[Bug tree-optimization/64493] New: ICE at -O3 on x86_64-linux-gnu

[Bug tree-optimization/64493] New: ICE at -O3 on x86_64-linux-gnu

[su at cs dot ucdavis.edu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64493

            Bug ID: 64493
           Summary: ICE at -O3 on x86_64-linux-gnu
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: su at cs dot ucdavis.edu

The following code causes an ICE when compiled with the current gcc trunk at
-O3 on x86_64-linux-gnu in both 32-bit and 64-bit modes. 

It is a regression from 4.9.x.

$ gcc-trunk -v
Using built-in specs.
COLLECT_GCC=gcc-trunk
COLLECT_LTO_WRAPPER=/usr/local/gcc-trunk/libexec/gcc/x86_64-unknown-linux-gnu/5.0.0/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with: ../gcc-trunk/configure --prefix=/usr/local/gcc-trunk
--enable-languages=c,c++ --disable-werror --enable-multilib
Thread model: posix
gcc version 5.0.0 20150104 (experimental) [trunk revision 219172] (GCC) 

$ 
$ gcc-trunk -O2 small.c; a.out
$ gcc-4.9 -O3 small.c; a.out
$ 
$ gcc-trunk -O3 small.c
small.c: In function ‘main’:
small.c:6:1: error: definition in block 13 does not dominate use in block 12
 main ()
 ^
for SSA_NAME: vect_c.29_53 in statement:
vect_e.35_1 = vect_c.29_53 | vect_e.35_18;
small.c:6:1: internal compiler error: verify_ssa failed
0xc8c6b1 verify_ssa(bool, bool)
    ../../gcc-trunk/gcc/tree-ssa.c:1062
0x9daae5 execute_function_todo
    ../../gcc-trunk/gcc/passes.c:1947
0x9db523 execute_todo
    ../../gcc-trunk/gcc/passes.c:1997
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <http://gcc.gnu.org/bugs.html> for instructions.
$ 


------------------------------


#include <assert.h>

int a, b, c, d, e, f, g, h;

int
main ()
{
  for (; a; a--)
    for (d = 1; d <= 0; d++)
      for (; d;)
    if (h)
      {
        assert (g);
        assert (0);
      }

  for (f = 4; f; f--)
    {
      for (b = 0; b < 2; b++)
    c |= 1;
      e |= c;
    }

  return 0;
}
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https://gcc.gnu.org/bugzilla/show_bug.cgi?idc251

Bernd Edlinger <bernd.edlinger at hotmail dot de> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |bernd.edlinger at hotmail dot de

--- Comment #1 from Bernd Edlinger <bernd.edlinger at hotmail dot de> ---
Dmitry,

we fixed that one, but the latest LLVM tree needs still to be merged to GCC.

Bernd.

[Bug tree-optimization/64493] [4.8/4.9/5 Regression] ICE at -O3 on x86_64-linux-gnu

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64493

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2015-01-05
                 CC|                            |jakub at gcc dot gnu.org
   Target Milestone|---                         |4.8.5
            Summary|ICE at -O3 on               |[4.8/4.9/5 Regression] ICE
                   |x86_64-linux-gnu            |at -O3 on x86_64-linux-gnu
     Ever confirmed|0                           |1

--- Comment #1 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
To avoid the #include, I've used
int a, b, c, d, e, f, g, h;

int
main ()
{
  for (; a; a--)
    for (d = 1; d <= 0; d++)
      for (; d;)
    if (h)
      {
        if (!g) __builtin_abort ();
        if (!0) __builtin_abort ();
      }

  for (f = 4; f; f--)
    {
      for (b = 0; b < 2; b++)
    c |= 1;
      e |= c;
    }

  return 0;
}

and that started to ICE with r181990.

[Bug tree-optimization/64493] [4.8/4.9/5 Regression] ICE at -O3 on x86_64-linux-gnu

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64493

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P2

[Bug tree-optimization/64493] [4.8/4.9/5 Regression] ICE at -O3 on x86_64-linux-gnu

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64493

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 #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Mine.

[Bug tree-optimization/64493] [4.8/4.9/5 Regression] ICE at -O3 on x86_64-linux-gnu

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64493

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
I tried to make a runtime testcase that tests for proper vectorization but
all vectorized code ends up being dead.  Nevertheless the following fixes
the ICE:

Index: gcc/tree-vect-loop.c
===================================================================
--- gcc/tree-vect-loop.c        (revision 219520)
+++ gcc/tree-vect-loop.c        (working copy)
@@ -4580,7 +4580,10 @@ vect_finalize_reduction:
                            && !STMT_VINFO_LIVE_P (exit_phi_vinfo))
                           || double_reduc);

-              STMT_VINFO_VEC_STMT (exit_phi_vinfo) = epilog_stmt;
+             if (double_reduc)
+               STMT_VINFO_VEC_STMT (exit_phi_vinfo) = inner_phi;
+             else
+               STMT_VINFO_VEC_STMT (exit_phi_vinfo) = epilog_stmt;
               if (!double_reduc
                   || STMT_VINFO_DEF_TYPE (exit_phi_vinfo)
                       != vect_double_reduction_def)

and the generated code looks reasonable.  I think we don't really support
the case where the inner reduction result is used in the outer loop (but
in !relevant stmts which end up dead).

Well.  Not 100% sure.

[Bug tree-optimization/64493] [4.8/4.9 Regression] ICE at -O3 on x86_64-linux-gnu

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64493

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |ice-on-valid-code
      Known to work|                            |5.0
            Summary|[4.8/4.9/5 Regression] ICE  |[4.8/4.9 Regression] ICE at
                   |at -O3 on x86_64-linux-gnu  |-O3 on x86_64-linux-gnu

--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed on trunk sofar.

[Bug tree-optimization/64493] [4.8/4.9/5 Regression] ICE at -O3 on x86_64-linux-gnu

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64493

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Wed Jan 14 08:32:18 2015
New Revision: 219579

URL: https://gcc.gnu.org/viewcvs?rev=219579&root=gcc&view=rev
Log:
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.

Added:
    trunk/gcc/testsuite/gcc.dg/vect/pr64493.c
    trunk/gcc/testsuite/gcc.dg/vect/pr64495.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-vect-loop.c

[Bug tree-optimization/64493] [4.8/4.9 Regression] ICE at -O3 on x86_64-linux-gnu

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64493

--- Comment #6 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/64493] [4.8 Regression] ICE at -O3 on x86_64-linux-gnu

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64493

--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> ---
Author: rguenth
Date: Tue Feb 24 14:05:46 2015
New Revision: 220940

URL: https://gcc.gnu.org/viewcvs?rev=220940&root=gcc&view=rev
Log:
2015-02-24  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.

Added:
    branches/gcc-4_8-branch/gcc/testsuite/gcc.dg/torture/pr64199.c
    branches/gcc-4_8-branch/gcc/testsuite/gcc.dg/vect/pr64493.c
    branches/gcc-4_8-branch/gcc/testsuite/gcc.dg/vect/pr64495.c
Modified:
    branches/gcc-4_8-branch/gcc/ChangeLog
    branches/gcc-4_8-branch/gcc/fold-const.c
    branches/gcc-4_8-branch/gcc/testsuite/ChangeLog
    branches/gcc-4_8-branch/gcc/tree-vect-loop.c

[Bug tree-optimization/64493] [4.8 Regression] ICE at -O3 on x86_64-linux-gnu

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64493

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
      Known to work|                            |4.8.5
         Resolution|---                         |FIXED
      Known to fail|                            |4.8.4

--- Comment #8 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed.