source: vendor/gcc/current/libf2c/libF77/qbitbits.c

Last change on this file was 1391, checked in by bird, 21 years ago

GCC v3.3.3 sources.

  • Property cvs2svn:cvs-rev set to 1.1.1.2
  • Property svn:eol-style set to native
  • Property svn:executable set to *
File size: 1011 bytes
Line 
1#include "f2c.h"
2
3#ifndef LONGBITS
4#define LONGBITS 32
5#endif
6
7#ifndef LONG8BITS
8#define LONG8BITS (2*LONGBITS)
9#endif
10
11integer
12qbit_bits (longint a, integer b, integer len)
13{
14 /* Assume 2's complement arithmetic */
15
16 ulongint x, y;
17
18 x = (ulongint) a;
19 y = (ulongint) - 1L;
20 x >>= b;
21 y <<= len;
22 return (longint) (x & y);
23}
24
25longint
26qbit_cshift (longint a, integer b, integer len)
27{
28 ulongint x, y, z;
29
30 x = (ulongint) a;
31 if (len <= 0)
32 {
33 if (len == 0)
34 return 0;
35 goto full_len;
36 }
37 if (len >= LONG8BITS)
38 {
39 full_len:
40 if (b >= 0)
41 {
42 b %= LONG8BITS;
43 return (longint) (x << b | x >> (LONG8BITS - b));
44 }
45 b = -b;
46 b %= LONG8BITS;
47 return (longint) (x << (LONG8BITS - b) | x >> b);
48 }
49 y = z = (unsigned long) -1;
50 y <<= len;
51 z &= ~y;
52 y &= x;
53 x &= z;
54 if (b >= 0)
55 {
56 b %= len;
57 return (longint) (y | (z & (x << b | x >> (len - b))));
58 }
59 b = -b;
60 b %= len;
61 return (longint) (y | (z & (x >> b | x << (len - b))));
62}
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