[Bug other/56273] New: [4.8 regression] Bogus -Warray-bounds warning

[Bug other/56273] New: [4.8 regression] Bogus -Warray-bounds warning

[daniel at constexpr dot org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56273

             Bug #: 56273
           Summary: [4.8 regression] Bogus -Warray-bounds warning
    Classification: Unclassified
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: other
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: daniel@constexpr.org


The following C++ code cause current gcc master to emit an incorrect array
bounds warning:

$ cat test.cpp 

struct type {
  bool a, b;
  bool get_b() { return b; }
};

type stuff[9u];

void bar();

void foo() {

  for(unsigned i = 0u; i < 9u; i++) {

    if(!stuff[i].a) {
      continue;
    }

    bar();

    for(unsigned j = i + 1u; j < 9u; j++) {
      if(stuff[j].a && stuff[j].get_b()) {
        return;
      }
    }

  }
}

$ g++-4.8.0-pre9999 -Warray-bounds -O3 -c test.cpp
test.cpp: In function ‘void foo()’:
test.cpp:22:17: warning: array subscript is above array bounds [-Warray-bounds]
       if(stuff[j].a && stuff[j].get_b()) {
                 ^

I appreciate static analyzers as much as everyone, but having false positives
in the normal warnings (especially ones enabled at -Wall) can be annoying.

GCC was build from git master just now:

$ g++-4.8.0-pre9999 -v
Using built-in specs.                                                           
COLLECT_GCC=g++-4.8.0-pre9999
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-pc-linux-gnu/4.8.0-pre9999/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with:
/var/tmp/portage/sys-devel/gcc-4.8.0_pre9999/work/gcc-4.8.0-9999/configure
--prefix=/usr --bindir=/usr/x86_64-pc-linux-gnu/gcc-bin/4.8.0-pre9999
--includedir=/usr/lib/gcc/x86_64-pc-linux-gnu/4.8.0-pre9999/include
--datadir=/usr/share/gcc-data/x86_64-pc-linux-gnu/4.8.0-pre9999
--mandir=/usr/share/gcc-data/x86_64-pc-linux-gnu/4.8.0-pre9999/man
--infodir=/usr/share/gcc-data/x86_64-pc-linux-gnu/4.8.0-pre9999/info
--with-gxx-include-dir=/usr/lib/gcc/x86_64-pc-linux-gnu/4.8.0-pre9999/include/g++-v4
--host=x86_64-pc-linux-gnu --build=x86_64-pc-linux-gnu --disable-altivec
--disable-fixed-point --with-ppl --with-cloog --disable-ppl-version-check
--with-cloog-include=/usr/include/cloog-ppl --enable-lto --enable-nls
--without-included-gettext --with-system-zlib --enable-obsolete
--disable-werror --enable-secureplt --enable-multilib
--with-multilib-list=m32,m64 --enable-libmudflap --disable-libssp
--enable-libgomp
--with-python-dir=/share/gcc-data/x86_64-pc-linux-gnu/4.8.0-pre9999/python
--enable-checking=release --disable-libgcj --enable-libstdcxx-time
--enable-languages=c,c++,fortran --enable-shared --enable-threads=posix
--enable-__cxa_atexit --enable-clocale=gnu --enable-targets=all
--with-bugurl=http://bugs.gentoo.org/ --with-pkgversion='Gentoo 4.8.0_pre9999'
Thread model: posix
gcc version 4.8.0-pre9999 20130210 (experimental) commit
bc85f3af1b43674782c9b5bb2240117f293b5530 (Gentoo 4.8.0_pre9999)

[Bug other/56273] [4.8 regression] Bogus -Warray-bounds warning

[daniel at constexpr dot org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56273

--- Comment #1 from Daniel Scharrer <daniel at constexpr dot org> 2013-02-10 07:07:40 UTC ---
The same code and command-line arguments do not produce a warning in gcc 4.7.2,
4.6.3, 4.5.4 and clang 3.2 as well as clang's static analyzer.

[Bug tree-optimization/56273] [4.8 regression] Bogus -Warray-bounds warning

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56273

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |diagnostic,
                   |                            |missed-optimization
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2013-02-10
          Component|other                       |tree-optimization
     Ever Confirmed|0                           |1

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> 2013-02-10 07:34:54 UTC ---
The problem is a missing VRP.  Basically ivopts changes:
  if (j_10 != 9)

Which works into:

  j_10 = ivtmp.12_56;
  if (ivtmp.12_56 != 9)
    goto <bb 7>;
  else
    goto <bb 6>;


Which does not work as VRP cannot figure out j_10 will never be 9.
I have some patches to VRP which improves this but I don't remember if it fixes
this case where there is an assignment which is used later on.

