benchtests/bench-memset-walk.c

   1 /* Measure memset function throughput with large data sizes.
   2    Copyright (C) 2017-2019 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    <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 SIMPLE_MEMSET simple_memset
  32 #else
  33 # define SIMPLE_MEMSET simple_wmemset
  34 #endif /* WIDE */
  35
  36 #include <assert.h>
  37 #include "json-lib.h"
  38
  39
  40 typedef CHAR *(*proto_t) (CHAR *, int, size_t);
  41
  42 CHAR *
  43 inhibit_loop_to_libcall
  44 SIMPLE_MEMSET (CHAR *s, int c, size_t n)
  45 {
  46   CHAR *r = s, *end = s + n;
  47   while (r < end)
  48     *r++ = c;
  49   return s;
  50 }
  51
  52 IMPL (SIMPLE_MEMSET, 1)
  53
  54 static void
  55 do_one_test (json_ctx_t *json_ctx, impl_t *impl, CHAR *s, CHAR *s_end,
  56              int c __attribute ((unused)), size_t n)
  57 {
  58   size_t i, iters = MIN_PAGE_SIZE / n;
  59   timing_t start, stop, cur;
  60
  61   TIMING_NOW (start);
  62   for (i = 0; i < iters && s <= s_end; s_end -= n, i++)
  63     CALL (impl, s, c, n);
  64   TIMING_NOW (stop);
  65
  66   TIMING_DIFF (cur, start, stop);
  67
  68   /* Get time taken per function call.  */
  69   json_element_double (json_ctx, (double) cur / i);
  70 }
  71
  72 static void
  73 do_test (json_ctx_t *json_ctx, int c, size_t len)
  74 {
  75   json_element_object_begin (json_ctx);
  76   json_attr_uint (json_ctx, "length", len);
  77   json_attr_uint (json_ctx, "char", c);
  78   json_array_begin (json_ctx, "timings");
  79
  80   FOR_EACH_IMPL (impl, 0)
  81     {
  82       do_one_test (json_ctx, impl, (CHAR *) buf1,
  83                    (CHAR *) buf1 + MIN_PAGE_SIZE - len, c, len);
  84       alloc_bufs ();
  85     }
  86
  87   json_array_end (json_ctx);
  88   json_element_object_end (json_ctx);
  89 }
  90
  91 int
  92 test_main (void)
  93 {
  94   json_ctx_t json_ctx;
  95   size_t i;
  96
  97   test_init ();
  98
  99   json_init (&json_ctx, 0, stdout);
 100
 101   json_document_begin (&json_ctx);
 102   json_attr_string (&json_ctx, "timing_type", TIMING_TYPE);
 103
 104   json_attr_object_begin (&json_ctx, "functions");
 105   json_attr_object_begin (&json_ctx, TEST_NAME);
 106   json_attr_string (&json_ctx, "bench-variant", "walk");
 107
 108   json_array_begin (&json_ctx, "ifuncs");
 109   FOR_EACH_IMPL (impl, 0)
 110     json_element_string (&json_ctx, impl->name);
 111   json_array_end (&json_ctx);
 112
 113   json_array_begin (&json_ctx, "results");
 114   for (i = START_SIZE; i <= MIN_PAGE_SIZE; i <<= 1)
 115       /* Test length alignments from 0-16 bytes.  */
 116       for (int j = 0; j < i && j < 16; j++)
 117         do_test (&json_ctx, 65, i + j);
 118
 119   for (i = START_SIZE; i <= MIN_PAGE_SIZE; i <<= 1)
 120       for (int j = 0; j < i && j < 16; j++)
 121         do_test (&json_ctx, 0, i + j);
 122
 123   json_array_end (&json_ctx);
 124   json_attr_object_end (&json_ctx);
 125   json_attr_object_end (&json_ctx);
 126   json_document_end (&json_ctx);
 127
 128   return ret;
 129 }
 130
 131 #include <support/test-driver.c>