benchtests/bench-memccpy.c

   1 /* Measure memccpy functions.
   2    Copyright (C) 2013-2018 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   size_t i, iters = INNER_LOOP_ITERS;
  62   timing_t start, stop, cur;
  63
  64   TIMING_NOW (start);
  65   for (i = 0; i < iters; ++i)
  66     {
  67       CALL (impl, dst, src, c, n);
  68     }
  69   TIMING_NOW (stop);
  70
  71   TIMING_DIFF (cur, start, stop);
  72
  73   TIMING_PRINT_MEAN ((double) cur, (double) iters);
  74 }
  75
  76 static void
  77 do_test (size_t align1, size_t align2, int c, size_t len, size_t n,
  78          int max_char)
  79 {
  80   size_t i;
  81   char *s1, *s2;
  82
  83   align1 &= 7;
  84   if (align1 + len >= page_size)
  85     return;
  86
  87   align2 &= 7;
  88   if (align2 + len >= page_size)
  89     return;
  90
  91   s1 = (char *) (buf1 + align1);
  92   s2 = (char *) (buf2 + align2);
  93
  94   for (i = 0; i < len - 1; ++i)
  95     {
  96       s1[i] = 32 + 23 * i % (max_char - 32);
  97       if (s1[i] == (char) c)
  98         --s1[i];
  99     }
 100   s1[len - 1] = c;
 101   for (i = len; i + align1 < page_size && i < len + 64; ++i)
 102     s1[i] = 32 + 32 * i % (max_char - 32);
 103
 104   printf ("Length %4zd, n %4zd, char %d, alignment %2zd/%2zd:", len, n, c, align1, align2);
 105
 106   FOR_EACH_IMPL (impl, 0)
 107     do_one_test (impl, s2, s1, c, len, n);
 108
 109   putchar ('\n');
 110 }
 111
 112 int
 113 test_main (void)
 114 {
 115   size_t i;
 116
 117   test_init ();
 118
 119   printf ("%28s", "");
 120   FOR_EACH_IMPL (impl, 0)
 121     printf ("\t%s", impl->name);
 122   putchar ('\n');
 123
 124   for (i = 1; i < 8; ++i)
 125     {
 126       do_test (i, i, 12, 16, 16, 127);
 127       do_test (i, i, 23, 16, 16, 255);
 128       do_test (i, 2 * i, 28, 16, 16, 127);
 129       do_test (2 * i, i, 31, 16, 16, 255);
 130       do_test (8 - i, 2 * i, 1, 1 << i, 2 << i, 127);
 131       do_test (2 * i, 8 - i, 17, 2 << i, 1 << i, 127);
 132       do_test (8 - i, 2 * i, 0, 1 << i, 2 << i, 255);
 133       do_test (2 * i, 8 - i, i, 2 << i, 1 << i, 255);
 134     }
 135
 136   for (i = 1; i < 8; ++i)
 137     {
 138       do_test (0, 0, i, 4 << i, 8 << i, 127);
 139       do_test (0, 0, i, 16 << i, 8 << i, 127);
 140       do_test (8 - i, 2 * i, i, 4 << i, 8 << i, 127);
 141       do_test (8 - i, 2 * i, i, 16 << i, 8 << i, 127);
 142     }
 143
 144   return ret;
 145 }
 146
 147 #include <support/test-driver.c>