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5bfb0404 | 1 | /* Measure memmove function combined throughput for different alignments. |
d614a753 | 2 | Copyright (C) 2017-2020 Free Software Foundation, Inc. |
5bfb0404 SP |
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 | |
5a82c748 | 17 | <https://www.gnu.org/licenses/>. */ |
5bfb0404 SP |
18 | |
19 | /* This microbenchmark measures the throughput of memmove for various sizes from | |
20 | 1 byte to 32MiB, doubling every iteration and then misaligning by 0-15 | |
21 | bytes. The copies are done from source to destination and then back and the | |
22 | source walks forward across the array and the destination walks backward by | |
23 | one byte each, thus measuring misaligned accesses as well. The idea is to | |
24 | avoid caching effects by copying a different string and far enough from each | |
25 | other, walking in different directions so that we can measure prefetcher | |
26 | efficiency (software or hardware) more closely than with a loop copying the | |
27 | same data over and over, which eventually only gives us L1 cache | |
28 | performance. */ | |
29 | ||
30 | #ifndef MEMMOVE_RESULT | |
31 | # define MEMMOVE_RESULT(dst, len) dst | |
eb332f9f | 32 | # define START_SIZE 128 |
5bfb0404 SP |
33 | # define MIN_PAGE_SIZE (getpagesize () + 32 * 1024 * 1024) |
34 | # define TEST_MAIN | |
35 | # define TEST_NAME "memmove" | |
36 | # define TIMEOUT (20 * 60) | |
37 | # include "bench-string.h" | |
38 | ||
39 | IMPL (memmove, 1) | |
40 | #endif | |
41 | ||
42 | #include "json-lib.h" | |
43 | ||
44 | typedef char *(*proto_t) (char *, const char *, size_t); | |
45 | ||
46 | static void | |
47 | do_one_test (json_ctx_t *json_ctx, impl_t *impl, char *dst, char *src, | |
48 | size_t len) | |
49 | { | |
4d7632ff | 50 | size_t i = 0; |
5bfb0404 SP |
51 | timing_t start, stop, cur; |
52 | ||
53 | char *dst_end = dst + MIN_PAGE_SIZE - len; | |
54 | char *src_end = src + MIN_PAGE_SIZE - len; | |
55 | ||
56 | TIMING_NOW (start); | |
4d7632ff SP |
57 | /* Copy the entire buffer backwards, LEN at a time. */ |
58 | for (; src_end >= src && dst <= dst_end; dst += len, src_end -= len, i++) | |
59 | CALL (impl, dst, src_end, len); | |
5bfb0404 SP |
60 | TIMING_NOW (stop); |
61 | ||
62 | TIMING_DIFF (cur, start, stop); | |
63 | ||
64 | /* Get time taken per function call. */ | |
4d7632ff | 65 | json_element_double (json_ctx, (double) cur / i); |
5bfb0404 SP |
66 | } |
67 | ||
68 | static void | |
69 | do_test (json_ctx_t *json_ctx, size_t len, bool overlap) | |
70 | { | |
71 | json_element_object_begin (json_ctx); | |
72 | json_attr_uint (json_ctx, "length", (double) len); | |
73 | json_array_begin (json_ctx, "timings"); | |
74 | ||
75 | if (overlap) | |
76 | buf2 = buf1; | |
77 | ||
5bfb0404 SP |
78 | FOR_EACH_IMPL (impl, 0) |
79 | do_one_test (json_ctx, impl, (char *) buf2, (char *) buf1, len); | |
80 | ||
81 | json_array_end (json_ctx); | |
82 | json_element_object_end (json_ctx); | |
83 | } | |
84 | ||
85 | int | |
86 | test_main (void) | |
87 | { | |
88 | json_ctx_t json_ctx; | |
5bfb0404 SP |
89 | |
90 | test_init (); | |
91 | ||
92 | json_init (&json_ctx, 0, stdout); | |
93 | ||
94 | json_document_begin (&json_ctx); | |
95 | json_attr_string (&json_ctx, "timing_type", TIMING_TYPE); | |
96 | ||
97 | json_attr_object_begin (&json_ctx, "functions"); | |
98 | json_attr_object_begin (&json_ctx, "memmove"); | |
99 | json_attr_string (&json_ctx, "bench-variant", "walk"); | |
100 | ||
101 | json_array_begin (&json_ctx, "ifuncs"); | |
102 | FOR_EACH_IMPL (impl, 0) | |
103 | json_element_string (&json_ctx, impl->name); | |
104 | json_array_end (&json_ctx); | |
105 | ||
106 | json_array_begin (&json_ctx, "results"); | |
107 | /* Non-overlapping buffers. */ | |
543477f7 | 108 | for (size_t i = START_SIZE; i <= MIN_PAGE_SIZE; i <<= 1) |
5bfb0404 | 109 | { |
46ae0732 WD |
110 | do_test (&json_ctx, i, false); |
111 | do_test (&json_ctx, i + 1, false); | |
5bfb0404 SP |
112 | } |
113 | ||
114 | /* Overlapping buffers. */ | |
543477f7 | 115 | for (size_t i = START_SIZE; i <= MIN_PAGE_SIZE; i <<= 1) |
5bfb0404 | 116 | { |
46ae0732 WD |
117 | do_test (&json_ctx, i, true); |
118 | do_test (&json_ctx, i + 1, true); | |
5bfb0404 SP |
119 | } |
120 | ||
121 | json_array_end (&json_ctx); | |
122 | json_attr_object_end (&json_ctx); | |
123 | json_attr_object_end (&json_ctx); | |
124 | json_document_end (&json_ctx); | |
125 | ||
126 | return ret; | |
127 | } | |
128 | ||
129 | #include <support/test-driver.c> |