[Bug ada/47005] New: [4.6 Regression] ACATS c62002a wrong code on arm-linux

[Bug ada/47005] New: [4.6 Regression] ACATS c62002a wrong code on arm-linux

[laurent at guerby dot net]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47005

           Summary: [4.6 Regression] ACATS c62002a wrong code on arm-linux
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: normal
          Priority: P3
         Component: ada
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: laurent@guerby.net
              Host: arm-linux
            Target: arm-linux
             Build: arm-linux


Now that we're back on bootstrap land :).

http://gcc.gnu.org/ml/gcc-testresults/2010-12/msg01578.html
LAST_UPDATED: Thu Dec 16 21:16:30 UTC 2010 (revision 167954)
Native configuration is armv7l-unknown-linux-gnueabi
Compiler version: 4.6.0 20101216 (experimental) [trunk revision 167954] (GCC) 
configure flags: --prefix=/n/44/guerby/install-trunk-167954
--enable-languages=c,ada,c++,fortran --enable-__cxa_atexit
--enable-threads=posix --disable-multilib


RUN c62002a

,.,. C62002A ACATS 2.5 10-12-18 02:26:25^M
---- C62002A CHECK THAT COMPONENTS OF ACCESS IN PARAMETERS MAY BE USED^M
                IN ASSIGNMENT CONTEXTS.^M
   * C62002A ASSIGNMENT TO COMPONENT OF RECORD ACCESS PARAMETER FAILED.^M
**** C62002A FAILED ****************************.^M


This one also fails on armv5tel-linux:

http://gcc.gnu.org/ml/gcc-testresults/2010-12/msg01276.html

This is the only Ada FAIL on arm-linux, 4.5 was clean so this is a regression.

[Bug ada/47005] [4.6 Regression] ACATS c62002a wrong code on arm-linux

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47005

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |4.6.0

[Bug ada/47005] [4.6 Regression] ACATS c62002a wrong code on arm-linux

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47005

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P5
                 CC|                            |jakub at gcc dot gnu.org

[Bug ada/47005] [4.6 Regression] ACATS c62002a is miscompiled at -O2

[ebotcazou at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47005

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2010.12.29 15:45:07
                 CC|                            |ebotcazou at gcc dot
                   |                            |gnu.org
            Summary|[4.6 Regression] ACATS      |[4.6 Regression] ACATS
                   |c62002a wrong code on       |c62002a is miscompiled at
                   |arm-linux                   |-O2
     Ever Confirmed|0                           |1

--- Comment #1 from Eric Botcazou <ebotcazou at gcc dot gnu.org> 2010-12-29 15:45:07 UTC ---
Does it also fail at lower optimization levels?

[Bug ada/47005] [4.6 Regression] ACATS c62002a is miscompiled at -O2

[laurent at guerby dot net]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47005

--- Comment #2 from Laurent GUERBY <laurent at guerby dot net> 2010-12-29 15:56:24 UTC ---
As of r168294 C62002A:

-O0: PASS 
-O1: PASS
-O2: FAIL
-O3: FAIL

On gcc56 PATH=/home/guerby/install-trunk-168294/bin:$PATH
if you want access to a compiler, the test is gnatchopped in /home/guerby/tmp.

[Bug ada/47005] [4.6 Regression] ACATS c62002a is miscompiled at -O2

[ebotcazou at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47005

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
         AssignedTo|unassigned at gcc dot       |ebotcazou at gcc dot
                   |gnu.org                     |gnu.org

--- Comment #3 from Eric Botcazou <ebotcazou at gcc dot gnu.org> 2010-12-29 16:22:50 UTC ---
Investigating.

[Bug ada/47005] [4.6 Regression] ACATS c62002a is miscompiled at -O2

[gnugcc at marino dot st]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47005

John Marino <gnugcc at marino dot st> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |gnugcc at marino dot st

--- Comment #4 from John Marino <gnugcc at marino dot st> 2010-12-30 23:11:56 UTC ---
I can confirm the same thing on i386 OpenBSD.  I do NOT see it on x86_64
OpenBSD though.  Note that OpenBSD uses SJLJ exception handling.

