1 |
jmc |
1.3 |
C $Header: /u/gcmpack/MITgcm/eesupp/src/mds_byteswapr4.F,v 1.2 2006/11/22 09:43:27 dimitri Exp $ |
2 |
jmc |
1.1 |
C $Name: $ |
3 |
|
|
|
4 |
|
|
#include "CPP_EEOPTIONS.h" |
5 |
|
|
|
6 |
|
|
subroutine MDS_BYTESWAPR4( n, arr ) |
7 |
|
|
C IN: |
8 |
jmc |
1.3 |
C n integer :: Number of 4-byte words in arr |
9 |
jmc |
1.1 |
C IN/OUT: |
10 |
jmc |
1.3 |
C arr real*4 :: Array declared as real*4(n) |
11 |
jmc |
1.1 |
C |
12 |
|
|
C Created: 05/05/99 adcroft@mit.edu (This is an unfortunate hack!!) |
13 |
|
|
|
14 |
|
|
implicit none |
15 |
dimitri |
1.2 |
|
16 |
|
|
#ifdef FAST_BYTESWAP |
17 |
|
|
|
18 |
|
|
C Arguments |
19 |
|
|
integer n |
20 |
|
|
integer(kind=4) arr(n), i32 |
21 |
|
|
|
22 |
|
|
C Local |
23 |
|
|
integer i |
24 |
|
|
|
25 |
|
|
i32(i) = ishft(i.and. z'ff000000', -24) .or. |
26 |
|
|
& ishft(i.and. z'00ff0000', -8) .or. |
27 |
|
|
& ishft(i.and. z'0000ff00', 8) .or. |
28 |
|
|
& ishft(i.and. z'000000ff', 24) |
29 |
|
|
do i = 1,n |
30 |
|
|
arr(i) = i32(arr(i)) |
31 |
|
|
enddo |
32 |
|
|
|
33 |
|
|
#else /* FAST_BYTESWAP */ |
34 |
|
|
|
35 |
jmc |
1.1 |
C Arguments |
36 |
|
|
integer n |
37 |
|
|
character*(*) arr |
38 |
dimitri |
1.2 |
|
39 |
jmc |
1.1 |
C Local |
40 |
|
|
integer i |
41 |
|
|
character*(1) cc |
42 |
dimitri |
1.2 |
|
43 |
jmc |
1.1 |
do i=1,4*n,4 |
44 |
|
|
cc=arr(i:i) |
45 |
|
|
arr(i:i)=arr(i+3:i+3) |
46 |
|
|
arr(i+3:i+3)=cc |
47 |
|
|
cc=arr(i+1:i+1) |
48 |
|
|
arr(i+1:i+1)=arr(i+2:i+2) |
49 |
|
|
arr(i+2:i+2)=cc |
50 |
|
|
enddo |
51 |
dimitri |
1.2 |
|
52 |
|
|
#endif /* FAST_BYTESWAP */ |
53 |
|
|
|
54 |
jmc |
1.1 |
return |
55 |
|
|
end |