https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70255
--- Comment #9 from joseph at codesourcery dot com <joseph at codesourcery dot com> --- I should point out that there is a proposed standard way of controlling various floating-point optimizations, in the form of pragmas in draft TS 18661-5 (current public draft N2004) (in this case, the FENV_ALLOW_ASSOCIATIVE_LAW pragma). That said, part 5 should be considered by far the most experimental and difficult to implement part of TS 18661, and given the limited interest seen so far in implementing C99/C11 Annex F or most of the parts of TS 18661, I wouldn't expect anything from part 5 to be implemented any time soon by GCC (or by any other implementation - limited interest in this area goes beyond just GCC).
