On Thu, Mar 21, 2002 at 12:33:45PM +1100, Bruce Evans wrote: > On Wed, 20 Mar 2002, Steve Kargl wrote: > > I forgot about the missing __pure2 in <math.h>. (It prevents gcc > doing optimizations like moving sqrt(2) out of loops.) There is > another thread on freebsd-standards about _MULTI_LIBM support. I
I'm not subscribed to freebsd-standards. Too many list, too little time. I guess I'll go browse the archive. > want the errno support completely removed so that we have a chance > of declaring math functions as __pure2 unconditionally. But maybe > we can't do this anyway, because math functions normally have the > side effect of setting IEEE exception flags. Can we do things like > > #ifpragma STDC FENV_ACCESS ON > double sqrt(double); > #else > double sqrt(double) __pure2; > #endif > > ? I don't know. I forgot about the libm PR until last week when someone else posted about paranoi.c failing several tests. I decided to check into the quality of libm and work on improvements. I still have a lot to learn. I think we'll only be able to add __pure2 on a case by case basis. For example, the POSIX sqrt(3) manpage states An application wishing to check for error situations should set errno to zero and call feclearexcept(FE_ALL_EXCEPT) before calling these functions. On return, if errno is non-zero or fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW |FE_UNDERFLOW) is non-zero, an error has occurred. > > > Also, are functions missing in libm with respect to the > > C99 standard? I would be willing to work on implementing > > these functions. > > Most are missing, if you count long double and complex support. Only > a few are, for double support. I noticed some easy ones like > isnormal() when I scanned the C99 draft standard today to check the > status if infnan.3. Garrett pointed me to the Open Group's docs. I didn't know the docs were available on-line. Complex functions are confined to complex.h. I suppose we need to implement complex.h, but I'll probably concentrate on math.h. -- Steve To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-current" in the body of the message
