[PATCH] D88823: [CodeGen][TailDuplicator] Don't duplicate blocks with INLINEASM_BR

[James Y Knight via Phabricator via llvm-commits]

jyknight added a comment.

> When we go to resolve this PHI node, there's no place to put the put the values that works in all situations; we can't split the critical edges and it's not valid to place the resolved instructions at the ends of the predecessor blocks.

We can (at least: should be able to) handle a PHI node in the indirect targets of an INLINEASM_BR, for any value which is not the output of the INLINEASM_BR itself. We place the required register copies prior to the INLINEASM_BR, rather than after it. This is handled by findPHICopyInsertPoint -- where we did have a bug already, fixed in f7a53d82c0902147909f28a9295a9d00b4b27d38 <https://reviews.llvm.org/rGf7a53d82c0902147909f28a9295a9d00b4b27d38>.

I also don't see anything wrong in this test-case. AFAICT, the phi looks to be handled correctly here. Perhaps it's been minimized too far, and is no longer showing the actual problem?


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D88823/new/

https://reviews.llvm.org/D88823