benchtests/bench-strsep.c

   1 /* Measure strsep functions.
   2    Copyright (C) 2013-2022 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #define TEST_MAIN
  20 #define TEST_NAME "strsep"
  21 #include "bench-string.h"
  22
  23 char *
  24 simple_strsep (char **s1, char *s2)
  25 {
  26   char *begin;
  27   char *s;
  28   size_t j = 0;
  29
  30   begin = *s1;
  31   s = begin;
  32   if (begin == NULL)
  33     return NULL;
  34   ssize_t s2len = strlen (s2);
  35   while (*s)
  36     {
  37       for (j = 0; j < s2len; j++)
  38         {
  39           if (*s == s2[j])
  40             {
  41               s[0] = '\0';
  42               *s1 = s + 1;
  43               return begin;
  44             }
  45         }
  46       s++;
  47     }
  48   *s1 = NULL;
  49   return begin;
  50 }
  51
  52 char *
  53 oldstrsep (char **stringp, const char *delim)
  54 {
  55   char *begin, *end;
  56
  57   begin = *stringp;
  58   if (begin == NULL)
  59     return NULL;
  60
  61   /* A frequent case is when the delimiter string contains only one
  62      character.  Here we don't need to call the expensive `strpbrk'
  63      function and instead work using `strchr'.  */
  64   if (delim[0] == '\0' || delim[1] == '\0')
  65     {
  66       char ch = delim[0];
  67
  68       if (ch == '\0')
  69         end = NULL;
  70       else
  71         {
  72           if (*begin == ch)
  73             end = begin;
  74           else if (*begin == '\0')
  75             end = NULL;
  76           else
  77             end = strchr (begin + 1, ch);
  78         }
  79     }
  80   else
  81     /* Find the end of the token.  */
  82     end = strpbrk (begin, delim);
  83
  84   if (end)
  85     {
  86       /* Terminate the token and set *STRINGP past NUL character.  */
  87       *end++ = '\0';
  88       *stringp = end;
  89     }
  90   else
  91     /* No more delimiters; this is the last token.  */
  92     *stringp = NULL;
  93
  94   return begin;
  95 }
  96
  97 typedef char *(*proto_t) (const char **, const char *);
  98
  99 IMPL (simple_strsep, 0)
 100 IMPL (strsep, 1)
 101 IMPL (oldstrsep, 2)
 102
 103 static void
 104 do_one_test (impl_t * impl, const char *s1, const char *s2)
 105 {
 106   size_t i, iters = INNER_LOOP_ITERS_SMALL;
 107   timing_t start, stop, cur;
 108
 109   TIMING_NOW (start);
 110   for (i = 0; i < iters; ++i)
 111     {
 112       const char *s1a = s1;
 113       CALL (impl, &s1a, s2);
 114       if (s1a != NULL)
 115         ((char*)s1a)[-1] = '1';
 116     }
 117   TIMING_NOW (stop);
 118
 119   TIMING_DIFF (cur, start, stop);
 120
 121   TIMING_PRINT_MEAN ((double) cur, (double) iters);
 122 }
 123
 124 static void
 125 do_test (size_t align1, size_t align2, size_t len1, size_t len2, int fail)
 126 {
 127   char *s2 = (char *) (buf2 + align2);
 128
 129   /* Search for a delimiter in a string containing mostly '0', so don't
 130      use '0' as a delimiter.  */
 131   static const char d[] = "123456789abcdefg";
 132 #define dl (sizeof (d) - 1)
 133   char *ss2 = s2;
 134   for (size_t l = len2; l > 0; l = l > dl ? l - dl : 0)
 135     {
 136       size_t t = l > dl ? dl : l;
 137       ss2 = mempcpy (ss2, d, t);
 138     }
 139   s2[len2] = '\0';
 140
 141   printf ("Length %4zd/%zd, alignment %2zd/%2zd, %s:",
 142           len1, len2, align1, align2, fail ? "fail" : "found");
 143
 144   FOR_EACH_IMPL (impl, 0)
 145   {
 146     char *s1 = (char *) (buf1 + align1);
 147     memset (s1, '0', len1);
 148     if (!fail)
 149       s1[len1 / 2] = '1';
 150     s1[len1] = '\0';
 151     do_one_test (impl, s1, s2);
 152   }
 153   putchar ('\n');
 154 }
 155
 156 static int
 157 test_main (void)
 158 {
 159   test_init ();
 160
 161   printf ("%23s", "");
 162   FOR_EACH_IMPL (impl, 0)
 163     printf ("\t%s", impl->name);
 164   putchar ('\n');
 165
 166   for (size_t klen = 2; klen < 32; ++klen)
 167     for (size_t hlen = 4 * klen; hlen < 8 * klen; hlen += klen)
 168       {
 169         do_test (0, 0, hlen, klen, 0);
 170         do_test (0, 0, hlen, klen, 1);
 171         do_test (0, 3, hlen, klen, 0);
 172         do_test (0, 3, hlen, klen, 1);
 173         do_test (0, 9, hlen, klen, 0);
 174         do_test (0, 9, hlen, klen, 1);
 175         do_test (0, 15, hlen, klen, 0);
 176         do_test (0, 15, hlen, klen, 1);
 177
 178         do_test (3, 0, hlen, klen, 0);
 179         do_test (3, 0, hlen, klen, 1);
 180         do_test (3, 3, hlen, klen, 0);
 181         do_test (3, 3, hlen, klen, 1);
 182         do_test (3, 9, hlen, klen, 0);
 183         do_test (3, 9, hlen, klen, 1);
 184         do_test (3, 15, hlen, klen, 0);
 185         do_test (3, 15, hlen, klen, 1);
 186
 187         do_test (9, 0, hlen, klen, 0);
 188         do_test (9, 0, hlen, klen, 1);
 189         do_test (9, 3, hlen, klen, 0);
 190         do_test (9, 3, hlen, klen, 1);
 191         do_test (9, 9, hlen, klen, 0);
 192         do_test (9, 9, hlen, klen, 1);
 193         do_test (9, 15, hlen, klen, 0);
 194         do_test (9, 15, hlen, klen, 1);
 195
 196         do_test (15, 0, hlen, klen, 0);
 197         do_test (15, 0, hlen, klen, 1);
 198         do_test (15, 3, hlen, klen, 0);
 199         do_test (15, 3, hlen, klen, 1);
 200         do_test (15, 9, hlen, klen, 0);
 201         do_test (15, 9, hlen, klen, 1);
 202         do_test (15, 15, hlen, klen, 0);
 203         do_test (15, 15, hlen, klen, 1);
 204       }
 205   do_test (0, 0, page_size - 1, 16, 0);
 206   do_test (0, 0, page_size - 1, 16, 1);
 207
 208   return ret;
 209 }
 210
 211 #include <support/test-driver.c>