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. |
6 | * |
7 | * Redistribution and use in source and binary forms, with or without |
8 | * modification, are permitted provided that the following |
9 | * conditions are met: |
10 | * |
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. |
17 | * |
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. |
31 | * |
32 | * ----------------------------------------------------------------------- */ |
33 | |
34 | /* |
35 | * sync.c the Netwide Disassembler synchronisation processing module |
36 | */ |
37 | |
38 | #include "compiler.h" |
39 | |
40 | #include <stdio.h> |
41 | #include <stdlib.h> |
42 | #include <limits.h> |
43 | |
44 | #include "nasmlib.h" |
45 | #include "sync.h" |
46 | |
47 | #define SYNC_MAX_SHIFT 31 |
48 | #define SYNC_MAX_SIZE (1U << SYNC_MAX_SHIFT) |
49 | |
50 | /* initial # of sync points (*must* be power of two)*/ |
51 | #define SYNC_INITIAL_CHUNK (1U << 12) |
52 | |
53 | /* |
54 | * This lot manages the current set of sync points by means of a |
55 | * heap (priority queue) structure. |
56 | */ |
57 | |
58 | static struct Sync { |
59 | uint64_t pos; |
60 | uint32_t length; |
61 | } *synx; |
62 | |
63 | static uint32_t max_synx, nsynx; |
64 | |
65 | static inline void swap_sync(uint32_t dst, uint32_t src) |
66 | { |
67 | struct Sync t = synx[dst]; |
68 | synx[dst] = synx[src]; |
69 | synx[src] = t; |
70 | } |
71 | |
72 | void init_sync(void) |
73 | { |
74 | max_synx = SYNC_INITIAL_CHUNK; |
75 | synx = nasm_malloc((max_synx + 1) * sizeof(*synx)); |
76 | nsynx = 0; |
77 | } |
78 | |
79 | void add_sync(uint64_t pos, uint32_t length) |
80 | { |
81 | uint32_t i; |
82 | |
83 | if (nsynx >= max_synx) { |
84 | if (max_synx >= SYNC_MAX_SIZE) /* too many sync points! */ |
85 | return; |
86 | max_synx = (max_synx << 1); |
87 | synx = nasm_realloc(synx, (max_synx + 1) * sizeof(*synx)); |
88 | } |
89 | |
90 | nsynx++; |
91 | synx[nsynx].pos = pos; |
92 | synx[nsynx].length = length; |
93 | |
94 | for (i = nsynx; i > 1; i /= 2) { |
95 | if (synx[i / 2].pos > synx[i].pos) |
96 | swap_sync(i / 2, i); |
97 | } |
98 | } |
99 | |
100 | uint64_t next_sync(uint64_t position, uint32_t *length) |
101 | { |
102 | while (nsynx > 0 && synx[1].pos + synx[1].length <= position) { |
103 | uint32_t i, j; |
104 | |
105 | swap_sync(nsynx, 1); |
106 | nsynx--; |
107 | |
108 | i = 1; |
109 | while (i * 2 <= nsynx) { |
110 | j = i * 2; |
111 | if (synx[j].pos < synx[i].pos && |
112 | (j + 1 > nsynx || synx[j + 1].pos > synx[j].pos)) { |
113 | swap_sync(j, i); |
114 | i = j; |
115 | } else if (j + 1 <= nsynx && synx[j + 1].pos < synx[i].pos) { |
116 | swap_sync(j + 1, i); |
117 | i = j + 1; |
118 | } else |
119 | break; |
120 | } |
121 | } |
122 | |
123 | if (nsynx > 0) { |
124 | if (length) |
125 | *length = synx[1].length; |
126 | return synx[1].pos; |
127 | } else { |
128 | if (length) |
129 | *length = 0L; |
130 | return 0; |
131 | } |
132 | } |
133 | |