[Bug bootstrap/59235] New: [4.9 regression] SEGV in sparc_output_scratch_registers

[Bug bootstrap/59235] New: [4.9 regression] SEGV in sparc_output_scratch_registers

[ro at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59235

            Bug ID: 59235
           Summary: [4.9 regression] SEGV in
                    sparc_output_scratch_registers
           Product: gcc
           Version: 4.9.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: bootstrap
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ro at gcc dot gnu.org
                CC: ebotcazou at gcc dot gnu.org, law at gcc dot gnu.org
              Host: sparc-sun-solaris2.*
            Target: sparc-sun-solaris2.*
             Build: sparc-sun-solaris2.*

Solaris/SPARC bootstrap got broken between rev 204842 and 205096: the stage2
sparcv9 libgcc fails to configure, as can be seen with the following testcase:

$ cat conftest.c
int
main (void)
{
  return 0;
}
$ ./cc1 -fpreprocessed conftest.c -mptr64 -mstack-bias -mno-v8plus -mcpu=v9
-quiet -m64 -o conftest.s
conftest.c: In function 'main':
Segmentation Fault

The SEGV happens here:

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 1 (LWP 1)]
0x0069c314 in sparc_output_scratch_registers(__FILE*) [clone .part.32] ()
(gdb) where
#0  0x0069c314 in sparc_output_scratch_registers(__FILE*) [clone .part.32] ()
#1  0x0069c3ac in sparc_asm_function_prologue(__FILE*, long long) ()
#2  0x00281df0 in final_start_function(rtx_def*, __FILE*, int) ()
#3  0x00282294 in (anonymous namespace)::pass_final::execute() ()
#4  0x003d3050 in execute_one_pass(opt_pass*) ()
#5  0x003d32e0 in execute_pass_list(opt_pass*) ()
#6  0x003d3304 in execute_pass_list(opt_pass*) ()
#7  0x003d3304 in execute_pass_list(opt_pass*) ()
#8  0x001c7bd4 in expand_function(cgraph_node*) ()
#9  0x001c9d74 in compile() ()
#10 0x001ca050 in finalize_compilation_unit() ()
#11 0x000d4f3c in c_write_global_declarations() ()
#12 0x004876a8 in compile_file() ()
#13 0x00489784 in toplev_main(int, char**) ()
#14 0x000c1074 in _start ()

A reghunt traced this to the following patch:

2013-11-19  Jeff Law  <law@redhat.com>

    * tree-ssa-threadedge.c (thread_across_edge): After threading
    through a joiner, allow threading a normal block requiring duplication.

    * tree-ssa-threadupdate.c (thread_block_1): Improve code to detect

I'm currently running a bootstrap with the patch reverted to see if everything
is ok without.

  Rainer

[Bug bootstrap/59235] [4.9 regression] SEGV in sparc_output_scratch_registers

[ro at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59235

Rainer Orth <ro at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.9.0

[Bug bootstrap/59235] [4.9 regression] SEGV in sparc_output_scratch_registers

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59235

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P1

[Bug bootstrap/59235] [4.9 regression] SEGV in sparc_output_scratch_registers

[law at redhat dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59235

--- Comment #1 from Jeffrey A. Law <law at redhat dot com> ---
Probably the same dumb oversight that's causing 59221.  I will, of course,
verify that and take appropriate action. It's things like this that sometimes
makes me question bootstrapping and regression testing's value :(

[Bug bootstrap/59235] [4.9 regression] SEGV in sparc_output_scratch_registers

[law at redhat dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59235

--- Comment #2 from Jeffrey A. Law <law at redhat dot com> ---
Ranier,

The only sparc box in the farm is the painfully slow gcc54 which someone else
is hammering so bad there's no way I can reasonably test if the fix for 59221
also fixes this bug.

Can you update your local tree and rebuild and let me know if this problem is
resolved or not.  It'd be greatly appreciated.

Thanks,
jeff

[Bug bootstrap/59235] [4.9 regression] SEGV in sparc_output_scratch_registers

[ebotcazou at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59235

Eric Botcazou <ebotcazou at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2013-11-21
     Ever confirmed|0                           |1

--- Comment #3 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
> Probably the same dumb oversight that's causing 59221.  I will, of course,
> verify that and take appropriate action. It's things like this that
> sometimes makes me question bootstrapping and regression testing's value :(

Note that this is precisely a bootstrap failure, just not on your platform.

[Bug bootstrap/59235] [4.9 regression] SEGV in sparc_output_scratch_registers

[ro at CeBiTec dot Uni-Bielefeld.DE]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59235

--- Comment #4 from ro at CeBiTec dot Uni-Bielefeld.DE <ro at CeBiTec dot Uni-Bielefeld.DE> ---
> --- Comment #2 from Jeffrey A. Law <law at redhat dot com> ---
> Ranier,
>
> The only sparc box in the farm is the painfully slow gcc54 which someone else
> is hammering so bad there's no way I can reasonably test if the fix for 59221
> also fixes this bug.
>
> Can you update your local tree and rebuild and let me know if this problem is
> resolved or not.  It'd be greatly appreciated.

Done.  The two bootstraps (one at r205213 with your patch reverted, the
other at r205233) completed successfully, and with the exception of one
failure that turned out to be spurious and several go failures that I
don't trust to be real at the moment, testsuite results were identical.

Thanks.
        Rainer

[Bug bootstrap/59235] [4.9 regression] SEGV in sparc_output_scratch_registers

[law at redhat dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59235

Jeffrey A. Law <law at redhat dot com> changed:

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

--- Comment #5 from Jeffrey A. Law <law at redhat dot com> ---
Per c#4.

*** This bug has been marked as a duplicate of bug 59221 ***