On Wed, Mar 7, 2012 at 11:11 AM, Richard Sandiford
> Jakub Jelinek <ja...@redhat.com> writes:
>> On Wed, Mar 07, 2012 at 09:52:51AM +0000, Richard Sandiford wrote:
>>> This patch restores x86_64-linux-gnu bootstrap after my patch for 52372.
>>> Applied as obvious.
>>> Sorry for the breakage.
>> Was it really necessary to move these out of the global rtx array?
>> Now you completely unnecessarily have 4 new GTY roots with all the overhead
>> it has. Wouldn't just moving their initialization elsewhere be sufficient?
> It had to be outside the "global" array, because that's a per-target thing.
> E.g. MIPS16 and non-MIPS16 have separate target_rtl structures, but ought
> to have the same pc_rtx (just as they ought to have the same const0_rtx, etc.)
> I hadn't realised that the overhead of 4 roots was much greater than the
> overhead of one root pointing to a 4-element array. We could have a new
> 4-element array if that's a problem.
Why can't you put the same RTXen in the per-target rtl structures?