1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
|
#include "upb_table.h"
#include "test_util.h"
#include <assert.h>
#include <map>
#include <ext/hash_map>
#include <sys/resource.h>
struct table_entry {
struct upb_inttable_entry e;
int32_t value; /* key+2 */
};
double get_usertime()
{
struct rusage usage;
getrusage(RUSAGE_SELF, &usage);
return usage.ru_utime.tv_sec + (usage.ru_utime.tv_usec/1000000.0);
}
static uint32_t max(uint32_t a, uint32_t b) { return a > b ? a : b; }
/* num_entries must be a power of 2. */
void test(int32_t *keys, size_t num_entries)
{
/* Initialize structures. */
struct table_entry *entries = new table_entry[num_entries];
struct upb_inttable table;
int32_t largest_key = 0;
std::map<int32_t, int32_t> m;
__gnu_cxx::hash_map<int32_t, int32_t> hm;
for(size_t i = 0; i < num_entries; i++) {
int32_t key = keys[i];
largest_key = max(largest_key, key);
entries[i].e.key = key;
entries[i].value = key*2;
m[key] = key*2;
hm[key] = key*2;
}
upb_inttable_init(&table, entries, num_entries, sizeof(struct table_entry));
printf("size: %lu\n", sizeof(struct table_entry));
delete[] entries;
/* Test correctness. */
for(int32_t i = 0; i < largest_key; i++) {
struct table_entry *e = (struct table_entry*)upb_inttable_lookup(
&table, i, sizeof(struct table_entry));
if(m.find(i) != m.end()) { /* Assume map implementation is correct. */
assert(e);
assert(e->e.key == i);
assert(e->value == i*2);
assert(m[i] == i*2);
assert(hm[i] == i*2);
} else {
assert(e == NULL);
}
}
/* Test performance. We only test lookups for keys that are known to exist. */
uintptr_t x = 0;
const unsigned int iterations = 0xFFFFFF;
const int32_t mask = num_entries - 1;
printf("Measuring sequential loop overhead...");
fflush(stdout);
double before = get_usertime();
for(unsigned int i = 0; i < iterations; i++) {
int32_t key = keys[i & mask];
x += key;
}
double seq_overhead = get_usertime() - before;
printf("%0.3f seconds for %d iterations\n", seq_overhead, iterations);
printf("Measuring random loop overhead...");
rand();
fflush(stdout);
before = get_usertime();
for(unsigned int i = 0; i < iterations; i++) {
int32_t key = keys[rand() & mask];
x += key;
}
double rand_overhead = get_usertime() - before;
printf("%0.3f seconds for %d iterations\n", rand_overhead, iterations);
printf("upb_table(seq): ");
fflush(stdout);
before = get_usertime();
for(unsigned int i = 0; i < iterations; i++) {
int32_t key = keys[i & mask];
struct table_entry *e = (struct table_entry*)upb_inttable_lookup(
&table, key, sizeof(struct table_entry));
x += (uintptr_t)e;
}
double total = get_usertime() - before;
double without_overhead = total - seq_overhead;
printf("%0.3f seconds (%0.3f - %0.3f overhead) for %d iterations. %s/s\n", without_overhead, total, seq_overhead, iterations, eng(iterations/without_overhead, 3, false));
printf("upb_table(rand): ");
fflush(stdout);
before = get_usertime();
for(unsigned int i = 0; i < iterations; i++) {
int32_t key = keys[rand() & mask];
struct table_entry *e = (struct table_entry*)upb_inttable_lookup(
&table, key, sizeof(struct table_entry));
x += (uintptr_t)e;
}
total = get_usertime() - before;
without_overhead = total - rand_overhead;
printf("%0.3f seconds (%0.3f - %0.3f overhead) for %d iterations. %s/s\n", without_overhead, total, rand_overhead, iterations, eng(iterations/without_overhead, 3, false));
printf("map(seq): ");
fflush(stdout);
before = get_usertime();
for(unsigned int i = 0; i < iterations; i++) {
int32_t key = keys[i & mask];
x += m[key];
}
total = get_usertime() - before;
without_overhead = total - seq_overhead;
printf("%0.3f seconds (%0.3f - %0.3f overhead) for %d iterations. %s/s\n", without_overhead, total, seq_overhead, iterations, eng(iterations/without_overhead, 3, false));
printf("map(rand): ");
fflush(stdout);
before = get_usertime();
for(unsigned int i = 0; i < iterations; i++) {
int32_t key = keys[rand() & mask];
x += m[key];
}
total = get_usertime() - before;
without_overhead = total - rand_overhead;
printf("%0.3f seconds (%0.3f - %0.3f overhead) for %d iterations. %s/s\n", without_overhead, total, rand_overhead, iterations, eng(iterations/without_overhead, 3, false));
printf("hash_map(seq): ");
fflush(stdout);
before = get_usertime();
for(unsigned int i = 0; i < iterations; i++) {
int32_t key = keys[i & mask];
x += hm[key];
}
total = get_usertime() - before;
without_overhead = total - seq_overhead;
printf("%0.3f seconds (%0.3f - %0.3f overhead) for %d iterations. %s/s\n", without_overhead, total, seq_overhead, iterations, eng(iterations/without_overhead, 3, false));
printf("hash_map(rand): ");
fflush(stdout);
before = get_usertime();
for(unsigned int i = 0; i < iterations; i++) {
int32_t key = keys[rand() & mask];
x += hm[key];
}
total = get_usertime() - before;
without_overhead = total - rand_overhead;
printf("%0.3f seconds (%0.3f - %0.3f overhead) for %d iterations. %s/s\n\n", without_overhead, total, rand_overhead, iterations, eng(iterations/without_overhead, 3, false));
upb_inttable_free(&table);
}
int32_t *get_contiguous_keys(int32_t num)
{
int32_t *buf = new int32_t[num];
for(int32_t i = 0; i < num; i++)
buf[i] = i;
return buf;
}
int main()
{
int32_t *keys1 = get_contiguous_keys(8);
printf("Contiguous 1-8 ====\n");
test(keys1, 8);
delete[] keys1;
int32_t *keys2 = get_contiguous_keys(64);
printf("Contiguous 1-64 ====\n");
test(keys2, 64);
delete[] keys2;
int32_t *keys3 = get_contiguous_keys(512);
printf("Contiguous 1-512 ====\n");
test(keys3, 512);
delete[] keys3;
int32_t *keys4 = new int32_t[64];
for(int32_t i = 0; i < 64; i++) {
if(i < 32)
keys4[i] = i;
else
keys4[i] = 10100+i;
}
printf("1-32 and 10033-10064 ====\n");
test(keys4, 64);
delete[] keys4;
}
|
