benchtests/bench-strncat.c

   1 /* Measure strncat functions.
   2    Copyright (C) 2013-2015 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    <http://www.gnu.org/licenses/>.  */
  18
  19 #define TEST_MAIN
  20 #define TEST_NAME "strncat"
  21 #include "bench-string.h"
  22
  23 typedef char *(*proto_t) (char *, const char *, size_t);
  24 char *stupid_strncat (char *, const char *, size_t);
  25 char *simple_strncat (char *, const char *, size_t);
  26
  27 IMPL (stupid_strncat, 0)
  28 IMPL (strncat, 2)
  29
  30 char *
  31 stupid_strncat (char *dst, const char *src, size_t n)
  32 {
  33   char *ret = dst;
  34   while (*dst++ != '\0');
  35   --dst;
  36   while (n--)
  37     if ( (*dst++ = *src++) == '\0')
  38       return ret;
  39   *dst = '\0';
  40   return ret;
  41 }
  42
  43 static void
  44 do_one_test (impl_t *impl, char *dst, const char *src, size_t n)
  45 {
  46   size_t k = strlen (dst), i, iters = INNER_LOOP_ITERS;
  47   timing_t start, stop, cur;
  48
  49   if (CALL (impl, dst, src, n) != dst)
  50     {
  51       error (0, 0, "Wrong result in function %s %p != %p", impl->name,
  52              CALL (impl, dst, src, n), dst);
  53       ret = 1;
  54       return;
  55     }
  56
  57   size_t len = strlen (src);
  58   if (memcmp (dst + k, src, len + 1 > n ? n : len + 1) != 0)
  59     {
  60       error (0, 0, "Incorrect cancatination in function %s",
  61              impl->name);
  62       ret = 1;
  63       return;
  64     }
  65   if (n < len && dst[k + n] != '\0')
  66     {
  67       error (0, 0, "There is no zero in the end of output string in %s",
  68              impl->name);
  69       ret = 1;
  70       return;
  71     }
  72
  73   TIMING_NOW (start);
  74   for (i = 0; i < iters; ++i)
  75     {
  76       dst[k] = '\0';
  77       CALL (impl, dst, src, n);
  78     }
  79   TIMING_NOW (stop);
  80
  81   TIMING_DIFF (cur, start, stop);
  82
  83   TIMING_PRINT_MEAN ((double) cur, (double) iters);
  84 }
  85
  86 static void
  87 do_test (size_t align1, size_t align2, size_t len1, size_t len2,
  88          size_t n, int max_char)
  89 {
  90   size_t i;
  91   char *s1, *s2;
  92
  93   align1 &= 7;
  94   if (align1 + len1 >= page_size)
  95     return;
  96   if (align1 + n > page_size)
  97     return;
  98   align2 &= 7;
  99   if (align2 + len1 + len2 >= page_size)
 100     return;
 101   if (align2 + len1 + n > page_size)
 102     return;
 103   s1 = (char *) (buf1 + align1);
 104   s2 = (char *) (buf2 + align2);
 105
 106   for (i = 0; i < len1; ++i)
 107     s1[i] = 32 + 23 * i % (max_char - 32);
 108   s1[len1] = '\0';
 109
 110   for (i = 0; i < len2; i++)
 111     s2[i] = 32 + 23 * i % (max_char - 32);
 112
 113   printf ("Length %4zd/%4zd, alignment %2zd/%2zd, N %4zd:",
 114           len1, len2, align1, align2, n);
 115
 116   FOR_EACH_IMPL (impl, 0)
 117     {
 118       s2[len2] = '\0';
 119       do_one_test (impl, s2, s1, n);
 120     }
 121
 122   putchar ('\n');
 123 }
 124
 125 int
 126 main (void)
 127 {
 128   size_t i, n;
 129
 130   test_init ();
 131
 132   printf ("%28s", "");
 133   FOR_EACH_IMPL (impl, 0)
 134     printf ("\t%s", impl->name);
 135   putchar ('\n');
 136
 137   for (n = 2; n <= 2048; n*=4)
 138     {
 139       do_test (0, 2, 2, 2, n, 127);
 140       do_test (0, 0, 4, 4, n, 127);
 141       do_test (4, 0, 4, 4, n, 255);
 142       do_test (0, 0, 8, 8, n, 127);
 143       do_test (0, 8, 8, 8, n, 127);
 144
 145       for (i = 1; i < 8; ++i)
 146         {
 147           do_test (0, 0, 8 << i, 8 << i, n, 127);
 148           do_test (8 - i, 2 * i, 8 << i, 8 << i, n, 127);
 149           do_test (0, 0, 8 << i, 2 << i, n, 127);
 150           do_test (8 - i, 2 * i, 8 << i, 2 << i, n, 127);
 151         }
 152
 153       for (i = 1; i < 8; ++i)
 154         {
 155           do_test (i, 2 * i, 8 << i, 1, n, 127);
 156           do_test (2 * i, i, 8 << i, 1, n, 255);
 157           do_test (i, i, 8 << i, 10, n, 127);
 158         }
 159     }
 160
 161   return ret;
 162 }