benchtests/bench-memccpy.c

   1 /* Measure memccpy functions.
   2    Copyright (C) 2013-2017 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 "memccpy"
  21 #include "bench-string.h"
  22
  23 void *simple_memccpy (void *, const void *, int, size_t);
  24 void *stupid_memccpy (void *, const void *, int, size_t);
  25
  26 IMPL (stupid_memccpy, 0)
  27 IMPL (simple_memccpy, 0)
  28 IMPL (memccpy, 1)
  29
  30 void *
  31 simple_memccpy (void *dst, const void *src, int c, size_t n)
  32 {
  33   const char *s = src;
  34   char *d = dst;
  35
  36   while (n-- > 0)
  37     if ((*d++ = *s++) == (char) c)
  38       return d;
  39
  40   return NULL;
  41 }
  42
  43 void *
  44 stupid_memccpy (void *dst, const void *src, int c, size_t n)
  45 {
  46   void *p = memchr (src, c, n);
  47
  48   if (p != NULL)
  49     return mempcpy (dst, src, p - src + 1);
  50
  51   memcpy (dst, src, n);
  52   return NULL;
  53 }
  54
  55 typedef void *(*proto_t) (void *, const void *, int c, size_t);
  56
  57 static void
  58 do_one_test (impl_t *impl, void *dst, const void *src, int c, size_t len,
  59              size_t n)
  60 {
  61   void *expect = len > n ? NULL : (char *) dst + len;
  62   size_t i, iters = INNER_LOOP_ITERS;
  63   timing_t start, stop, cur;
  64
  65   if (CALL (impl, dst, src, c, n) != expect)
  66     {
  67       error (0, 0, "Wrong result in function %s %p %p", impl->name,
  68              CALL (impl, dst, src, c, n), expect);
  69       ret = 1;
  70       return;
  71     }
  72
  73   if (memcmp (dst, src, len > n ? n : len) != 0)
  74     {
  75       error (0, 0, "Wrong result in function %s", impl->name);
  76       ret = 1;
  77       return;
  78     }
  79
  80   TIMING_NOW (start);
  81   for (i = 0; i < iters; ++i)
  82     {
  83       CALL (impl, dst, src, c, n);
  84     }
  85   TIMING_NOW (stop);
  86
  87   TIMING_DIFF (cur, start, stop);
  88
  89   TIMING_PRINT_MEAN ((double) cur, (double) iters);
  90 }
  91
  92 static void
  93 do_test (size_t align1, size_t align2, int c, size_t len, size_t n,
  94          int max_char)
  95 {
  96   size_t i;
  97   char *s1, *s2;
  98
  99   align1 &= 7;
 100   if (align1 + len >= page_size)
 101     return;
 102
 103   align2 &= 7;
 104   if (align2 + len >= page_size)
 105     return;
 106
 107   s1 = (char *) (buf1 + align1);
 108   s2 = (char *) (buf2 + align2);
 109
 110   for (i = 0; i < len - 1; ++i)
 111     {
 112       s1[i] = 32 + 23 * i % (max_char - 32);
 113       if (s1[i] == (char) c)
 114         --s1[i];
 115     }
 116   s1[len - 1] = c;
 117   for (i = len; i + align1 < page_size && i < len + 64; ++i)
 118     s1[i] = 32 + 32 * i % (max_char - 32);
 119
 120   printf ("Length %4zd, n %4zd, char %d, alignment %2zd/%2zd:", len, n, c, align1, align2);
 121
 122   FOR_EACH_IMPL (impl, 0)
 123     do_one_test (impl, s2, s1, c, len, n);
 124
 125   putchar ('\n');
 126 }
 127
 128 int
 129 test_main (void)
 130 {
 131   size_t i;
 132
 133   test_init ();
 134
 135   printf ("%28s", "");
 136   FOR_EACH_IMPL (impl, 0)
 137     printf ("\t%s", impl->name);
 138   putchar ('\n');
 139
 140   for (i = 1; i < 8; ++i)
 141     {
 142       do_test (i, i, 12, 16, 16, 127);
 143       do_test (i, i, 23, 16, 16, 255);
 144       do_test (i, 2 * i, 28, 16, 16, 127);
 145       do_test (2 * i, i, 31, 16, 16, 255);
 146       do_test (8 - i, 2 * i, 1, 1 << i, 2 << i, 127);
 147       do_test (2 * i, 8 - i, 17, 2 << i, 1 << i, 127);
 148       do_test (8 - i, 2 * i, 0, 1 << i, 2 << i, 255);
 149       do_test (2 * i, 8 - i, i, 2 << i, 1 << i, 255);
 150     }
 151
 152   for (i = 1; i < 8; ++i)
 153     {
 154       do_test (0, 0, i, 4 << i, 8 << i, 127);
 155       do_test (0, 0, i, 16 << i, 8 << i, 127);
 156       do_test (8 - i, 2 * i, i, 4 << i, 8 << i, 127);
 157       do_test (8 - i, 2 * i, i, 16 << i, 8 << i, 127);
 158     }
 159
 160   return ret;
 161 }
 162
 163 #include <support/test-driver.c>