[PATCH] D91901: [RISCV] Move shift ComplexPatterns and custom isel to PatFrags with predicates

[Alex Bradbury via Phabricator via llvm-commits]

asb added a subscriber: efriedma.
asb added a comment.

Interesting. So to summarise my views on pros/cons

Pros:

- Replacing some hand-coded pattern matching with patterns in tablegen
- Avoid the mentioned weirdness of ComplexPattern

Cons:

- Moves more C++ snippets into tablegen (more painful to edit and maintain proper formatting etc)
- The fact IsRV64 is checked after PatFrag predicates is a bit surprising / easy to get wrong

Neutral:

- Unusual approach - other targets don't seem to look through operands in PatFrag.

Overall I think being able to drop some hand-written matching means I think this makes sense. Does anyone else have views? e.g. @efriedma


Repository:
  rG LLVM Github Monorepo

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https://reviews.llvm.org/D91901