benchtests/bench-strncpy.c

   1 /* Measure strncpy 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 #ifndef STRNCPY_RESULT
  20 # define STRNCPY_RESULT(dst, len, n) dst
  21 # define TEST_MAIN
  22 # define TEST_NAME "strncpy"
  23 # include "bench-string.h"
  24
  25 char *simple_strncpy (char *, const char *, size_t);
  26 char *stupid_strncpy (char *, const char *, size_t);
  27
  28 IMPL (stupid_strncpy, 0)
  29 IMPL (simple_strncpy, 0)
  30 IMPL (strncpy, 1)
  31
  32 char *
  33 simple_strncpy (char *dst, const char *src, size_t n)
  34 {
  35   char *ret = dst;
  36   while (n--)
  37     if ((*dst++ = *src++) == '\0')
  38       {
  39         while (n--)
  40           *dst++ = '\0';
  41         return ret;
  42       }
  43   return ret;
  44 }
  45
  46 char *
  47 stupid_strncpy (char *dst, const char *src, size_t n)
  48 {
  49   size_t nc = strnlen (src, n);
  50   size_t i;
  51
  52   for (i = 0; i < nc; ++i)
  53     dst[i] = src[i];
  54   for (; i < n; ++i)
  55     dst[i] = '\0';
  56   return dst;
  57 }
  58 #endif
  59
  60 typedef char *(*proto_t) (char *, const char *, size_t);
  61
  62 static void
  63 do_one_test (impl_t *impl, char *dst, const char *src, size_t len, size_t n)
  64 {
  65   size_t i, iters = INNER_LOOP_ITERS;
  66   timing_t start, stop, cur;
  67
  68   if (CALL (impl, dst, src, n) != STRNCPY_RESULT (dst, len, n))
  69     {
  70       error (0, 0, "Wrong result in function %s %p %p", impl->name,
  71              CALL (impl, dst, src, n), dst);
  72       ret = 1;
  73       return;
  74     }
  75
  76   if (memcmp (dst, src, len > n ? n : len) != 0)
  77     {
  78       error (0, 0, "Wrong result in function %s", impl->name);
  79       ret = 1;
  80       return;
  81     }
  82
  83   if (n > len)
  84     {
  85       size_t i;
  86
  87       for (i = len; i < n; ++i)
  88         if (dst [i] != '\0')
  89           {
  90             error (0, 0, "Wrong result in function %s", impl->name);
  91             ret = 1;
  92             return;
  93           }
  94     }
  95
  96   TIMING_NOW (start);
  97   for (i = 0; i < iters; ++i)
  98     {
  99       CALL (impl, dst, src, n);
 100     }
 101   TIMING_NOW (stop);
 102
 103   TIMING_DIFF (cur, start, stop);
 104
 105   TIMING_PRINT_MEAN ((double) cur, (double) iters);
 106 }
 107
 108 static void
 109 do_test (size_t align1, size_t align2, size_t len, size_t n, int max_char)
 110 {
 111   size_t i;
 112   char *s1, *s2;
 113
 114   align1 &= 7;
 115   if (align1 + len >= page_size)
 116     return;
 117
 118   align2 &= 7;
 119   if (align2 + len >= page_size)
 120     return;
 121
 122   s1 = (char *) (buf1 + align1);
 123   s2 = (char *) (buf2 + align2);
 124
 125   for (i = 0; i < len; ++i)
 126     s1[i] = 32 + 23 * i % (max_char - 32);
 127   s1[len] = 0;
 128   for (i = len + 1; i + align1 < page_size && i < len + 64; ++i)
 129     s1[i] = 32 + 32 * i % (max_char - 32);
 130
 131   printf ("Length %4zd, n %4zd, alignment %2zd/%2zd:", len, n, align1, align2);
 132
 133   FOR_EACH_IMPL (impl, 0)
 134     do_one_test (impl, s2, s1, len, n);
 135
 136   putchar ('\n');
 137 }
 138
 139 int
 140 test_main (void)
 141 {
 142   size_t i;
 143
 144   test_init ();
 145
 146   printf ("%28s", "");
 147   FOR_EACH_IMPL (impl, 0)
 148     printf ("\t%s", impl->name);
 149   putchar ('\n');
 150
 151   for (i = 1; i < 8; ++i)
 152     {
 153       do_test (i, i, 16, 16, 127);
 154       do_test (i, i, 16, 16, 255);
 155       do_test (i, 2 * i, 16, 16, 127);
 156       do_test (2 * i, i, 16, 16, 255);
 157       do_test (8 - i, 2 * i, 1 << i, 2 << i, 127);
 158       do_test (2 * i, 8 - i, 2 << i, 1 << i, 127);
 159       do_test (8 - i, 2 * i, 1 << i, 2 << i, 255);
 160       do_test (2 * i, 8 - i, 2 << i, 1 << i, 255);
 161     }
 162
 163   for (i = 1; i < 8; ++i)
 164     {
 165       do_test (0, 0, 4 << i, 8 << i, 127);
 166       do_test (0, 0, 16 << i, 8 << i, 127);
 167       do_test (8 - i, 2 * i, 4 << i, 8 << i, 127);
 168       do_test (8 - i, 2 * i, 16 << i, 8 << i, 127);
 169     }
 170
 171   return ret;
 172 }
 173
 174 #include "../test-skeleton.c"