[PATCH] Optimize logarithm addition and subtraction

[MCC CS]

> Sent: Sunday, August 05, 2018 at 8:17 PM
> From: "Marc Glisse" <marc.glisse@inria.fr>
> To: "MCC CS" <mcccs@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))