[PATCH] D133739: [RISCV][ISel] Fold extensions when all the users can consume them

[Quentin Colombet via Phabricator via llvm-commits]

qcolombet added a comment.

The "NFC" refactoring is at https://reviews.llvm.org/D134703.
Then this diff has been updated to take advantage of it.

I'm not super happy about the hardcoded threshold.

Ideally, I think we'd like to do this kind of matching in a machine pass. The problem with that is we would need to duplicate some of the combines in that machine pass (e.g., like how we produce `vwmacc`). That would be a perfect fit for GISel :D.

Anyhow, if you guys don't like the SDISel patch (this patch and its child), we can avoid spending time on code review and start thinking about a machine pass. (The "NFC" patch, catch potentially interesting cases though.)


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D133739/new/

https://reviews.llvm.org/D133739