benchtests/bench-strncmp.c

   1 /* Measure strncmp functions.
   2    Copyright (C) 2013-2019 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 #ifdef WIDE
  21 # define TEST_NAME "wcsncmp"
  22 #else
  23 # define TEST_NAME "strncmp"
  24 #endif /* !WIDE */
  25 #include "bench-string.h"
  26 #include "json-lib.h"
  27
  28 #ifdef WIDE
  29 # define L(str) L##str
  30 # define SIMPLE_STRNCMP simple_wcsncmp
  31
  32 /* Wcsncmp uses signed semantics for comparison, not unsigned.
  33    Avoid using substraction since possible overflow.  */
  34 int
  35 simple_wcsncmp (const CHAR *s1, const CHAR *s2, size_t n)
  36 {
  37   wchar_t c1, c2;
  38
  39   while (n--)
  40     {
  41       c1 = *s1++;
  42       c2 = *s2++;
  43       if (c1 == L ('\0') || c1 != c2)
  44         return c1 > c2 ? 1 : (c1 < c2 ? -1 : 0);
  45     }
  46   return 0;
  47 }
  48
  49 #else
  50 # define L(str) str
  51 # define SIMPLE_STRNCMP simple_strncmp
  52
  53 /* Strncmp uses unsigned semantics for comparison.  */
  54 int
  55 simple_strncmp (const char *s1, const char *s2, size_t n)
  56 {
  57   int ret = 0;
  58
  59   while (n-- && (ret = *(unsigned char *) s1 - * (unsigned char *) s2++) == 0
  60          && *s1++);
  61   return ret;
  62 }
  63
  64 #endif /* !WIDE */
  65
  66 typedef int (*proto_t) (const CHAR *, const CHAR *, size_t);
  67
  68 IMPL (SIMPLE_STRNCMP, 0)
  69 IMPL (STRNCMP, 1)
  70
  71
  72 static void
  73 do_one_test (json_ctx_t *json_ctx, impl_t *impl, const CHAR *s1, const CHAR
  74              *s2, size_t n, int exp_result)
  75 {
  76   size_t i, iters = INNER_LOOP_ITERS8;
  77   timing_t start, stop, cur;
  78
  79   TIMING_NOW (start);
  80   for (i = 0; i < iters; ++i)
  81     {
  82       CALL (impl, s1, s2, n);
  83     }
  84   TIMING_NOW (stop);
  85
  86   TIMING_DIFF (cur, start, stop);
  87
  88   json_element_double (json_ctx, (double) cur / (double) iters);
  89 }
  90
  91 static void
  92 do_test_limit (json_ctx_t *json_ctx, size_t align1, size_t align2, size_t len,
  93                size_t n, int max_char, int exp_result)
  94 {
  95   size_t i, align_n;
  96   CHAR *s1, *s2;
  97
  98   align1 &= 15;
  99   align2 &= 15;
 100   align_n = (page_size - n * CHARBYTES) & 15;
 101
 102   json_element_object_begin (json_ctx);
 103   json_attr_uint (json_ctx, "strlen", (double) len);
 104   json_attr_uint (json_ctx, "len", (double) n);
 105   json_attr_uint (json_ctx, "align1", (double) align1);
 106   json_attr_uint (json_ctx, "align2", (double) align2);
 107   json_array_begin (json_ctx, "timings");
 108
 109   FOR_EACH_IMPL (impl, 0)
 110     {
 111       alloc_bufs ();
 112       s1 = (CHAR *) (buf1 + page_size - n * CHARBYTES);
 113       s2 = (CHAR *) (buf2 + page_size - n * CHARBYTES);
 114
 115       if (align1 < align_n)
 116         s1 = (CHAR *) ((char *) s1 - (align_n - align1));
 117
 118       if (align2 < align_n)
 119         s2 = (CHAR *) ((char *) s2 - (align_n - align2));
 120
 121       for (i = 0; i < n; i++)
 122         s1[i] = s2[i] = 1 + 23 * i % max_char;
 123
 124       if (len < n)
 125         {
 126           s1[len] = 0;
 127           s2[len] = 0;
 128           if (exp_result < 0)
 129             s2[len] = 32;
 130           else if (exp_result > 0)
 131             s1[len] = 64;
 132         }
 133
 134       do_one_test (json_ctx, impl, s1, s2, n, exp_result);
 135     }
 136
 137   json_array_end (json_ctx);
 138   json_element_object_end (json_ctx);
 139 }
 140
 141 static void
 142 do_test (json_ctx_t *json_ctx, size_t align1, size_t align2, size_t len, size_t
 143          n, int max_char, int exp_result)
 144 {
 145   size_t i;
 146   CHAR *s1, *s2;
 147
 148   if (n == 0)
 149     return;
 150
 151   align1 &= 63;
 152   if (align1 + (n + 1) * CHARBYTES >= page_size)
 153     return;
 154
 155   align2 &= 7;
 156   if (align2 + (n + 1) * CHARBYTES >= page_size)
 157     return;
 158
 159   json_element_object_begin (json_ctx);
 160   json_attr_uint (json_ctx, "strlen", (double) len);
 161   json_attr_uint (json_ctx, "len", (double) n);
 162   json_attr_uint (json_ctx, "align1", (double) align1);
 163   json_attr_uint (json_ctx, "align2", (double) align2);
 164   json_array_begin (json_ctx, "timings");
