[Bug c/61944] New: loop-iv.c:2610 signed integer overflow

[zeccav at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61944

            Bug ID: 61944
           Summary: loop-iv.c:2610 signed integer overflow
           Product: gcc
           Version: 4.9.1
            Status: UNCONFIRMED
          Severity: minor
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zeccav at gmail dot com

// from pr42049.c
// gcc -funroll-loops -O
// ../../gcc-4.9.1/gcc/loop-iv.c:2610:14: runtime error: 
// signed integer overflow: 7 - -9223372036854775808 cannot be represented in
type 'long int'
// "max = (up - down) / inc + 1;"
extern char *strcpy (char *s1, const char *s2);
struct S { char s[4]; };

int
foo (int x, char **y)
{
  struct S s[9];
  long i;
  for (i = 2; i  && i < 8; i++)
    strcpy (s[i].s, y[i + 1]);
}