eglibc-2.10.1/sysdeps/ieee754/dbl-64
e_tan2.c line: 406 calls
EMULV in dla.h which overflows

test case
#include <stdio.h>
#include <math.h>
#include <float.h>
#include <fenv.h>

double call_atan2(double x, double y)
        {
        volatile double a = x;
        volatile double b = y;
        volatile double r = atan2(x, y);

        return r;
        }

int main(void)
        {
        double piby4 = call_atan2(DBL_MAX, DBL_MAX);
        fexcept_t fe = fetestexcept(FE_OVERFLOW);
        char *word = fe ? "overflowed" : "";

        printf("atan2(%e, %e) => %e %s\n", DBL_MAX, DBL_MAX, piby4, word);
        return 0;
        }