[Bug tree-optimization/56273] [4.8 regression] Bogus -Warray-bounds warning

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56273

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
         AssignedTo|unassigned at gcc dot       |rguenth at gcc dot gnu.org
                   |gnu.org                     |
   Target Milestone|---                         |4.8.0

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> 2013-02-10 12:18:10 UTC ---
I will have a look.

[Bug tree-optimization/56273] [4.8 regression] Bogus -Warray-bounds warning

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56273

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> 2013-02-11 09:32:31 UTC ---
(In reply to comment #2)
> The problem is a missing VRP.  Basically ivopts changes:
>   if (j_10 != 9)
> 
> Which works into:
> 
>   j_10 = ivtmp.12_56;
>   if (ivtmp.12_56 != 9)
>     goto <bb 7>;
>   else
>     goto <bb 6>;
> 
> 
> Which does not work as VRP cannot figure out j_10 will never be 9.
> I have some patches to VRP which improves this but I don't remember if it fixes
> this case where there is an assignment which is used later on.

A similar case was PR55079 which was

   j_10 = ivtmp.12_56 + 1;
   if (ivtmp.12_56 == 5)
     ...

I handled already.  Extending this to copies should be easy.  If I do that
it still doesn't work.

That's because we warn for stuff[j_15] and j_15 is [9, 16] (we completely
peel the loop).  The access is guarded with

  <bb 30>:
  j_55 = ivtmp.12_56 + 8;
  j_72 = ivtmp.12_56 + 8;
  if (j_72 != 9)
    goto <bb 31>;
  else
    goto <bb 3>;

  <bb 31>:
  # j_15 = PHI <j_55(30)>
  _12 = stuff[j_15].a;
  if (_12 != 0)

but j_72 is [9, 16] as well and ivtmp.12_56: [1, 9].  Improving VRP to
see that j_55 is != 9 in bb31 will only lead to [10, 16] which is also
out-of-bounds.

It might very well be that folding the < test to != in VRP1 causes most
of the issues.  Indeed -fdisable-tree-vrp1 "fixes" the testcase.  We
should probably delay that optimization to VRP2 only, thus don't do

Folding statement: if (i_1 <= 8)
Simplified relational if (i_1 <= 8)
 into if (i_1 != 9)

(simplify_cond_using_ranges).

[Bug tree-optimization/56273] [4.8 regression] Bogus -Warray-bounds warning

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56273

--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> 2013-02-11 10:52:39 UTC ---
One of the reasons this all happens is of course that after complete unrolling
we miss a pass that does full redundancy removal and const/copy propagation.
For the latter we abuse VRP (but cripple it), for the former we have DOM,
but that is scheduled after VRP.

I wonder if we should simply move VRP after DOM.  Like with

Index: gcc/passes.c
===================================================================
--- gcc/passes.c        (revision 195938)
+++ gcc/passes.c        (working copy)
@@ -1488,7 +1488,6 @@ init_optimization_passes (void)
       NEXT_PASS (pass_lower_vector_ssa);
       NEXT_PASS (pass_cse_reciprocals);
       NEXT_PASS (pass_reassoc);
-      NEXT_PASS (pass_vrp);
       NEXT_PASS (pass_strength_reduction);
       NEXT_PASS (pass_dominator);
       /* The only const/copy propagation opportunities left after
@@ -1497,6 +1496,7 @@ init_optimization_passes (void)
         only examines PHIs to discover const/copy propagation
         opportunities.  */
       NEXT_PASS (pass_phi_only_cprop);
+      NEXT_PASS (pass_vrp);
       NEXT_PASS (pass_cd_dce);
       NEXT_PASS (pass_tracer);

as DOM also performs constant/copy propagation.  That doesn't fix the
warning but makes the IL that we feed into VRP2 much more suitable to
its working.

A patch to disable the < -> != transform fixes this bug and I am going
to test that.

