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5bfb0404 | 1 | /* Measure memmove function combined throughput for different alignments. |
dff8da6b | 2 | Copyright (C) 2017-2024 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 | ||
ac759b1f NG |
39 | #define NO_OVERLAP 0 |
40 | #define PARTIAL_OVERLAP 1 | |
41 | #define COMPLETE_OVERLAP 2 | |
42 | ||
5bfb0404 SP |
43 | IMPL (memmove, 1) |
44 | #endif | |
45 | ||
46 | #include "json-lib.h" | |
47 | ||
48 | typedef char *(*proto_t) (char *, const char *, size_t); | |
49 | ||
50 | static void | |
51 | do_one_test (json_ctx_t *json_ctx, impl_t *impl, char *dst, char *src, | |
52 | size_t len) | |
53 | { | |
4d7632ff | 54 | size_t i = 0; |
5bfb0404 SP |
55 | timing_t start, stop, cur; |
56 | ||
57 | char *dst_end = dst + MIN_PAGE_SIZE - len; | |
58 | char *src_end = src + MIN_PAGE_SIZE - len; | |
59 | ||
60 | TIMING_NOW (start); | |
4d7632ff SP |
61 | /* Copy the entire buffer backwards, LEN at a time. */ |
62 | for (; src_end >= src && dst <= dst_end; dst += len, src_end -= len, i++) | |
63 | CALL (impl, dst, src_end, len); | |
5bfb0404 SP |
64 | TIMING_NOW (stop); |
65 | ||
66 | TIMING_DIFF (cur, start, stop); | |
67 | ||
68 | /* Get time taken per function call. */ | |
4d7632ff | 69 | json_element_double (json_ctx, (double) cur / i); |
5bfb0404 SP |
70 | } |
71 | ||
72 | static void | |
ac759b1f | 73 | do_test (json_ctx_t *json_ctx, size_t len, int overlap, int both_ways) |
5bfb0404 | 74 | { |
ac759b1f NG |
75 | char *s1, *s2, *tmp; |
76 | size_t repeats; | |
5bfb0404 | 77 | |
ac759b1f NG |
78 | s1 = (char *) (buf1); |
79 | s2 = (char *) (buf2); | |
80 | if (overlap != NO_OVERLAP) | |
81 | s2 = s1; | |
82 | if (overlap == PARTIAL_OVERLAP) | |
83 | s2 += len / 2; | |
5bfb0404 | 84 | |
ac759b1f NG |
85 | for (repeats = both_ways ? 2 : 1; repeats; --repeats) |
86 | { | |
87 | json_element_object_begin (json_ctx); | |
88 | json_attr_uint (json_ctx, "length", (double) len); | |
89 | json_attr_string(json_ctx, "overlap", | |
90 | overlap == NO_OVERLAP ? "none" | |
91 | : overlap == PARTIAL_OVERLAP ? "partial" | |
92 | : "complete"); | |
93 | json_attr_uint (json_ctx, "dst > src", (double) (s2 > s1)); | |
94 | json_array_begin (json_ctx, "timings"); | |
95 | ||
96 | ||
97 | FOR_EACH_IMPL (impl, 0) | |
98 | do_one_test (json_ctx, impl, (char *) buf2, (char *) buf1, len); | |
5bfb0404 | 99 | |
ac759b1f NG |
100 | json_array_end (json_ctx); |
101 | json_element_object_end (json_ctx); | |
102 | ||
103 | tmp = s1; | |
104 | s1 = s2; | |
105 | s2 = tmp; | |
106 | } | |
5bfb0404 SP |
107 | } |
108 | ||
109 | int | |
110 | test_main (void) | |
111 | { | |
112 | json_ctx_t json_ctx; | |
5bfb0404 SP |
113 | |
114 | test_init (); | |
115 | ||
116 | json_init (&json_ctx, 0, stdout); | |
117 | ||
118 | json_document_begin (&json_ctx); | |
119 | json_attr_string (&json_ctx, "timing_type", TIMING_TYPE); | |
120 | ||
121 | json_attr_object_begin (&json_ctx, "functions"); | |
122 | json_attr_object_begin (&json_ctx, "memmove"); | |
123 | json_attr_string (&json_ctx, "bench-variant", "walk"); | |
124 | ||
125 | json_array_begin (&json_ctx, "ifuncs"); | |
126 | FOR_EACH_IMPL (impl, 0) | |
127 | json_element_string (&json_ctx, impl->name); | |
128 | json_array_end (&json_ctx); | |
129 | ||
130 | json_array_begin (&json_ctx, "results"); | |
131 | /* Non-overlapping buffers. */ | |
543477f7 | 132 | for (size_t i = START_SIZE; i <= MIN_PAGE_SIZE; i <<= 1) |
5bfb0404 | 133 | { |
ac759b1f NG |
134 | do_test (&json_ctx, i, NO_OVERLAP, 1); |
135 | do_test (&json_ctx, i + 1, NO_OVERLAP, 1); | |
136 | } | |
137 | ||
138 | /* Partially-overlapping buffers. */ | |
139 | for (size_t i = START_SIZE; i <= MIN_PAGE_SIZE / 2; i <<= 1) | |
140 | { | |
141 | do_test (&json_ctx, i, PARTIAL_OVERLAP, 1); | |
142 | do_test (&json_ctx, i + 1, PARTIAL_OVERLAP, 1); | |
5bfb0404 SP |
143 | } |
144 | ||
ac759b1f | 145 | /* Complete-overlapping buffers. */ |
543477f7 | 146 | for (size_t i = START_SIZE; i <= MIN_PAGE_SIZE; i <<= 1) |
5bfb0404 | 147 | { |
ac759b1f NG |
148 | do_test (&json_ctx, i, COMPLETE_OVERLAP, 0); |
149 | do_test (&json_ctx, i + 1, COMPLETE_OVERLAP, 0); | |
5bfb0404 SP |
150 | } |
151 | ||
152 | json_array_end (&json_ctx); | |
153 | json_attr_object_end (&json_ctx); | |
154 | json_attr_object_end (&json_ctx); | |
155 | json_document_end (&json_ctx); | |
156 | ||
157 | return ret; | |
158 | } | |
159 | ||
160 | #include <support/test-driver.c> |