[Bug rtl-optimization/48721] New: [4.6/4.7 Regression] ICE: verify_flow_info failed: missing barrier after block 6 with -foptimize-sibling-calls -fsched2-use-superblocks

[Bug rtl-optimization/48721] New: [4.6/4.7 Regression] ICE: verify_flow_info failed: missing barrier after block 6 with -foptimize-sibling-calls -fsched2-use-superblocks

[zsojka at seznam dot cz]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48721

           Summary: [4.6/4.7 Regression] ICE: verify_flow_info failed:
                    missing barrier after block 6 with
                    -foptimize-sibling-calls -fsched2-use-superblocks
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: rtl-optimization
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: zsojka@seznam.cz
              Host: x86_64-pc-linux-gnu
            Target: x86_64-pc-linux-gnu


Created attachment 24070
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=24070
reduced testcase

Compiler output:
$ gcc -O -foptimize-sibling-calls -fsched2-use-superblocks -fschedule-insns2
-mtune=core2 testcase.c 
testcase.c: In function 'internal_state_transition':
testcase.c:73:1: error: missing barrier after block 6
testcase.c:73:1: internal compiler error: verify_flow_info failed
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.

Tested revisions:
r172826 - crash
4.6 r172337 - crash
4.5 r172337 - crash

[Bug rtl-optimization/48721] [4.6/4.7 Regression] ICE: verify_flow_info failed: missing barrier after block 6 with -foptimize-sibling-calls -fsched2-use-superblocks

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48721

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.6.1

[Bug rtl-optimization/48721] [4.6/4.7 Regression] ICE: verify_flow_info failed: missing barrier after block 6 with -foptimize-sibling-calls -fsched2-use-superblocks

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48721

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P2

[Bug rtl-optimization/48721] [4.6/4.7 Regression] ICE: verify_flow_info failed: missing barrier after block 6 with -foptimize-sibling-calls -fsched2-use-superblocks

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48721

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.6.1                       |4.6.2

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-06-27 12:32:42 UTC ---
GCC 4.6.1 is being released.

[Bug rtl-optimization/48721] [4.6 Regression] ICE: verify_flow_info failed: missing barrier after block 6 with -foptimize-sibling-calls -fsched2-use-superblocks

[ubizjak at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48721

Uros Bizjak <ubizjak at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|                            |4.7.0
            Summary|[4.6/4.7 Regression] ICE:   |[4.6 Regression] ICE:
                   |verify_flow_info failed:    |verify_flow_info failed:
                   |missing barrier after block |missing barrier after block
                   |6 with                      |6 with
                   |-foptimize-sibling-calls    |-foptimize-sibling-calls
                   |-fsched2-use-superblocks    |-fsched2-use-superblocks
      Known to fail|4.7.0                       |

--- Comment #2 from Uros Bizjak <ubizjak at gmail dot com> 2011-08-01 08:27:01 UTC ---
Compiles OK with gcc 4.7.0 20110801 (experimental) [trunk revision 176998].

[Bug rtl-optimization/48721] [4.6/4.7 Regression] ICE: verify_flow_info failed: missing barrier after block 6 with -foptimize-sibling-calls -fsched2-use-superblocks

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48721

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|4.7.0                       |
            Summary|[4.6 Regression] ICE:       |[4.6/4.7 Regression] ICE:
                   |verify_flow_info failed:    |verify_flow_info failed:
                   |missing barrier after block |missing barrier after block
                   |6 with                      |6 with
                   |-foptimize-sibling-calls    |-foptimize-sibling-calls
                   |-fsched2-use-superblocks    |-fsched2-use-superblocks
      Known to fail|                            |4.7.0

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> 2011-08-25 00:52:24 UTC ---
Fails for me with 4.7.0  20110823 (experimental) [trunk revision 178018]
(x86_64-unknown-linux-gnu).

gcc -O -foptimize-sibling-calls -fsched2-use-superblocks -fschedule-insns2
-mtune=core2 t.c

Note the tune at the end.

[Bug rtl-optimization/48721] [4.6/4.7 Regression] ICE: verify_flow_info failed: missing barrier after block 6 with -foptimize-sibling-calls -fsched2-use-superblocks

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48721

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2011-08-25
     Ever Confirmed|0                           |1

[Bug rtl-optimization/48721] [4.6/4.7 Regression] ICE: verify_flow_info failed: missing barrier after block 6 with -foptimize-sibling-calls -fsched2-use-superblocks

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48721

--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> 2011-08-25 01:39:51 UTC ---
begin_move_insn is not creating the needed barrier.

[Bug rtl-optimization/48721] [4.6/4.7 Regression] ICE: verify_flow_info failed: missing barrier after block 6 with -foptimize-sibling-calls -fsched2-use-superblocks

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48721

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.6.2                       |4.6.3

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-10-26 17:13:26 UTC ---
GCC 4.6.2 is being released.

