I have a doubt about ifort_64 compiler. I compiled and ran
program using ifort_64
[dshetty@rob ~]$ ifort_64 testd1.f
[dshetty@rob ~]$ ./a.out
1 2.225073858507201E-308
2 1.797693134862316E+308
3 1.110223024625157E-016
4 2.220446049250313E-016
5 0.301029995663981
0.000000000000000E+000
NaN
0.000000000000000E+000
0.000000000000000E+000
21404579840.0000
and when the same program compiled with ifort on the same machine
[dshetty@rob ~]$ ifort testd1.f
[dshetty@rob~]$ ./a.out
1 2.225073858507201E-308
2 1.797693134862316E+308
3 1.110223024625157E-016
4 2.220446049250313E-016
5 0.301029995663981
2.225073858507201E-308
1.797693134862316E+308
1.110223024625157E-016
2.220446049250313E-016
0.301029995663981
Is there anything wrong with the way I am running the code?
Below is the code :testd1.f
PROGRAM MAIN
double precision x(5)
x(1)=D1MACH(1)
x(2)=D1MACH(2)
x(3)=D1MACH(3)
x(4)=D1MACH(4)
x(5)=D1MACH(5)
WRITE(*,*)x(1)
WRITE(*,*)x(2)
WRITE(*,*)x(3)
WRITE(*,*)x(4)
WRITE(*,*)x(5)
END
!DECK D1MACH
DOUBLE PRECISION FUNCTION D1MACH (I)
IMPLICIT NONE
INTEGER :: I
DOUBLE PRECISION :: B, X
X = 1.0D0
B = RADIX(X)
SELECT CASE (I)
CASE (1)
D1MACH = B**(MINEXPONENT(X)-1) ! the smallest positive magnitude.
CASE (2)
D1MACH = HUGE(X) ! the largest magnitude.
CASE (3)
D1MACH = B**(-DIGITS(X)) ! the smallest relative spacing.
CASE (4)
D1MACH = B**(1-DIGITS(X)) ! the largest relative spacing.
CASE (5)
D1MACH = log10(B)
CASE DEFAULT
WRITE (*, FMT = 9000)
9000 FORMAT ('1ERROR 1 IN D1MACH - I OUT OF BOUNDS')
STOP
END SE
LECT
write(*,*)I, D1MACH
RETURN
thanx
