[Bug tree-optimization/57124] 254.gap@spec2000 got miscompare after r198413

[law at redhat dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57124



--- Comment #2 from Jeffrey A. Law <law at redhat dot com> 2013-05-01 05:13:38 
UTC ---

__attribute__ ((noinline))

foo(short unsigned int *p1, short unsigned int *p2)

{

  short unsigned int x1, x4;

  int x2, x3, x5, x6;

  unsigned int x7;



  x1 = *p1;

  x2 = (int) x1;

  x3 = x2 * 65536;

  x4 = *p2;

  x5 = (int) x4;

  x6 = x3 + x4;

  x7 = (unsigned int) x6;

  if (x7 <= 268435455U)

    abort ();

  exit (0);

}



main()

{

  short unsigned int x, y;

  x = -5;

  y = -10;

  foo (&x, &y);

}





Is a much reduced testcase.  Ultimately we have a range for x6 that's [0,

+INF(OVF)] at which point it's not safe to replace x7 with x6 in the

conditional.