[Bug math/6794] New: ilogb() does not raise exceptions or set errno on domain errors

["mtk dot manpages at gmail dot com" <sourceware-bugzilla at sourceware dot org>]

The POSIX.1 specification of ilogb() says:

==
Domain Error
    The x argument is zero, NaN, or ±Inf, or the correct value is not
representable as an integer.

    If the integer expression (math_errhandling & MATH_ERRNO) is non-zero, then
errno shall be set to [EDOM]. If the integer expression (math_errhandling &
MATH_ERREXCEPT) is non-zero, then the invalid floating-point exception shall be
raised
==

However, in all of the above cases, errno is not set on error, and in some of
the cases, no exceptions is raised.  In all cases errno should be set to EDOM
and an FE_INVALID exception should be raised.


Background: 
On error, many glibc math functions both set errno and raise an exception
(fetestexcept(3)).  For example, the following  function all do this: acos(),
asin(), cosh(), sinh(), acosh(), asinh(), exp(), exp2(), ldexp(), log(),
log10(), log2().  However, there is much inconsistency.  Some functions raise an
exception, but don't set errno.  Some functions set errno for some errors, but
not others.  A few set errno, but don't raise an exception.  This series of bug
reports documents deviations from what I consider the ideal: all functions
should BOTH set errno AND raise an exception for all errors.

All of these reports relate to tests on glibc 2.8 (as provided by SUSE 11.0).

-- 
           Summary: ilogb() does not raise exceptions or set errno on domain
                    errors
           Product: glibc
           Version: unspecified
            Status: NEW
          Severity: normal
          Priority: P2
         Component: math
        AssignedTo: aj at suse dot de
        ReportedBy: mtk dot manpages at gmail dot com
                CC: glibc-bugs at sources dot redhat dot com


http://sourceware.org/bugzilla/show_bug.cgi?id=6794

------- You are receiving this mail because: -------
You are on the CC list for the bug, or are watching someone who is.