[Bug middle-end/46204] New: g++.dg/torture/stackalign/throw-1.C fails to compile on IA64

[Bug middle-end/46204] New: g++.dg/torture/stackalign/throw-1.C fails to compile on IA64

[sje at cup dot hp.com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46204

           Summary: g++.dg/torture/stackalign/throw-1.C fails to compile
                    on IA64
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Keywords: link-failure
          Severity: normal
          Priority: P3
         Component: middle-end
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: sje@cup.hp.com
              Host: ia64-*-*
            Target: ia64-*-*
             Build: ia64-*-*


I am not sure exactly where this is going wrong but when
g++.dg/torture/stackalign/throw-1.C is compiled with -O3 -funroll-loops on IA64
I get an undefined label.

Here is a cutdown test case based on that test:

int global, global2;
int main()
{
        int i,j,k,l,m,n;
   for (i=0; i < global; i++)
   for (k=0; k < j; k++)
   for (l=0; l < k; l++)
   for (m=0; m < l; m++)
       global2 = k;
 throw 0;
}

When I compile it I get:

g++ -O3 -funroll-loops x.C
/tmp/ccVWUtRi.o: In function `main':
x.C:(.text+0xc2): undefined reference to `.L34'
collect2: ld returned 1 exit status

[Bug rtl-optimization/46204] g++.dg/torture/stackalign/throw-1.C fails to compile on IA64

[sje at cup dot hp.com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46204

Steve Ellcey <sje at cup dot hp.com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2010.10.29 21:38:07
                 CC|                            |abel at gcc dot gnu.org
          Component|middle-end                  |rtl-optimization
     Ever Confirmed|0                           |1

--- Comment #1 from Steve Ellcey <sje at cup dot hp.com> 2010-10-29 21:38:07 UTC ---
It looks like this is a bug in the selective scheduler.  If I use
-fno-selective-scheduling then the label in question is not removed
and the program compiles correctly.

Marking it as confirmed since I see it in H.J. and Andreas test runs
sent to gcc-testresults.

[Bug rtl-optimization/46204] g++.dg/torture/stackalign/throw-1.C fails to compile on IA64

[amonakov at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46204

Alexander Monakov <amonakov at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
                 CC|                            |amonakov at gcc dot gnu.org

--- Comment #2 from Alexander Monakov <amonakov at gcc dot gnu.org> 2010-11-02 17:30:54 UTC ---
The scheduler is confused by a conditional jump to the next instruction (and
the fact that the containing BB has only one outgoing edge, which is also
marked fallthru).  When we delete the successor block, we don't notice that we
are also deleting the label used in that fallthru condjump.

I'm testing the following patch:

diff --git a/gcc/sel-sched-ir.c b/gcc/sel-sched-ir.c
index 141c935..9d6635b 100644
--- a/gcc/sel-sched-ir.c
+++ b/gcc/sel-sched-ir.c
@@ -3616,6 +3616,19 @@ maybe_tidy_empty_bb (basic_block bb, bool
recompute_toporder_p)
               rescan_p = true;
               break;
             }
+      else if (single_succ_p (pred_bb) && any_condjump_p (BB_END (pred_bb)))
+        {
+          if (INSN_SCHED_TIMES (BB_END (pred_bb)) == 0
+          && !IN_CURRENT_FENCE_P (BB_END (pred_bb)))
+        {
+          if (!sel_remove_insn (BB_END (pred_bb), false, false))
+            tidy_fallthru_edge (e);
+        }
+          else
+        sel_redirect_edge_and_branch (e, succ_bb);
+          rescan_p = true;
+          break;
+        }
         }
     }

[Bug rtl-optimization/46204] g++.dg/torture/stackalign/throw-1.C fails to compile on IA64

[amonakov at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46204

Alexander Monakov <amonakov at gcc dot gnu.org> changed:

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

--- Comment #4 from Alexander Monakov <amonakov at gcc dot gnu.org> 2010-11-13 09:30:14 UTC ---
Fixed.

[Bug rtl-optimization/46204] g++.dg/torture/stackalign/throw-1.C fails to compile on IA64

[amonakov at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46204

--- Comment #3 from Alexander Monakov <amonakov at gcc dot gnu.org> 2010-11-13 09:28:55 UTC ---
Author: amonakov
Date: Sat Nov 13 09:28:52 2010
New Revision: 166697

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=166697
Log:
    PR rtl-optimization/46204
    * sel-sched-ir.c (maybe_tidy_empty_bb): Remove second argument.
    Update all callers.  Do not recompute topological order.  Adjust
    fallthrough edges following a degenerate conditional jump.


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

[Bug rtl-optimization/46204] g++.dg/torture/stackalign/throw-1.C fails to compile on IA64

[abel at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46204

--- Comment #5 from Andrey Belevantsev <abel at gcc dot gnu.org> 2011-04-07 06:51:52 UTC ---
Author: abel
Date: Thu Apr  7 06:51:49 2011
New Revision: 172078

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=172078
Log:
        Backport from mainline
        2010-11-12  Alexander Monakov  <amonakov@ispras.ru>

        PR rtl-optimization/46204
         sel-sched-ir.c (maybe_tidy_empty_bb): Remove second argument.
        pdate all callers.  Do not recompute topological order.  Adjust
        allthrough edges following a degenerate conditional jump.


Modified:
    branches/gcc-4_5-branch/gcc/ChangeLog
    branches/gcc-4_5-branch/gcc/sel-sched-ir.c