[Bug tree-optimization/56273] [4.8 regression] Bogus -Warray-bounds warning

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56273

--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> 2013-02-11 13:33:29 UTC ---
Author: rguenth
Date: Mon Feb 11 13:33:19 2013
New Revision: 195940

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=195940
Log:
2013-02-11  Richard Biener  <rguenther@suse.de>

    PR tree-optimization/56273
    * tree-vrp.c (simplify_cond_using_ranges): Disable for the
    first VRP run.
    (check_array_ref): Fix missing newline in dumps.
    (search_for_addr_array): Likewise.

    * g++.dg/warn/Warray-bounds-6.C: New testcase.
    * gcc.dg/tree-ssa/pr21559.c: Adjust.
    * gcc.dg/tree-ssa/vrp17.c: Likewise.
    * gcc.dg/tree-ssa/vrp18.c: Likewise.
    * gcc.dg/tree-ssa/vrp23.c: Likewise.
    * gcc.dg/tree-ssa/vrp24.c: Likewise.

Added:
    trunk/gcc/testsuite/g++.dg/warn/Warray-bounds-6.C
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gcc.dg/tree-ssa/pr21559.c
    trunk/gcc/testsuite/gcc.dg/tree-ssa/vrp17.c
    trunk/gcc/testsuite/gcc.dg/tree-ssa/vrp18.c
    trunk/gcc/testsuite/gcc.dg/tree-ssa/vrp23.c
    trunk/gcc/testsuite/gcc.dg/tree-ssa/vrp24.c
    trunk/gcc/tree-vrp.c

[Bug tree-optimization/56273] [4.8 regression] Bogus -Warray-bounds warning

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56273

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

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

--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> 2013-02-11 13:34:06 UTC ---
Fixed.

[Bug tree-optimization/56273] [4.8 regression] Bogus -Warray-bounds warning

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56273

--- Comment #8 from Richard Biener <rguenth at gcc dot gnu.org> 2013-02-11 15:09:02 UTC ---
Author: rguenth
Date: Mon Feb 11 15:08:51 2013
New Revision: 195942

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=195942
Log:
2013-02-11  Richard Biener  <rguenther@suse.de>

        PR tree-optimization/56273
    * gcc.dg/tree-ssa/vrp17.c: Disable tail-merging.

Modified:
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gcc.dg/tree-ssa/vrp17.c

[Bug tree-optimization/56273] [4.8 regression] Bogus -Warray-bounds warning

[vincenzo.innocente at cern dot ch]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56273

--- Comment #9 from vincenzo Innocente <vincenzo.innocente at cern dot ch> 2013-02-12 16:24:11 UTC ---
I am just rebuilding (Updated to revision 195983.) and noticed
/home/data/newsoft/gcc-build/./gcc/xgcc -B/home/data/newsoft/gcc-build/./gcc/
-B/afs/cern.ch/user/i/innocent/w2/x86_64-unknown-linux-gnu/bin/
-B/afs/cern.ch/user/i/innocent/w2/x86_64-unknown-linux-gnu/lib/ -isystem
/afs/cern.ch/user/i/innocent/w2/x86_64-unknown-linux-gnu/include -isystem
/afs/cern.ch/user/i/innocent/w2/x86_64-unknown-linux-gnu/sys-include    -g -O2
-ftree-vectorize -fPIC -O2 -g -O2 -ftree-vectorize -fPIC -DIN_GCC   -W -Wall
-Wno-narrowing -Wwrite-strings -Wcast-qual -Wstrict-prototypes
-Wmissing-prototypes -Wold-style-definition  -isystem ./include  -I. -I.
-I../.././gcc -I../../../gcc-trunk/libgcc -I../../../gcc-trunk/libgcc/.
-I../../../gcc-trunk/libgcc/../gcc -I../../../gcc-trunk/libgcc/../include
-I../../../gcc-trunk/libgcc/config/libbid -DENABLE_DECIMAL_BID_FORMAT  -g0
-finhibit-size-directive -fno-inline -fno-exceptions
-fno-zero-initialized-in-bss -fno-toplevel-reorder -fno-tree-vectorize
-fno-stack-protector  -I. -I. -I../.././gcc -I../../../gcc-trunk/libgcc
-I../../../gcc-trunk/libgcc/. -I../../../gcc-trunk/libgcc/../gcc
-I../../../gcc-trunk/libgcc/../include
-I../../../gcc-trunk/libgcc/config/libbid -DENABLE_DECIMAL_BID_FORMAT -o
crtend.o -MT crtend.o -MD -MP -MF crtend.dep  -fno-omit-frame-pointer
-fno-asynchronous-unwind-tables -c ../../../gcc-trunk/libgcc/crtstuff.c
-DCRT_END
../../../gcc-trunk/libgcc/crtstuff.c: In function 'frame_dummy':
../../../gcc-trunk/libgcc/crtstuff.c:463:19: warning: array subscript is above
array bounds [-Warray-bounds]
   if (__JCR_LIST__[0])

is this real or bogus?

