benchtests/bench-strncmp.c

   1 /* Measure strncmp 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 #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 # include <wchar.h>
  30
  31 # define L(str) L##str
  32 # define STRNCMP wcsncmp
  33 # define SIMPLE_STRNCMP simple_wcsncmp
  34 # define STUPID_STRNCMP stupid_wcsncmp
  35 # define CHAR wchar_t
  36 # define CHARBYTES 4
  37
  38 /* Wcsncmp uses signed semantics for comparison, not unsigned.
  39    Avoid using substraction since possible overflow.  */
  40 int
  41 simple_wcsncmp (const CHAR *s1, const CHAR *s2, size_t n)
  42 {
  43   wchar_t c1, c2;
  44
  45   while (n--)
  46     {
  47       c1 = *s1++;
  48       c2 = *s2++;
  49       if (c1 == L ('\0') || c1 != c2)
  50         return c1 > c2 ? 1 : (c1 < c2 ? -1 : 0);
  51     }
  52   return 0;
  53 }
  54
  55 int
  56 stupid_wcsncmp (const CHAR *s1, const CHAR *s2, size_t n)
  57 {
  58   wchar_t c1, c2;
  59   size_t ns1 = wcsnlen (s1, n) + 1, ns2 = wcsnlen (s2, n) + 1;
  60
  61   n = ns1 < n ? ns1 : n;
  62   n = ns2 < n ? ns2 : n;
  63
  64   while (n--)
  65     {
  66       c1 = *s1++;
  67       c2 = *s2++;
  68       if (c1 != c2)
  69         return c1 > c2 ? 1 : -1;
  70     }
  71   return 0;
  72 }
  73
  74 #else
  75 # define L(str) str
  76 # define STRNCMP strncmp
  77 # define SIMPLE_STRNCMP simple_strncmp
  78 # define STUPID_STRNCMP stupid_strncmp
  79 # define CHAR char
  80 # define CHARBYTES 1
  81
  82 /* Strncmp uses unsigned semantics for comparison.  */
  83 int
  84 simple_strncmp (const char *s1, const char *s2, size_t n)
  85 {
  86   int ret = 0;
  87
  88   while (n-- && (ret = *(unsigned char *) s1 - * (unsigned char *) s2++) == 0
  89          && *s1++);
  90   return ret;
  91 }
  92
  93 int
  94 stupid_strncmp (const char *s1, const char *s2, size_t n)
  95 {
  96   size_t ns1 = strnlen (s1, n) + 1, ns2 = strnlen (s2, n) + 1;
  97   int ret = 0;
  98
  99   n = ns1 < n ? ns1 : n;
 100   n = ns2 < n ? ns2 : n;
 101   while (n-- && (ret = *(unsigned char *) s1++ - *(unsigned char *) s2++) == 0);
 102   return ret;
 103 }
 104
 105 #endif /* !WIDE */
 106
 107 typedef int (*proto_t) (const CHAR *, const CHAR *, size_t);
 108
 109 IMPL (STUPID_STRNCMP, 0)
 110 IMPL (SIMPLE_STRNCMP, 0)
 111 IMPL (STRNCMP, 1)
 112
 113
 114 static void
 115 do_one_test (json_ctx_t *json_ctx, impl_t *impl, const CHAR *s1, const CHAR
 116              *s2, size_t n, int exp_result)
 117 {
 118   size_t i, iters = INNER_LOOP_ITERS;
 119   timing_t start, stop, cur;
 120
 121   TIMING_NOW (start);
 122   for (i = 0; i < iters; ++i)
 123     {
 124       CALL (impl, s1, s2, n);
 125     }
 126   TIMING_NOW (stop);
 127
 128   TIMING_DIFF (cur, start, stop);
 129
 130   json_element_double (json_ctx, (double) cur / (double) iters);
 131 }
 132
 133 static void
 134 do_test_limit (json_ctx_t *json_ctx, size_t align1, size_t align2, size_t len,
 135                size_t n, int max_char, int exp_result)
 136 {
 137   size_t i, align_n;
 138   CHAR *s1, *s2;
 139
 140   align1 &= 15;
 141   align2 &= 15;
 142   align_n = (page_size - n * CHARBYTES) & 15;
 143
 144   json_element_object_begin (json_ctx);
 145   json_attr_uint (json_ctx, "strlen", (double) len);
 146   json_attr_uint (json_ctx, "len", (double) n);
 147   json_attr_uint (json_ctx, "align1", (double) align1);
 148   json_attr_uint (json_ctx, "align2", (double) align2);
 149   json_array_begin (json_ctx, "timings");
 150
 151   FOR_EACH_IMPL (impl, 0)
 152     {
 153       realloc_bufs ();
 154       s1 = (CHAR *) (buf1 + page_size - n * CHARBYTES);
 155       s2 = (CHAR *) (buf2 + page_size - n * CHARBYTES);
 156
 157       if (align1 < align_n)
 158         s1 = (CHAR *) ((char *) s1 - (align_n - align1));
 159
 160       if (align2 < align_n)
 161         s2 = (CHAR *) ((char *) s2 - (align_n - align2));
 162
 163       for (i = 0; i < n; i++)
 164         s1[i] = s2[i] = 1 + 23 * i % max_char;
 165
 166       if (len < n)
 167         {
 168           s1[len] = 0;
 169           s2[len] = 0;
 170           if (exp_result < 0)
 171             s2[len] = 32;
 172           else if (exp_result > 0)
 173             s1[len] = 64;
 174         }
 175
 176       do_one_test (json_ctx, impl, s1, s2, n, exp_result);
 177     }
 178
 179   json_array_end (json_ctx);
 180   json_element_object_end (json_ctx);
 181 }
 182
 183 static void
 184 do_test (json_ctx_t *json_ctx, size_t align1, size_t align2, size_t len, size_t
 185          n, int max_char, int exp_result)
 186 {
 187   size_t i;
 188   CHAR *s1, *s2;
 189
 190   if (n == 0)
 191     return;
 192
 193   align1 &= 63;
 194   if (align1 + (n + 1) * CHARBYTES >= page_size)
 195     return;
 196
 197   align2 &= 7;
 198   if (align2 + (n + 1) * CHARBYTES >= page_size)
 199     return;
 200
 201   json_element_object_begin (json_ctx);
 202   json_attr_uint (json_ctx, "strlen", (double) len);
 203   json_attr_uint (json_ctx, "len", (double) n);
 204   json_attr_uint (json_ctx, "align1", (double) align1);
 205   json_attr_uint (json_ctx, "align2", (double) align2);
 206   json_array_begin (json_ctx, "timings");
 207
 208   FOR_EACH_IMPL (impl, 0)
 209     {
 210       realloc_bufs ();
 211       s1 = (CHAR *) (buf1 + align1);
 212       s2 = (CHAR *) (buf2 + align2);
 213
 214       for (i = 0; i < n; i++)
 215         s1[i] = s2[i] = 1 + (23 << ((CHARBYTES - 1) * 8)) * i % max_char;
 216
 217       s1[n] = 24 + exp_result;
 218       s2[n] = 23;
 219       s1[len] = 0;
 220       s2[len] = 0;
 221       if (exp_result < 0)
 222         s2[len] = 32;
 223       else if (exp_result > 0)
 224         s1[len] = 64;
 225       if (len >= n)
 226         s2[n - 1] -= exp_result;
 227
 228       do_one_test (json_ctx, impl, s1, s2, n, exp_result);
 229     }
 230
 231   json_array_end (json_ctx);
 232   json_element_object_end (json_ctx);
 233 }
 234
 235 int
 236 test_main (void)
 237 {
 238   json_ctx_t json_ctx;
 239   size_t i;
 240
 241   test_init ();
 242
 243   json_init (&json_ctx, 0, stdout);
 244
 245   json_document_begin (&json_ctx);
 246   json_attr_string (&json_ctx, "timing_type", TIMING_TYPE);
 247
 248   json_attr_object_begin (&json_ctx, "functions");
