about summary refs log tree commit diff
path: root/benchtests/bench-strcmp.c
blob: b07060f01166f1e71d5dcb9f97e4159a644fe991 (plain) (blame)
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
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
/* Measure strcmp and wcscmp functions.
   Copyright (C) 2013-2024 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <https://www.gnu.org/licenses/>.  */

#define TEST_MAIN
#ifdef WIDE
# define TEST_NAME "wcscmp"
#else
# define TEST_NAME "strcmp"
#endif
#include "bench-string.h"
#include "json-lib.h"

#ifdef WIDE
# define CHARBYTESLOG 2
# define MIDCHAR 0x7fffffff
# define LARGECHAR 0xfffffffe
#else
# define CHARBYTESLOG 0
# define MIDCHAR 0x7f
# define LARGECHAR 0xfe

int
generic_strcmp (const char *s1, const char *s2);

IMPL (generic_strcmp, 0)

#endif

typedef int (*proto_t) (const CHAR *, const CHAR *);

IMPL (STRCMP, 1)

static void
do_one_test (json_ctx_t *json_ctx, impl_t *impl,
	     const CHAR *s1, const CHAR *s2,
	     int exp_result)
{
  size_t i, iters = INNER_LOOP_ITERS8 / 2;
  timing_t start, stop, cur;

  TIMING_NOW (start);
  for (i = 0; i < iters; ++i)
    {
      CALL (impl, s1, s2);
    }
  TIMING_NOW (stop);

  TIMING_DIFF (cur, start, stop);

  json_element_double (json_ctx, (double) cur / (double) iters);
}

static void
do_test (json_ctx_t *json_ctx, size_t align1, size_t align2, size_t len,
         int max_char, int exp_result, int at_end)
{
  size_t i;

  CHAR *s1, *s2;

  if (len == 0)
    return;

  align1 &= ~(CHARBYTES - 1);
  align2 &= ~(CHARBYTES - 1);

  align1 &= (getpagesize () - 1);
  if (align1 + (len + 1) * CHARBYTES >= page_size)
    return;

  align2 &= (getpagesize () - 1);
  if (align2 + (len + 1) * CHARBYTES >= page_size)
    return;

  /* Put them close to the end of page.  */
  if (at_end)
    {
      i = align1 + CHARBYTES * (len + 2);
      align1 = ((page_size - i) / 16 * 16) + align1;
      i = align2 + CHARBYTES * (len + 2);
      align2 = ((page_size - i) / 16 * 16) + align2;
    }

  s1 = (CHAR *)(buf1 + align1);
  s2 = (CHAR *)(buf2 + align2);

  for (i = 0; i < len; i++)
    s1[i] = s2[i] = 1 + (23 << ((CHARBYTES - 1) * 8)) * i % max_char;

  s1[len] = s2[len] = 0;
  s1[len + 1] = 23;
  s2[len + 1] = 24 + exp_result;
  s2[len - 1] -= exp_result;

  json_element_object_begin (json_ctx);
  json_attr_uint (json_ctx, "length", (double)len);
  json_attr_uint (json_ctx, "align1", (double)align1);
  json_attr_uint (json_ctx, "align2", (double)align2);
  json_array_begin (json_ctx, "timings");

  FOR_EACH_IMPL (impl, 0)
    do_one_test (json_ctx, impl, s1, s2, exp_result);

  json_array_end (json_ctx);
  json_element_object_end (json_ctx);
}

static void
do_one_test_page_boundary (json_ctx_t *json_ctx, CHAR *s1, CHAR *s2,
			   size_t align1, size_t align2, size_t len,
			   int exp_result)
{
  json_element_object_begin (json_ctx);
  json_attr_uint (json_ctx, "length", (double) len);
  json_attr_uint (json_ctx, "align1", (double) align1);
  json_attr_uint (json_ctx, "align2", (double) align2);
  json_array_begin (json_ctx, "timings");
  FOR_EACH_IMPL (impl, 0)
    do_one_test (json_ctx, impl, s1, s2, exp_result);
  json_array_end (json_ctx);
  json_element_object_end (json_ctx);
}

static void
do_test_page_boundary (json_ctx_t *json_ctx)
{
  /* To trigger bug 25933, we need a size that is equal to the vector
     length times 4. In the case of AVX2 for Intel, we need 32 * 4.  We
     make this test generic and run it for all architectures as additional
     boundary testing for such related algorithms.  */
  size_t size = 32 * 4;
  size_t len;
  CHAR *s1 = (CHAR *) (buf1 + (BUF1PAGES - 1) * page_size);
  CHAR *s2 = (CHAR *) (buf2 + (BUF1PAGES - 1) * page_size);
  int exp_result;

  memset (s1, 'a', page_size);
  memset (s2, 'a', page_size);

  s1[(page_size / CHARBYTES) - 1] = (CHAR) 0;
  s2[(page_size / CHARBYTES) - 1] = (CHAR) 0;

