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| author | Bob Wilson <bob.wilson@apple.com> | 2009-08-13 02:13:04 +0000 |
|---|---|---|
| committer | Bob Wilson <bob.wilson@apple.com> | 2009-08-13 02:13:04 +0000 |
| commit | 28865062c1ef60e47f0ac23a5ebc22eaf0d1b184 (patch) | |
| tree | aed8ba9d820810441919ce14522ff56a2bc66d77 | |
| parent | ac55b85438da378bab227fd34167bb0c4a9249aa (diff) | |
| download | external_llvm-28865062c1ef60e47f0ac23a5ebc22eaf0d1b184.zip external_llvm-28865062c1ef60e47f0ac23a5ebc22eaf0d1b184.tar.gz external_llvm-28865062c1ef60e47f0ac23a5ebc22eaf0d1b184.tar.bz2 | |
Add a comment to describe why vector shuffles are legalized to custom DAG nodes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78884 91177308-0d34-0410-b5e6-96231b3b80d8
| -rw-r--r-- | lib/Target/ARM/ARMISelLowering.cpp | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp index 4074fc7..785a7de 100644 --- a/lib/Target/ARM/ARMISelLowering.cpp +++ b/lib/Target/ARM/ARMISelLowering.cpp @@ -2439,6 +2439,10 @@ static SDValue LowerVECTOR_SHUFFLE(SDValue Op, SelectionDAG &DAG) { DebugLoc dl = Op.getDebugLoc(); EVT VT = Op.getValueType(); + // Convert shuffles that are directly supported on NEON to target-specific + // DAG nodes, instead of keeping them as shuffles and matching them again + // during code selection. This is more efficient and avoids the possibility + // of inconsistencies between legalization and selection. if (SVN->isSplat() && SVN->getSplatIndex() == 0) return DAG.getNode(ARMISD::VSPLAT0, dl, VT, SVN->getOperand(0)); if (isVREVMask(SVN, 64)) |