diff options
Diffstat (limited to 'contrib/libf2c/libF77/lbitbits.c')
-rw-r--r-- | contrib/libf2c/libF77/lbitbits.c | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/contrib/libf2c/libF77/lbitbits.c b/contrib/libf2c/libF77/lbitbits.c new file mode 100644 index 0000000..75e9f9c --- /dev/null +++ b/contrib/libf2c/libF77/lbitbits.c @@ -0,0 +1,62 @@ +#include "f2c.h" + +#ifndef LONGBITS +#define LONGBITS 32 +#endif + + integer +#ifdef KR_headers +lbit_bits(a, b, len) integer a, b, len; +#else +lbit_bits(integer a, integer b, integer len) +#endif +{ + /* Assume 2's complement arithmetic */ + + unsigned long x, y; + + x = (unsigned long) a; + y = (unsigned long)-1L; + x >>= b; + y <<= len; + return (integer)(x & ~y); + } + + integer +#ifdef KR_headers +lbit_cshift(a, b, len) integer a, b, len; +#else +lbit_cshift(integer a, integer b, integer len) +#endif +{ + unsigned long x, y, z; + + x = (unsigned long)a; + if (len <= 0) { + if (len == 0) + return 0; + goto full_len; + } + if (len >= LONGBITS) { + full_len: + if (b >= 0) { + b %= LONGBITS; + return (integer)(x << b | x >> LONGBITS -b ); + } + b = -b; + b %= LONGBITS; + return (integer)(x << LONGBITS - b | x >> b); + } + y = z = (unsigned long)-1; + y <<= len; + z &= ~y; + y &= x; + x &= z; + if (b >= 0) { + b %= len; + return (integer)(y | z & (x << b | x >> len - b)); + } + b = -b; + b %= len; + return (integer)(y | z & (x >> b | x << len - b)); + } |