[2759] | 1 | SUBROUTINE G2LIB_GBYTE(IN,IOUT,ISKIP,NBYTE) |
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| 2 | character*1 in(*) |
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| 3 | integer iout(*) |
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| 4 | CALL G2LIB_GBYTES(IN,IOUT,ISKIP,NBYTE,0,1) |
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| 5 | RETURN |
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| 6 | END |
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| 7 | |
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| 8 | SUBROUTINE G2LIB_SBYTE(OUT,IN,ISKIP,NBYTE) |
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| 9 | character*1 out(*) |
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| 10 | integer in(*) |
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| 11 | CALL G2LIB_SBYTES(OUT,IN,ISKIP,NBYTE,0,1) |
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| 12 | RETURN |
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| 13 | END |
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| 14 | |
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| 15 | SUBROUTINE G2LIB_GBYTES(IN,IOUT,ISKIP,NBYTE,NSKIP,N) |
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| 16 | C Get bytes - unpack bits: Extract arbitrary size values from a |
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| 17 | C packed bit string, right justifying each value in the unpacked |
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| 18 | C array. |
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| 19 | C IN = character*1 array input |
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| 20 | C IOUT = unpacked array output |
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| 21 | C ISKIP = initial number of bits to skip |
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| 22 | C NBYTE = number of bits to take |
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| 23 | C NSKIP = additional number of bits to skip on each iteration |
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| 24 | C N = number of iterations |
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| 25 | C v1.1 |
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| 26 | C |
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| 27 | character*1 in(*) |
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| 28 | integer iout(*) |
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| 29 | integer ones(8), tbit, bitcnt |
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| 30 | save ones |
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| 31 | data ones/1,3,7,15,31,63,127,255/ |
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| 32 | |
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| 33 | c nbit is the start position of the field in bits |
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| 34 | nbit = iskip |
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| 35 | do i = 1, n |
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| 36 | bitcnt = nbyte |
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| 37 | index=nbit/8+1 |
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| 38 | ibit=mod(nbit,8) |
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| 39 | nbit = nbit + nbyte + nskip |
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| 40 | |
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| 41 | c first byte |
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| 42 | tbit = min(bitcnt,8-ibit) |
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| 43 | itmp = iand(mova2i(in(index)),ones(8-ibit)) |
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| 44 | if (tbit.ne.8-ibit) itmp = ishft(itmp,tbit-8+ibit) |
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| 45 | index = index + 1 |
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| 46 | bitcnt = bitcnt - tbit |
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| 47 | |
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| 48 | c now transfer whole bytes |
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| 49 | do while (bitcnt.ge.8) |
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| 50 | itmp = ior(ishft(itmp,8),mova2i(in(index))) |
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| 51 | bitcnt = bitcnt - 8 |
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| 52 | index = index + 1 |
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| 53 | enddo |
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| 54 | |
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| 55 | c get data from last byte |
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| 56 | if (bitcnt.gt.0) then |
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| 57 | itmp = ior(ishft(itmp,bitcnt),iand(ishft(mova2i(in(index)), |
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| 58 | 1 -(8-bitcnt)),ones(bitcnt))) |
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| 59 | endif |
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| 60 | |
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| 61 | iout(i) = itmp |
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| 62 | enddo |
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| 63 | |
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| 64 | RETURN |
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| 65 | END |
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| 66 | |
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| 67 | SUBROUTINE G2LIB_SBYTES(OUT,IN,ISKIP,NBYTE,NSKIP,N) |
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| 68 | C Store bytes - pack bits: Put arbitrary size values into a |
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| 69 | C packed bit string, taking the low order bits from each value |
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| 70 | C in the unpacked array. |
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| 71 | C IOUT = packed array output |
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| 72 | C IN = unpacked array input |
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| 73 | C ISKIP = initial number of bits to skip |
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| 74 | C NBYTE = number of bits to pack |
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| 75 | C NSKIP = additional number of bits to skip on each iteration |
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| 76 | C N = number of iterations |
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| 77 | C v1.1 |
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| 78 | C |
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| 79 | character*1 out(*) |
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| 80 | integer in(N), bitcnt, ones(8), tbit |
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| 81 | save ones |
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| 82 | data ones/ 1, 3, 7, 15, 31, 63,127,255/ |
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| 83 | |
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| 84 | c number bits from zero to ... |
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| 85 | c nbit is the last bit of the field to be filled |
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| 86 | |
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| 87 | nbit = iskip + nbyte - 1 |
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| 88 | do i = 1, n |
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| 89 | itmp = in(i) |
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| 90 | bitcnt = nbyte |
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| 91 | index=nbit/8+1 |
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| 92 | ibit=mod(nbit,8) |
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| 93 | nbit = nbit + nbyte + nskip |
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| 94 | |
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| 95 | c make byte aligned |
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| 96 | if (ibit.ne.7) then |
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| 97 | tbit = min(bitcnt,ibit+1) |
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| 98 | imask = ishft(ones(tbit),7-ibit) |
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| 99 | itmp2 = iand(ishft(itmp,7-ibit),imask) |
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| 100 | itmp3 = iand(mova2i(out(index)), 255-imask) |
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| 101 | out(index) = char(ior(itmp2,itmp3)) |
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| 102 | bitcnt = bitcnt - tbit |
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| 103 | itmp = ishft(itmp, -tbit) |
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| 104 | index = index - 1 |
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| 105 | endif |
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| 106 | |
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| 107 | c now byte aligned |
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| 108 | |
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| 109 | c do by bytes |
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| 110 | do while (bitcnt.ge.8) |
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| 111 | out(index) = char(iand(itmp,255)) |
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| 112 | itmp = ishft(itmp,-8) |
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| 113 | bitcnt = bitcnt - 8 |
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| 114 | index = index - 1 |
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| 115 | enddo |
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| 116 | |
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| 117 | c do last byte |
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| 118 | |
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| 119 | if (bitcnt.gt.0) then |
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| 120 | itmp2 = iand(itmp,ones(bitcnt)) |
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| 121 | itmp3 = iand(mova2i(out(index)), 255-ones(bitcnt)) |
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| 122 | out(index) = char(ior(itmp2,itmp3)) |
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| 123 | endif |
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| 124 | enddo |
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| 125 | |
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| 126 | return |
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| 127 | end |
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