67 lines
1.1 KiB
C
67 lines
1.1 KiB
C
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#include "f2c.h"
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#ifndef LONGBITS
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#define LONGBITS 32
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#endif
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#ifndef LONG8BITS
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#define LONG8BITS (2*LONGBITS)
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#endif
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integer
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#ifdef KR_headers
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qbit_bits(a, b, len) longint a; integer b, len;
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#else
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qbit_bits(longint a, integer b, integer len)
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#endif
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{
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/* Assume 2's complement arithmetic */
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ulongint x, y;
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x = (ulongint) a;
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y = (ulongint)-1L;
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x >>= b;
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y <<= len;
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return (longint)(x & y);
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}
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longint
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#ifdef KR_headers
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qbit_cshift(a, b, len) longint a; integer b, len;
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#else
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qbit_cshift(longint a, integer b, integer len)
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#endif
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{
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ulongint x, y, z;
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x = (ulongint)a;
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if (len <= 0) {
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if (len == 0)
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return 0;
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goto full_len;
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}
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if (len >= LONG8BITS) {
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full_len:
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if (b >= 0) {
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b %= LONG8BITS;
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return (longint)(x << b | x >> LONG8BITS - b );
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}
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b = -b;
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b %= LONG8BITS;
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return (longint)(x << LONG8BITS - b | x >> b);
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}
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y = z = (unsigned long)-1;
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y <<= len;
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z &= ~y;
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y &= x;
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x &= z;
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if (b >= 0) {
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b %= len;
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return (longint)(y | z & (x << b | x >> len - b));
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}
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b = -b;
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b %= len;
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return (longint)(y | z & (x >> b | x << len - b));
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}
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