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