[Bug target/52941] SH Target: Add support for movco.l / movli.l atomics on SH4A

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

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52941

--- Comment #7 from Oleg Endo <olegendo at gcc dot gnu.org> 2012-04-17 00:03:19 UTC ---
Created attachment 27173
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=27173
Proposed patch

(In reply to comment #6)
> The patch looks just fine.  I don't mind whether those atomics are
> fully optimized or not ATM.  Programs having atomics in the minor
> loop are pathological in the first place, I think.

I was also concerned about the code size in sync.md...
Anyway, how about the attached patch instead?  It now should do all atomics for
-mhard-atomic.  
I've scrapped the LUT and whatnot and the code size (both generated and in the
compiler) now looks more reasonable.  Only one thing ... is it safe to do the
"@-r15", "@+r15" stuff in the atomic sequence?  I remember there were some
border cases where things would blow up, but can't recall.  I've also briefly
checked with atomic vars being on the stack and it looks OK.