http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50880
--- Comment #5 from Richard B. Kreckel <kreckel at ginac dot de> 2011-10-28 07:06:57 UTC --- On 10/27/2011 11:24 AM, paolo.carlini at oracle dot com wrote: > Thus, to understand and clarify why this has not been noticed so far, you are > on a target which doesn't support in the underlying C library these complex > functions, right? Because normally (eg, on Linux) these days we just forward > to > __builtin_cacosh*, the code you are touching is just a "surrogate", a > "fallback", which doesn't get right all the special cases, NaNs, infinity. Well, I didn't "notice" it. Searching for bugs involving branch cut positions of inverse trig functions in a range of FOSS projects is a pet project of mine. ;-) BTW: I noticed that my patch tests if (__z.real() < -0.0), which is correct, but the sign of zero looks eccentric and might potentially confuse future readers. I suggest removing it. It doesn't matter at all, anyhow.
