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NetBSD/usr.bin/nbperf/nbperf-bdz.c
joerg 97b3b0515b Fix a comment.
2010-03-01 21:46:58 +00:00

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/* $NetBSD: nbperf-bdz.c,v 1.3 2010/03/01 21:46:58 joerg Exp $ */
/*-
* Copyright (c) 2009 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Joerg Sonnenberger.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__RCSID("$NetBSD: nbperf-bdz.c,v 1.3 2010/03/01 21:46:58 joerg Exp $");
#include <err.h>
#include <inttypes.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "nbperf.h"
/*
* A full description of the algorithm can be found in:
* "Simple and Space-Efficient Minimal Perfect Hash Functions"
* by Botelho, Pagh and Ziviani, proceeedings of WADS 2007.
*/
/*
* The algorithm is based on random, acyclic 3-graphs.
*
* Each edge in the represents a key. The vertices are the reminder of
* the hash function mod n. n = cm with c > 1.23. This ensures that
* an acyclic graph can be found with a very high probality.
*
* An acyclic graph has an edge order, where at least one vertex of
* each edge hasn't been seen before. It is declares the first unvisited
* vertex as authoritive for the edge and assigns a 2bit value to unvisited
* vertices, so that the sum of all vertices of the edge modulo 4 is
* the index of the authoritive vertex.
*/
#include "graph3.h"
struct state {
struct graph3 graph;
uint32_t *visited;
uint32_t *holes64k;
uint16_t *holes256;
uint8_t *holes256_64;
uint8_t *holes256_128;
uint8_t *holes256_192;
uint8_t *g;
uint32_t *result_map;
};
static void
assign_nodes(struct state *state)
{
struct edge3 *e;
size_t i, j;
uint32_t t, r, holes;
for (i = 0; i < state->graph.v; ++i)
state->g[i] = 3;
for (i = 0; i < state->graph.e; ++i) {
j = state->graph.output_order[i];
e = &state->graph.edges[j];
if (!state->visited[e->left]) {
r = 0;
t = e->left;
} else if (!state->visited[e->middle]) {
r = 1;
t = e->middle;
} else {
if (state->visited[e->right])
abort();
r = 2;
t = e->right;
}
state->visited[t] = 2 + j;
if (state->visited[e->left] == 0)
state->visited[e->left] = 1;
if (state->visited[e->middle] == 0)
state->visited[e->middle] = 1;
if (state->visited[e->right] == 0)
state->visited[e->right] = 1;
state->g[t] = (9 + r - state->g[e->left] - state->g[e->middle]
- state->g[e->right]) % 3;
}
holes = 0;
for (i = 0; i < state->graph.v; ++i) {
if (i % 65536 == 0)
state->holes64k[i >> 16] = holes;
if (i % 256 == 0)
state->holes256[i >> 8] = holes - state->holes64k[i >> 16];
if (i % 256 == 64)
state->holes256_64[i >> 8] = holes - state->holes256[i >> 8] - state->holes64k[i >> 16];
if (i % 256 == 128)
state->holes256_128[i >> 8] = holes - state->holes256[i >> 8] - state->holes64k[i >> 16];
if (i % 256 == 192)
state->holes256_192[i >> 8] = holes - state->holes256[i >> 8] - state->holes64k[i >> 16];
if (state->visited[i] > 1) {
j = state->visited[i] - 2;
state->result_map[j] = i - holes;
}
if (state->g[i] == 3)
++holes;
}
if (i % 65536 != 0)
state->holes64k[(i >> 16) + 1] = holes;
if (i % 256 != 0)
state->holes256[(i >> 8) + 1] = holes - state->holes64k[((i >> 8) + 1) >> 8];
if (i % 256 != 64)
state->holes256_64[(i >> 8) + 1] = holes - state->holes256[(i >> 8) + 1] - state->holes64k[((i >> 8) + 1) >> 8];
if (i % 256 != 128)
state->holes256_128[(i >> 8) + 1] = holes - state->holes256[(i >> 8) + 1] - state->holes64k[((i >> 8) + 1) >> 8];
if (i % 256 != 192)
