NASM 2.07rc7
[nasm.git] / sync.c
blob7dd943ca06be524d5034ed0e28c63cfb74709821
1 /* ----------------------------------------------------------------------- *
2 *
3 * Copyright 1996-2009 The NASM Authors - All Rights Reserved
4 * See the file AUTHORS included with the NASM distribution for
5 * the specific copyright holders.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following
9 * conditions are met:
11 * * Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * * Redistributions in binary form must reproduce the above
14 * copyright notice, this list of conditions and the following
15 * disclaimer in the documentation and/or other materials provided
16 * with the distribution.
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
19 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
20 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
21 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
22 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
23 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
25 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
26 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
29 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
30 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 * ----------------------------------------------------------------------- */
35 * sync.c the Netwide Disassembler synchronisation processing module
38 #include "compiler.h"
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <limits.h>
43 #include <inttypes.h>
45 #include "nasmlib.h"
46 #include "sync.h"
48 #define SYNC_MAX 4096 /* max # of sync points (initial) */
51 * This lot manages the current set of sync points by means of a
52 * heap (priority queue) structure.
55 static struct Sync {
56 uint32_t pos;
57 uint32_t length;
58 } *synx;
59 static int max_synx, nsynx;
61 void init_sync(void)
63 max_synx = SYNC_MAX-1;
64 synx = nasm_malloc(SYNC_MAX * sizeof(*synx));
65 nsynx = 0;
68 void add_sync(uint32_t pos, uint32_t length)
70 int i;
72 if (nsynx >= max_synx) {
73 max_synx = (max_synx << 1)+1;
74 synx = nasm_realloc(synx, (max_synx+1) * sizeof(*synx));
77 nsynx++;
78 synx[nsynx].pos = pos;
79 synx[nsynx].length = length;
81 for (i = nsynx; i > 1; i /= 2) {
82 if (synx[i / 2].pos > synx[i].pos) {
83 struct Sync t;
84 t = synx[i / 2]; /* structure copy */
85 synx[i / 2] = synx[i]; /* structure copy again */
86 synx[i] = t; /* another structure copy */
91 uint32_t next_sync(uint32_t position, uint32_t *length)
93 while (nsynx > 0 && synx[1].pos + synx[1].length <= position) {
94 int i, j;
95 struct Sync t;
96 t = synx[nsynx]; /* structure copy */
97 synx[nsynx] = synx[1]; /* structure copy */
98 synx[1] = t; /* ditto */
100 nsynx--;
102 i = 1;
103 while (i * 2 <= nsynx) {
104 j = i * 2;
105 if (synx[j].pos < synx[i].pos &&
106 (j + 1 > nsynx || synx[j + 1].pos > synx[j].pos)) {
107 t = synx[j]; /* structure copy */
108 synx[j] = synx[i]; /* lots of these... */
109 synx[i] = t; /* ...aren't there? */
110 i = j;
111 } else if (j + 1 <= nsynx && synx[j + 1].pos < synx[i].pos) {
112 t = synx[j + 1]; /* structure copy */
113 synx[j + 1] = synx[i]; /* structure <yawn> copy */
114 synx[i] = t; /* structure copy <zzzz....> */
115 i = j + 1;
116 } else
117 break;
121 if (nsynx > 0) {
122 if (length)
123 *length = synx[1].length;
124 return synx[1].pos;
125 } else {
126 if (length)
127 *length = 0L;
128 return 0;