Yes, I think so. Regards, Wei.
On Wed, Jun 19, 2013 at 2:00 PM, Xinliang David Li <davi...@google.com> wrote: > Should the patch be ported to in 48 branch? > > thanks, > > David > > On Wed, Jun 19, 2013 at 11:46 AM, Vladimir Makarov <vmaka...@redhat.com> > wrote: >> On 13-06-19 1:23 AM, Wei Mi wrote: >>> >>> Ping. >>> >>> On Wed, Jun 12, 2013 at 2:44 PM, Wei Mi <w...@google.com> wrote: >>>> >>>> Hi, >>>> >>>> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57518 >>>> >>>> pr57518 happened because update_equiv_regs in IRA marked a reg >>>> equivalent with a mem, lowered its mem_cost in scan_one_insn, set >>>> NO_REGS to its rclass, but didn't consider the reg was used in >>>> paradoxical subreg which prevented the reg from being replaced by mem >>>> in LRA phase. >>>> >>>> This patch is to check whether a reg is used in a paradoxical subreg >>>> in update_equiv_regs before reg is set as equivalent to a mem. >>>> >>>> bootstrap and regression test on x86_64-linux-gnu ok. Is it ok for >>>> trunk and gcc-4.8 branch? >>>> >>>> >> Thanks for working on this PR, Wei, and sorry for the delay with the answer >> (I was on vacation). >> >> In general, the PR analysis and the proposed solution looks ok. I only >> worry that you are adding additional full scan of all RTL code. It might >> add 0.5% to GCC compilation time if data cache is rewritten (which will >> happen for moderate size or big functions). It would be nice to do it on >> some other existing RTL traversing. Unfortunately, this info is calculated >> later (reg_max_width in reload or biggest_mode in LRA). I am in doubt that >> other solutions I see now are better: >> >> o calculate this info in regstat_... function and store it in reg_info_p >> o calculate it with update_equiv_regs and use it for invalidation the >> equiv info later >> >> The first one increases reg_info_p footprint and calculation is done many >> times although it is used once. >> The second one results in complicated code. >> >> So I think the current patch is ok to commit. >> >> Thanks, again. >> >> >>
