[Bug bootstrap/52391] [4.7/4.8 regression] genattrtab almost 5X slower for m68k than in 4.6 and earlier releases

[steven at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52391

--- Comment #13 from Steven Bosscher <steven at gcc dot gnu.org> 2012-05-05 10:13:48 UTC ---
Created attachment 27316
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=27316
Difference in insn-attrtab.c before/after applyin
PR52391_compare_IOP_tree_v1.diff

tmp-attrtab.c is *with* the patch applied, insn-attrtab.c is without patch, for
GCC trunk at r186902.

Typical difference:

$ grep m68k_sched_branch_type v1_insn-attrtab.diff | grep "^\-" | wc
    116     464    4524
$ grep m68k_sched_branch_type v1_insn-attrtab.diff | grep "^\+" | wc
   2360    9440   92040

If someone could help interpret the differences, I'd be very grateful. With or
without patch, insn-attrtab is a monster...