[PATCH] D57377: [CGP] Add support for sinking operands to their users, if they are free.

Wed Jan 30 08:59:13 PST 2019

spatel added a comment.

We already have various sinking transforms in CGP, so this is the right approach IMO. I do wonder if we could adapt the existing (cmp/and-mask/etc) sinking that we already have in CGP to use this hook as a refinement, but that can be a follow-up of this patch.

I'm not sure yet if/how we'd use this with x86 shuffles, but there's always hope. :) 
You might be interested in looking at some recent DAGCombiner and x86 patches that are motivated by narrowing the width of vector ops and shuffles:
D55126 <https://reviews.llvm.org/D55126>
D55866 <https://reviews.llvm.org/D55866>
D56604 <https://reviews.llvm.org/D56604>
D56875 <https://reviews.llvm.org/D56875>
D57156 <https://reviews.llvm.org/D57156>
D57336 <https://reviews.llvm.org/D57336>

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D57377/new/

https://reviews.llvm.org/D57377