Test case:

// gcc main.c -std=c99 -lm
#include <stdio.h>
#include <fenv.h>
#include <stdlib.h>  // abs function for int argument

extern float j0f(float);
extern double j0(double);

#define i32(a)    (((int*)&(a))[0])

int main() {
    float a,r1,r2;

    i32(a)=0x413caa1f;    //argument

    fesetround(FE_TONEAREST);

    r1 = j0f(a);  //actual result
    r2 = j0(a);   //actual result 2

    printf("inputs: a = (0x%08x)\t%e\n", i32(a), a);
    printf("actual    = (0x%08x)\t%.13e\n", i32(r1), r1);
    printf("expected  = (0x%08x)\t%.13e\n", i32(r2), r2);
    printf("error     = %d ulp\n", abs(i32(r1) - i32(r2)));

    return 0;
}

Result:

inputs: a = (0x413caa1f)        1.179153e+01
actual    = (0xb471e828)        -2.2529331999976e-07
expected  = (0xb471d452)        -2.2522115727952e-07
error     = 5078 ulp