[Bug middle-end/38857] New: [4.4 Regression] ICE in selective scheduler

[Bug middle-end/38857] New: [4.4 Regression] ICE in selective scheduler

[sje at cup dot hp dot com]

With this test case the selective scheduler is hitting a gcc_assert in
sel-sched-ir.c  I see this on IA64 Linux or on IA64 HP-UX when in 64 bit mode. 

In both cases it happens when compiling with -O3.

x.c: In function 'dv_guess_qnos':
x.c:22: internal compiler error: in sel_move_insn, at sel-sched-ir.c:1395
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.


Test case:


static const int vs_total_ac_bits = 2680;
typedef struct EncBlockInfo {
      short mb[64];
      unsigned char next[64];
} EncBlockInfo;
inline void dv_guess_qnos(EncBlockInfo* blks, int* qnos) {
      int size[5];
      int j, k, a, prev;
      EncBlockInfo* b;
      for(a=2; a==2 || vs_total_ac_bits < size[0]; a+=a){
         for (j=0; j<6*5; j++, b++) {
             for (k= b->next[prev]; k<64; k= b->next[k]) {
                 if(b->mb[k] < a && b->mb[k] > -a){
                     b->next[prev] = b->next[k];
                 }
                 else{
                     prev = k;
                 }
             }
         }
     }
}


-- 
           Summary: [4.4 Regression] ICE in selective scheduler
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: sje at cup dot hp dot com
GCC target triplet: ia64-*-*


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38857

[Bug middle-end/38857] [4.4 Regression] ICE in selective scheduler

[pinskia at gcc dot gnu dot org]

-- 

pinskia at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pinskia at gcc dot gnu dot
                   |                            |org
   Target Milestone|---                         |4.4.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38857

[Bug middle-end/38857] [4.4 Regression] ICE in selective scheduler

[rguenth at gcc dot gnu dot org]

------- Comment #1 from rguenth at gcc dot gnu dot org  2009-01-19 09:49 -------
P1 as this happens on a secondary target with -O3.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|                            |4.3.3
           Priority|P3                          |P1


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38857

[Bug middle-end/38857] [4.4 Regression] ICE in selective scheduler

[steven at gcc dot gnu dot org]

------- Comment #2 from steven at gcc dot gnu dot org  2009-01-19 22:49 -------
Yah, seen -> CONFIRMED


-- 

steven 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         |2009-01-19 22:49:52
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38857

[Bug middle-end/38857] [4.4 Regression] ICE in selective scheduler

[amonakov at gcc dot gnu dot org]

------- Comment #3 from amonakov at gcc dot gnu dot org  2009-01-20 15:45 -------
The assert that fails is checking whether an instruction was correctly
disconnected from the insn stream (at its original location) to be inserted on
the scheduling boundary by adjusting PREV_INSN/NEXT_INSN links (we try to move
instructions instead of removing and reissuing new instruction to avoid cost of
re-initialization of associated structures).

There are two different versions of code to decide whether it is appropriate to
move an instruction for places where instructions are disconnected or inserted
into the stream, as different scheduler data is available there.  Attached
patch (by Andrey) changes it so that decision is made at instruction's original
location and saved until we need to move/issue it at the scheduling boundary in
should_move parameter.

Bootstrapped & regtested on ia64-linux.  I will include the testcase when
sending patch to gcc-patches@
Steven, can you please also check if it fixes the testcase you've seen fail on
this assert?


-- 

amonakov at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |amonakov at gcc dot gnu dot
                   |                            |org
         AssignedTo|unassigned at gcc dot gnu   |amonakov at gcc dot gnu dot
                   |dot org                     |org
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2009-01-19 22:49:52         |2009-01-20 15:45:10
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38857

[Bug middle-end/38857] [4.4 Regression] ICE in selective scheduler

[amonakov at gcc dot gnu dot org]

------- Comment #4 from amonakov at gcc dot gnu dot org  2009-01-20 15:47 -------
Created an attachment (id=17153)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=17153&action=view)
proposed patch


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38857

[Bug middle-end/38857] [4.4 Regression] ICE in selective scheduler

[sje at cup dot hp dot com]

------- Comment #5 from sje at cup dot hp dot com  2009-01-20 23:12 -------
I tested the patch on my original code (that the included test was cut down
from) and it compiled that program with no problem.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38857

[Bug middle-end/38857] [4.4 Regression] ICE in selective scheduler

[steven at gcc dot gnu dot org]

------- Comment #6 from steven at gcc dot gnu dot org  2009-01-20 23:16 -------
-static bool code_motion_path_driver (insn_t, av_set_t, ilist_t,
-                                     cmpd_local_params_p, void *);
+static int code_motion_path_driver (insn_t, av_set_t, ilist_t,
+                                    cmpd_local_params_p, void *);

You probably don't want this bit...?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38857

[Bug middle-end/38857] [4.4 Regression] ICE in selective scheduler

[amonakov at gcc dot gnu dot org]

------- Comment #7 from amonakov at gcc dot gnu dot org  2009-01-22 12:19 -------
(In reply to comment #6)
> -static bool code_motion_path_driver (insn_t, av_set_t, ilist_t,
> -                                     cmpd_local_params_p, void *);
> +static int code_motion_path_driver (insn_t, av_set_t, ilist_t,
> +                                    cmpd_local_params_p, void *);
> 
> You probably don't want this bit...?
> 

The function returns -1 in some circumstances.  This change is not relevant to
the ICE in question, but is nevertheless a correction (maybe not the best, as
'return true' and 'return false' are used in function's body).  I'm not sure
what's best here -- to include this in PR fix submission, or as a separate
patch.

