[Bug tree-optimization/26806] New: ICE at gcc/tree-gimple.c:269

[Bug tree-optimization/26806] New: ICE at gcc/tree-gimple.c:269

[jb at gcc dot gnu dot org]

The capacita benchmark, part of the polyhedron benchmark suite, fails with the
ICE in the summary. BT:

#0  0x080d0276 in is_gimple_reg_type (type=0x0) at
../../trunk/gcc/tree-gimple.c:269
#1  0x080d0519 in is_gimple_val (t=0xb7852fa4) at
../../trunk/gcc/tree-gimple.c:368
#2  0x083e60c0 in verify_expr (tp=0xb7ba5728, walk_subtrees=0xbfa13e08,
data=0x0)
    at ../../trunk/gcc/tree-cfg.c:3469
#3  0x08363911 in walk_tree (tp=0xb7ba5728, func=0x83e5c20 <verify_expr>,
data=0x0,
    pset=0x0) at ../../trunk/gcc/tree.c:7306
#4  0x083ed9f7 in verify_stmts () at ../../trunk/gcc/tree-cfg.c:3506
#5  0x083ff8c9 in verify_ssa (check_modified_stmt=1 '\001')
    at ../../trunk/gcc/tree-ssa.c:643
#6  0x0837f1ca in execute_todo (flags=8375) at ../../trunk/gcc/passes.c:794
#7  0x0837f42a in execute_one_pass (pass=0x8690d48) at
../../trunk/gcc/passes.c:884
#8  0x0837f587 in execute_pass_list (pass=0x8690d48) at
../../trunk/gcc/passes.c:909
#9  0x0837f59b in execute_pass_list (pass=0x85cea00) at
../../trunk/gcc/passes.c:910
#10 0x080cfb93 in tree_rest_of_compilation (fndecl=0xb7b4ce80)
    at ../../trunk/gcc/tree-optimize.c:418
#11 0x083cc8b2 in cgraph_expand_function (node=0xb7b53a80)
    at ../../trunk/gcc/cgraphunit.c:1102
#12 0x083cdccb in cgraph_optimize () at ../../trunk/gcc/cgraphunit.c:1167
#13 0x0809ce2f in gfc_be_parse_file (set_yydebug=0)
    at ../../trunk/gcc/fortran/f95-lang.c:302
#14 0x08350676 in toplev_main (argc=3, argv=0xbfa14084) at
../../trunk/gcc/toplev.c:999
#15 0xb7d9dea2 in __libc_start_main () from /lib/tls/i686/cmov/libc.so.6
#16 0x0804af01 in _start () at ../sysdeps/i386/elf/start.S:119

(gdb) up 7
#7  0x0837f42a in execute_one_pass (pass=0x8690d48) at
../../trunk/gcc/passes.c:884
884       execute_todo (todo_after | pass->todo_flags_finish);
(gdb) print *pass
$1 = {name = 0x85acd37 "phicprop", gate = 0x8428830 <gate_dominator>,
  execute = 0x842adc0 <eliminate_degenerate_phis>, sub = 0x0, next = 0x85dc900,
  static_pass_number = 58, tv_id = 43, properties_required = 584,
  properties_provided = 0, properties_destroyed = 2048, todo_flags_start = 0,
  todo_flags_finish = 8375, letter = 0 '\0'}

Undisclosed sources on IRC tell me that this bug is due to the new pass Jeff
has contributed.


-- 
           Summary: ICE at gcc/tree-gimple.c:269
           Product: gcc
           Version: 4.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: law at redhat dot com
        ReportedBy: jb at gcc dot gnu dot org
  GCC host triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26806

[Bug tree-optimization/26806] ICE at gcc/tree-gimple.c:269

[jb at gcc dot gnu dot org]

------- Comment #1 from jb at gcc dot gnu dot org  2006-03-22 17:10 -------
Created an attachment (id=11097)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=11097&action=view)
Testcase

Testcase that demonstrates the ICE. 


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26806

[Bug tree-optimization/26806] [4.2 Regression] ICE at gcc/tree-gimple.c:269

[pinskia at gcc dot gnu dot org]

-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |law at redhat dot com
         AssignedTo|law at redhat dot com       |unassigned at gcc dot gnu
                   |                            |dot org
           Keywords|                            |ice-on-valid-code
            Summary|ICE at gcc/tree-gimple.c:269|[4.2 Regression] ICE at
                   |                            |gcc/tree-gimple.c:269
   Target Milestone|---                         |4.2.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26806

[Bug tree-optimization/26806] [4.2 Regression] ICE at gcc/tree-gimple.c:269

[pinskia at gcc dot gnu dot org]

