Comparison of Fortran and C for division by 0

test_sgnd.c

// command gcc -Wall -Wextra -pedantic test_sgnd.c -lm -o test_sgnd_c && ./test_sgnd_c
#include <stdio.h>
#include <math.h>

// Test sgnd = dp*(dx/ABS(dx)) for all combinations of [1, 0, -0, 1]
int main(void)
{
    const double dp[4] = {  1.0,  0.0, -0.0,  -1.0 };
    const double dx[4] = {  1.0,  0.0, -0.0,  -1.0 };

    puts("   dp        dx        sgnd");
    for (int i = 0; i < 4; ++i) {
        for (int j = 0; j < 4; ++j) {
            double sgnd = dp[i] * (dx[j] / fabs(dx[j]));
	    //double sgnd = copysign(dp[i], dx[j]);
            printf("%8.2f %8.2f %8.2f\n", dp[i], dx[j], sgnd);
        }
    }
    return 0;
}

test_sgnd.f

C     Command gfortran -std=legacy -Wall -Wsurprising -Waliasing -Wconversion          -Wimplicit-interface -pedantic -fcheck=all -g          -o test_sgnd test_sgnd.f && ./test_sgnd
      PROGRAM TEST_SGND
C     Test sgnd = dp*(dx/ABS(dx)) for all combinations of [1, 0, -0, 1]
      IMPLICIT NONE
      DOUBLE PRECISION dp(4), dx(4), sgnd
      INTEGER i, j

C     Values (note −0.0 to exercise negative-zero on IEEE targets)
      DATA dp /  1.0D0, 0.0D0, -0.0D0, -1.0D0 /
      DATA dx /  1.0D0, 0.0D0, -0.0D0, -1.0D0 /

      PRINT *, '   dp        dx        sgnd'
      DO 20 i = 1, 4
         DO 10 j = 1, 4
            sgnd = dp(i) * (dx(j) / ABS(dx(j)))
            PRINT '(F8.2,1X,F8.2,1X,F8.2)', dp(i), dx(j), sgnd
10       CONTINUE
20    CONTINUE
      END