On 04/03/24 14:52, Alejandro Colomar wrote: > Hi Morten, > > On Thu, Feb 29, 2024 at 07:28:10PM -0500, Morten Welinder wrote: >> I came across some minor issues in some math man pages. >> >> M. >> >> >> >> logb: >> The formula "floor(log2(x))" should be "floor(log2(fabs(x)))". (Or >> ...abs(...) if it's meant to be math and not C.) > > Confirmed. This is a bug in glibc too, BTW. That text seems to be > copied from their manual. > > ISO C says this function is specified in ANSI/IEEE 854, but I don't have > access to that document, so I'm not sure what's the specification of the > function. I'm not sure if it should fail for negative values (like > log2(3)) or not; although the standard mentions the behavior for > negative infinity, so it probably is specified to work for negative > values too. > > So, the behavior of the function seems to be correct, and it's just the > manual that needs to be fixed. > > I've CCed glibc, in case they want to comment. But yeah, your > suggestion seems correct. It does seems to be an error on manual, could you send a patch to fix it?
