Synopsis: [libm] fma(3) does not respect rounding mode using extended precision
State-Changed-From-To: open->closed State-Changed-By: das State-Changed-When: Fri Dec 3 07:01:28 UTC 2010 State-Changed-Why: Thanks for the report! This limitation is described in the source for fma(), and unfortunately, it is unlikely to ever change. There are several reasons: - We are a long way from having the necessary compiler support to make dynamic precision changes work as expected. - Dynamic FPU precision changes aren't officially supported, and fpsetprec() has been documented as deprecated for many years. - The only supported architecture that can have this problem due to dynamic precision changes is i386, and even then only for non-SSE2 builds. - The cost and complexity associated with making every function in libm detect and adapt to dynamic precision changes is prohibitive. I have updated the manpage for fpsetprec() to explain that changing the FPU precision isn't supported by the compiler or libraries. http://www.freebsd.org/cgi/query-pr.cgi?pr=133583 _______________________________________________ freebsd-bugs@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-bugs To unsubscribe, send any mail to "freebsd-bugs-unsubscr...@freebsd.org"
