1 /*********************************************************************** 2 * * 3 * This software is part of the ast package * 4 * Copyright (c) 1985-2007 AT&T Knowledge Ventures * 5 * and is licensed under the * 6 * Common Public License, Version 1.0 * 7 * by AT&T Knowledge Ventures * 8 * * 9 * A copy of the License is available at * 10 * http://www.opensource.org/licenses/cpl1.0.txt * 11 * (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) * 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 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