state->holes256_192[(i >> 8) + 1] = holes - state->holes256[(i >> 8) + 1] - state->holes64k[((i >> 8) + 1) >> 8];
}
static void
print_hash(struct nbperf *nbperf, struct state *state)
{
size_t i, j;
uint32_t sum;
fprintf(nbperf->output, "#include <stdlib.h>\n");
fprintf(nbperf->output, "#include <strings.h>\n\n");
fprintf(nbperf->output, "%suint32_t\n",
nbperf->static_hash ? "static " : "");
fprintf(nbperf->output,
"%s(const void * __restrict key, size_t keylen)\n",
nbperf->hash_name);
fprintf(nbperf->output, "{\n");
fprintf(nbperf->output,
"\tstatic const uint32_t g[%" PRId32 "] = {\n",
(state->graph.v + 15) / 16);
for (i = 0; i < state->graph.v; i += 16) {
for (j = 0, sum = 0; j < 16; ++j)
sum |= (uint32_t)state->g[i + j] << (2 * j);
fprintf(nbperf->output, "%s0x%08" PRIx32 "ULL,%s",
(i / 16 % 4 == 0 ? "\t " : " "),
sum,
(i / 16 % 4 == 3 ? "\n" : ""));
}
fprintf(nbperf->output, "%s\t};\n", (i / 16 % 4 ? "\n" : ""));
fprintf(nbperf->output,
"\tstatic const uint32_t holes64k[%" PRId32 "] = {\n",
(state->graph.v + 65535) / 65536);
for (i = 0; i < state->graph.v; i += 65536)
fprintf(nbperf->output, "%s0x%08" PRIx32 ",%s",
(i / 65536 % 4 == 0 ? "\t " : " "),
state->holes64k[i >> 16],
(i / 65536 % 4 == 3 ? "\n" : ""));
fprintf(nbperf->output, "%s\t};\n", (i / 65536 % 4 ? "\n" : ""));
fprintf(nbperf->output,
"\tstatic const uint16_t holes256[%" PRId32 "] = {\n",
(state->graph.v + 255) / 256);
for (i = 0; i < state->graph.v; i += 256)
fprintf(nbperf->output, "%s0x%04" PRIx32 ",%s",
(i / 256 % 4 == 0 ? "\t " : " "),
state->holes256[i >> 8],
(i / 256 % 4 == 3 ? "\n" : ""));
fprintf(nbperf->output, "%s\t};\n", (i / 256 % 4 ? "\n" : ""));
fprintf(nbperf->output,
"\tstatic const uint8_t holes256_64[%" PRId32 "] = {\n",
(state->graph.v + 255) / 256);
for (i = 64; i < state->graph.v; i += 256)
fprintf(nbperf->output, "%s0x%02" PRIx32 ",%s",
(i / 256 % 4 == 0 ? "\t " : " "),
state->holes256_64[i >> 8],
(i / 256 % 4 == 3 ? "\n" : ""));
fprintf(nbperf->output, "%s\t};\n", (i / 256 % 4 ? "\n" : ""));
fprintf(nbperf->output,
"\tstatic const uint8_t holes256_128[%" PRId32 "] = {\n",
(state->graph.v + 255) / 256);
for (i = 128; i < state->graph.v; i += 256)
fprintf(nbperf->output, "%s0x%02" PRIx32 ",%s",
(i / 256 % 4 == 0 ? "\t " : " "),
state->holes256_128[i >> 8],
(i / 256 % 4 == 3 ? "\n" : ""));
fprintf(nbperf->output, "%s\t};\n", (i / 256 % 4 ? "\n" : ""));
fprintf(nbperf->output,
"\tstatic const uint8_t holes256_192[%" PRId32 "] = {\n",
(state->graph.v + 255) / 256);
for (i = 192; i < state->graph.v; i += 256)
fprintf(nbperf->output, "%s0x%02" PRIx32 ",%s",
(i / 256 % 4 == 0 ? "\t " : " "),
state->holes256_192[i >> 8],
(i / 256 % 4 == 3 ? "\n" : ""));
fprintf(nbperf->output, "%s\t};\n", (i / 256 % 4 ? "\n" : ""));
fprintf(nbperf->output, "\tuint32_t h[%zu];\n\n", nbperf->hash_size);
fprintf(nbperf->output, "\tuint32_t m;\n");
fprintf(nbperf->output, "\tuint32_t a1, a2, b1, b2, c1, c2, idx, idx2;\n\n");
(*nbperf->print_hash)(nbperf, "\t", "key", "keylen", "h");
fprintf(nbperf->output, "\n\th[0] = h[0] %% %" PRIu32 ";\n", state->graph.v);
fprintf(nbperf->output, "\th[1] = h[1] %% %" PRIu32 ";\n", state->graph.v);
fprintf(nbperf->output, "\th[2] = h[2] %% %" PRIu32 ";\n", state->graph.v);
fprintf(nbperf->output, "\n\ta1 = h[0] >> 4;\n");
fprintf(nbperf->output, "\ta2 = 2 * (h[0] & 15);\n");
fprintf(nbperf->output, "\tb1 = h[1] >> 4;\n");
fprintf(nbperf->output, "\tb2 = 2 * (h[1] & 15);\n");
