s.egerton added a comment.

We have a patch to add codegen pattern matching 
(https://reviews.llvm.org/D67348). Unfortunately we have found that we will not 
be able to rely on pattern matching here to guarantee that these instructions 
are emitted in all situations due to differences in optimisation levels and the 
complexity of some instructions.
The approach of using arch-specific intrinsics in the middle end 
(https://reviews.llvm.org/D66479) was an alternative way to bridge the gap 
between the C level builtins and the Bitmanip instructions.

Thinking about it more, this could be approved and eventually have the inline 
asm parts replaced after the arch-specific intrinsics patch is approved.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D67661/new/

https://reviews.llvm.org/D67661



_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits

Reply via email to