struct s {
        int c;
        int a[];
} s;
int f;

void fun(void);
void foo(void)
{
        for (f = 1;;)
                if (s.a[f])
                        fun();
}

/*
 * check-name: global var as loop index
 * check-command: test-linearize -Wno-decl -fdump-ir=mem2reg $file
 * check-output-ignore
 * check-output-contains: load\\..*\\[f\\]
 */