[Bug target/63679] [5 Regression][AArch64] Failure to constant fold.

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63679

--- Comment #29 from Tejas Belagod <belagod at gcc dot gnu.org> ---
(In reply to rguenther@suse.de from comment #28)
> On Mon, 9 Feb 2015, belagod at gcc dot gnu.org wrote:
> 
> > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63679
> > 
> > --- Comment #27 from Tejas Belagod <belagod at gcc dot gnu.org> ---
> > We'd want to scalarize this early preferably in SRA as it gives a chance to
> > passes like vectorization to vectorize more loops. I checked that
> > sra-max-scalarization-Osize{-Ospeed} had no effect on scalarizing 'a = *.LC0'
> 
> because SRA can't scalarize 'a = *.LC0'.  But yes, ideally we'd change
> gimplification to never decompose initializers but have SRA do it.
> But that's of course not a GCC 5 thing.
> 
> It has the advantage of splitting the initialization only when it is
> (likely) profitable and otherwise leave it to the target to decide
> how to expand the initialization (and it opens up the possibility
> to directly use a constant-pool entry if the data is readonly).

Which cost function(s) control this profitability of early splitting?