[Bug rtl-optimization/52543] lower-subreg.c: code bloat of 300%-400% for multi-word memory splits

[olegendo at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52543

--- Comment #14 from Oleg Endo <olegendo at gcc dot gnu.org> 2012-09-06 22:13:22 UTC ---
(In reply to comment #0)
>  
> For the __flash address space no preparation is needed, but a 32-bit read can
> use post-increment addressing whereas a split to 4 byte moves won't use
> post-increment because GCC is completely afraid of pre-/post-modify addressing.
> 

BTW, the reason for the auto-inc-dec problem is described in PR 50749.
I've started writing a replacement for the auto-inc-dec pass, but it will take
some time.