[Bug c/52286] wrong code bug

[regehr at cs dot utah.edu]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52286

John Regehr <regehr at cs dot utah.edu> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |chenyang at cs dot utah.edu

--- Comment #1 from John Regehr <regehr at cs dot utah.edu> 2012-02-16 18:48:18 
UTC ---
[regehr@gamow 1]$ current-gcc -O0 small.c ; ./a.out 
1
[regehr@gamow 1]$ current-gcc -O1 small.c ; ./a.out 
0
[regehr@gamow 1]$ current-gcc -v
Using built-in specs.
COLLECT_GCC=current-gcc
COLLECT_LTO_WRAPPER=/uusoc/exports/scratch/regehr/z/compiler-install/gcc-r184311-install/bin/../libexec/gcc/x86_64-unknown-linux-gnu/4.7.0/lto-wrapper
Target: x86_64-unknown-linux-gnu
Configured with: ../configure --with-libelf=/usr/local --enable-lto
--prefix=/home/regehr/z/compiler-install/gcc-r184311-install
--program-prefix=r184311- --enable-languages=c,c++
Thread model: posix
gcc version 4.7.0 20120216 (experimental) (GCC) 
[regehr@gamow 1]$ cat small.c
int printf ( const char *, ... );

int c,
  a,
  b;

int
fn1 ( void )
{
  return c < 0;
}

int
main (  )
{
  b = ( ~a | 0 >= 0 ) & 0x98685255F;
  printf ( "%d\n", ( ( b ) < 0 ) );
  return 0;
}