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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 | c6800b55e694b5953eaca25d826d5efd661aa37f (patch) | |
| tree | 5db53b013e18b6bbe08f7894935c9393e485b8ac /llvm | |
| parent | d0cfa88785cf951f0b049e87870965a268de139e (diff) | |
| download | bcm5719-llvm-c6800b55e694b5953eaca25d826d5efd661aa37f.tar.gz bcm5719-llvm-c6800b55e694b5953eaca25d826d5efd661aa37f.zip | |
Add a comment to describe why vector shuffles are legalized to custom DAG nodes.
llvm-svn: 78884
Diffstat (limited to 'llvm')
| -rw-r--r-- | llvm/lib/Target/ARM/ARMISelLowering.cpp | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/llvm/lib/Target/ARM/ARMISelLowering.cpp b/llvm/lib/Target/ARM/ARMISelLowering.cpp index 4074fc7f219..785a7ded6d3 100644 --- a/llvm/lib/Target/ARM/ARMISelLowering.cpp +++ b/llvm/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)) |
