[Bug tree-optimization/46801] New: [4.6 Regression] FAIL: gnat.dg/pack9.adb scan-tree-dump-not optimized "gnat_rcheck"

[Bug tree-optimization/46801] New: [4.6 Regression] FAIL: gnat.dg/pack9.adb scan-tree-dump-not optimized "gnat_rcheck"

[danglin at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46801

           Summary: [4.6 Regression] FAIL: gnat.dg/pack9.adb
                    scan-tree-dump-not optimized "gnat_rcheck"
           Product: gcc
           Version: 4.6.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: danglin@gcc.gnu.org
              Host: hppa2.0w-hp-hpux11.11
            Target: hppa2.0w-hp-hpux11.11
             Build: hppa2.0w-hp-hpux11.11


Executing on host: /test/gnu/gcc/objdir/gcc/gnatmake
--GCC=/test/gnu/gcc/objdir/
gcc/xgcc --GNATBIND=/test/gnu/gcc/objdir/gcc/gnatbind
--GNATLINK=/test/gnu/gcc/o
bjdir/gcc/gnatlink -cargs -B/test/gnu/gcc/objdir/gcc -largs
--GCC=/test/gnu/gcc/
objdir/gcc/xgcc\ -B/test/gnu/gcc/objdir/gcc\  -margs
--RTS=/test/gnu/gcc/objdir/
hppa2.0w-hp-hpux11.11/./libada -q -f
/test/gnu/gcc/gcc/gcc/testsuite/gnat.dg/pac
k9.adb  -O2 -gnatp -fdump-tree-optimized -c -S  -o pack9.s    (timeout = 300)
PASS: gnat.dg/pack9.adb (test for excess errors)
FAIL: gnat.dg/pack9.adb scan-tree-dump-not optimized "gnat_rcheck"

-bash-3.2$ ./xgcc -B./ -v
Reading specs from ./specs
COLLECT_GCC=./xgcc
COLLECT_LTO_WRAPPER=./lto-wrapper
Target: hppa2.0w-hp-hpux11.11
Configured with: ../gcc/configure --with-gnu-as --with-as=/opt/gnu/bin/as
--enable-shared --with-local-prefix=/opt/gnu --prefix=/opt/gnu/gcc/gcc-4.6
--with-gmp=/opt/gnu/gcc/gcc-4.6.0 --enable-threads=posix --enable-debug=no
--disable-nls --without-cloog --without-ppl
--enable-languages=c,c++,objc,fortran,java,ada,obj-c++
Thread model: posix
gcc version 4.6.0 20101203 (experimental) [trunk revision 167444] (GCC)

[Bug tree-optimization/46801] [4.6 Regression] FAIL: gnat.dg/pack9.adb scan-tree-dump-not optimized "gnat_rcheck"

[dave at hiauly1 dot hia.nrc.ca]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46801

--- Comment #1 from dave at hiauly1 dot hia.nrc.ca 2010-12-04 18:01:04 UTC ---
Attached tree dump.

[Bug tree-optimization/46801] [4.6 Regression] FAIL: gnat.dg/pack9.adb scan-tree-dump-not optimized "gnat_rcheck"

[ebotcazou at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46801

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

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

--- Comment #2 from Eric Botcazou <ebotcazou at gcc dot gnu.org> 2010-12-06 07:06:44 UTC ---
http://gcc.gnu.org/ml/gcc-patches/2010-11/msg02722.html

[Bug tree-optimization/46801] [4.6 Regression] FAIL: gnat.dg/pack9.adb scan-tree-dump-not optimized "gnat_rcheck"

[ebotcazou at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46801

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Target|hppa2.0w-hp-hpux11.11       |
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2010.12.06 07:08:21
               Host|hppa2.0w-hp-hpux11.11       |
     Ever Confirmed|0                           |1
              Build|hppa2.0w-hp-hpux11.11       |

--- Comment #3 from Eric Botcazou <ebotcazou at gcc dot gnu.org> 2010-12-06 07:08:21 UTC ---
This is a pessimization in SRA.  Probably definitive I'm afraid...

[Bug tree-optimization/46801] [4.6 Regression] FAIL: gnat.dg/pack9.adb scan-tree-dump-not optimized "gnat_rcheck"

[jamborm at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46801

--- Comment #4 from Martin Jambor <jamborm at gcc dot gnu.org> 2010-12-15 18:13:27 UTC ---
(In reply to comment #2)
> http://gcc.gnu.org/ml/gcc-patches/2010-11/msg02722.html

Does this mean it also fails on i586 or is this a hppa thing?
Thanks.

