[PATCH] D107330: [GlobalISel] Combine shr(shl x, c1), c2 to G_SBFX/G_UBFX

[Jay Foad via Phabricator via llvm-commits]

foad added a comment.

> Looks like SextInreg combine has a higher precedence, as no other tests were affected. Should we skip this new combine if n==k?

I don't know! Is there a well defined way of ensuring that SextInreg has higher precedence? Or is it just luck?

(Actually from an engineering perspective I would prefer that we just have a single combine, that generates sext_inreg if signed&&n==k and sbfx/ubfx otherwise. But I'm not sure that other globalisel folks would agree.)


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D107330/new/

https://reviews.llvm.org/D107330