 249   json_attr_object_begin (&json_ctx, TEST_NAME);
 250   json_attr_string (&json_ctx, "bench-variant", "default");
 251
 252   json_array_begin (&json_ctx, "ifuncs");
 253   FOR_EACH_IMPL (impl, 0)
 254     json_element_string (&json_ctx, impl->name);
 255   json_array_end (&json_ctx);
 256
 257   json_array_begin (&json_ctx, "results");
 258
 259   for (i =0; i < 16; ++i)
 260     {
 261       do_test (&json_ctx, 0, 0, 8, i, 127, 0);
 262       do_test (&json_ctx, 0, 0, 8, i, 127, -1);
 263       do_test (&json_ctx, 0, 0, 8, i, 127, 1);
 264       do_test (&json_ctx, i, i, 8, i, 127, 0);
 265       do_test (&json_ctx, i, i, 8, i, 127, 1);
 266       do_test (&json_ctx, i, i, 8, i, 127, -1);
 267       do_test (&json_ctx, i, 2 * i, 8, i, 127, 0);
 268       do_test (&json_ctx, 2 * i, i, 8, i, 127, 1);
 269       do_test (&json_ctx, i, 3 * i, 8, i, 127, -1);
 270       do_test (&json_ctx, 0, 0, 8, i, 255, 0);
 271       do_test (&json_ctx, 0, 0, 8, i, 255, -1);
 272       do_test (&json_ctx, 0, 0, 8, i, 255, 1);
 273       do_test (&json_ctx, i, i, 8, i, 255, 0);
 274       do_test (&json_ctx, i, i, 8, i, 255, 1);
 275       do_test (&json_ctx, i, i, 8, i, 255, -1);
 276       do_test (&json_ctx, i, 2 * i, 8, i, 255, 0);
 277       do_test (&json_ctx, 2 * i, i, 8, i, 255, 1);
 278       do_test (&json_ctx, i, 3 * i, 8, i, 255, -1);
 279     }
 280
 281   for (i = 1; i < 8; ++i)
 282     {
 283       do_test (&json_ctx, 0, 0, 8 << i, 16 << i, 127, 0);
 284       do_test (&json_ctx, 0, 0, 8 << i, 16 << i, 127, 1);
 285       do_test (&json_ctx, 0, 0, 8 << i, 16 << i, 127, -1);
 286       do_test (&json_ctx, 0, 0, 8 << i, 16 << i, 255, 0);
 287       do_test (&json_ctx, 0, 0, 8 << i, 16 << i, 255, 1);
 288       do_test (&json_ctx, 0, 0, 8 << i, 16 << i, 255, -1);
 289       do_test (&json_ctx, 8 - i, 2 * i, 8 << i, 16 << i, 127, 0);
 290       do_test (&json_ctx, 8 - i, 2 * i, 8 << i, 16 << i, 127, 1);
 291       do_test (&json_ctx, 2 * i, i, 8 << i, 16 << i, 255, 0);
 292       do_test (&json_ctx, 2 * i, i, 8 << i, 16 << i, 255, 1);
 293     }
 294
 295   do_test_limit (&json_ctx, 4, 0, 21, 20, 127, 0);
 296   do_test_limit (&json_ctx, 0, 4, 21, 20, 127, 0);
 297   do_test_limit (&json_ctx, 8, 0, 25, 24, 127, 0);
 298   do_test_limit (&json_ctx, 0, 8, 25, 24, 127, 0);
 299
 300   for (i = 0; i < 8; ++i)
 301     {
 302       do_test_limit (&json_ctx, 0, 0, 17 - i, 16 - i, 127, 0);
 303       do_test_limit (&json_ctx, 0, 0, 17 - i, 16 - i, 255, 0);
 304       do_test_limit (&json_ctx, 0, 0, 15 - i, 16 - i, 127, 0);
 305       do_test_limit (&json_ctx, 0, 0, 15 - i, 16 - i, 127, 1);
 306       do_test_limit (&json_ctx, 0, 0, 15 - i, 16 - i, 127, -1);
 307       do_test_limit (&json_ctx, 0, 0, 15 - i, 16 - i, 255, 0);
 308       do_test_limit (&json_ctx, 0, 0, 15 - i, 16 - i, 255, 1);
 309       do_test_limit (&json_ctx, 0, 0, 15 - i, 16 - i, 255, -1);
 310     }
 311
 312   json_array_end (&json_ctx);
 313   json_attr_object_end (&json_ctx);
 314   json_attr_object_end (&json_ctx);
 315   json_document_end (&json_ctx);
 316
 317   return ret;
 318 }
 319
 320 #include <support/test-driver.c>