  /* Iterate over a size that is just below where we expect the bug to
     trigger up to the size we expect will trigger the bug e.g. [99-128].
     Likewise iterate the start of two strings between 30 and 31 bytes
     away from the boundary to simulate alignment changes.  */
  for (size_t s = 99; s <= size; s++)
    for (size_t s1a = 30; s1a < 32; s1a++)
      for (size_t s2a = 30; s2a < 32; s2a++)
	{
	  size_t align1 = (page_size / CHARBYTES - s) - s1a;
	  size_t align2 = (page_size / CHARBYTES - s) - s2a;
	  CHAR *s1p = s1 + align1;
	  CHAR *s2p = s2 + align2;
	  len = (page_size / CHARBYTES) - 1 - align1;
	  exp_result = STRCMP (s1p, s2p);
	  do_one_test_page_boundary (json_ctx, s1p, s2p, align1, align2,
				     len, exp_result);
	}
}

int
test_main (void)
{
  json_ctx_t json_ctx;
  size_t i, j, k;
  size_t pg_sz = getpagesize ();

  test_init ();

  json_init (&json_ctx, 0, stdout);

  json_document_begin (&json_ctx);
  json_attr_string (&json_ctx, "timing_type", TIMING_TYPE);

  json_attr_object_begin (&json_ctx, "functions");
  json_attr_object_begin (&json_ctx, TEST_NAME);
  json_attr_string (&json_ctx, "bench-variant", "default");

  json_array_begin (&json_ctx, "ifuncs");
  FOR_EACH_IMPL (impl, 0)
    json_element_string (&json_ctx, impl->name);
  json_array_end (&json_ctx);

  json_array_begin (&json_ctx, "results");
  for (k = 0; k < 2; ++k)
    {
      for (i = 1; i < 32; ++i)
        {
          do_test (&json_ctx, CHARBYTES * i, CHARBYTES * i, i, MIDCHAR, 0, k);
          do_test (&json_ctx, CHARBYTES * i, CHARBYTES * i, i, MIDCHAR, 1, k);
          do_test (&json_ctx, CHARBYTES * i, CHARBYTES * i, i, MIDCHAR, -1, k);
        }

      for (i = 1; i <= 8192;)
        {
          /* No page crosses.  */
          do_test (&json_ctx, 0, 0, i, MIDCHAR, 0, k);
          do_test (&json_ctx, i * CHARBYTES, 0, i, MIDCHAR, 0, k);
          do_test (&json_ctx, 0, i * CHARBYTES, i, MIDCHAR, 0, k);

          /* False page crosses.  */
          do_test (&json_ctx, pg_sz / 2, pg_sz / 2 - CHARBYTES, i, MIDCHAR, 0,
                   k);
          do_test (&json_ctx, pg_sz / 2 - CHARBYTES, pg_sz / 2, i, MIDCHAR, 0,
                   k);

          do_test (&json_ctx, pg_sz - (i * CHARBYTES), 0, i, MIDCHAR, 0, k);
          do_test (&json_ctx, 0, pg_sz - (i * CHARBYTES), i, MIDCHAR, 0, k);

          /* Real page cross.  */
          for (j = 16; j < 128; j += 16)
            {
              do_test (&json_ctx, pg_sz - j, 0, i, MIDCHAR, 0, k);
              do_test (&json_ctx, 0, pg_sz - j, i, MIDCHAR, 0, k);

              do_test (&json_ctx, pg_sz - j, pg_sz - j / 2, i, MIDCHAR, 0, k);
              do_test (&json_ctx, pg_sz - j / 2, pg_sz - j, i, MIDCHAR, 0, k);
            }

          if (i < 32)
            {
              ++i;
            }
          else if (i < 160)
            {
              i += 8;
            }
          else if (i < 512)
            {
              i += 32;
            }
          else
            {
              i *= 2;
            }
        }

      for (i = 1; i < 10 + CHARBYTESLOG; ++i)
        {
          do_test (&json_ctx, 0, 0, 2 << i, MIDCHAR, 0, k);
          do_test (&json_ctx, 0, 0, 2 << i, LARGECHAR, 0, k);
          do_test (&json_ctx, 0, 0, 2 << i, MIDCHAR, 1, k);
          do_test (&json_ctx, 0, 0, 2 << i, LARGECHAR, 1, k);
          do_test (&json_ctx, 0, 0, 2 << i, MIDCHAR, -1, k);
          do_test (&json_ctx, 0, 0, 2 << i, LARGECHAR, -1, k);
          do_test (&json_ctx, 0, CHARBYTES * i, 2 << i, MIDCHAR, 1, k);
          do_test (&json_ctx, CHARBYTES * i, CHARBYTES * (i + 1), 2 << i,
                   LARGECHAR, 1, k);
        }

      for (i = 1; i < 8; ++i)
        {
          do_test (&json_ctx, CHARBYTES * i, 2 * CHARBYTES * i, 8 << i,
                   MIDCHAR, 0, k);
          do_test (&json_ctx, 2 * CHARBYTES * i, CHARBYTES * i, 8 << i,
                   LARGECHAR, 0, k);
          do_test (&json_ctx, CHARBYTES * i, 2 * CHARBYTES * i, 8 << i,
                   MIDCHAR, 1, k);
          do_test (&json_ctx, 2 * CHARBYTES * i, CHARBYTES * i, 8 << i,
                   LARGECHAR, 1, k);
          do_test (&json_ctx, CHARBYTES * i, 2 * CHARBYTES * i, 8 << i,
                   MIDCHAR, -1, k);
          do_test (&json_ctx, 2 * CHARBYTES * i, CHARBYTES * i, 8 << i,
                   LARGECHAR, -1, k);
        }
    }
  do_test_page_boundary (&json_ctx);

  json_array_end (&json_ctx);
  json_attr_object_end (&json_ctx);
  json_attr_object_end (&json_ctx);
  json_document_end (&json_ctx);

  return ret;
}

#include <support/test-driver.c>

#ifndef WIDE
# undef STRCMP
# define STRCMP generic_strcmp
# include <string/strcmp.c>
#endif