845bc3d0c7f309e932a4d59d703d007787ac49b.zip | |
TargetLowering::SimplifyDemandedBits - early-out for UNDEF ops. NFCI.
llvm-svn: 360579
Diffstat (limited to 'llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp index fc7e7d9c3ce..89298133a0d 100644 --- a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp @@ -588,6 +588,10 @@ bool TargetLowering::SimplifyDemandedBits( // Don't know anything. Known = KnownBits(BitWidth); + // Undef operand. + if (Op.isUndef()) + return false; + if (Op.getOpcode() == ISD::Constant) { // We know all of the bits for a constant! Known.One = cast<ConstantSDNode>(Op)->getAPIntValue(); @@ -610,9 +614,7 @@ bool TargetLowering::SimplifyDemandedBits( DemandedElts = APInt::getAllOnesValue(NumElts); } else if (OriginalDemandedBits == 0 || OriginalDemandedElts == 0) { // Not demanding any bits/elts from Op. - if (!Op.isUndef()) - return TLO.CombineTo(Op, TLO.DAG.getUNDEF(VT)); - return false; + return TLO.CombineTo(Op, TLO.DAG.getUNDEF(VT)); } else if (Depth == 6) { // Limit search depth. return false; } |
