1 /*        $NetBSD: graph2.c,v 1.6 2021/01/28 18:52:43 joerg Exp $     */
2 /*-
3  * Copyright (c) 2009 The NetBSD Foundation, Inc.
4  * All rights reserved.
5  *
6  * This code is derived from software contributed to The NetBSD Foundation
7  * by Joerg Sonnenberger.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  *
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in
17  *    the documentation and/or other materials provided with the
18  *    distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
24  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
27  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
30  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #if HAVE_NBTOOL_CONFIG_H
35 #include "nbtool_config.h"
36 #endif
37 
38 #include <sys/cdefs.h>
39 __RCSID("$NetBSD: graph2.c,v 1.6 2021/01/28 18:52:43 joerg Exp $");
40 
41 #include <err.h>
42 #include <inttypes.h>
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include <string.h>
46 
47 #include "nbperf.h"
48 #include "graph2.h"
49 
50 void
SIZED2(_setup)51 SIZED2(_setup)(struct SIZED(graph) *graph, uint32_t v, uint32_t e)
52 {
53           graph->v = v;
54           graph->e = e;
55 
56           graph->verts = calloc(sizeof(*graph->verts), v);
57           graph->edges = calloc(sizeof(*graph->edges), e);
58           graph->output_order = calloc(sizeof(uint32_t), e);
59 
60           if (graph->verts == NULL || graph->edges == NULL ||
61               graph->output_order == NULL)
62                     err(1, "malloc failed");
63 }
64 
65 void
SIZED2(_free)66 SIZED2(_free)(struct SIZED(graph) *graph)
67 {
68           free(graph->verts);
69           free(graph->edges);
70           free(graph->output_order);
71 
72           graph->verts = NULL;
73           graph->edges = NULL;
74           graph->output_order = NULL;
75 }
76 
77 static struct nbperf *sorting_nbperf;
78 static struct SIZED(graph) *sorting_graph;
79 static int sorting_found;
80 
sorting_cmp(const void * a_,const void * b_)81 static int sorting_cmp(const void *a_, const void *b_)
82 {
83           const uint32_t *a = a_, *b = b_;
84           int i;
85           const struct SIZED(edge) *ea = &sorting_graph->edges[*a],
86               *eb = &sorting_graph->edges[*b];
87           for (i = 0; i < GRAPH_SIZE; ++i) {
88                     if (ea->vertices[i] < eb->vertices[i])
89                               return -1;
90                     if (ea->vertices[i] > eb->vertices[i])
91                               return 1;
92           }
93           if (sorting_nbperf->keylens[*a] < sorting_nbperf->keylens[*b])
94                     return -1;
95           if (sorting_nbperf->keylens[*a] > sorting_nbperf->keylens[*b])
96                     return 1;
97           i = memcmp(sorting_nbperf->keys[*a], sorting_nbperf->keys[*b],
98               sorting_nbperf->keylens[*a]);
99           if (i == 0)
100                     sorting_found = 1;
101           return i;
102 }
103 
104 static int
SIZED2(_check_duplicates)105 SIZED2(_check_duplicates)(struct nbperf *nbperf, struct SIZED(graph) *graph)
106 {
107           size_t i;
108           uint32_t *key_index = calloc(sizeof(*key_index), graph->e);
109 
110           if (key_index == NULL)
111                     err(1, "malloc failed");
112           for (i = 0; i < graph->e; ++i)
113                     key_index[i] = i;
114 
115           sorting_nbperf = nbperf;
116           sorting_graph = graph;
117           sorting_found = 0;
118           qsort(key_index, graph->e, sizeof(*key_index), sorting_cmp);
119           if (sorting_found)
120                     goto found_dups;
121           /*
122            * Any duplicate must have been found as part of the qsort,
123            * as it can't sort consecutive elements in the output without
124            * comparing them at least once.
