[Bug c/14621] libm tan failure for pi/2 argument

[bangerth at dealii dot org]

------- Additional Comments From bangerth at dealii dot org  2004-03-17 21:18 -------
Of course tan(pi/2) is infinite. However, M_PI_2!=pi/2 (the former 
being a finite precision floating point number, the latter a 
transcendental non-rational number; it should be obvious from 
these characterizations that there is no way they are equal). 
 
That a range error _may_ occur is not a mandate that it _must_ occur. 
In particular, the man pages on linux do not say anything about setting 
errno at all. And still, even if they did, the implementation of tan() 
is not under the control of gcc, but is part of libc. Please complain 
to them if you still believe that you are right. You better guard against 
people citing the C99 standard, though, which also does not say anything 
about errno in section 7.12.4.7. 
 
W. 

-- 
           What    |Removed                     |Added
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             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |INVALID


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14621