[PATCH] D149083: [PowerPC] Optimize VPERM and fix code order for swapping vector operands on LE

[Maryam Moghadas via Phabricator via llvm-commits]

maryammo added inline comments.


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Comment at: llvm/lib/Target/PowerPC/PPCISelLowering.cpp:10238
       NeedSwap = !NeedSwap;
     }
   }
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stefanp wrote:
> Now that the swap has been moved down should this also be moved down? Or at least part of it?
> I ask because I've noticed that there are a number of tests where a new `vmr` has been introduced and I'm wondering if that's why.
In the following code section (line 10286), it uses the `NeedSwap` to adjust the mask, so this single-use operand swap needs to happen before that. 
You are right, there are new `vmr`s, they seem to be needed based on the new vector operand order in the `xxperm` instruction. 


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  https://reviews.llvm.org/D149083/new/

https://reviews.llvm.org/D149083