1 /***********************************************************************
2 * *
3 * This software is part of the ast package *
4 * Copyright (c) 1985-2011 AT&T Intellectual Property *
5 * and is licensed under the *
6 * Eclipse Public License, Version 1.0 *
7 * by AT&T Intellectual Property *
8 * *
9 * A copy of the License is available at *
10 * http://www.eclipse.org/org/documents/epl-v10.html *
11 * (with md5 checksum b35adb5213ca9657e911e9befb180842) *
12 * *
13 * Information and Software Systems Research *
14 * AT&T Research *
15 * Florham Park NJ *
16 * *
17 * Glenn Fowler <gsf@research.att.com> *
18 * David Korn <dgk@research.att.com> *
19 * Phong Vo <kpv@research.att.com> *
20 * *
21 ***********************************************************************/
22 #pragma prototyped
23 /*
24 * Glenn Fowler
25 * AT&T Research
26 *
27 * internal representation conversion support
28 */
29
30 #include <ast.h>
31 #include <swap.h>
32
33 /*
34 * return the swap operation for external to internal conversion
35 * if size<0 then (-size) used and (-size==4)&&(op==3) => op=7
36 * this is a workaround for 4 byte magic predicting 8 byte swap
37 */
38
39 int
swapop(const void * internal,const void * external,int size)40 swapop(const void* internal, const void* external, int size)
41 {
42 register int op;
43 register int z;
44 char tmp[sizeof(intmax_t)];
45
46 if ((z = size) < 0)
47 z = -z;
48 if (z <= 1)
49 return 0;
50 if (z <= sizeof(intmax_t))
51 for (op = 0; op < z; op++)
52 if (!memcmp(internal, swapmem(op, external, tmp, z), z))
53 {
54 if (size < 0 && z == 4 && op == 3)
55 op = 7;
56 return op;
57 }
58 return -1;
59 }
60