File: bench-strcmp.c

package info (click to toggle)
glibc 2.19-18+deb8u4
  • links: PTS, VCS
  • area: main
  • in suites: jessie, jessie-backports
  • size: 204,416 kB
  • ctags: 144,800
  • sloc: ansic: 970,361; asm: 241,207; sh: 10,069; makefile: 8,475; cpp: 3,595; perl: 2,077; pascal: 1,839; awk: 1,704; yacc: 317; sed: 73
file content (241 lines) | stat: -rw-r--r-- 5,798 bytes parent folder | download | duplicates (10)
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
/* Measure strcmp and wcscmp functions.
   Copyright (C) 2013-2014 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
   <http://www.gnu.org/licenses/>.  */

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

#ifdef WIDE
# include <wchar.h>

# define L(str) L##str
# define STRCMP wcscmp
# define STRCPY wcscpy
# define STRLEN wcslen
# define MEMCPY wmemcpy
# define SIMPLE_STRCMP simple_wcscmp
# define STUPID_STRCMP stupid_wcscmp
# define CHAR wchar_t
# define UCHAR wchar_t
# define CHARBYTES 4
# define CHARBYTESLOG 2
# define CHARALIGN __alignof__ (CHAR)
# define MIDCHAR 0x7fffffff
# define LARGECHAR 0xfffffffe
# define CHAR__MAX WCHAR_MAX
# define CHAR__MIN WCHAR_MIN

/* Wcscmp uses signed semantics for comparison, not unsigned */
/* Avoid using substraction since possible overflow */

int
simple_wcscmp (const wchar_t *s1, const wchar_t *s2)
{
  wchar_t c1, c2;
  do
    {
      c1 = *s1++;
      c2 = *s2++;
      if (c2 == L'\0')
      return c1 - c2;
    }
  while (c1 == c2);

  return c1 < c2 ? -1 : 1;
}

int
stupid_wcscmp (const wchar_t *s1, const wchar_t *s2)
{
  size_t ns1 = wcslen (s1) + 1;
  size_t ns2 = wcslen (s2) + 1;
  size_t n = ns1 < ns2 ? ns1 : ns2;
  int ret = 0;

  wchar_t c1, c2;

  while (n--) {
    c1 = *s1++;
    c2 = *s2++;
    if ((ret = c1 < c2 ? -1 : c1 == c2 ? 0 : 1) != 0)
      break;
  }
  return ret;
}

#else
# include <limits.h>

# define L(str) str
# define STRCMP strcmp
# define STRCPY strcpy
# define STRLEN strlen
# define MEMCPY memcpy
# define SIMPLE_STRCMP simple_strcmp
# define STUPID_STRCMP stupid_strcmp
# define CHAR char
# define UCHAR unsigned char
# define CHARBYTES 1
# define CHARBYTESLOG 0
# define CHARALIGN 1
# define MIDCHAR 0x7f
# define LARGECHAR 0xfe
# define CHAR__MAX CHAR_MAX
# define CHAR__MIN CHAR_MIN

/* Strcmp uses unsigned semantics for comparison. */
int
simple_strcmp (const char *s1, const char *s2)
{
  int ret;

  while ((ret = *(unsigned char *) s1 - *(unsigned char*) s2++) == 0 && *s1++);
  return ret;
}

int
stupid_strcmp (const char *s1, const char *s2)
{
  size_t ns1 = strlen (s1) + 1;
  size_t ns2 = strlen (s2) + 1;
  size_t n = ns1 < ns2 ? ns1 : ns2;
  int ret = 0;

  while (n--)
    if ((ret = *(unsigned char *) s1++ - *(unsigned char *) s2++) != 0)
      break;
  return ret;
}
#endif

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

IMPL (STUPID_STRCMP, 1)
IMPL (SIMPLE_STRCMP, 1)
IMPL (STRCMP, 1)

static void
do_one_test (impl_t *impl,
	     const CHAR *s1, const CHAR *s2,
	     int exp_result)
{
  size_t i, iters = INNER_LOOP_ITERS;
  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);

  TIMING_PRINT_MEAN ((double) cur, (double) iters);
}

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

  CHAR *s1, *s2;

  if (len == 0)
    return;

  align1 &= 63;
  if (align1 + (len + 1) * CHARBYTES >= page_size)
    return;

  align2 &= 63;
  if (align2 + (len + 1) * CHARBYTES >= page_size)
    return;

  /* Put them close to the end of page.  */
  i = align1 + CHARBYTES * (len + 2);
  s1 = (CHAR *) (buf1 + ((page_size - i) / 16 * 16) + align1);
  i = align2 + CHARBYTES * (len + 2);
  s2 = (CHAR *) (buf2 + ((page_size - i) / 16 * 16)  + 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;

  printf ("Length %4zd, alignment %2zd/%2zd:", len, align1, align2);

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

  putchar ('\n');
}

int
test_main (void)
{
  size_t i;

  test_init ();

  printf ("%23s", "");
  FOR_EACH_IMPL (impl, 0)
    printf ("\t%s", impl->name);
  putchar ('\n');

  for (i = 1; i < 32; ++i)
    {
      do_test (CHARBYTES * i, CHARBYTES * i, i, MIDCHAR, 0);
      do_test (CHARBYTES * i, CHARBYTES * i, i, MIDCHAR, 1);
      do_test (CHARBYTES * i, CHARBYTES * i, i, MIDCHAR, -1);
    }

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

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

  return ret;
}

#include "../test-skeleton.c"