[Bug rtl-optimization/52715] New: [4.8 Regression] ICE: in reset_sched_cycles_in_current_ebb, at sel-sched.c:7140 with -fselective-scheduling2 -funroll-loops --param=max-average-unrolled-insns=406

[Bug rtl-optimization/52715] New: [4.8 Regression] ICE: in reset_sched_cycles_in_current_ebb, at sel-sched.c:7140 with -fselective-scheduling2 -funroll-loops --param=max-average-unrolled-insns=406

[zsojka at seznam dot cz]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52715

             Bug #: 52715
           Summary: [4.8 Regression] ICE: in
                    reset_sched_cycles_in_current_ebb, at sel-sched.c:7140
                    with -fselective-scheduling2 -funroll-loops
                    --param=max-average-unrolled-insns=406
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: rtl-optimization
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: zsojka@seznam.cz


Created attachment 26986
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=26986
reduced testcase

Compiler output:
$ gcc -O2 -fno-omit-frame-pointer -fprefetch-loop-arrays -fno-rename-registers
-fsel-sched-pipelining -fselective-scheduling2 -funroll-loops
--param=max-average-unrolled-insns=406 testcase.c         
testcase.c: In function 'CRYPTO_cbc128_decrypt':
testcase.c:19:1: internal compiler error: in reset_sched_cycles_in_current_ebb,
at sel-sched.c:7140
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.

Tested revisions:
r185773 - crash
4.7 r185191 - OK

[Bug rtl-optimization/52715] [4.8 Regression] ICE: in reset_sched_cycles_in_current_ebb, at sel-sched.c:7140 with -fselective-scheduling2 -funroll-loops --param=max-average-unrolled-insns=406

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52715

Richard Guenther <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.8.0

[Bug rtl-optimization/52715] [4.8 Regression] ICE: in reset_sched_cycles_in_current_ebb, at sel-sched.c:7140 with -fselective-scheduling2 -funroll-loops --param=max-average-unrolled-insns=406

[abel at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52715

Andrey Belevantsev <abel at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2012-03-26
         AssignedTo|unassigned at gcc dot       |abel at gcc dot gnu.org
                   |gnu.org                     |
     Ever Confirmed|0                           |1

--- Comment #1 from Andrey Belevantsev <abel at gcc dot gnu.org> 2012-03-26 12:26:53 UTC ---
Sigh.  Of course optimizing calculation of whether an insn change the state as
in PR 52203 was wrong, one needs to calculate this right before actually
scheduling the insn as the state may change.  Thus, reverting the fix for 52203
and doing the below instead is not only safe but correct:

diff --git a/gcc/sel-sched.c b/gcc/sel-sched.c
index 2829f60..f5ae9817 100644
--- a/gcc/sel-sched.c
+++ b/gcc/sel-sched.c
@@ -7127,8 +7124,14 @@ reset_sched_cycles_in_current_ebb (void)

       if (real_insn)
        {
+         static state_t temp = NULL;
+
+         if (!temp)
+           temp = xmalloc (dfa_state_size);
+         memcpy (temp, curr_state, dfa_state_size);
+
          cost = state_transition (curr_state, insn);
-         if (!empty)
+         if (memcmp (temp, curr_state, dfa_state_size))
            issued_insns++;

           if (sched_verbose >= 2)

[Bug rtl-optimization/52715] [4.8 Regression] ICE: in reset_sched_cycles_in_current_ebb, at sel-sched.c:7140 with -fselective-scheduling2 -funroll-loops --param=max-average-unrolled-insns=406

[abel at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52715

--- Comment #2 from Andrey Belevantsev <abel at gcc dot gnu.org> 2012-04-13 09:36:47 UTC ---
Author: abel
Date: Fri Apr 13 09:36:42 2012
New Revision: 186410

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=186410
Log:
        PR rtl-optimization/52203
        PR rtl-optimization/52715

        Revert the 2012-03-07 fix for PR 52203.
        * sel-sched.c (reset_sched_cycles_in_current_ebb): Check that
        the insn does not modify DFA right before issuing, adjust
        issue_rate accordingly.


Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/sel-sched.c

[Bug rtl-optimization/52715] [4.8 Regression] ICE: in reset_sched_cycles_in_current_ebb, at sel-sched.c:7140 with -fselective-scheduling2 -funroll-loops --param=max-average-unrolled-insns=406

[abel at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52715

Andrey Belevantsev <abel at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED

--- Comment #3 from Andrey Belevantsev <abel at gcc dot gnu.org> 2012-04-17 11:14:48 UTC ---
Fixed on trunk, good on 4.7 as well as the wrong fix was never backported
there.