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author | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2018-12-27 16:34:38 +0000 |
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committer | Samuel Thibault <samuel.thibault@ens-lyon.org> | 2018-12-27 16:34:38 +0000 |
commit | 7576c27563a3e43c0a276bf222244bcaf220a6fa (patch) | |
tree | ad96fd1f1b9b57a50005db7803f6b79e748bb820 /benchtests/bench-memmove-walk.c | |
parent | ab5f5211585bf0f33bbfa2d4aaf17e4f0d1fa564 (diff) | |
parent | 064374be911f72dfaec8a75f06da1f9fc1827712 (diff) |
Merge branch 't/hurdsig-global-dispositions' into refs/top-bases/t/hurdsig-SA_SIGINFO
Diffstat (limited to 'benchtests/bench-memmove-walk.c')
-rw-r--r-- | benchtests/bench-memmove-walk.c | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/benchtests/bench-memmove-walk.c b/benchtests/bench-memmove-walk.c new file mode 100644 index 0000000000..80a7d62d4d --- /dev/null +++ b/benchtests/bench-memmove-walk.c @@ -0,0 +1,137 @@ +/* Measure memmove function combined throughput for different alignments. + Copyright (C) 2017-2018 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +/* This microbenchmark measures the throughput of memmove for various sizes from + 1 byte to 32MiB, doubling every iteration and then misaligning by 0-15 + bytes. The copies are done from source to destination and then back and the + source walks forward across the array and the destination walks backward by + one byte each, thus measuring misaligned accesses as well. The idea is to + avoid caching effects by copying a different string and far enough from each + other, walking in different directions so that we can measure prefetcher + efficiency (software or hardware) more closely than with a loop copying the + same data over and over, which eventually only gives us L1 cache + performance. */ + +#ifndef MEMMOVE_RESULT +# define MEMMOVE_RESULT(dst, len) dst +# define START_SIZE 128 +# define MIN_PAGE_SIZE (getpagesize () + 32 * 1024 * 1024) +# define TEST_MAIN +# define TEST_NAME "memmove" +# define TIMEOUT (20 * 60) +# include "bench-string.h" + +IMPL (memmove, 1) +#endif + +#include "json-lib.h" + +typedef char *(*proto_t) (char *, const char *, size_t); + +static void +do_one_test (json_ctx_t *json_ctx, impl_t *impl, char *dst, char *src, + size_t len) +{ + size_t i = 0; + timing_t start, stop, cur; + + char *dst_end = dst + MIN_PAGE_SIZE - len; + char *src_end = src + MIN_PAGE_SIZE - len; + + TIMING_NOW (start); + /* Copy the entire buffer backwards, LEN at a time. */ + for (; src_end >= src && dst <= dst_end; dst += len, src_end -= len, i++) + CALL (impl, dst, src_end, len); + TIMING_NOW (stop); + + TIMING_DIFF (cur, start, stop); + + /* Get time taken per function call. */ + json_element_double (json_ctx, (double) cur / i); +} + +static void +do_test (json_ctx_t *json_ctx, size_t len, bool overlap) +{ + json_element_object_begin (json_ctx); + json_attr_uint (json_ctx, "length", (double) len); + json_array_begin (json_ctx, "timings"); + + if (overlap) + buf2 = buf1; + + FOR_EACH_IMPL (impl, 0) + do_one_test (json_ctx, impl, (char *) buf2, (char *) buf1, len); + + json_array_end (json_ctx); + json_element_object_end (json_ctx); +} + +int +test_main (void) +{ + json_ctx_t json_ctx; + + test_init (); + + json_init (&json_ctx, 0, stdout); + + json_document_begin (&json_ctx); + json_attr_string (&json_ctx, "timing_type", TIMING_TYPE); + + json_attr_object_begin (&json_ctx, "functions"); + json_attr_object_begin (&json_ctx, "memmove"); + json_attr_string (&json_ctx, "bench-variant", "walk"); + + json_array_begin (&json_ctx, "ifuncs"); + FOR_EACH_IMPL (impl, 0) + json_element_string (&json_ctx, impl->name); + json_array_end (&json_ctx); + + json_array_begin (&json_ctx, "results"); + /* Non-overlapping buffers. */ + for (size_t i = START_SIZE; i <= MIN_PAGE_SIZE; i <<= 1) + { + /* Test length alignments from 0-16 bytes. */ + for (int j = 0; j < 8; j++) + { + do_test (&json_ctx, i + j, false); + do_test (&json_ctx, i + 16 - j, false); + } + } + + /* Overlapping buffers. */ + for (size_t i = START_SIZE; i <= MIN_PAGE_SIZE; i <<= 1) + { + /* Test length alignments from 0-16 bytes. */ + for (int j = 0; j < 8; j++) + { + do_test (&json_ctx, i + j, true); + do_test (&json_ctx, i + 16 - j, true); + } + } + + json_array_end (&json_ctx); + json_attr_object_end (&json_ctx); + json_attr_object_end (&json_ctx); + json_document_end (&json_ctx); + + return ret; +} + +#include <support/test-driver.c> |