O0 - passes
O1 - passes
O2 - fails
O3 - fails


Using built-in specs.
COLLECT_GCC=gnatgcc
COLLECT_LTO_WRAPPER=/usr/local/libexec/gcc/i386-aux-openbsd4.7/4.6.0/lto-wrapper
Target: i386-aux-openbsd4.7
Configured with: /home/marino/gnat_port/gen_5/work/gcc-4.6-20101221/configure
--enable-languages=c,ada --build=i386-aux-openbsd4.7 --program-prefix=gnat
--prefix=/usr/local --with-system-zlib --with-gmp=/usr/local
--with-mpfr=/usr/local --with-mpc=/usr/local --with-libiconv-prefix=/usr/local
--enable-threads=yes --enable-shared --disable-bootstrap --disable-libgomp
--disable-libssp --disable-nls
Thread model: posix
gcc version 4.6.0 20101221 (experimental) -=> GNAT AUX [OpenBSD] (GCC)

[Bug ada/47005] [4.6 Regression] ACATS c62002a is miscompiled at -O2

[ebotcazou at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47005

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |WAITING
                 CC|ebotcazou at gcc dot        |
                   |gnu.org                     |

--- Comment #5 from Eric Botcazou <ebotcazou at gcc dot gnu.org> 2011-01-04 10:57:54 UTC ---
Reconfirm with an up-to-date tree, ACATS was clean on i586/SJLJ this morning.

[Bug ada/47005] [4.6 Regression] ACATS c62002a is miscompiled at -O2

[laurent at guerby dot net]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47005

--- Comment #6 from Laurent GUERBY <laurent at guerby dot net> 2011-01-04 12:18:49 UTC ---
The autotesters should pick this change within a day or two.

[Bug ada/47005] [4.6 Regression] ACATS c62002a is miscompiled at -O2

[gnugcc at marino dot st]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47005

--- Comment #7 from John Marino <gnugcc at marino dot st> 2011-01-04 13:27:52 UTC ---
I confirm that test c62002a is still failing on OpenBSD i386 as of today (SVN
168458)

[Bug tree-optimization/47005] [4.6 Regression] ACATS c62002a is miscompiled at -O2

[ebotcazou at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47005

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |NEW
          Component|ada                         |tree-optimization

--- Comment #8 from Eric Botcazou <ebotcazou at gcc dot gnu.org> 2011-01-04 17:13:43 UTC ---
OK, fixing...

[Bug tree-optimization/47005] [4.6 Regression] ACATS c62002a is miscompiled at -O2

[ebotcazou at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47005

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED

[Bug tree-optimization/47005] [4.6 Regression] ACATS c62002a is miscompiled at -O2

[ebotcazou at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47005

--- Comment #9 from Eric Botcazou <ebotcazou at gcc dot gnu.org> 2011-01-05 11:23:43 UTC ---
Author: ebotcazou
Date: Wed Jan  5 11:23:40 2011
New Revision: 168508

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=168508
Log:
    PR tree-optimization/47005
    * tree-sra.c (struct access): Add 'non_addressable' bit.
    (create_access): Set it for a DECL_NONADDRESSABLE_P field.
    (decide_one_param_reduction): Return 0 if the parameter is passed by
    reference and one of the accesses in the group is non_addressable.

Added:
    trunk/gcc/testsuite/gnat.dg/opt14.adb
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-sra.c

[Bug tree-optimization/47005] [4.6 Regression] ACATS c62002a is miscompiled at -O2

[ebotcazou at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47005

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

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

--- Comment #10 from Eric Botcazou <ebotcazou at gcc dot gnu.org> 2011-01-05 11:26:29 UTC ---
Done.

[Bug tree-optimization/47005] [4.6 Regression] ACATS c62002a is miscompiled at -O2

[gnugcc at marino dot st]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47005

--- Comment #11 from John Marino <gnugcc at marino dot st> 2011-01-05 13:49:47 UTC ---
I rebuilt OpenBSD i386 using then Jan 5 daily bump (SVN 168495) and patched it
with tree-src.c file.

ACATS 62002a now passes, thanks.

