On Thu, 1 Jul 2021, liuhongt via Gcc-patches wrote: > +/* Optimize for code like (_Float16) __builtin_ceif ((float) f16) > + since it's not handled in frontend. */
Much the same comments apply as for sqrt. But in this case, the conversion code is in match.pd - right now, specific to pairs of types (float, double) and (float, long double). And it's logically valid for any pair of same-radix floating-point types, the values of one of which are a subset of the values of the other (a strict subset, for it actually to be an interesting optimization). (So when making it apply to more general types, take care that it does *not* apply to the __ibm128 / _Float128 pair on powerpc64le, in either order, because neither of those types has values a subset of the other.) (Also, the match.pd code isn't handling roundeven at present, but that should be a trivial addition to it.) -- Joseph S. Myers jos...@codesourcery.com
