> Sent: Sunday, August 05, 2018 at 8:17 PM > From: "Marc Glisse" <marc.gli...@inria.fr> > To: "MCC CS" <mc...@gmx.com> > Cc: gcc-patches@gcc.gnu.org > Subject: Re: [PATCH] Optimize logarithm addition and subtraction > > On Sun, 5 Aug 2018, MCC CS wrote: > > > this patch reduces calls to logarithm functions by > > merging log a + log b => log a*b and > > this makes sense. > > > + /* x * logN(a) + y * logN(b) -> x * y * logN(a * b). */ > > this on the other hand... Can you explain the math? > > -- > Marc Glisse >
Oops, please ignore the patch at the top and review the second patch. I must have done A mistake somewhere. It's actually x * y * log(a^(1/y)b^(1/x))
