on 2022/5/13 04:16, Segher Boessenkool wrote: > Hi Piotr, > > On Tue, May 03, 2022 at 12:21:12PM +0200, pku...@freebsd.org wrote: >> FreeBSD/powerpc* has feenableexcept() defined in fenv.h header. > > Declared, not defined. These are required to be real functions (on all > platforms that have these functions), not macros or inlines or whatever. >
Piotr's reply "FreeBSD doesn't have this function in libm, it's implemented in /usr/include/fenv.h." from [1] made me feel like it's a definition instead of declaration. So I thought the check should use AC_LINK_IFELSE instead, since one fenv.h which doesn't have the definition can still pass the proposed AC_COMPILE_IFELSE check. I just did a further search, the powerpc fenv.h [2] does include the definition of feenableexcept. By comparison, the x86 fenv.h [3] doesn't. But I'm not sure if it's the same as what Piotr's environments have. Hope it's similar. :-) [1] https://gcc.gnu.org/pipermail/gcc-patches/2022-April/593193.html [2] https://github.com/freebsd/freebsd-src/blob/main/lib/msun/powerpc/fenv.h [3] https://github.com/freebsd/freebsd-src/blob/main/lib/msun/x86/fenv.h BR, Kewen
