http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34678
--- Comment #24 from Vincent Lefèvre <vincent-gcc at vinc17 dot net> --- (In reply to Nick Maclaren from comment #23) > If __STDC_IEC_559__ is unset or does not have the value 1, setting > STDC FENV_ACCESS to "on" is undefined behaviour (see 6.10.8.3, 7.6 and > Annex F), unless the implementation explicitly chooses to extend the > language to support it. You're wrong. The C standard doesn't say that. 6.10.8.3 says: "__STDC_IEC_559__ The integer constant 1, intended to indicate conformance to the specifications in annex F (IEC 60559 floating-point arithmetic)." and nothing about STDC FENV_ACCESS. In 7.6, only 7.6.1 is specifically about the FENV_ACCESS pragma, and it specifies under which conditions the behavior is undefined, but nothing related to __STDC_IEC_559__ and Annex F. Annex F doesn't apply in the case __STDC_IEC_559__ is unset.
