[Bug target/40419] __attribute__((mips16)) is broken on trunk.

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

------- Comment #3 from rsandifo at gcc dot gnu dot org  2010-06-05 07:27 -------
Kenny, I too don't like target_reinit, and FWIW
I fought the same battle before the patch was submitted.
The argument then, and I suspect the argument now,
is that although the function is horribly inefficient,
it still performs a useful function.  The best way of
making it efficient (the argument goes) is to gradually
wean GCC off using global variables for target-specific
stuff.  And as that happens, target_reinit would get
quicker for all targets.

As I remember it, even those supporting target_reinit
didn't really _like_ the thing, but simply accepted
it as the best we could do without major restructuring.

As far as the IRA thing goes: as we talked about elsewhere,
that's simply a bug.  target_reinit should call ira_init.
(Remember that target_reinit predates IRA, so this certainly
isn't the fault of anyone on the "target_reinit side".
It's just one of those things that happens, and needs
to be fixed when the problem shows up.)

What you're doing is probably fine for your port,
but other targets (like MIPS for the MIPS16 switch)
need to do more than modify registers.  Things like
rtx costs change too, and those costs are cached
in various global variables.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40419