View Bug Activity | Format For Printing
exp10() correctly raises exceptions for overflow and underflow. However, errno is only set to ERANGE for the overflow case. For underflow, it is not set. It should also be set to ERANGE in the latter case. Note also that exp10() is inconsistent with exp2() and exp(), both of which always set errno for bother underflow and overflow. 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).
Created an attachment (id=2852) test program Sample run showing problem. Note that errno is set for overflow, but not for underflow. $ /tmp/mt_exp10 -- -1e5 errno == 0 fetestexcept() says: FE_UNDERFLOW FE_INEXACT exp10(-1.00000000000000000e+05)=0.00000000000000000e+00 0 FE_UNDERFLOW +0 $ /tmp/mt_exp10 -- 1e5 errno == ERANGE fetestexcept() says: FE_OVERFLOW FE_INEXACT exp10(1.00000000000000000e+05)=inf ERANGE FE_OVERFLOW +inf