------- Comment #11 from carlos at codesourcery dot com 2009-04-21 20:16 ------- Yes, if gcc does not determine that "sizeof (x) == sizeof (double)" then it would have to emit code for the if-then-else statement and this would create a reference to an undefined __signbitl. Has this ever happened? I've never seen it.
At present glibc does not create an long double alias for the double __signbit function, but for the sake of correctness it probably should. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39491
