[Bug tree-optimization/55883] New: with -fwrapv, (x < 0 && -x < 0) is assumed to be false

[xi.wang at gmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55883



             Bug #: 55883

           Summary: with -fwrapv, (x < 0 && -x < 0) is assumed to be false

    Classification: Unclassified

           Product: gcc

           Version: 4.7.2

            Status: UNCONFIRMED

          Severity: normal

          Priority: P3

         Component: tree-optimization

        AssignedTo: unassig...@gcc.gnu.org

        ReportedBy: xi.w...@gmail.com





This is slightly different from Bug 22493.



#include <limits.h>

void abort ();

void f(int i)

{

  if (i<0 && -i<0)

    return;

  abort ();

}



int main(void)

{

  f(INT_MIN);

  return 0;

}



The program should not abort if compiled with -fwrapv.  4.7.2 and 4.6.3 seem to

miscompile it.  4.8 is good.