[PATCH] D144534: [InstCombine] Fold (fcmp_oeq (fabs x) +Inf) into is_fpclass(x, fcInf)

[Qiu Chaofan via Phabricator via llvm-commits]

qiucf added a comment.

In D144534#4144155 <https://reviews.llvm.org/D144534#4144155>, @arsenm wrote:

> I think this is a backwards canonicalization decision and fabs + fcmp will be more broadly understood

Do you think this peephole should exist in backend? For targets with hardware instruction supporting `is.fpclass`, the intrinsic is more efficient than fabs+fcmp. Or, after `__builtin_isinf_sign` producing `is.fpclass` from frontend, this will not be needed?


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https://reviews.llvm.org/D144534