awips2/nativeLib/rary.ohd.pproc.gribit/TEXT/sbyte.f
2017-04-21 18:33:55 -06:00

89 lines
3.5 KiB
Fortran

SUBROUTINE SBYTE(IOUT,IN,ISKIP,NBYTE)
C THIS PROGRAM WRITTEN BY.....
C DR. ROBERT C. GAMMILL, CONSULTANT
C NATIONAL CENTER FOR ATMOSPHERIC RESEARCH
C JULY 1972
C
C THIS IS THE FORTRAN 32 bit VERSION OF SBYTE.
C Changes for SiliconGraphics IRIS-4D/25
C SiliconGraphics 3.3 FORTRAN 77
C MARCH 1991 RUSSELL E. JONES
C NATIONAL WEATHER SERVICE
C
INTEGER IN
INTEGER IOUT(*)
INTEGER MASKS(32)
C
SAVE
C
C ================================= RCS keyword statements ==========
CHARACTER*68 RCSKW1,RCSKW2
DATA RCSKW1,RCSKW2 / '
.$Source: /fs/hseb/ob72/wfo_rfc/precip_proc/source/gribit/src/RCS/sbyte.f,v $
. $', '
.$Id: sbyte.f,v 1.1 2006/05/03 13:43:59 gsood Exp $
. $' /
C ===================================================================
C
C
DATA NBITSW/32/
C
C DATA MASKS /Z'00000001',Z'00000003',Z'00000007',Z'0000000F',
C & Z'0000001F',Z'0000003F',Z'0000007F',Z'000000FF',
C & Z'000001FF',Z'000003FF',Z'000007FF',Z'00000FFF',
C & Z'00001FFF',Z'00003FFF',Z'00007FFF',Z'0000FFFF',
C & Z'0001FFFF',Z'0003FFFF',Z'0007FFFF',Z'000FFFFF',
C & Z'001FFFFF',Z'003FFFFF',Z'007FFFFF',Z'00FFFFFF',
C & Z'01FFFFFF',Z'03FFFFFF',Z'07FFFFFF',Z'0FFFFFFF',
C & Z'1FFFFFFF',Z'3FFFFFFF',Z'7FFFFFFF',Z'FFFFFFFF'/
C
C MASK TABLE PUT IN DECIMAL SO IT WILL COMPILE ON AN 32 BIT
C COMPUTER
C
DATA MASKS / 1, 3, 7, 15, 31, 63, 127, 255, 511, 1023, 2047,
& 4095, 8191, 16383, 32767, 65535, 131071, 262143, 524287,
& 1048575, 2097151, 4194303, 8388607, 16777215, 33554431,
& 67108863, 134217727, 268435455, 536870911, 1073741823,
& 2147483647, -1/
C
C NBYTE MUST BE LESS THAN OR EQUAL TO NBITSW
C
ICON = NBITSW - NBYTE
IF (ICON.LT.0) RETURN
MASK = MASKS(NBYTE)
C
C INDEX TELLS HOW MANY WORDS INTO IOUT THE NEXT BYTE IS TO BE STORED.
C
INDEX = ISHFT(ISKIP,-5)
C
C II TELLS HOW MANY BITS IN FROM THE LEFT SIDE OF THE WORD TO STORE IT.
C
II = MOD(ISKIP,NBITSW)
C
J = IAND(MASK,IN)
MOVEL = ICON - II
C
C BYTE IS TO BE STORED IN MIDDLE OF WORD. SHIFT LEFT.
C
IF (MOVEL.GT.0) THEN
MSK = ISHFT(MASK,MOVEL)
IOUT(INDEX+1) = IOR(IAND(NOT(MSK),IOUT(INDEX+1)),
& ISHFT(J,MOVEL))
C
C THE BYTE IS TO BE SPLIT ACROSS A WORD BREAK.
C
ELSE IF (MOVEL.LT.0) THEN
MSK = MASKS(NBYTE+MOVEL)
IOUT(INDEX+1) = IOR(IAND(NOT(MSK),IOUT(INDEX+1)),
& ISHFT(J,MOVEL))
ITEMP = IAND(MASKS(NBITSW+MOVEL),IOUT(INDEX+2))
IOUT(INDEX+2) = IOR(ITEMP,ISHFT(J,NBITSW+MOVEL))
C
C BYTE IS TO BE STORED RIGHT-ADJUSTED.
C
ELSE
IOUT(INDEX+1) = IOR(IAND(NOT(MASK),IOUT(INDEX+1)),J)
ENDIF
C
RETURN
END