[Bug tree-optimization/47005] [4.6 Regression] ACATS c62002a is miscompiled at -O2

[ebotcazou at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47005

--- Comment #12 from Eric Botcazou <ebotcazou at gcc dot gnu.org> 2011-01-05 13:54:30 UTC ---
> ACATS 62002a now passes, thanks.

Thanks for confirming.  ACATS is clean on both i386 and i586 Linux SJLJ now,
are there any remaining failures on BSD platforms?

[Bug tree-optimization/47005] [4.6 Regression] ACATS c62002a is miscompiled at -O2

[gnugcc at marino dot st]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47005

--- Comment #13 from John Marino <gnugcc at marino dot st> 2011-01-05 15:14:36 UTC ---
(In reply to comment #12)
> Thanks for confirming.  ACATS is clean on both i386 and i586 Linux SJLJ now,
> are there any remaining failures on BSD platforms?

There are no ACATS or gnat.dg failures on the ZCX platforms (FreeBSD,
DragonFlyBSD, NetBSD: i386 and x86_64)

The regression tests just completed for OpenBSD i386.
There is one failure on ACATS (cb1010a timeout)* 
Between yesterday and today, the test sse_nolib result went from passing to
"UNSUPPORTED"


Comments:
1) Between yesterday and today, test c390001 wouldn't even compile, but now it
passes.
2)* I haven't investigated cb1010a timeout yet, but I think the problem is with
OpenBSD, not gnat
3) the STACK_CHECK_STATIC_BUILTIN macro value has no effect on OpenBSD.  I was
expecting failures on c5210[3x,4x,4y] and cb1010[a,b,c] but they don't fail.
4) Despite DWARF2_UNWIND_INFO being set to 0 (meaning MD_UNWIND_SUPPORT macro
is ignored), the null_deref and stack_check gnat.dg tests pass.  in gdb, the
segfault comes and then the program just exits normally.
5) I don't know if the behavior of 3) and 4) is normal for an SJLJ target, or
if it's because apparently there's some missing support on OpenBSD for DWARF2
(if I try to set OpenBSD32 to ZCX handling the compile breaks with the
unwind_context structure considered illegal), and commit commits also indicate
something is missing for OpenBSD.

The summary is that the OpenBSD port is currently better then it has ever been,
and one remaining ACATS failure is probably related to how OpenBSD handles
their stack.  As of today, I don't have any errors to report, but that may
change as I discover more about the issues I just outlined above.

[Bug tree-optimization/47005] [4.6 Regression] ACATS c62002a is miscompiled at -O2

[ebotcazou at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47005

--- Comment #14 from Eric Botcazou <ebotcazou at gcc dot gnu.org> 2011-01-05 15:33:24 UTC ---
> The regression tests just completed for OpenBSD i386.
> There is one failure on ACATS (cb1010a timeout)* 

This is a stack checking test.

> 3) the STACK_CHECK_STATIC_BUILTIN macro value has no effect on OpenBSD.  I was
> expecting failures on c5210[3x,4x,4y] and cb1010[a,b,c] but they don't fail.

The tests should pass w and w/o it on x86, but it's better to define it.

> 4) Despite DWARF2_UNWIND_INFO being set to 0 (meaning MD_UNWIND_SUPPORT macro
> is ignored), the null_deref and stack_check gnat.dg tests pass.  in gdb, the
> segfault comes and then the program just exits normally.

This is expected with SJLJ exceptions, you don't need MD_UNWIND_SUPPORT.

> The summary is that the OpenBSD port is currently better then it has ever been,
> and one remaining ACATS failure is probably related to how OpenBSD handles
> their stack.  As of today, I don't have any errors to report, but that may
> change as I discover more about the issues I just outlined above.

Great, thanks for the detailed report.

[Bug tree-optimization/47005] [4.6 Regression] ACATS c62002a is miscompiled at -O2

[gnugcc at marino dot st]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47005

--- Comment #15 from John Marino <gnugcc at marino dot st> 2011-01-05 16:25:56 UTC ---
[off PR]

Hi Eric,
Can you clarify one statement?
Regarding the ten "stack-check" tests as I can them (c5210[3x,4x,4y], 
cb1010[a,c,d], null_deref[1,2], stack-check[1,2]), I now understand that 
it is expected that these tests pass on SJLJ targets.

