[Bug tree-optimization/23117] New: ICE on valid code while building libgcc

[Bug tree-optimization/23117] New: ICE on valid code while building libgcc

[raj dot khem at gmail dot com]

The latest compiler build from CVS sources on 07-28-2005 segfaults while
building libgcc for arm-softfloat target with -O2,O2,Os opt levels. The error
does not happen when -O1 is used

The program compiles fine when I use my host compiler which is gcc version 4.0.1
20050727 (Red Hat 4.0.1-5)

error log
================================

 __do_global_ctors_aux
Analyzing compilation unitPerforming intraprocedural optimizations
Assembling functions:
 __do_global_ctors_aux
/home/kraj/a.c: In function '__do_global_ctors_aux':
/home/kraj/a.c:8: 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.

====================================

How to reporoduce

gcc -O2 -c testcase.c

testcase.c
====================================
typedef void (*func_ptr) (void);

static func_ptr __CTOR_END__[1] = {(func_ptr) 0 };

static void  __attribute__((used))  __do_global_ctors_aux (void)
{
  func_ptr *p;
  for (p = __CTOR_END__ - 1; *p != (func_ptr) -1; p--)
    (*p) ();
}

=======================================================

-- 
           Summary: ICE on valid code while building libgcc
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: raj dot khem at gmail dot com
                CC: gcc-bugs at gcc dot gnu dot org
  GCC host triplet: i686-host_pc-linux-gnu
GCC target triplet: arm-softfloat-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23117

[Bug c/23117] ICE on valid code while building libgcc

[raj dot khem at gmail dot com]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|tree-optimization           |c


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23117

[Bug middle-end/23117] ICE on valid code while building libgcc

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pinskia at gcc dot gnu dot
                   |                            |org
          Component|c                           |middle-end
           Keywords|                            |build, ice-on-valid-code


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23117

[Bug rtl-optimization/23117] [4.1 Regression] ICE on valid code while building libgcc

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-07-28 20:06 -------
Confirmed, backtrace:
#0  0x007f7a4c in add_branch_dependences (head=0x1e918f0, tail=0x1e918f0) at ../../gcc/sched-
rgn.c:1987
#1  0x007f818c in compute_block_backward_dependences (bb=0) at ../../gcc/sched-rgn.c:2142
#2  0x007f8a80 in schedule_region (rgn=3) at ../../gcc/sched-rgn.c:2290
#3  0x007f9828 in schedule_insns (dump_file=0x0) at ../../gcc/sched-rgn.c:2547
#4  0x007f9e14 in rest_of_handle_sched2 () at ../../gcc/sched-rgn.c:2700
#5  0x0063bbd0 in execute_one_pass (pass=0x8a4e94) at ../../gcc/passes.c:793


This is an RTL optimization bug.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
          Component|middle-end                  |rtl-optimization
     Ever Confirmed|                            |1
   GCC host triplet|i686-host_pc-linux-gnu      |
 GCC target triplet|arm-softfloat-linux-gnu     |arm-*-linux-gnu
   Last reconfirmed|0000-00-00 00:00:00         |2005-07-28 20:06:10
               date|                            |
            Summary|ICE on valid code while     |[4.1 Regression] ICE on
                   |building libgcc             |valid code while building
                   |                            |libgcc
   Target Milestone|---                         |4.1.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23117

[Bug rtl-optimization/23117] [4.1 Regression] ICE on valid code while building libgcc

[raj dot khem at gmail dot com]

------- Additional Comments From raj dot khem at gmail dot com  2005-07-28 22:02 -------
This seems to have been caused by some checkin that went in after 7/27/2005 (i.e
only checkins that went in today 7/28) because when I cvs up -D 2005-07-27 I
dont get the segfault.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23117

[Bug rtl-optimization/23117] [4.1 Regression] ICE on valid code while building libgcc

[raj dot khem at gmail dot com]

------- Additional Comments From raj dot khem at gmail dot com  2005-07-28 22:20 -------
(In reply to comment #2)
> This seems to have been caused by some checkin that went in after 7/27/2005 (i.e
> only checkins that went in today 7/28) because when I cvs up -D 2005-07-27 I
> dont get the segfault.