 165
 166   FOR_EACH_IMPL (impl, 0)
 167     {
 168       alloc_bufs ();
 169       s1 = (CHAR *) (buf1 + align1);
 170       s2 = (CHAR *) (buf2 + align2);
 171
 172       for (i = 0; i < n; i++)
 173         s1[i] = s2[i] = 1 + (23 << ((CHARBYTES - 1) * 8)) * i % max_char;
 174
 175       s1[n] = 24 + exp_result;
 176       s2[n] = 23;
 177       s1[len] = 0;
 178       s2[len] = 0;
 179       if (exp_result < 0)
 180         s2[len] = 32;
 181       else if (exp_result > 0)
 182         s1[len] = 64;
 183       if (len >= n)
 184         s2[n - 1] -= exp_result;
 185
 186       do_one_test (json_ctx, impl, s1, s2, n, exp_result);
 187     }
 188
 189   json_array_end (json_ctx);
 190   json_element_object_end (json_ctx);
 191 }
 192
 193 int
 194 test_main (void)
 195 {
 196   json_ctx_t json_ctx;
 197   size_t i;
 198
 199   test_init ();
 200
 201   json_init (&json_ctx, 0, stdout);
 202
 203   json_document_begin (&json_ctx);
 204   json_attr_string (&json_ctx, "timing_type", TIMING_TYPE);
 205
 206   json_attr_object_begin (&json_ctx, "functions");
 207   json_attr_object_begin (&json_ctx, TEST_NAME);
 208   json_attr_string (&json_ctx, "bench-variant", "default");
 209
 210   json_array_begin (&json_ctx, "ifuncs");
 211   FOR_EACH_IMPL (impl, 0)
 212     json_element_string (&json_ctx, impl->name);
 213   json_array_end (&json_ctx);
 214
 215   json_array_begin (&json_ctx, "results");
 216
 217   for (i =0; i < 16; ++i)
 218     {
 219       do_test (&json_ctx, 0, 0, 8, i, 127, 0);
 220       do_test (&json_ctx, 0, 0, 8, i, 127, -1);
 221       do_test (&json_ctx, 0, 0, 8, i, 127, 1);
 222       do_test (&json_ctx, i, i, 8, i, 127, 0);
 223       do_test (&json_ctx, i, i, 8, i, 127, 1);
 224       do_test (&json_ctx, i, i, 8, i, 127, -1);
 225       do_test (&json_ctx, i, 2 * i, 8, i, 127, 0);
 226       do_test (&json_ctx, 2 * i, i, 8, i, 127, 1);
 227       do_test (&json_ctx, i, 3 * i, 8, i, 127, -1);
 228       do_test (&json_ctx, 0, 0, 8, i, 255, 0);
 229       do_test (&json_ctx, 0, 0, 8, i, 255, -1);
 230       do_test (&json_ctx, 0, 0, 8, i, 255, 1);
 231       do_test (&json_ctx, i, i, 8, i, 255, 0);
 232       do_test (&json_ctx, i, i, 8, i, 255, 1);
 233       do_test (&json_ctx, i, i, 8, i, 255, -1);
 234       do_test (&json_ctx, i, 2 * i, 8, i, 255, 0);
 235       do_test (&json_ctx, 2 * i, i, 8, i, 255, 1);
 236       do_test (&json_ctx, i, 3 * i, 8, i, 255, -1);
 237     }
 238
 239   for (i = 1; i < 8; ++i)
 240     {
 241       do_test (&json_ctx, 0, 0, 8 << i, 16 << i, 127, 0);
 242       do_test (&json_ctx, 0, 0, 8 << i, 16 << i, 127, 1);
 243       do_test (&json_ctx, 0, 0, 8 << i, 16 << i, 127, -1);
 244       do_test (&json_ctx, 0, 0, 8 << i, 16 << i, 255, 0);
 245       do_test (&json_ctx, 0, 0, 8 << i, 16 << i, 255, 1);
 246       do_test (&json_ctx, 0, 0, 8 << i, 16 << i, 255, -1);
 247       do_test (&json_ctx, 8 - i, 2 * i, 8 << i, 16 << i, 127, 0);
 248       do_test (&json_ctx, 8 - i, 2 * i, 8 << i, 16 << i, 127, 1);
 249       do_test (&json_ctx, 2 * i, i, 8 << i, 16 << i, 255, 0);
 250       do_test (&json_ctx, 2 * i, i, 8 << i, 16 << i, 255, 1);
 251     }
 252
 253   do_test_limit (&json_ctx, 4, 0, 21, 20, 127, 0);
 254   do_test_limit (&json_ctx, 0, 4, 21, 20, 127, 0);
 255   do_test_limit (&json_ctx, 8, 0, 25, 24, 127, 0);
 256   do_test_limit (&json_ctx, 0, 8, 25, 24, 127, 0);
 257
 258   for (i = 0; i < 8; ++i)
 259     {
 260       do_test_limit (&json_ctx, 0, 0, 17 - i, 16 - i, 127, 0);
 261       do_test_limit (&json_ctx, 0, 0, 17 - i, 16 - i, 255, 0);
 262       do_test_limit (&json_ctx, 0, 0, 15 - i, 16 - i, 127, 0);
 263       do_test_limit (&json_ctx, 0, 0, 15 - i, 16 - i, 127, 1);
 264       do_test_limit (&json_ctx, 0, 0, 15 - i, 16 - i, 127, -1);
 265       do_test_limit (&json_ctx, 0, 0, 15 - i, 16 - i, 255, 0);
 266       do_test_limit (&json_ctx, 0, 0, 15 - i, 16 - i, 255, 1);
 267       do_test_limit (&json_ctx, 0, 0, 15 - i, 16 - i, 255, -1);
 268     }
 269
 270   json_array_end (&json_ctx);
 271   json_attr_object_end (&json_ctx);
 272   json_attr_object_end (&json_ctx);
 273   json_document_end (&json_ctx);
 274
 275   return ret;
 276 }
 277
 278 #include <support/test-driver.c>