Are these true passes meaning SJLJ targets are fully capable of handling 
stack overflow and segfaults?  Or are these results just false positives?

Thanks,
John


ebotcazou at gcc dot gnu.org wrote:
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47005
> 
> --- Comment #14 from Eric Botcazou <ebotcazou at gcc dot gnu.org> 2011-01-05 15:33:24 UTC ---
>> The regression tests just completed for OpenBSD i386.
>> There is one failure on ACATS (cb1010a timeout)* 
> 
> This is a stack checking test.
> 
>> 3) the STACK_CHECK_STATIC_BUILTIN macro value has no effect on OpenBSD.  I was
>> expecting failures on c5210[3x,4x,4y] and cb1010[a,b,c] but they don't fail.
> 
> The tests should pass w and w/o it on x86, but it's better to define it.
> 
>> 4) Despite DWARF2_UNWIND_INFO being set to 0 (meaning MD_UNWIND_SUPPORT macro
>> is ignored), the null_deref and stack_check gnat.dg tests pass.  in gdb, the
>> segfault comes and then the program just exits normally.
> 
> This is expected with SJLJ exceptions, you don't need MD_UNWIND_SUPPORT.
> 
>> The summary is that the OpenBSD port is currently better then it has ever been,
>> and one remaining ACATS failure is probably related to how OpenBSD handles
>> their stack.  As of today, I don't have any errors to report, but that may
>> change as I discover more about the issues I just outlined above.
> 
> Great, thanks for the detailed report.
>

[Bug tree-optimization/47005] [4.6 Regression] ACATS c62002a is miscompiled at -O2

[ebotcazou at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47005

--- Comment #16 from Eric Botcazou <ebotcazou at gcc dot gnu.org> 2011-01-05 16:55:57 UTC ---
> Regarding the ten "stack-check" tests as I can them (c5210[3x,4x,4y], 
> cb1010[a,c,d], null_deref[1,2], stack-check[1,2]), I now understand that 
> it is expected that these tests pass on SJLJ targets.

null_deref[1,2] are not really about stack checking, but I get the point.

> Are these true passes meaning SJLJ targets are fully capable of handling 
> stack overflow and segfaults?  Or are these results just false positives?

Stack checking per se is orthogonal to ZCX vs SJLJ.  What isn't orthogonal is
the handling of segfaults (hence the connection to stack checking done with
probes): SJLJ handles segfaults out of the box whereas ZCX needs
MD_UNWIND_SUPPORT.  So, yes, the aforementioned 10 special tests are expected
to pass on SJLJ targets out of the box, i.e. without additional target-specific
support.

[Bug tree-optimization/47005] [4.6 Regression] ACATS c62002a is miscompiled at -O2

[laurent at guerby dot net]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47005

--- Comment #17 from Laurent GUERBY <laurent at guerby dot net> 2011-01-08 22:48:51 UTC ---
For reference ACATS is now clean on arm-linux as well:

http://gcc.gnu.org/ml/gcc-testresults/2011-01/msg00648.html

LAST_UPDATED: Fri Jan  7 00:49:12 UTC 2011 (revision 168562)
Native configuration is armv7l-unknown-linux-gnueabi
        === acats Summary ===
# of expected passes        2321
# of unexpected failures    0

Thanks Eric :).

[Bug tree-optimization/47005] [4.6 Regression] ACATS c62002a is miscompiled at -O2

[ebotcazou at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47005

--- Comment #18 from Eric Botcazou <ebotcazou at gcc dot gnu.org> 2011-01-09 08:45:01 UTC ---
> For reference ACATS is now clean on arm-linux as well:
> 
> http://gcc.gnu.org/ml/gcc-testresults/2011-01/msg00648.html
> 
> LAST_UPDATED: Fri Jan  7 00:49:12 UTC 2011 (revision 168562)
> Native configuration is armv7l-unknown-linux-gnueabi
>         === acats Summary ===
> # of expected passes        2321
> # of unexpected failures    0
> 
> Thanks Eric :).

You're welcome.  Thanks for reporting the problem.