2 * Copyright (c) 2008-2009 Apple Inc. All rights reserved.
4 * @APPLE_APACHE_LICENSE_HEADER_START@
6 * Licensed under the Apache License, Version 2.0 (the "License");
7 * you may not use this file except in compliance with the License.
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15 * See the License for the specific language governing permissions and
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24 struct __dispatch_benchmark_data_s {
25 #if HAVE_MACH_ABSOLUTE_TIME
26 mach_timebase_info_data_t tbi;
35 _dispatch_benchmark_init(void *context)
37 struct __dispatch_benchmark_data_s *bdata = context;
38 // try and simulate performance of real benchmark as much as possible
39 // keep 'f', 'c' and 'cnt' in registers
40 register void (*f)(void *) = bdata->func;
41 register void *c = bdata->ctxt;
42 register size_t cnt = bdata->count;
44 uint64_t start, delta;
50 #if HAVE_MACH_ABSOLUTE_TIME
53 kr = mach_timebase_info(&bdata->tbi);
54 dispatch_assert_zero(kr);
57 start = _dispatch_absolute_time();
62 delta = _dispatch_absolute_time() - start;
65 #if HAVE_MACH_ABSOLUTE_TIME
66 lcost *= bdata->tbi.numer;
67 lcost /= bdata->tbi.denom;
71 bdata->loop_cost = lcost;
76 dispatch_benchmark(size_t count, void (^block)(void))
78 struct Block_basic *bb = (void *)block;
79 return dispatch_benchmark_f(count, block, (void *)bb->Block_invoke);
84 dispatch_benchmark_f(size_t count, register void *ctxt, register void (*func)(void *))
86 static struct __dispatch_benchmark_data_s bdata = {
87 .func = (void *)dummy_function,
88 .count = 10000000ul, // ten million
90 static dispatch_once_t pred;
91 uint64_t ns, start, delta;
93 __uint128_t conversion, big_denom;
95 long double conversion, big_denom;
99 dispatch_once_f(&pred, &bdata, _dispatch_benchmark_init);
101 if (slowpath(count == 0)) {
105 start = _dispatch_absolute_time();
110 delta = _dispatch_absolute_time() - start;
113 #if HAVE_MACH_ABSOLUTE_TIME
114 conversion *= bdata.tbi.numer;
115 big_denom = bdata.tbi.denom;
120 conversion /= big_denom;
123 return ns - bdata.loop_cost;