[Bug tree-optimization/46494] New: [4.3/4.4/4.5/4.6 Regression] ICE: verify_flow_info failed when casting-out attribute noreturn with -fno-tree-ccp -fno-tree-fre -ftree-vrp

[Bug tree-optimization/46494] New: [4.3/4.4/4.5/4.6 Regression] ICE: verify_flow_info failed when casting-out attribute noreturn with -fno-tree-ccp -fno-tree-fre -ftree-vrp

[zsojka at seznam dot cz]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46494

           Summary: [4.3/4.4/4.5/4.6 Regression] ICE: verify_flow_info
                    failed when casting-out attribute noreturn with
                    -fno-tree-ccp -fno-tree-fre -ftree-vrp
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: zsojka@seznam.cz
              Host: x86_64-pc-linux-gnu
            Target: x86_64-pc-linux-gnu


Created attachment 22416
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=22416
reduced testcase

+++ This bug was initially created as a clone of Bug #46165 +++

The testcase for PR46165 fails at least in 4.4, 4.5 and 4.6 with following
message:

Compiler output:
$ gcc -O -fno-tree-ccp -fno-tree-fre -ftree-vrp testcase.c 
testcase.c: In function 'g':
testcase.c:2:6: error: control flow in the middle of basic block 2
testcase.c:2:6: 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:
r166763 - crash
4.5 r166509 - crash
4.4 r166509 - crash

The original bisect shown it might be caused by r119657, so I am leaving the
4.3 regression mark.

[Bug tree-optimization/46494] [4.3/4.4/4.5/4.6 Regression] ICE: verify_flow_info failed when casting-out attribute noreturn with -fno-tree-ccp -fno-tree-fre -ftree-vrp

[hjl.tools at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46494

H.J. Lu <hjl.tools at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2010.11.16 01:32:45
     Ever Confirmed|0                           |1

--- Comment #1 from H.J. Lu <hjl.tools at gmail dot com> 2010-11-16 01:32:45 UTC ---
I verified that revision 119657 is the trigger.

[Bug tree-optimization/46494] [4.3/4.4/4.5/4.6 Regression] ICE: verify_flow_info failed when casting-out attribute noreturn with -fno-tree-ccp -fno-tree-fre -ftree-vrp

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46494

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.3.6

[Bug tree-optimization/46494] [4.3/4.4/4.5/4.6 Regression] ICE: verify_flow_info failed when casting-out attribute noreturn with -fno-tree-ccp -fno-tree-fre -ftree-vrp

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46494

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

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

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> 2010-11-22 15:01:42 UTC ---
In vrp the problem is just that loop_optimizer_finalize (unnecessarily) calls
verify_flow_info.  VRP already has TODO_cleanup_cfg and loop_optimizer_finalize
is the last thing done in execute_vrp, so the cfg will be properly cleaned up.

I'd say a fix could be if we had an argument to loop_optimizer_finalize whether
to do flow verification or not, and pass 0 here in vrp, perhaps other places
too.

[Bug tree-optimization/46494] [4.3/4.4/4.5/4.6 Regression] ICE: verify_flow_info failed when casting-out attribute noreturn with -fno-tree-ccp -fno-tree-fre -ftree-vrp

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46494

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |ice-checking
           Priority|P3                          |P2

--- Comment #3 from Richard Guenther <rguenth at gcc dot gnu.org> 2010-11-25 16:02:19 UTC ---
Make it return a TODO instead.  Of course the

#ifdef ENABLE_CHECKING
  /* FIXME: no point to verify flow info after bundling on ia64.  Use this
     hack for achieving this.  */
  if (!reload_completed)
    verify_flow_info ();
#endif

hack is odd and probably instead should go into verify_flow_info.

[Bug tree-optimization/46494] [4.3/4.4/4.5/4.6 Regression] ICE: verify_flow_info failed when casting-out attribute noreturn with -fno-tree-ccp -fno-tree-fre -ftree-vrp

[ebotcazou at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46494

Eric Botcazou <ebotcazou at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
                 CC|                            |ebotcazou at gcc dot
                   |                            |gnu.org
         AssignedTo|unassigned at gcc dot       |ebotcazou at gcc dot
                   |gnu.org                     |gnu.org

--- Comment #4 from Eric Botcazou <ebotcazou at gcc dot gnu.org> 2011-02-14 08:40:11 UTC ---
Fixing.

[Bug tree-optimization/46494] [4.3/4.4/4.5/4.6 Regression] ICE: verify_flow_info failed when casting-out attribute noreturn with -fno-tree-ccp -fno-tree-fre -ftree-vrp

[ebotcazou at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46494

--- Comment #5 from Eric Botcazou <ebotcazou at gcc dot gnu.org> 2011-02-14 17:59:13 UTC ---
Author: ebotcazou
Date: Mon Feb 14 17:59:10 2011
New Revision: 170141

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=170141
Log:
    PR tree-optimization/46494
    * loop-unroll.c (split_edge_and_insert): Adjust comment.
    * loop-init.c (loop_optimizer_finalize): Do not call verify_flow_info.
    (pass_rtl_loop_done): Add TODO_verify_flow.
    * fwprop.c (pass_rtl_fwprop): Likewise.
    * modulo-sched.c (pass_sms): Likewise.
    * tree-ssa-dom.c (pass_dominator): Likewise.
    * tree-ssa-loop-ch.c (pass_ch): Likewise.
    * tree-ssa-loop.c (pass_complete_unrolli): Likewise.
    (pass_tree_loop_done): Likewise.
    * tree-ssa-pre.c (execute_pre): Likewise.
    * tree-ssa-reassoc.c (pass_reassoc): Likewise.
    * tree-ssa-sink.c (pass_sink_code): Likewise.
    * tree-vrp.c (pass_vrp): Likewise.

Added:
    trunk/gcc/testsuite/gcc.dg/pr46494.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/fwprop.c
    trunk/gcc/loop-init.c
    trunk/gcc/loop-unroll.c
    trunk/gcc/modulo-sched.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-ssa-dom.c
    trunk/gcc/tree-ssa-loop-ch.c
    trunk/gcc/tree-ssa-loop.c
    trunk/gcc/tree-ssa-pre.c
    trunk/gcc/tree-ssa-reassoc.c
    trunk/gcc/tree-ssa-sink.c
    trunk/gcc/tree-vrp.c

[Bug tree-optimization/46494] [4.3/4.4/4.5/4.6 Regression] ICE: verify_flow_info failed when casting-out attribute noreturn with -fno-tree-ccp -fno-tree-fre -ftree-vrp

[ebotcazou at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46494

Eric Botcazou <ebotcazou at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|4.3.6                       |4.6.0

--- Comment #6 from Eric Botcazou <ebotcazou at gcc dot gnu.org> 2011-02-14 18:01:42 UTC ---
Not user-visible on release branches.