[Bug c/52653] New: GCC 4.6.* bug on i386 Linux and mingw platforms

[Bug c/52653] New: GCC 4.6.* bug on i386 Linux and mingw platforms

[borut.razem at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52653

             Bug #: 52653
           Summary: GCC 4.6.* bug on i386 Linux and mingw platforms
    Classification: Unclassified
           Product: gcc
           Version: 4.6.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: borut.razem@gmail.com


The following code hangs the gcc 4.6.* compiler on i386 Linux and mingw
platforms.

Content of t.c:
----8<----
#define double2ul(val)  (((val) < 0) ? (((val) < -2147483647.0) ? 0x80000000UL
: (unsigned long) -((long) -(val))) : (unsigned long) (val))

extern double bar ();

/* This seems to be a GCC 4.6.[012] bug on i386 Linux and mingw platforms
 */
void
foo (void)
{
  int x = 100000 >> double2ul (bar ());
}
---->8----

Command:
gcc -c t.c

Compiler hangs on OS version:
$ uname -srvmpo
Linux 2.6.32-5-686 #1 SMP Wed Jan 11 12:29:30 UTC 2012 i686 unknown GNU/Linux

Compiler version:
$ gcc --version
gcc (GCC) 4.6.1
Copyright (C) 2011 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

It compiles correctly on OS version:
$ uname -srvmpo
Linux 3.0.0-16-generic #29-Ubuntu SMP Tue Feb 14 12:48:51 UTC 2012 x86_64
x86_64 GNU/Linux

Compiler version$ gcc --version
gcc (Ubuntu/Linaro 4.6.1-9ubuntu3) 4.6.1
Copyright (C) 2011 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Borut

[Bug c/52653] GCC 4.6.* bug on i386 Linux and mingw platforms

[mikpe at it dot uu.se]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52653

Mikael Pettersson <mikpe at it dot uu.se> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |mikpe at it dot uu.se

--- Comment #1 from Mikael Pettersson <mikpe at it dot uu.se> 2012-03-21 10:50:31 UTC ---
I can reproduce the gcc hang on i686-linux with 4.6.3.  4.5.3 and older don't
hang.

[Bug middle-end/52653] GCC 4.6.* bug on i386 Linux and mingw platforms

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52653

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2012-03-21
          Component|c                           |middle-end
     Ever Confirmed|0                           |1

--- Comment #2 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-03-21 11:50:52 UTC ---
We iterate endlessly between lshift_double and rshift_double if
-count == count.

[Bug middle-end/52653] GCC 4.6.* bug on i386 Linux and mingw platforms

[mikpe at it dot uu.se]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52653

--- Comment #3 from Mikael Pettersson <mikpe at it dot uu.se> 2012-03-21 12:55:55 UTC ---
It's caused by r158372, but silent with 4.7.0 on i686.  Duplicate of PR50708.

[Bug middle-end/52653] GCC 4.6.* bug on i386 Linux and mingw platforms

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52653

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

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

--- Comment #4 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-03-28 14:23:40 UTC ---
.

*** This bug has been marked as a duplicate of bug 50708 ***