[Bug tree-optimization/56273] [4.8 regression] Bogus -Warray-bounds warning

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56273

--- Comment #10 from Andrew Pinski <pinskia at gcc dot gnu.org> 2013-02-12 23:50:03 UTC ---
(In reply to comment #9)
> ../../../gcc-trunk/libgcc/crtstuff.c: In function 'frame_dummy':
> ../../../gcc-trunk/libgcc/crtstuff.c:463:19: warning: array subscript is above
> array bounds [-Warray-bounds]
>    if (__JCR_LIST__[0])
> 
> is this real or bogus?

Real and bogus at the same time.
STATIC void *__JCR_LIST__[]
  __attribute__ ((used, section(JCR_SECTION_NAME), aligned(sizeof(void*))))
  = { };

So it has a size of 0 so reading 0 is above the array bounds but this is not
normal code.

[Bug tree-optimization/56273] [4.8 regression] Bogus -Warray-bounds warning

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56273

--- Comment #11 from Richard Biener <rguenth at gcc dot gnu.org> 2013-02-21 10:52:44 UTC ---
Author: rguenth
Date: Thu Feb 21 10:52:39 2013
New Revision: 196200

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=196200
Log:
2013-02-21  Richard Biener  <rguenther@suse.de>

    PR tree-optimization/56415
    Revert
    2013-02-11  Richard Biener  <rguenther@suse.de>

    PR tree-optimization/56273
    * tree-vrp.c (simplify_cond_using_ranges): Disable for the
    first VRP run.

    * g++.dg/warn/Warray-bounds-6.C: New testcase.
    * gcc.dg/tree-ssa/pr21559.c: Adjust.
    * gcc.dg/tree-ssa/vrp17.c: Likewise.
    * gcc.dg/tree-ssa/vrp18.c: Likewise.
    * gcc.dg/tree-ssa/vrp23.c: Likewise.
    * gcc.dg/tree-ssa/vrp24.c: Likewise.

Removed:
    trunk/gcc/testsuite/g++.dg/warn/Warray-bounds-6.C
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gcc.dg/tree-ssa/pr21559.c
    trunk/gcc/testsuite/gcc.dg/tree-ssa/vrp17.c
    trunk/gcc/testsuite/gcc.dg/tree-ssa/vrp18.c
    trunk/gcc/testsuite/gcc.dg/tree-ssa/vrp23.c
    trunk/gcc/testsuite/gcc.dg/tree-ssa/vrp24.c
    trunk/gcc/tree-vrp.c

[Bug tree-optimization/56273] [4.8 regression] Bogus -Warray-bounds warning

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56273

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |ASSIGNED
            Version|unknown                     |4.8.0
         Resolution|FIXED                       |

--- Comment #12 from Richard Biener <rguenth at gcc dot gnu.org> 2013-02-21 10:54:02 UTC ---
Re-open, patch has been reverted.

[Bug tree-optimization/56273] [4.8 regression] Bogus -Warray-bounds warning

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56273

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P2
             Status|ASSIGNED                    |NEW
         AssignedTo|rguenth at gcc dot gnu.org  |unassigned at gcc dot
                   |                            |gnu.org

--- Comment #13 from Richard Biener <rguenth at gcc dot gnu.org> 2013-03-08 15:33:17 UTC ---
I give up.  We have to live with this false positive.

[Bug tree-optimization/56273] [4.8/4.9 regression] Bogus -Warray-bounds warning

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56273

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.8.0                       |4.8.1

--- Comment #14 from Jakub Jelinek <jakub at gcc dot gnu.org> 2013-03-22 14:43:00 UTC ---
GCC 4.8.0 is being released, adjusting target milestone.

[Bug tree-optimization/56273] [4.8/4.9 regression] Bogus -Warray-bounds warning

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56273

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.8.1                       |4.8.2

--- Comment #15 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 4.8.1 has been released.

[Bug tree-optimization/56273] [4.8/4.9 regression] Bogus -Warray-bounds warning

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56273

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.8.2                       |4.8.3

--- Comment #16 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 4.8.2 has been released.