FWIW, there're a couple more unrelated changes:
1) check if a reg is actually a hard reg
       if (REG_P (*cur_rtx)
+          && HARD_REGISTER_P (*cur_rtx)
           && hard_regno_nregs[REGNO(*cur_rtx)][GET_MODE (*cur_rtx)] > 1)

and
2) Do not merge info from successors if not relevant
   /* Merge data, clean up, etc.  */
-  if (code_motion_path_driver_info->after_merge_succs)
+  if (res != -1 && code_motion_path_driver_info->after_merge_succs)
     code_motion_path_driver_info->after_merge_succs (&lparams, static_params);

Again, I will submit them separately if so desired.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38857

[Bug middle-end/38857] [4.4 Regression] ICE in selective scheduler

[jakub at gcc dot gnu dot org]

------- Comment #8 from jakub at gcc dot gnu dot org  2009-01-25 11:31 -------
I think it is fine to submit the patch as is, assuming you've
bootstrapped/regtested it.  Please mail it to gcc-patches for review.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38857

[Bug middle-end/38857] [4.4 Regression] ICE in selective scheduler

[amonakov at gcc dot gnu dot org]

------- Comment #9 from amonakov at gcc dot gnu dot org  2009-01-29 10:53 -------
Subject: Bug 38857

Author: amonakov
Date: Thu Jan 29 10:53:15 2009
New Revision: 143753

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=143753
Log:
2009-01-29  Andrey Belevantsev  <abel@ispras.ru>
            Alexander Monakov  <amonakov@ispras.ru>

        PR middle-end/38857
        * sel-sched.c (count_occurrences_1): Check that *cur_rtx is a hard
        register.
        (move_exprs_to_boundary): Change return type and pass through
        should_move from move_op.  Relax assert.  Update usage ...
        (schedule_expr_on_boundary): ... here.  Use should_move instead of
        cant_move.
        (move_op_orig_expr_found): Indicate that insn was disconnected from
        stream.
        (code_motion_process_successors): Do not call after_merge_succs
        callback if original expression was not found when traversing any of
        the branches.
        (code_motion_path_driver): Change return type.  Update prototype.
        (move_op): Update comment.  Add a new parameter (should_move).  Update
        prototype.  Set *should_move based on indication provided by
        move_op_orig_expr_found.

2009-01-29  Steve Ellcey  <sje@cup.hp.com>

        PR middle-end/38857
        * gcc.c-torture/compile/pr38857.c: New test.


Added:
    trunk/gcc/testsuite/gcc.c-torture/compile/pr38857.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/sel-sched.c
    trunk/gcc/testsuite/ChangeLog


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38857

[Bug middle-end/38857] [4.4 Regression] ICE in selective scheduler

[amonakov at gcc dot gnu dot org]

------- Comment #10 from amonakov at gcc dot gnu dot org  2009-01-29 10:55 -------
Fixed with above commit.


-- 

amonakov at gcc dot gnu dot org changed:

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38857

[Bug middle-end/38857] [4.4 Regression] ICE in selective scheduler

[hjl at gcc dot gnu dot org]

------- Comment #11 from hjl at gcc dot gnu dot org  2009-01-29 17:06 -------
Subject: Bug 38857

Author: hjl
Date: Thu Jan 29 17:06:01 2009
New Revision: 143762

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=143762
Log:
2009-01-29  H.J. Lu  <hongjiu.lu@intel.com>

        Backport from mainline:
        2009-01-29  Steve Ellcey  <sje@cup.hp.com>

        PR middle-end/38857
        * gcc.c-torture/compile/pr38857.c: New test.

        2009-01-28  Richard Guenther  <rguenther@suse.de>

        PR tree-optimization/38926
        * gcc.c-torture/compile/pr38926.c: New testcase.

Added:
    branches/gcc-4_3-branch/gcc/testsuite/gcc.c-torture/compile/pr38857.c
      - copied unchanged from r143760,
trunk/gcc/testsuite/gcc.c-torture/compile/pr38857.c
    branches/gcc-4_3-branch/gcc/testsuite/gcc.c-torture/compile/pr38926.c
      - copied unchanged from r143759,
trunk/gcc/testsuite/gcc.c-torture/compile/pr38926.c
Modified:
    branches/gcc-4_3-branch/gcc/testsuite/ChangeLog


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38857