fprintf(nbperf->output, "\tc1 = h[2] >> 4;\n");
fprintf(nbperf->output, "\tc2 = 2 * (h[2] & 15);\n");
fprintf(nbperf->output,
"\tidx = h[(((g[a1] >> a2) & 3) + ((g[b1] >> b2) & 3) +\n"
"\t ((g[c1] >> c2) & 3)) %% 3];\n\n");
fprintf(nbperf->output,
"\tswitch ((idx >> 5) & 7) {\n"
"\tcase 0:\n"
"\t\tidx2 = idx - holes64k[idx >> 16] - holes256[idx >> 8];\n"
"\t\tbreak;\n"
"\tcase 1: case 2:\n"
"\t\tidx2 = idx - holes64k[idx >> 16] - holes256[idx >> 8]\n"
"\t\t - holes256_64[idx >> 8];\n"
"\t\tbreak;\n"
"\tcase 3: case 4:\n"
"\t\tidx2 = idx - holes64k[idx >> 16] - holes256[idx >> 8]\n"
"\t\t - holes256_128[idx >> 8];\n"
"\t\tbreak;\n"
"\tcase 5: case 6:\n"
"\t\tidx2 = idx - holes64k[idx >> 16] - holes256[idx >> 8]\n"
"\t\t - holes256_192[idx >> 8];\n"
"\t\tbreak;\n"
"\tcase 7:\n"
"\t\tidx2 = idx - holes64k[(idx + 32) >> 16] -\n"
"\t\t holes256[(idx + 32) >> 8];\n"
"\t\tbreak;\n"
"\tdefault:\n"
"\t\tabort();\n"
"\t}\n"
"\tswitch ((idx >> 4) & 3) {\n"
"\tcase 1:\n"
"\t\tm = (g[(idx >> 4) - 1] & (g[(idx >> 4) - 1] >> 1) & 0x55555555U);\n"
"\t\tidx2 -= popcount32(m);\n"
"\tcase 0:\n"
"\t\tm = (g[idx >> 4] & (g[idx >> 4] >> 1) & 0x55555555U);\n"
"\t\tm &= ((2U << (2 * (idx & 15))) - 1);\n"
"\t\tidx2 -= popcount32(m);\n"
"\t\tbreak;\n"
"\tcase 2:\n"
"\t\tm = (g[(idx >> 4) + 1] & (g[(idx >> 4) + 1] >> 1) & 0x55555555U);\n"
"\t\tidx2 += popcount32(m);\n"
"\tcase 3:\n"
"\t\tm = (g[idx >> 4] & (g[idx >> 4] >> 1) & 0x55555555U);\n"
"\t\tm &= ~((2U << (2 * (idx & 15))) - 1);\n"
"\t\tidx2 += popcount32(m);\n"
"\t\tbreak;\n"
"\t}\n\n");
fprintf(nbperf->output,
"\treturn idx2;\n");
fprintf(nbperf->output, "}\n");
if (nbperf->map_output != NULL) {
for (i = 0; i < state->graph.e; ++i)
fprintf(nbperf->map_output, "%" PRIu32 "\n",
state->result_map[i]);
}
}
int
bdz_compute(struct nbperf *nbperf)
{
struct state state;
int retval = -1;
uint32_t v, e;
if (nbperf->c == 0)
nbperf->c = 1.24;
if (nbperf->c < 1.24)
errx(1, "The argument for option -c must be at least 1.24");
if (nbperf->hash_size < 3)
errx(1, "The hash function must generate at least 3 values");
(*nbperf->seed_hash)(nbperf);
e = nbperf->n;
v = nbperf->c * nbperf->n;
if (1.24 * nbperf->n > v)
++v;
if (v < 10)
v = 10;
graph3_setup(&state.graph, v, e);
state.holes64k = calloc(sizeof(uint32_t), (v + 65535) / 65536 + 1);
state.holes256 = calloc(sizeof(uint16_t), (v + 255) / 256 + 1);
state.holes256_64 = calloc(sizeof(uint8_t), (v + 255) / 256 + 1);
state.holes256_128 = calloc(sizeof(uint8_t), (v + 255) / 256 + 1);
state.holes256_192 = calloc(sizeof(uint8_t), (v + 255) / 256 + 1);
state.g = calloc(sizeof(uint32_t), v);
state.visited = calloc(sizeof(uint32_t), v);
state.result_map = calloc(sizeof(uint32_t), e);
if (state.holes64k == NULL || state.holes256 == NULL ||
state.holes256_64 == NULL || state.holes256_128 == NULL ||
state.holes256_192 == NULL || state.g == NULL ||
state.visited == NULL || state.result_map == NULL)
err(1, "malloc failed");
if (graph3_hash(nbperf, &state.graph))
goto failed;
if (graph3_output_order(&state.graph))
goto failed;
assign_nodes(&state);
print_hash(nbperf, &state);
retval = 0;
failed:
graph3_free(&state.graph);
free(state.visited);
free(state.g);
free(state.holes64k);
free(state.holes256);
free(state.holes256_64);
free(state.holes256_128);
free(state.holes256_192);
free(state.result_map);
return retval;
}
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