[Bug tree-optimization/56273] [4.8/4.9 regression] Bogus -Warray-bounds warning

[law at redhat dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56273

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |law at redhat dot com

--- Comment #17 from Jeffrey A. Law <law at redhat dot com> ---
So what would be the problem with running DOM after full loop unrolling.  We've
known since the early 90s that CSE/cprop after loop unrolling was profitable at
the RTL level.  It wouldn't be a surprise at all that it'd be profitable at the
tree level.  And presumably if we're doing full loop unrolling, then we're
typically an -O3 compile and the extra DOM or VRP pass would be justified from
a compile-time standpoint.

[Bug tree-optimization/56273] [4.8/4.9/4.10 regression] Bogus -Warray-bounds warning

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56273

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.8.3                       |4.8.4

--- Comment #18 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 4.8.3 is being released, adjusting target milestone.

[Bug tree-optimization/56273] [4.8/4.9/5 regression] Bogus -Warray-bounds warning

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56273

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.8.4                       |4.8.5

--- Comment #19 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
GCC 4.8.4 has been released.

[Bug tree-optimization/56273] [4.8/4.9 regression] Bogus -Warray-bounds warning

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56273

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|                            |5.0
            Summary|[4.8/4.9/5 regression]      |[4.8/4.9 regression] Bogus
                   |Bogus -Warray-bounds        |-Warray-bounds warning
                   |warning                     |

--- Comment #20 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed in GCC 5.

--- Comment #21 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Tue Jan 27 09:49:29 2015
New Revision: 220157

URL: https://gcc.gnu.org/viewcvs?rev=220157&root=gcc&view=rev
Log:
2015-01-27  Richard Biener  <rguenther@suse.de>

    PR tree-optimization/56273
    PR tree-optimization/59124
    PR tree-optimization/64277
    * tree-vrp.c (vrp_finalize): Emit array-bound warnings only
    from the first VRP pass.

    * g++.dg/warn/Warray-bounds-6.C: New testcase.
    * gcc.dg/Warray-bounds-12.c: Likewise.
    * gcc.dg/Warray-bounds-13.c: Likewise.

Added:
    trunk/gcc/testsuite/g++.dg/warn/Warray-bounds-6.C
    trunk/gcc/testsuite/gcc.dg/Warray-bounds-12.c
    trunk/gcc/testsuite/gcc.dg/Warray-bounds-13.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-vrp.c

[Bug tree-optimization/56273] [4.8/4.9 regression] Bogus -Warray-bounds warning

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56273

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to work|                            |5.0
            Summary|[4.8/4.9/5 regression]      |[4.8/4.9 regression] Bogus
                   |Bogus -Warray-bounds        |-Warray-bounds warning
                   |warning                     |

--- Comment #20 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed in GCC 5.

--- Comment #21 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Tue Jan 27 09:49:29 2015
New Revision: 220157

URL: https://gcc.gnu.org/viewcvs?rev=220157&root=gcc&view=rev
Log:
2015-01-27  Richard Biener  <rguenther@suse.de>

    PR tree-optimization/56273
    PR tree-optimization/59124
    PR tree-optimization/64277
    * tree-vrp.c (vrp_finalize): Emit array-bound warnings only
    from the first VRP pass.

    * g++.dg/warn/Warray-bounds-6.C: New testcase.
    * gcc.dg/Warray-bounds-12.c: Likewise.
    * gcc.dg/Warray-bounds-13.c: Likewise.

Added:
    trunk/gcc/testsuite/g++.dg/warn/Warray-bounds-6.C
    trunk/gcc/testsuite/gcc.dg/Warray-bounds-12.c
    trunk/gcc/testsuite/gcc.dg/Warray-bounds-13.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-vrp.c

[Bug tree-optimization/56273] [4.8/4.9 regression] Bogus -Warray-bounds warning

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56273

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |rguenth at gcc dot gnu.org

--- Comment #22 from Richard Biener <rguenth at gcc dot gnu.org> ---
Mine for backporting.

[Bug tree-optimization/56273] [4.8/4.9 regression] Bogus -Warray-bounds warning

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56273

--- Comment #23 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Thu Feb 19 14:13:16 2015
New Revision: 220815

URL: https://gcc.gnu.org/viewcvs?rev=220815&root=gcc&view=rev
Log:
2015-02-19  Richard Biener  <rguenther@suse.de>

    Backport from mainline
    2014-12-09  Richard Biener  <rguenther@suse.de>

    PR middle-end/64199
    * fold-const.c (fold_binary_loc): Use TREE_OVERFLOW_P.

