[PATCH] D143074: [LangRef] improve documentation of SNaN in the default FP environment

[James Y Knight via Phabricator via llvm-commits]

jyknight added a comment.

> The property of SNaN like SNan + 0.0 -> QNaN is not related to exceptions and must be preserved in default environment also.

Neither GCC nor Clang have considered sNaN-related semantics important to provide by default thus far, and I don't think we ought to start now, either. We should continue to support them on an opt-in basis -- at least as far as the end-to-end behavior goes for Clang users. (If there's some good reason to do so, it'd be fine to contemplate changing the IR-level defaults.)


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  https://reviews.llvm.org/D143074/new/

https://reviews.llvm.org/D143074