[PATCH] D89392: [GlobalISel] Fold unary opcodes in CSEMIRBuilder

[Dominik Montada via Phabricator via llvm-commits]

gargaroff added a comment.

Let me maybe add a suggestion: in my eyes the big problem here is that the combine that is introduced here can produce potentially illegal instructions, if run during / after the legalizer. So without a check whether the combine would produce something valid, I don't think it's a good idea to implement this.
The other combines are not problematic, since they don't change the types.


Repository:
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  https://reviews.llvm.org/D89392/new/

https://reviews.llvm.org/D89392