Amends, To narrow it further the problem is caused by some checkin that happened
on 7/27 because upto 0:00 hours it builds ok but not cvs up -D "2005-07-27 23:59"

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23117

[Bug rtl-optimization/23117] [4.1 Regression] ICE on valid code while building libgcc

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-07-28 22:35 -------
Did the build which worked include the fix for PR rtl-optimization/17808?  You can find out by looking 
at ChangeLog.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23117

[Bug rtl-optimization/23117] [4.1 Regression] ICE on valid code while building libgcc

[steven at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
OtherBugsDependingO|                            |17808
              nThis|                            |
         AssignedTo|unassigned at gcc dot gnu   |steven at gcc dot gnu dot
                   |dot org                     |org
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2005-07-28 20:06:10         |2005-07-28 23:37:19
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23117

[Bug rtl-optimization/23117] [4.1 Regression] ICE on valid code while building libgcc

[steven at gcc dot gnu dot org]

------- Additional Comments From steven at gcc dot gnu dot org  2005-07-28 23:31 -------
Try this, like Richard Earnshaw is doing. 
 
Index: sched-rgn.c 
=================================================================== 
RCS file: /cvs/gcc/gcc/gcc/sched-rgn.c,v 
retrieving revision 1.99 
diff -u -p -r1.99 sched-rgn.c 
--- sched-rgn.c 27 Jul 2005 16:28:34 -0000      1.99 
+++ sched-rgn.c 28 Jul 2005 23:31:29 -0000 
@@ -1977,17 +1977,17 @@ add_branch_dependences (rtx head, rtx ta 
   if (!reload_completed || ! JUMP_P (tail)) 
     return; 
 
-  insn = PREV_INSN (tail); 
+  insn = tail; 
   while (insn != head) 
     { 
+      insn = PREV_INSN (insn); 
+ 
       /* Note that we want to add this dependency even when 
         sched_insns_conditions_mutex_p returns true.  The whole point 
         is that we _want_ this dependency, even if these insns really 
         are independent.  */ 
       if (INSN_P (insn) && GET_CODE (PATTERN (insn)) == COND_EXEC) 
        add_dependence (tail, insn, REG_DEP_ANTI); 
- 
-      insn = PREV_INSN (insn); 
     } 
 #endif 
 } 
 

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23117

[Bug rtl-optimization/23117] [4.1 Regression] ICE on valid code while building libgcc

[raj dot khem at gmail dot com]

------- Additional Comments From raj dot khem at gmail dot com  2005-07-29 03:50 -------
The problem indeed was caused by checkin for PR rtl-optimization/17808. I
verified it.

Then I tried the Steven's fix above and I was able to build the GCC and rest of
toolchain.
I havent tested the compiler.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23117

[Bug rtl-optimization/23117] [4.1 Regression] ICE on valid code while building libgcc

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-07-29 09:32 -------
Subject: Bug 23117

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	rearnsha@gcc.gnu.org	2005-07-29 09:32:16

Modified files:
	gcc            : ChangeLog sched-rgn.c 

Log message:
	Richard Earnshaw  <richard.earnshaw@arm.com>
	Steven Bosscher  <stevenb@suse.de>
	
	PR rtl-optimization/23117
	* sched-rgn.c (add_branch_dependences): Handle COND_EXEC correctly
	when head == tail.  Tidy comment.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&r1=2.9597&r2=2.9598
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/sched-rgn.c.diff?cvsroot=gcc&r1=1.99&r2=1.100



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23117

[Bug rtl-optimization/23117] [4.1 Regression] ICE on valid code while building libgcc

[rearnsha at gcc dot gnu dot org]

------- Additional Comments From rearnsha at gcc dot gnu dot org  2005-07-29 09:33 -------
Fixed with suggested patch.

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23117

[Bug rtl-optimization/23117] [4.1 Regression] ICE on valid code while building libgcc

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-07-29 16:31 -------
*** Bug 23136 has been marked as a duplicate of this bug. ***

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23117