------- Comment #2 from pinskia at gcc dot gnu dot org  2006-03-22 17:27 -------
Confirmed, shorter testcase:
module solv_cap
  integer,       private, save :: Ng1=0, Ng2=0
contains
  subroutine FourirG(G)
    real, intent(in out), dimension(0:,0:) :: G
    complex, allocatable, dimension(:,:)   :: t
    allocate( t(0:2*Ng1-1,0:2*Ng2-1) )
    t(0:Ng1,0:Ng2-1)    = G(:,0:Ng2-1)      ! Fill one quadrant (one extra row)
    t(0:Ng1,Ng2:2*Ng2-1) = G(:,Ng2:1:-1)    ! This quadrant using symmetry
  end subroutine FourirG
end module solv_cap


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|0                           |1
   Last reconfirmed|0000-00-00 00:00:00         |2006-03-22 17:27:29
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26806

[Bug tree-optimization/26806] [4.2 Regression] ICE at gcc/tree-gimple.c:269

[law at redhat dot com]

------- Comment #3 from law at redhat dot com  2006-03-22 18:14 -------
Subject: Re:  [4.2 Regression] ICE at
        gcc/tree-gimple.c:269

On Wed, 2006-03-22 at 17:27 +0000, pinskia at gcc dot gnu dot org wrote:
> 
> ------- Comment #2 from pinskia at gcc dot gnu dot org  2006-03-22 17:27 -------
> Confirmed, shorter testcase:
> module solv_cap
>   integer,       private, save :: Ng1=0, Ng2=0
> contains
>   subroutine FourirG(G)
>     real, intent(in out), dimension(0:,0:) :: G
>     complex, allocatable, dimension(:,:)   :: t
>     allocate( t(0:2*Ng1-1,0:2*Ng2-1) )
>     t(0:Ng1,0:Ng2-1)    = G(:,0:Ng2-1)      ! Fill one quadrant (one extra row)
>     t(0:Ng1,Ng2:2*Ng2-1) = G(:,Ng2:1:-1)    ! This quadrant using symmetry
>   end subroutine FourirG
> end module
Options/flags?  I've been unable to reproduce this.
jeff


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26806

[Bug tree-optimization/26806] [4.2 Regression] ICE at gcc/tree-gimple.c:269

[pinskia at gcc dot gnu dot org]

------- Comment #4 from pinskia at gcc dot gnu dot org  2006-03-22 18:19 -------
(In reply to comment #3)
> Options/flags?  I've been unable to reproduce this.

Just -O2.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   GCC host triplet|i686-pc-linux-gnu           |
 GCC target triplet|                            |i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26806

[Bug tree-optimization/26806] [4.2 Regression] ICE at gcc/tree-gimple.c:269

[pinskia at gcc dot gnu dot org]

------- Comment #5 from pinskia at gcc dot gnu dot org  2006-03-23 00:09 -------
I see a similar failure in galgel on Diego's testers:
/home/cygnus/dnovillo/perf/sbox/gcc/local.i686/inst.tobiano/bin/gfortran -c -o
bifgel.o  -ffixed-form -ffloat-store          -O2 -march=pentium4
-mtune=generic    bifgel.f90
Error from make 'specmake  build 2> make.err | tee make.out':
bifgel.f90: In function 'bifgel':
bifgel.f90:1: internal compiler error: Segmentation fault
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.

But I cannot reduce that or debug that because I don't have the source to SPEC.


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pinskia at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26806

[Bug tree-optimization/26806] [4.2 Regression] ICE at gcc/tree-gimple.c:269

[pinskia at gcc dot gnu dot org]

------- Comment #6 from pinskia at gcc dot gnu dot org  2006-03-23 00:36 -------
Well we get a SSA_NAME in the free list:
<ssa_name 0x2aaaab13a690 nothrow var <var_decl 0x2aaaab123e70 ng2.13> def_stmt
<ssa_name 0x2aaaab132a80>
    version 66 in-free-list>


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26806

[Bug tree-optimization/26806] [4.2 Regression] ICE at gcc/tree-gimple.c:269

[pinskia at gcc dot gnu dot org]

------- Comment #7 from pinskia at gcc dot gnu dot org  2006-03-23 00:40 -------
The statement is:
D.939_75 = ng2.13D.965_8 + ng2.13D.965_66


Oh, before we had:
  D.939_75 = ng2.13_66 + ng2.13_66;

Looks like phicprop does not replace both ng2.13_66.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26806

[Bug tree-optimization/26806] [4.2 Regression] ICE at gcc/tree-gimple.c:269

[pinskia at gcc dot gnu dot org]

------- Comment #8 from pinskia at gcc dot gnu dot org  2006-03-23 01:54 -------
The only thing I can think of what is causing this is the replacement is
causing the use info to go bad as there are two uses in this one statement.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26806

[Bug tree-optimization/26806] [4.2 Regression] ICE at gcc/tree-gimple.c:269

[law at redhat dot com]

