[PATCH] D100166: [PowerPC] stop reverse mem op generation when the feeder has more than one users

[ChenZheng via Phabricator via llvm-commits]

shchenz added inline comments.


================
Comment at: llvm/lib/Target/PowerPC/PPCISelLowering.cpp:14375
+    // instruction, it is not profitable to replace it with a reverse store as
+    // the reverse store has no DForm.
+    if (!SVN->hasOneUse())
----------------
nemanjai wrote:
> It is not clear why the fact that there is no D-Form makes this unprofitable.
> Perhaps:
> ```
> // If there are other uses of the shuffle, the swap cannot be avoided.
> // Forcing the use of an X-Form (since swapped stores only have 
> // X-Forms) without removing the swap is unprofitable.
> ```
Thanks. It was updated in the commit.


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  https://reviews.llvm.org/D100166/new/

https://reviews.llvm.org/D100166