benchtests/bench-memset-walk.c

   1 /* Measure memset function throughput with large data sizes.
   2    Copyright (C) 2017-2018 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 #ifndef WIDE
  21 # define TEST_NAME "memset"
  22 #else
  23 # define TEST_NAME "wmemset"
  24 #endif /* WIDE */
  25 #define START_SIZE 128
  26 #define MIN_PAGE_SIZE (getpagesize () + 32 * 1024 * 1024)
  27 #define TIMEOUT (20 * 60)
  28 #include "bench-string.h"
  29
  30 #ifndef WIDE
  31 # define MEMSET memset
  32 # define CHAR char
  33 # define SIMPLE_MEMSET simple_memset
  34 # define MEMCMP memcmp
  35 #else
  36 # include <wchar.h>
  37 # define MEMSET wmemset
  38 # define CHAR wchar_t
  39 # define SIMPLE_MEMSET simple_wmemset
  40 # define MEMCMP wmemcmp
  41 #endif /* WIDE */
  42
  43 #include <assert.h>
  44 #include "json-lib.h"
  45
  46
  47 typedef CHAR *(*proto_t) (CHAR *, int, size_t);
  48
  49 CHAR *
  50 inhibit_loop_to_libcall
  51 SIMPLE_MEMSET (CHAR *s, int c, size_t n)
  52 {
  53   CHAR *r = s, *end = s + n;
  54   while (r < end)
  55     *r++ = c;
  56   return s;
  57 }
  58
  59 IMPL (SIMPLE_MEMSET, 1)
  60
  61 static void
  62 do_one_test (json_ctx_t *json_ctx, impl_t *impl, CHAR *s, CHAR *s_end,
  63              int c __attribute ((unused)), size_t n)
  64 {
  65   size_t i, iters = MIN_PAGE_SIZE / n;
  66   timing_t start, stop, cur;
  67
  68   TIMING_NOW (start);
  69   for (i = 0; i < iters && s <= s_end; s_end -= n, i++)
  70     CALL (impl, s, c, n);
  71   TIMING_NOW (stop);
  72
  73   TIMING_DIFF (cur, start, stop);
  74
  75   /* Get time taken per function call.  */
  76   json_element_double (json_ctx, (double) cur / i);
  77 }
  78
  79 static void
  80 do_test (json_ctx_t *json_ctx, int c, size_t len)
  81 {
  82   json_element_object_begin (json_ctx);
  83   json_attr_uint (json_ctx, "length", len);
  84   json_attr_uint (json_ctx, "char", c);
  85   json_array_begin (json_ctx, "timings");
  86
  87   FOR_EACH_IMPL (impl, 0)
  88     {
  89       do_one_test (json_ctx, impl, (CHAR *) buf1,
  90                    (CHAR *) buf1 + MIN_PAGE_SIZE - len, c, len);
  91       realloc_bufs ();
  92     }
  93
  94   json_array_end (json_ctx);
  95   json_element_object_end (json_ctx);
  96 }
  97
  98 int
  99 test_main (void)
 100 {
 101   json_ctx_t json_ctx;
 102   size_t i;
 103
 104   test_init ();
 105
 106   json_init (&json_ctx, 0, stdout);
 107
 108   json_document_begin (&json_ctx);
 109   json_attr_string (&json_ctx, "timing_type", TIMING_TYPE);
 110
 111   json_attr_object_begin (&json_ctx, "functions");
 112   json_attr_object_begin (&json_ctx, TEST_NAME);
 113   json_attr_string (&json_ctx, "bench-variant", "walk");
 114
 115   json_array_begin (&json_ctx, "ifuncs");
 116   FOR_EACH_IMPL (impl, 0)
 117     json_element_string (&json_ctx, impl->name);
 118   json_array_end (&json_ctx);
 119
 120   json_array_begin (&json_ctx, "results");
 121   for (i = START_SIZE; i <= MIN_PAGE_SIZE; i <<= 1)
 122       /* Test length alignments from 0-16 bytes.  */
 123       for (int j = 0; j < i && j < 16; j++)
 124         do_test (&json_ctx, 65, i + j);
 125
 126   for (i = START_SIZE; i <= MIN_PAGE_SIZE; i <<= 1)
 127       for (int j = 0; j < i && j < 16; j++)
 128         do_test (&json_ctx, 0, i + j);
 129
 130   json_array_end (&json_ctx);
 131   json_attr_object_end (&json_ctx);
 132   json_attr_object_end (&json_ctx);
 133   json_document_end (&json_ctx);
 134
 135   return ret;
 136 }
 137
 138 #include <support/test-driver.c>