[Bug c/54321] New: ice in tree_low_cst at -O3

[Bug c/54321] New: ice in tree_low_cst at -O3

[dcb314 at hotmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54321

             Bug #: 54321
           Summary: ice in tree_low_cst at -O3
    Classification: Unclassified
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: dcb314@hotmail.com


Created attachment 28050
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=28050
C source code

I just tried to compile the package fcron-3.0.6-5
on gcc-4.8 trunk dated 20120819 on an AMD x86_64 box.

The compiler said

fileconf.c: In function 'read_period':
fileconf.c:1317:1: internal compiler error: in tree_low_cst, at tree.c:6546
 read_period(char *ptr, cf_t *cf)
 ^
Please submit a full bug report,
with preprocessed source if appropriate.
See <http://gcc.gnu.org/bugs.html> for instructions.

Preprocessed source code attached. Flag -O3 required.

[Bug c/54321] ice in tree_low_cst at -O3

[markus at trippelsdorf dot de]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54321

Markus Trippelsdorf <markus at trippelsdorf dot de> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |markus at trippelsdorf dot
                   |                            |de

--- Comment #1 from Markus Trippelsdorf <markus at trippelsdorf dot de> 2012-08-19 11:08:45 UTC ---
typedef struct
{
    char cl_mins[0];
}
cl_t;
cl_t *a;
void fn1 ()
{
    char *b = a->cl_mins;
    int c = 0;
    b[0] = 0;
    while (++c < 9)
        b[c] = 255;
}

[Bug middle-end/54321] [4.8 Regression] ice in tree_low_cst at -O3

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54321

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |ice-on-valid-code
          Component|c                           |middle-end
   Target Milestone|---                         |4.8.0
            Summary|ice in tree_low_cst at -O3  |[4.8 Regression] ice in
                   |                            |tree_low_cst at -O3

[Bug middle-end/54321] [4.8 Regression] ice in tree_low_cst at -O3

[hjl.tools at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54321

H.J. Lu <hjl.tools at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2012-08-19
                 CC|                            |rguenth at gcc dot gnu.org
     Ever Confirmed|0                           |1

--- Comment #2 from H.J. Lu <hjl.tools at gmail dot com> 2012-08-19 18:53:56 UTC ---
It is caused by revision 188232:

http://gcc.gnu.org/ml/gcc-cvs/2012-06/msg00142.html

[Bug middle-end/54321] [4.8 Regression] ice in tree_low_cst at -O3

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54321

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

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

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-08-19 20:22:39 UTC ---
Created attachment 28053
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=28053
gcc48-pr54321.patch

The bug is pretty much obvious, val2 is first checked for host_integerp (val2,
0) but then tree_low_cst (val2, 1) is used.  As the middle argument to memset
is int, we should use tree_low_cst (val2, 0).

I'll bootstrap/regtest this momentarily.

[Bug middle-end/54321] [4.8 Regression] ice in tree_low_cst at -O3

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54321

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-08-20 09:12:11 UTC ---
Author: jakub
Date: Mon Aug 20 09:12:05 2012
New Revision: 190526

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=190526
Log:
    PR tree-optimization/54321
    * tree-ssa-forwprop.c (simplify_builtin_call): Pass 0 instead of 1
    as second argument to tree_low_cst call on val2.

    * gcc.c-torture/compile/pr54321.c: New test.

Added:
    trunk/gcc/testsuite/gcc.c-torture/compile/pr54321.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-ssa-forwprop.c

[Bug middle-end/54321] [4.8 Regression] ice in tree_low_cst at -O3

[jakub at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54321

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

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

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-08-20 09:14:54 UTC ---
Fixed.