[Bug rtl-optimization/48721] [4.6/4.7 Regression] ICE: verify_flow_info failed: missing barrier after block 6 with -foptimize-sibling-calls -fsched2-use-superblocks

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48721

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jakub at gcc dot gnu.org

--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-11-30 12:45:14 UTC ---
Slightly reduced testcase:

/* PR rtl-optimization/48721 */
/* { dg-do compile } */
/* { dg-options "-O -foptimize-sibling-calls -fsched2-use-superblocks
-fschedule-insns2 -mtune=core2" } */

extern unsigned char a[];
extern int b[], d[], e[], f[], g[], *h[], m[], *n[], o[];
extern char c[];

struct S
{
  unsigned char s1;
  int s2, s3, s4, s5, s6, s7, s8;
};

__attribute__((noinline, noclone)) int
foo (int x)
{
  return 0;
}

int
bar (int x, struct S *y)
{
  int z;
  switch (x)
    {
    case 1:
    case 2:
      {
    int t2, t4, t5, t6, t7, t8;
    z = o[y->s8 * 6];
    t8 = *n[m[x] * 5];
    t4 = *h[y->s7];
    t7 = z;
    z = g[f[x] + y->s6];
    t6 = e[y->s5];
    t5 = d[c[x] + y->s3 * 17];
    if (z)
      t2 = b[z];
    if (a[z] != y->s1)
      return foo (x);
    y->s8 = t8;
    y->s4 = t4;
    y->s7 = t7;
    y->s6 = t6;
    y->s5 = t5;
    y->s2 = t2;
      }
    }
  return 0;
}

[Bug rtl-optimization/48721] [4.6/4.7 Regression] ICE: verify_flow_info failed: missing barrier after block 6 with -foptimize-sibling-calls -fsched2-use-superblocks

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48721

--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-11-30 12:51:35 UTC ---
Created attachment 25951
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=25951
gcc47-pr48721.patch

begin_move_insn can be easily fixed, the question is why we try to schedule the
tail call insn over the restore of r12, which is a call saved register and
therefore has to be restored.

[Bug rtl-optimization/48721] [4.6/4.7 Regression] ICE: verify_flow_info failed: missing barrier after block 6 with -foptimize-sibling-calls -fsched2-use-superblocks

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48721

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |vmakarov at gcc dot gnu.org

--- Comment #8 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-11-30 12:55:15 UTC ---
Vlad, could you please look at that?

[Bug rtl-optimization/48721] [4.6/4.7 Regression] ICE: verify_flow_info failed: missing barrier after block 6 with -foptimize-sibling-calls -fsched2-use-superblocks

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48721

--- Comment #9 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-11-30 13:21:59 UTC ---
Created attachment 25952
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=25952
gcc47-pr48721.patch

Perhaps we should just consider tail calls as full barriers like asm volatile
etc., scheduling some insn after them doesn't make much sense, that is just a
fancy way of removing them and I'd hope that insn removal is the job of DCE and
similar optimizations, but not of the scheduler.

[Bug rtl-optimization/48721] [4.6/4.7 Regression] ICE: verify_flow_info failed: missing barrier after block 6 with -foptimize-sibling-calls -fsched2-use-superblocks

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48721

--- Comment #10 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-11-30 18:53:50 UTC ---
Author: jakub
Date: Wed Nov 30 18:53:46 2011
New Revision: 181855

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=181855
Log:
    PR rtl-optimization/48721
    * sched-ebb.c (begin_move_insn): Insert empty unreachable
    block after BARRIER if insn is followed by it.

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

[Bug rtl-optimization/48721] [4.6/4.7 Regression] ICE: verify_flow_info failed: missing barrier after block 6 with -foptimize-sibling-calls -fsched2-use-superblocks

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48721

--- Comment #11 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-11-30 18:58:36 UTC ---
Author: jakub
Date: Wed Nov 30 18:58:33 2011
New Revision: 181856

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=181856
Log:
    PR rtl-optimization/48721
    * sched-deps.c (sched_analyze_insn): For SIBLING_CALL_P set
    reg_pending_barrier to TRUE_BARRIER.

    * gcc.target/i386/pr48721.c: New test.

Added:
    trunk/gcc/testsuite/gcc.target/i386/pr48721.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/sched-deps.c
    trunk/gcc/testsuite/ChangeLog

[Bug rtl-optimization/48721] [4.6 Regression] ICE: verify_flow_info failed: missing barrier after block 6 with -foptimize-sibling-calls -fsched2-use-superblocks

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48721

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
      Known to work|                            |4.7.0
         AssignedTo|unassigned at gcc dot       |jakub at gcc dot gnu.org
                   |gnu.org                     |
            Summary|[4.6/4.7 Regression] ICE:   |[4.6 Regression] ICE:
                   |verify_flow_info failed:    |verify_flow_info failed:
                   |missing barrier after block |missing barrier after block
                   |6 with                      |6 with
                   |-foptimize-sibling-calls    |-foptimize-sibling-calls
                   |-fsched2-use-superblocks    |-fsched2-use-superblocks
      Known to fail|4.7.0                       |

--- Comment #12 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-11-30 20:07:12 UTC ---
Fixed on the trunk so far.

[Bug rtl-optimization/48721] [4.6 Regression] ICE: verify_flow_info failed: missing barrier after block 6 with -foptimize-sibling-calls -fsched2-use-superblocks

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48721

--- Comment #13 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-12-08 13:34:02 UTC ---
Author: jakub
Date: Thu Dec  8 13:33:58 2011
New Revision: 182111

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=182111
Log:
    Backport from mainline
    2011-11-30  Jakub Jelinek  <jakub@redhat.com>

    PR rtl-optimization/48721
    * sched-deps.c (sched_analyze_insn): For SIBLING_CALL_P set
    reg_pending_barrier to TRUE_BARRIER.

    * gcc.target/i386/pr48721.c: New test.

Added:
    branches/gcc-4_6-branch/gcc/testsuite/gcc.target/i386/pr48721.c
Modified:
    branches/gcc-4_6-branch/gcc/ChangeLog
    branches/gcc-4_6-branch/gcc/sched-deps.c
    branches/gcc-4_6-branch/gcc/testsuite/ChangeLog

[Bug rtl-optimization/48721] [4.6 Regression] ICE: verify_flow_info failed: missing barrier after block 6 with -foptimize-sibling-calls -fsched2-use-superblocks

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48721

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

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

--- Comment #14 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-12-08 13:42:18 UTC ---
Fixed.