------- Comment #9 from law at redhat dot com  2006-03-23 09:48 -------
Subject: Re:  [4.2 Regression] ICE at
        gcc/tree-gimple.c:269

On Thu, 2006-03-23 at 00:09 +0000, pinskia at gcc dot gnu dot org wrote:
> 
> ------- Comment #5 from pinskia at gcc dot gnu dot org  2006-03-23 00:09 -------
> I see a similar failure in galgel on Diego's testers:
> /home/cygnus/dnovillo/perf/sbox/gcc/local.i686/inst.tobiano/bin/gfortran -c -o
> bifgel.o  -ffixed-form -ffloat-store          -O2 -march=pentium4
> -mtune=generic    bifgel.f90
> Error from make 'specmake  build 2> make.err | tee make.out':
> bifgel.f90: In function 'bifgel':
> bifgel.f90:1: internal compiler error: Segmentation fault
> Please submit a full bug report,
> with preprocessed source if appropriate.
> See <URL:http://gcc.gnu.org/bugs.html> for instructions.
> 
> But I cannot reduce that or debug that because I don't have the source to SPEC.
This is arguably a bug in the code to walk immediate uses; if a
statement has multiple uses of the same SSA_NAME and you modify
the statement during the imm-uses walk, there are cases where
the imm-uses walk will miss the second use within the statement.

The net result in this particular case is we fail to propagate
away a use (because it wasn't visited due to the bug noted above),
we then proceed to remove the SSA_NAME (as all its uses should have
been removed).

Andrew is aware of the problem and we kicked around some ideas
for how to resolve it long term.  I've got a couple of short-term
workarounds that I'm testing.

jeff


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26806

[Bug tree-optimization/26806] [4.2 Regression] ICE at gcc/tree-gimple.c:269

[pinskia at gcc dot gnu dot org]

------- Comment #10 from pinskia at gcc dot gnu dot org  2006-03-23 21:05 -------
*** Bug 26832 has been marked as a duplicate of this bug. ***


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |anlauf at gmx dot de


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26806

[Bug tree-optimization/26806] [4.2 Regression] ICE at gcc/tree-gimple.c:269

[law at redhat dot com]

------- Comment #11 from law at redhat dot com  2006-03-24 06:45 -------
*** Bug 26833 has been marked as a duplicate of this bug. ***


-- 

law at redhat dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |malitzke at metronets dot
                   |                            |com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26806

[Bug tree-optimization/26806] [4.2 Regression] ICE at gcc/tree-gimple.c:269

[law at redhat dot com]

------- Comment #12 from law at redhat dot com  2006-03-24 07:49 -------
Subject: Re:   New: ICE at
        gcc/tree-gimple.c:269

On Wed, 2006-03-22 at 16:47 +0000, jb at gcc dot gnu dot org wrote:
> The capacita benchmark, part of the polyhedron benchmark suite, fails with the
> ICE in the summary. BT:
[ ... ]

The root cause of this problem is the immediate-use iterators
not visiting an immediate use in certain circumstances.  Andrew
and I have discussed this a little and Andrew thinks he may be
able to fix the iterator -- however, that's not likely to happen
until he returns from some travel.

In the mean time this change works around the immediate-use
iterator problem.  Basically we re-start the iterator if we
have an LHS which we expect to have no uses, but which still
has immediate uses after the iterator exits.

[ The first version actually split the loop into two phases one
  to propagate into all uses, the other to fold and simplify 
  statements after propagation.  That works.  But this is much
  simpler. ]


This fixes pr26806 and pr26833.

Bootstrapped and regression tested on i686-pc-linux-gnu.


------- Comment #13 from law at redhat dot com  2006-03-24 07:49 -------
Created an attachment (id=11109)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=11109&action=view)


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26806

[Bug tree-optimization/26806] [4.2 Regression] ICE at gcc/tree-gimple.c:269

[pinskia at gcc dot gnu dot org]

------- Comment #14 from pinskia at gcc dot gnu dot org  2006-03-24 13:29 -------
*** Bug 26836 has been marked as a duplicate of this bug. ***


-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |uttamp at us dot ibm dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26806

[Bug tree-optimization/26806] [4.2 Regression] ICE at gcc/tree-gimple.c:269

[malitzke at metronets dot com]

------- Comment #15 from malitzke at metronets dot com  2006-03-24 14:30 -------
re this PR 26806 and PR 26833 (judged equivalent) the  yasm--0.4.0 referred to
in PR 26833 compiled OK with the temporary fix and passed an extensive battery
of tests included in yasm-0.4.0. Documentation issues (irrelevant to GCC) were
faked out.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26806

[Bug tree-optimization/26806] [4.2 Regression] ICE at gcc/tree-gimple.c:269

[law at redhat dot com]

------- Comment #16 from law at redhat dot com  2006-04-13 16:39 -------
Fixed a couple weeks ago.


-- 

law at redhat dot com changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26806