wzssyqa wrote: > > > I'm not sure this is correct. At least the way alive models the flag, I > > > believe this would also allow returning -0.0 even if both operands are > > > 0.0, which is not a legal outcome. > > > > > > That sounds like a bad modeling. It shouldn't permit synthesizing a -0 out > > of nowhere > > Hm, how would you suggest to model it? Considering an example like > https://discourse.llvm.org/t/rfc-clarify-the-behavior-of-fp-operations-on-bit-strings-with-nsz-flag/85981/4?u=nikic, > looking at it from the perspective of the select only, requires it to > convert a 0.0 into -0.0 "out of nowhere". > > I guess we could specify the semantics of nsz per-operation and use something > different for minnum...
In fact we already do so. ``` If the intrinsic is marked with the nsz attribute, then the effect is as in the definition in C and IEEE-754-2008: the result of minnum(-0.0, +0.0) may be either -0.0 or +0.0. ``` https://github.com/llvm/llvm-project/pull/113133 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
