1 /* sync.c the Netwide Disassembler synchronisation processing module
3 * The Netwide Assembler is copyright (C) 1996 Simon Tatham and
4 * Julian Hall. All rights reserved. The software is
5 * redistributable under the licence given in the file "Licence"
6 * distributed in the NASM archive.
15 #define SYNC_MAX 4096 /* max # of sync points */
18 * This lot manages the current set of sync points by means of a
19 * heap (priority queue) structure.
28 void init_sync(void) {
30 * I'd like to allocate an array of size SYNC_MAX, then write
31 * `synx--' which would allow numbering the array from one
32 * instead of zero without wasting memory. Sadly I don't trust
33 * this to work in 16-bit Large model, so it's staying the way
34 * it is. Btw, we don't care about freeing this array, since it
35 * has to last for the duration of the program and will then be
36 * auto-freed on exit. And I'm lazy ;-)
38 * Speaking of 16-bit Large model, that's also the reason I'm
39 * not declaring this array statically - by doing it
40 * dynamically I avoid problems with the total size of DGROUP
43 synx = malloc((SYNC_MAX+1) * sizeof(*synx));
45 fprintf(stderr, "ndisasm: not enough memory for sync array\n");
51 void add_sync(unsigned long pos, unsigned long length) {
54 if (nsynx == SYNC_MAX)
55 return; /* can't do anything - overflow */
58 synx[nsynx].pos = pos;
59 synx[nsynx].length = length;
61 for (i = nsynx; i > 1; i /= 2) {
62 if (synx[i/2].pos > synx[i].pos) {
64 t = synx[i/2]; /* structure copy */
65 synx[i/2] = synx[i]; /* structure copy again */
66 synx[i] = t; /* another structure copy */
71 unsigned long next_sync(unsigned long position, unsigned long *length) {
72 while (nsynx > 0 && synx[1].pos + synx[1].length <= position) {
75 t = synx[nsynx]; /* structure copy */
76 synx[nsynx] = synx[1]; /* structure copy */
77 synx[1] = t; /* ditto */
82 while (i*2 <= nsynx) {
84 if (synx[j].pos < synx[i].pos &&
85 (j+1 > nsynx || synx[j+1].pos > synx[j].pos)) {
86 t = synx[j]; /* structure copy */
87 synx[j] = synx[i]; /* lots of these... */
88 synx[i] = t; /* ...aren't there? */
90 } else if (j+1 <= nsynx && synx[j+1].pos < synx[i].pos) {
91 t = synx[j+1]; /* structure copy */
92 synx[j+1] = synx[i]; /* structure <yawn> copy */
93 synx[i] = t; /* structure copy <zzzz....> */
102 *length = synx[1].length;