Long floating-point number

Sample Fortran usage (by Value) C function (by Value)

Sample Fortran usage (by Value)	C function (by Value)
`REAL8 X, Y, CENTRY X = 12.5D0 Y = CENTRY((X)) PRINT , 1 'VALUE RETURNED TO FORTRAN:', Y END`	`#pragma linkage (centry,FORTRAN) #include <stdio.h> double centry(double x) { printf("C arg value: %f\n",x); return(x); }`

REAL*8 X, Y, CENTRY
X = 12.5D0
Y = CENTRY((X))
PRINT *,
1  'VALUE RETURNED TO FORTRAN:', Y
END

#pragma linkage (centry,FORTRAN)
#include <stdio.h>
double centry(double x)
{
  printf("C arg value: %f\n",x);
  return(x);
}

Sample Fortran usage C function (by Reference)

Sample Fortran usage	C function (by Reference)
`REAL8 X, Y, CENTRY X = 5.0D0 Y = CENTRY(X) PRINT , 1 'VALUE RETURNED TO FORTRAN:', Y END`	`#pragma linkage (centry,FORTRAN) #include <stdio.h> double centry(double x) { printf ("C double arg value: %f\n",x); return(*x); }`

REAL*8 X, Y, CENTRY
X = 5.0D0
Y = CENTRY(X)
PRINT *,
1  'VALUE RETURNED TO FORTRAN:', Y
END

#pragma linkage (centry,FORTRAN)
#include <stdio.h>
double centry(double *x)
{
  printf
    ("C double arg value: %f\n",*x);
  return(*x);
}