mirror of
git://gcc.gnu.org/git/gcc.git
synced 2024-12-24 14:59:53 +08:00
63 lines
1.0 KiB
C
63 lines
1.0 KiB
C
|
#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));
|
||
|
}
|