[Bug tree-optimization/46801] [4.6 Regression] FAIL: gnat.dg/pack9.adb scan-tree-dump-not optimized "gnat_rcheck"

[ebotcazou at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46801

--- Comment #5 from Eric Botcazou <ebotcazou at gcc dot gnu.org> 2010-12-15 18:21:38 UTC ---
> Does this mean it also fails on i586 or is this a hppa thing?

It fails everywhere.

[Bug tree-optimization/46801] [4.6 Regression] FAIL: gnat.dg/pack9.adb scan-tree-dump-not optimized "gnat_rcheck"

[jamborm at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46801

--- Comment #6 from Martin Jambor <jamborm at gcc dot gnu.org> 2010-12-28 14:36:58 UTC ---
This seems to be a fallout from the fix to PR 46351 and PR 46377
(revision 166535, patch at
http://gcc.gnu.org/ml/gcc-patches/2010-11/msg00933.html).

The problem is that struct pack9__copy__t___PAD apparently contains
aggregate bit-fields which we reject in type_internals_preclude_sra_p
even before we make the variable a candidate.  This seems to be a good
reason to have another look at the rather crude fix, although my
still fresh memories of the bit-field mess make me refrain from any
promises of a quick better solution.

[Bug tree-optimization/46801] [4.6 Regression] FAIL: gnat.dg/pack9.adb scan-tree-dump-not optimized "gnat_rcheck"

[jamborm at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46801

--- Comment #7 from Martin Jambor <jamborm at gcc dot gnu.org> 2010-12-29 00:07:02 UTC ---
Proposed fix posted to the mailing list:

http://gcc.gnu.org/ml/gcc-patches/2010-12/msg01912.html

[Bug tree-optimization/46801] [4.6 Regression] FAIL: gnat.dg/pack9.adb scan-tree-dump-not optimized "gnat_rcheck"

[ebotcazou at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46801

--- Comment #8 from Eric Botcazou <ebotcazou at gcc dot gnu.org> 2010-12-29 16:40:47 UTC ---
> Proposed fix posted to the mailing list:
> 
> http://gcc.gnu.org/ml/gcc-patches/2010-12/msg01912.html

Thanks a lot!

[Bug tree-optimization/46801] [4.6 Regression] FAIL: gnat.dg/pack9.adb scan-tree-dump-not optimized "gnat_rcheck"

[jamborm at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46801

--- Comment #9 from Martin Jambor <jamborm at gcc dot gnu.org> 2011-01-03 15:43:25 UTC ---
Author: jamborm
Date: Mon Jan  3 15:43:23 2011
New Revision: 168431

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=168431
Log:
2011-01-03  Martin Jambor  <mjambor@suse.cz>

    PR tree-optimization/46801
    * tree-sra.c (type_internals_preclude_sra_p): Check whether
    aggregate fields start at byte boundary instead of the bit-field flag.

    * testsuite/gnat.dg/pack9.adb: Remove xfail.


Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gnat.dg/pack9.adb
    trunk/gcc/tree-sra.c

[Bug tree-optimization/46801] [4.6 Regression] FAIL: gnat.dg/pack9.adb scan-tree-dump-not optimized "gnat_rcheck"

[jamborm at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46801

Martin Jambor <jamborm at gcc dot gnu.org> changed:

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

--- Comment #10 from Martin Jambor <jamborm at gcc dot gnu.org> 2011-01-03 15:46:26 UTC ---
Fixed.

[Bug tree-optimization/46801] [4.6 Regression] FAIL: gnat.dg/pack9.adb scan-tree-dump-not optimized "gnat_rcheck"

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46801

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

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

--- Comment #11 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-01-30 14:36:37 UTC ---
SRA does

 Pack9.Copy (struct pack9__r2 * const x, struct pack9__r2 * const y)
 {
+  integer t$i2;
   const struct pack9__r2 t;
   integer D.2584;
   integer D.2583;

 <bb 2>:
   t = *y_1(D);
-  D.2583_2 = t.i2;
+  t$i2_9 = y_1(D)->i2;
+  D.2583_2 = t$i2_9;
   D.2584_3 = y_1(D)->i2;
   D.2584_4 = D.2584_3;
   if (D.2583_2 != D.2584_4)
@@ -206,6 +58,7 @@

 <bb 4>:
   *x_5(D) = t;
+  x_5(D)->i2 = t$i2_9;
   return;

 }

thus eliminates 't' and makes D.2583_2 and D.2584_3 redundant (and VN
figure that out and remove the if stmt).

Value-numbering does not see that in

<bb 2>:
  t = *y_1(D);

<bb 3>:
  D.2584_2 = t.i2;
  D.2585_3 = y_1(D)->i2;

the two loads are the same (because it enters (only) the non-rewritten ops
into the hashtable).  See PR52054.