benchtests/bench-memccpy.c

   1 /* Measure memccpy functions.
   2    Copyright (C) 2013-2021 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 "memccpy"
  21 #include "bench-string.h"
  22
  23 void *
  24 generic_memccpy (void *dst, const void *src, int c, size_t n)
  25 {
  26   void *p = memchr (src, c, n);
  27
  28   if (p != NULL)
  29     return mempcpy (dst, src, p - src + 1);
  30
  31   memcpy (dst, src, n);
  32   return NULL;
  33 }
  34
  35 IMPL (memccpy, 1)
  36 IMPL (generic_memccpy, 0)
  37
  38 typedef void *(*proto_t) (void *, const void *, int c, size_t);
  39
  40 static void
  41 do_one_test (impl_t *impl, void *dst, const void *src, int c, size_t len,
  42              size_t n)
  43 {
  44   size_t i, iters = INNER_LOOP_ITERS_LARGE;
  45   timing_t start, stop, cur;
  46
  47   TIMING_NOW (start);
  48   for (i = 0; i < iters; ++i)
  49     {
  50       CALL (impl, dst, src, c, n);
  51     }
  52   TIMING_NOW (stop);
  53
  54   TIMING_DIFF (cur, start, stop);
  55
  56   TIMING_PRINT_MEAN ((double) cur, (double) iters);
  57 }
  58
  59 static void
  60 do_test (size_t align1, size_t align2, int c, size_t len, size_t n,
  61          int max_char)
  62 {
  63   size_t i;
  64   char *s1, *s2;
  65
  66   align1 &= 7;
  67   if (align1 + len >= page_size)
  68     return;
  69
  70   align2 &= 7;
  71   if (align2 + len >= page_size)
  72     return;
  73
  74   s1 = (char *) (buf1 + align1);
  75   s2 = (char *) (buf2 + align2);
  76
  77   for (i = 0; i < len - 1; ++i)
  78     {
  79       s1[i] = 32 + 23 * i % (max_char - 32);
  80       if (s1[i] == (char) c)
  81         --s1[i];
  82     }
  83   s1[len - 1] = c;
  84   for (i = len; i + align1 < page_size && i < len + 64; ++i)
  85     s1[i] = 32 + 32 * i % (max_char - 32);
  86
  87   printf ("Length %4zd, n %4zd, char %d, alignment %2zd/%2zd:", len, n, c, align1, align2);
  88
  89   FOR_EACH_IMPL (impl, 0)
  90     do_one_test (impl, s2, s1, c, len, n);
  91
  92   putchar ('\n');
  93 }
  94
  95 int
  96 test_main (void)
  97 {
  98   size_t i;
  99
 100   test_init ();
 101
 102   printf ("%28s", "");
 103   FOR_EACH_IMPL (impl, 0)
 104     printf ("\t%s", impl->name);
 105   putchar ('\n');
 106
 107   for (i = 1; i < 8; ++i)
 108     {
 109       do_test (i, i, 12, 16, 16, 127);
 110       do_test (i, i, 23, 16, 16, 255);
 111       do_test (i, 2 * i, 28, 16, 16, 127);
 112       do_test (2 * i, i, 31, 16, 16, 255);
 113       do_test (8 - i, 2 * i, 1, 1 << i, 2 << i, 127);
 114       do_test (2 * i, 8 - i, 17, 2 << i, 1 << i, 127);
 115       do_test (8 - i, 2 * i, 0, 1 << i, 2 << i, 255);
 116       do_test (2 * i, 8 - i, i, 2 << i, 1 << i, 255);
 117     }
 118
 119   for (i = 1; i < 8; ++i)
 120     {
 121       do_test (0, 0, i, 4 << i, 8 << i, 127);
 122       do_test (0, 0, i, 16 << i, 8 << i, 127);
 123       do_test (8 - i, 2 * i, i, 4 << i, 8 << i, 127);
 124       do_test (8 - i, 2 * i, i, 16 << i, 8 << i, 127);
 125     }
 126
 127   return ret;
 128 }
 129
 130 #include <support/test-driver.c>