    * gcc.dg/torture/pr64199.c: New testcase.

    2015-01-14  Richard Biener  <rguenther@suse.de>

    PR tree-optimization/64493
    PR tree-optimization/64495
    * tree-vect-loop.c (vect_finalize_reduction): For double-reductions
    assign the proper vectorized PHI to the inner loop exit PHIs.

    * gcc.dg/vect/pr64493.c: New testcase.
    * gcc.dg/vect/pr64495.c: Likewise.

    2015-01-27  Richard Biener  <rguenther@suse.de>

    PR tree-optimization/56273
    PR tree-optimization/59124
    PR tree-optimization/64277
    * tree-vrp.c (vrp_finalize): Emit array-bound warnings only
    from the first VRP pass.

    * g++.dg/warn/Warray-bounds-6.C: New testcase.
    * gcc.dg/Warray-bounds-12.c: Likewise.
    * gcc.dg/Warray-bounds-13.c: Likewise.

    2015-02-19  Richard Biener  <rguenther@suse.de>

    Backport from mainline
    2015-01-15  Richard Biener  <rguenther@suse.de>

    PR middle-end/64365
    * tree-data-ref.c (dr_analyze_indices): Make sure that accesses
    for MEM_REF access functions with the same base can never partially
    overlap.

    * gcc.dg/torture/pr64365.c: New testcase.

Added:
    branches/gcc-4_9-branch/gcc/testsuite/g++.dg/warn/Warray-bounds-6.C
    branches/gcc-4_9-branch/gcc/testsuite/gcc.dg/Warray-bounds-12.c
    branches/gcc-4_9-branch/gcc/testsuite/gcc.dg/Warray-bounds-13.c
    branches/gcc-4_9-branch/gcc/testsuite/gcc.dg/torture/pr64199.c
    branches/gcc-4_9-branch/gcc/testsuite/gcc.dg/torture/pr64365.c
    branches/gcc-4_9-branch/gcc/testsuite/gcc.dg/vect/pr64493.c
    branches/gcc-4_9-branch/gcc/testsuite/gcc.dg/vect/pr64495.c
Modified:
    branches/gcc-4_9-branch/gcc/ChangeLog
    branches/gcc-4_9-branch/gcc/fold-const.c
    branches/gcc-4_9-branch/gcc/testsuite/ChangeLog
    branches/gcc-4_9-branch/gcc/tree-data-ref.c
    branches/gcc-4_9-branch/gcc/tree-vect-loop.c
    branches/gcc-4_9-branch/gcc/tree-vrp.c

[Bug tree-optimization/56273] [4.8 regression] Bogus -Warray-bounds warning

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56273

--- Comment #24 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Tue Feb 24 12:49:11 2015
New Revision: 220939

URL: https://gcc.gnu.org/viewcvs?rev=220939&root=gcc&view=rev
Log:
2015-02-24  Richard Biener  <rguenther@suse.de>

        Backport from mainline
        2015-01-27  Richard Biener  <rguenther@suse.de>

    PR tree-optimization/56273
    PR tree-optimization/59124
    PR tree-optimization/64277
    * tree-vrp.c (vrp_finalize): Emit array-bound warnings only
    from the first VRP pass.

    * g++.dg/warn/Warray-bounds-6.C: New testcase.
    * gcc.dg/Warray-bounds-12.c: Likewise.
    * gcc.dg/Warray-bounds-13.c: Likewise.

Added:
    branches/gcc-4_8-branch/gcc/testsuite/g++.dg/warn/Warray-bounds-6.C
    branches/gcc-4_8-branch/gcc/testsuite/gcc.dg/Warray-bounds-12.c
    branches/gcc-4_8-branch/gcc/testsuite/gcc.dg/Warray-bounds-13.c
Modified:
    branches/gcc-4_8-branch/gcc/ChangeLog
    branches/gcc-4_8-branch/gcc/testsuite/ChangeLog
    branches/gcc-4_8-branch/gcc/tree-vrp.c

[Bug tree-optimization/56273] [4.8 regression] Bogus -Warray-bounds warning

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56273

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED
      Known to fail|                            |4.8.4

--- Comment #25 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed.