[Bug debug/48826] New: ICE in dwarf2out_var_location, at dwarf2out.c:22013

[Bug debug/48826] New: ICE in dwarf2out_var_location, at dwarf2out.c:22013

[rmansfield at qnx dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48826

           Summary: ICE in dwarf2out_var_location, at dwarf2out.c:22013
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: debug
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: rmansfield@qnx.com
              Host: i686-linux-gnu
            Target: mips-unknown-linux-uclibc
             Build: i686-linux-gnu


$ cat ice.i
int foo() {
  return bar();
}
$ ./xgcc -v
Using built-in specs.
COLLECT_GCC=./xgcc
Target: mips-unknown-linux-uclibc
Configured with: ../configure --target=mips-unknown-linux-uclibc
--prefix=/home/ryan/x-tools/mips-unknown-linux-uclibc
--with-sysroot=/home/ryan/x-tools/mips-unknown-linux-uclibc/mips-unknown-linux-uclibc/sys-root
--enable-languages=c --disable-multilib --with-float=soft --enable-__cxa_atexit
--with-local-prefix=/home/ryan/x-tools/mips-unknown-linux-uclibc/mips-unknown-linux-uclibc/sys-root
--disable-nls --enable-threads=posix --enable-symvers=gnu --enable-c99
--enable-long-long --enable-target-optspace
Thread model: posix
gcc version 4.7.0 20110429 (experimental) [trunk revision 173156] (GCC) 
$ ./xgcc -B. -O -g ice.i
ice.i: In function 'foo':
ice.i:3:1: internal compiler error: in dwarf2out_var_location, at
dwarf2out.c:22013
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.

[Bug debug/48826] ICE in dwarf2out_var_location, at dwarf2out.c:22013

[rmansfield at qnx dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48826

--- Comment #1 from Ryan Mansfield <rmansfield at qnx dot com> 2011-05-04 13:01:31 UTC ---
The change that introduced this ICE is rev171033.

http://gcc.gnu.org/viewcvs?view=revision&revision=171033

[Bug debug/48826] ICE in dwarf2out_var_location, at dwarf2out.c:22013

[rmansfield at qnx dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48826

Ryan Mansfield <rmansfield at qnx dot com> changed:

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

--- Comment #2 from Ryan Mansfield <rmansfield at qnx dot com> 2011-05-04 14:06:56 UTC ---
After rev171033 debugging is completely broken for this mips configuration.
i.e. everything build I compile with -g ICEs this way.

[Bug debug/48826] ICE in dwarf2out_var_location, at dwarf2out.c:22013

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48826

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-05-04 14:10:20 UTC ---
Most probably the backend is reordering insns after var-tracking, it shouldn't
be doing that.  ARM/SH/S390 backends all have fixed similar bugs very quickly
after this patch went in.

[Bug debug/48826] ICE in dwarf2out_var_location, at dwarf2out.c:22013

[rmansfield at qnx dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48826

--- Comment #4 from Ryan Mansfield <rmansfield at qnx dot com> 2011-05-05 13:19:43 UTC ---
The issue with ARM/SH/S390 backends appears to be there was a literal pool
split happening in between a call insn and the NOTE_INSN_CALL_ARG_LOCATION. It
looks like on mips the issue, at least for my testcase, is the gp store in
mips_split_call is getting emitted in between the call insn and the note.

(call_insn 39 5 40 (parallel [
            (set (reg:SI 2 $2)
                (call (mem:SI (reg:SI 25 $25 [196]) [0 S4 A32])
                    (const_int 16 [0x10])))
            (clobber (reg:SI 31 $31))
            (clobber (reg:SI 28 $28))
        ]) /home/ryan/ice.i:2 575 {call_value_split}
     (nil)
    (expr_list:REG_DEP_TRUE (use (reg:SI 79 $fakec))
        (expr_list:REG_DEP_TRUE (use (reg:SI 28 $28))
            (nil))))

(insn 40 39 32 (set (reg:SI 28 $28)
        (mem/c:SI (plus:SI (reg/f:SI 29 $sp)
                (const_int 16 [0x10])) [0 S4 A32])) /home/ryan/ice.i:2 280
{*movsi_internal}
     (nil))

(note 32 40 7 (expr_list:REG_DEP_TRUE (concat:SI (reg:SI 79 $fakec)
        (reg:SI 79 $fakec))
    (expr_list:REG_DEP_TRUE (concat:SI (reg:SI 28 $28)
            (reg:SI 28 $28))
        (nil))) NOTE_INSN_CALL_ARG_LOCATION)

[Bug rtl-optimization/48826] ICE in dwarf2out_var_location, at dwarf2out.c:22013

[rsandifo at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48826

rsandifo@gcc.gnu.org <rsandifo at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2011.05.22 21:06:18
                 CC|                            |rsandifo at gcc dot gnu.org
          Component|debug                       |rtl-optimization
         AssignedTo|unassigned at gcc dot       |rsandifo at gcc dot gnu.org
                   |gnu.org                     |
     Ever Confirmed|0                           |1

--- Comment #5 from rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> 2011-05-22 21:06:18 UTC ---
About to post a patch.

[Bug rtl-optimization/48826] ICE in dwarf2out_var_location, at dwarf2out.c:22013

[rsandifo at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48826

--- Comment #6 from rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> 2011-05-23 17:57:38 UTC ---
Author: rsandifo
Date: Mon May 23 17:57:35 2011
New Revision: 174080

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=174080
Log:
gcc/
    PR rtl-optimization/48826
    * emit-rtl.c (try_split): When splitting a call that is followed
    by a NOTE_INSN_CALL_ARG_LOCATION, move the note after the new call.

Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/emit-rtl.c

[Bug rtl-optimization/48826] ICE in dwarf2out_var_location, at dwarf2out.c:22013

[rsandifo at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48826

rsandifo@gcc.gnu.org <rsandifo at gcc dot gnu.org> changed:

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

--- Comment #7 from rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> 2011-05-23 18:24:31 UTC ---
Fixed on trunk.

[Bug rtl-optimization/48826] ICE in dwarf2out_var_location, at dwarf2out.c:22013

[rsandifo at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48826

rsandifo@gcc.gnu.org <rsandifo at gcc dot gnu.org> changed:

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

--- Comment #8 from rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> 2011-05-23 18:27:33 UTC ---
*** Bug 48843 has been marked as a duplicate of this bug. ***

[Bug rtl-optimization/48826] ICE in dwarf2out_var_location, at dwarf2out.c:22013

[rmansfield at qnx dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48826

--- Comment #9 from Ryan Mansfield <rmansfield at qnx dot com> 2011-05-26 14:20:54 UTC ---
Richard, thanks for your patch. It fixed most of the failures I saw but there
are still cases where the note doesn't get moved after call split. The
following example ICEs with rev174285.

void  foo ()
{
  int *const pc = __builtin_return_address (0);
  bar (pc);
}

[Bug rtl-optimization/48826] ICE in dwarf2out_var_location, at dwarf2out.c:22013

[pangbw at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=48826

baoshan <pangbw at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pangbw at gmail dot com

--- Comment #10 from baoshan <pangbw at gmail dot com> ---
The code is broken in the latest code because beside NOTE instruction there
could be BARRIER too, for instance the RTX list I am seeing:

(call_insn 32 35 33 (parallel [
            (set (reg:SI 2 $2)
                (call (mem:SI (reg:SI 25 $25 [198]) [0  S4 A32])
                    (const_int 16 [0x10])))
            (clobber (reg:SI 31 $31))
            (clobber (reg:SI 28 $28))
        ]) min.c:20 603 {call_value_split}
     (nil)
    (expr_list (use (reg:SI 79 $fakec))
        (expr_list (use (reg:SI 28 $28))
            (expr_list:SI (use (reg:SI 5 $5))
                (expr_list:SI (use (reg:SI 4 $4))
                    (nil))))))
(insn 33 32 34 (set (reg:SI 28 $28)
        (mem/c:SI (plus:SI (reg/f:SI 29 $sp)
                (const_int 16 [0x10])) [0  S4 A32])) min.c:20 288
{*movsi_internal}
     (nil))
(barrier 34 33 18)
(barrier 18 34 30)
(note 30 18 21 (expr_list:REG_DEP_TRUE (concat:SI (pc)
        (unspec:SI [
                (reg:SI 28 $28)
            (const:SI (unspec:SI [
                            (symbol_ref:SI ("signal") [flags 0x41] 
<function_decl 0xb71f6700 signal>)
                ] 227))
                (reg:SI 79 $fakec)
            ] UNSPEC_LOAD_CALL))
    (expr_list:REG_DEP_TRUE (concat:SI (reg:SI 5 $5)
            (const_int 0 [0]))
        (expr_list:REG_DEP_TRUE (concat:SI (reg:SI 4 $4)
            (const_int 2 [0x2]))
            (nil)))) NOTE_INSN_CALL_ARG_LOCATION)
(note 21 30 0 NOTE_INSN_DELETED)

[Bug rtl-optimization/48826] ICE in dwarf2out_var_location, at dwarf2out.c:22013

[pangbw at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=48826

--- Comment #11 from baoshan <pangbw at gmail dot com> ---
And I don't thing it is the best place to fix this bug in function try_split().
Why not fix it at where the ICE occurs? It is just the wrong expectation from
function dwarf2out_var_location(). Why not just look forward further if the
'prev'is not what we want? I like to add this code before gcc_assert() to fix
this issue:

       while(prev && !CALL_P(prev) && !(GET_CODE (PATTERN (prev)) == SEQUENCE
                                 && CALL_P (XVECEXP (PATTERN (prev), 0, 0)))){
          gcc_assert(NONJUMP_INSN_P (prev));
      prev = prev_real_insn (prev);
        }