125            */
126 
127           free(key_index);
128           return 0;
129  found_dups:
130           nbperf->has_duplicates = 1;
131           return -1;
132 }
133 
134 static inline void
SIZED2(_add_edge)135 SIZED2(_add_edge)(struct SIZED(graph) *graph, uint32_t edge)
136 {
137           struct SIZED(edge) *e = graph->edges + edge;
138           struct SIZED(vertex) *v;
139           size_t i;
140 
141           for (i = 0; i < GRAPH_SIZE; ++i) {
142                     v = graph->verts + e->vertices[i];
143                     v->edges ^= edge;
144                     ++v->degree;
145           }
146 }
147 
148 static inline void
SIZED2(_remove_edge)149 SIZED2(_remove_edge)(struct SIZED(graph) *graph, uint32_t edge)
150 {
151           struct SIZED(edge) *e = graph->edges + edge;
152           struct SIZED(vertex) *v;
153           size_t i;
154 
155           for (i = 0; i < GRAPH_SIZE; ++i) {
156                     v = graph->verts + e->vertices[i];
157                     v->edges ^= edge;
158                     --v->degree;
159           }
160 }
161 
162 static inline void
SIZED2(_remove_vertex)163 SIZED2(_remove_vertex)(struct SIZED(graph) *graph, uint32_t vertex)
164 {
165           struct SIZED(vertex) *v = graph->verts + vertex;
166           uint32_t e;
167 
168           if (v->degree == 1) {
169                     e = v->edges;
170                     graph->output_order[--graph->output_index] = e;
171                     SIZED2(_remove_edge)(graph, e);
172           }
173 }
174 
175 int
SIZED2(_hash)176 SIZED2(_hash)(struct nbperf *nbperf, struct SIZED(graph) *graph)
177 {
178           struct SIZED(edge) *e;
179           uint32_t hashes[NBPERF_MAX_HASH_SIZE];
180           size_t i, j;
181 
182 #if GRAPH_SIZE == 2
183           if (nbperf->allow_hash_fudging && (graph->v & 1) != 0)
184                     errx(1, "vertex count must have lowest bit clear");
185 #else
186           if (nbperf->allow_hash_fudging && (graph->v & 3) != 0)
187                     errx(1, "vertex count must have lowest 2 bits clear");
188 #endif
189 
190 
191           memset(graph->verts, 0, sizeof(*graph->verts) * graph->v);
192           graph->hash_fudge = 0;
193 
194           for (i = 0; i < graph->e; ++i) {
195                     (*nbperf->compute_hash)(nbperf,
196                         nbperf->keys[i], nbperf->keylens[i], hashes);
197                     e = graph->edges + i;
198                     for (j = 0; j < GRAPH_SIZE; ++j) {
199                               e->vertices[j] = hashes[j] % graph->v;
200                               if (j == 1 && e->vertices[0] == e->vertices[1]) {
201                                         if (!nbperf->allow_hash_fudging)
202                                                   return -1;
203                                         e->vertices[1] ^= 1; /* toogle bit to differ */
204                                         graph->hash_fudge |= 1;
205                               }
206 #if GRAPH_SIZE == 3
207                               if (j == 2 && (e->vertices[0] == e->vertices[2] ||
208                                   e->vertices[1] == e->vertices[2])) {
209                                         if (!nbperf->allow_hash_fudging)
210                                                   return -1;
211                                         graph->hash_fudge |= 2;
212                                         e->vertices[2] ^= 1;
213                                         e->vertices[2] ^= 2 * (e->vertices[0] == e->vertices[2] ||
214                                             e->vertices[1] == e->vertices[2]);
215                               }
216 #endif
217                     }
218           }
219 
220           for (i = 0; i < graph->e; ++i)
221                     SIZED2(_add_edge)(graph, i);
222 
223           if (nbperf->check_duplicates) {
224                     nbperf->check_duplicates = 0;
225                     return SIZED2(_check_duplicates)(nbperf, graph);
226           }
227 
228           return 0;
229 }
230 
231 int
SIZED2(_output_order)232 SIZED2(_output_order)(struct SIZED(graph) *graph)
233 {
234           size_t i, j;
235           struct SIZED(edge) *e2;
236 
237           graph->output_index = graph->e;
238 
239           for (i = 0; i < graph->v; ++i)
240                     SIZED2(_remove_vertex)(graph, i);
241 
242           for (i = graph->e; graph->output_index > 0 && i > graph->output_index;) {
243                     e2 = graph->edges + graph->output_order[--i];
244                     for (j = 0; j < GRAPH_SIZE; ++j)
245                               SIZED2(_remove_vertex)(graph, e2->vertices[j]);
246           }
247 
248           if (graph->output_index != 0) {
249                     return -1;
250           }
251 
252           return 0;
253 }
254