[Bug rtl-optimization/98782] [11/12 Regression] Bad interaction between IPA frequences and IRA resulting in spills due to changes in BB frequencies

["tnfchris at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98782

--- Comment #25 from Tamar Christina <tnfchris at gcc dot gnu.org> ---
(In reply to hubicka from comment #24)
> > Awesome! thanks!
> > 
> > I wonder if we can get rid of the final magic parameter too, we run with
> > --param ipa-cp-unit-growth=80 too which seems to have no more effect on
> > exchange, though still a slight effect on leela but a 12% gain in imagick.
> 
> Interesting - this is Martin Jambor's area but I do not think we was
> aware of this.  I wonder how bug growth is really needed - 80% is quite
> a lot especially if imagemagick is already big binary.  Is this about
> LTO or non-LTO build?

It's with LTO, I'll see if non-LTO has the same benefit.  In terms of code-size
it looks like it accounts for a 20% increase for binary size, but the hot
function shrinks approx 6x. But of course this increase covers the entire
binaries and there are other hot functions like GetVirtualPixelsFromNexus that
also shrink significantly when specialized.