benchtests/bench-memcpy.c

   1 /* Measure memcpy 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 #ifndef MEMCPY_RESULT
  20 # define MEMCPY_RESULT(dst, len) dst
  21 # define MIN_PAGE_SIZE 131072
  22 # define TEST_MAIN
  23 # define TEST_NAME "memcpy"
  24 # include "bench-string.h"
  25
  26 char *simple_memcpy (char *, const char *, size_t);
  27 char *builtin_memcpy (char *, const char *, size_t);
  28
  29 IMPL (simple_memcpy, 0)
  30 IMPL (builtin_memcpy, 0)
  31 IMPL (memcpy, 1)
  32
  33 char *
  34 simple_memcpy (char *dst, const char *src, size_t n)
  35 {
  36   char *ret = dst;
  37   while (n--)
  38     *dst++ = *src++;
  39   return ret;
  40 }
  41
  42 char *
  43 builtin_memcpy (char *dst, const char *src, size_t n)
  44 {
  45   return __builtin_memcpy (dst, src, n);
  46 }
  47 #endif
  48
  49 typedef char *(*proto_t) (char *, const char *, size_t);
  50
  51 static void
  52 do_one_test (impl_t *impl, char *dst, const char *src,
  53              size_t len)
  54 {
  55   size_t i, iters = INNER_LOOP_ITERS;
  56   timing_t start, stop, cur;
  57
  58   /* Must clear the destination buffer set by the previous run.  */
  59   for (i = 0; i < len; i++)
  60     dst[i] = 0;
  61
  62   if (CALL (impl, dst, src, len) != MEMCPY_RESULT (dst, len))
  63     {
  64       error (0, 0, "Wrong result in function %s %p %p", impl->name,
  65              CALL (impl, dst, src, len), MEMCPY_RESULT (dst, len));
  66       ret = 1;
  67       return;
  68     }
  69
  70   if (memcmp (dst, src, len) != 0)
  71     {
  72       error (0, 0, "Wrong result in function %s dst \"%s\" src \"%s\"",
  73              impl->name, dst, src);
  74       ret = 1;
  75       return;
  76     }
  77
  78   TIMING_NOW (start);
  79   for (i = 0; i < iters; ++i)
  80     {
  81       CALL (impl, dst, src, len);
  82     }
  83   TIMING_NOW (stop);
  84
  85   TIMING_DIFF (cur, start, stop);
  86
  87   TIMING_PRINT_MEAN ((double) cur, (double) iters);
  88 }
  89
  90 static void
  91 do_test (size_t align1, size_t align2, size_t len)
  92 {
  93   size_t i, j;
  94   char *s1, *s2;
  95
  96   align1 &= 63;
  97   if (align1 + len >= page_size)
  98     return;
  99
 100   align2 &= 63;
 101   if (align2 + len >= page_size)
 102     return;
 103
 104   s1 = (char *) (buf1 + align1);
 105   s2 = (char *) (buf2 + align2);
 106
 107   for (i = 0, j = 1; i < len; i++, j += 23)
 108     s1[i] = j;
 109
 110   printf ("Length %4zd, alignment %2zd/%2zd:", len, align1, align2);
 111
 112   FOR_EACH_IMPL (impl, 0)
 113     do_one_test (impl, s2, s1, len);
 114
 115   putchar ('\n');
 116 }
 117
 118 int
 119 test_main (void)
 120 {
 121   size_t i;
 122
 123   test_init ();
 124
 125   printf ("%23s", "");
 126   FOR_EACH_IMPL (impl, 0)
 127     printf ("\t%s", impl->name);
 128   putchar ('\n');
 129
 130   for (i = 0; i < 18; ++i)
 131     {
 132       do_test (0, 0, 1 << i);
 133       do_test (i, 0, 1 << i);
 134       do_test (0, i, 1 << i);
 135       do_test (i, i, 1 << i);
 136     }
 137
 138   for (i = 0; i < 32; ++i)
 139     {
 140       do_test (0, 0, i);
 141       do_test (i, 0, i);
 142       do_test (0, i, i);
 143       do_test (i, i, i);
 144     }
 145
 146   for (i = 3; i < 32; ++i)
 147     {
 148       if ((i & (i - 1)) == 0)
 149         continue;
 150       do_test (0, 0, 16 * i);
 151       do_test (i, 0, 16 * i);
 152       do_test (0, i, 16 * i);
 153       do_test (i, i, 16 * i);
 154     }
 155
 156   for (i = 32; i < 64; ++i)
 157     {
 158       do_test (0, 0, 32 * i);
 159       do_test (i, 0, 32 * i);
 160       do_test (0, i, 32 * i);
 161       do_test (i, i, 32 * i);
 162     }
 163
 164   do_test (0, 0, getpagesize ());
 165
 166   return ret;
 167 }
 168
 169 #include <support/test-driver.c>