------- Additional Comments From jsm28 at gcc dot gnu dot org 2005-06-29 21:59 ------- It's come to my attention that C99 Annex F.4#1 specifies that the result is an unspecified value, with the "invalid" exception raised at runtime, rather than undefined behavior (in the absence of defining __STDC_IEC_559__, it's still undefined behavior). We don't currently implement FENV_ACCESS at all so the exception is irrelevant and I don't think we currently have any optimizations relying on the conversion being undefined rather than unspecified, but in any case the decimal fp work will answer the questions of what optimizations we do here and whether there is any performance cost to defining the results the way the decimal fp proposals do unconditionally.
-- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21360
