[PATCH] D116801: [PowerPC] Avoid perfect shuffle when mask has multiple uses

[Qiu Chaofan via Phabricator via llvm-commits]

qiucf marked an inline comment as done.
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Comment at: llvm/lib/Target/PowerPC/PPCISelLowering.cpp:10063
+  // cheaper to use load+vperm.
+  if (!MaskMap[PermMask].second) {
+    unsigned PFIndexes[4];
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shchenz wrote:
> Can we first check `isLittleEndian` and then `isFourElementShuffle` and then `MaskMap[PermMask].second` to improve the compile time?
`isFourElementShuffle` is also computed, when we think it's unprofitable to do perfect shuffle, it's meaningless to compute it.

Do you mean we check endian first, and only calculate `MaskMap` on big endian? That may improve compile time, but only before little-endian perfect shuffles are implemented.


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https://reviews.llvm.org/D116801