[Bug middle-end/54827] New: [4.8 Regression] 70% compile time regression building builtin-sched.c from Linux's perf

["markus at trippelsdorf dot de" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54827

             Bug #: 54827
           Summary: [4.8 Regression] 70% compile time regression building
                    builtin-sched.c from Linux's perf
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: markus@trippelsdorf.de


With gcc-4.7.2 I get:

 % time gcc -c -O3 -g builtin-sched.i
gcc -c -O3 -g builtin-sched.i  12.63s user 0.02s system 99% cpu 12.690 total

With current trunk:

 % time gcc -c -O3 -g  builtin-sched.i
gcc -c -O3 -g builtin-sched.i  40.54s user 0.03s system 99% cpu 40.703 total

perf report shows:
    54.58%      cc1  cc1                         [.] find_base_term(rtx_def*)
     8.02%      cc1  cc1                         [.]
ix86_find_base_term(rtx_def*)
     3.55%      cc1  cc1                         [.]
rtx_equal_for_memref_p(rtx_def const*, rtx_def const*)
     2.91%      cc1  cc1                         [.] true_dependence_1(rtx_def
const*, machine_mode, rtx_def*, rtx_def const*, rtx_def*, bool)
     2.79%      cc1  cc1                         [.] memrefs_conflict_p(int,
rtx_def*, int, rtx_def*, long)
     2.77%      cc1  cc1                         [.] exp_equiv_p(rtx_def
const*, rtx_def const*, int, bool)
     2.01%      cc1  cc1                         [.] for_each_rtx_1(rtx_def*,
int, int (*)(rtx_def**, void*), void*)
     1.76%      cc1  cc1                         [.] rtx_equal_p(rtx_def
const*, rtx_def const*)

-ftime-report:
Execution times (seconds)
 phase setup             :   0.01 ( 0%) usr   0.00 ( 0%) sys   0.01 ( 0%) wall 
  1101 kB ( 3%) ggc
 phase parsing           :   0.07 ( 0%) usr   0.07 (70%) sys   0.14 ( 0%) wall 
 13463 kB (32%) ggc
 phase opt and generate  :  39.64 (100%) usr   0.03 (30%) sys  39.79 (100%)
wall   26000 kB (62%) ggc
...
 variable tracking       :   1.58 ( 4%) usr   0.00 ( 0%) sys   1.57 ( 4%) wall 
  1210 kB ( 3%) ggc
 var-tracking dataflow   :  13.68 (34%) usr   0.00 ( 0%) sys  13.71 (34%) wall 
   107 kB ( 0%) ggc
 var-tracking emit       :  14.20 (36%) usr   0.00 ( 0%) sys  14.26 (36%) wall 
   435 kB ( 1%) ggc
...
 TOTAL                 :  39.74             0.10            39.96             
41799 kB