On 5/4/19 6:21 PM, Giuliano Belinassi wrote: > Hi > > On 04/30, Jeff Law wrote: >> On 4/30/19 8:00 AM, Jakub Jelinek wrote: >>> On Tue, Apr 30, 2019 at 07:57:20AM -0600, Jeff Law wrote: >>>>> Just curious, do we want to add math identities like above to match.pd ? >>>> I'd think so. >>>> >>>> >>>>> In practice, I am not sure how often we'd see "tanh * cosh" instead >>>>> of sinh directly in source, >>>> We're often surprised when what ultimately shows up in sources :-) And >>>> a transformation that allows us to turn two transcendentals and a >>>> multiplication into a single transcendental is going to be a big win. >>> > > I wonder why these kind of optimization are not in the EasyHacks page. I doubt anyone has really thought about them. It's certainly appropriate to add more stuff to that page ;-)
> It is somewhat easy to add it and can give huge performance > improvements. Agreed. > > There is a blogpost that I wrote about the previous patches I submitted > here. I tried to be didadic, discussing from the mathematical > standpoint, to floating point numbers, and GCC implementation. > Although there may be several english errors, I think it is still > useful: > > https://flusp.ime.usp.br/gcc/2019/03/26/making-gcc-optimize-some-trigonometric-functions/ Thanks. It's funny you mention high school math, I had to do a fair amount of refreshing when we were working on your patches ;-) jeff
