1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8
9 // UNSUPPORTED: c++03
10
11 #include <cstdint>
12 #include <cstddef>
13 #include <functional>
14
15 #include "benchmark/benchmark.h"
16
17 #include "GenerateInput.h"
18 #include "test_macros.h"
19
20 constexpr std::size_t TestNumInputs = 1024;
21
22 template <class HashFn, class GenInputs>
BM_Hash(benchmark::State & st,HashFn fn,GenInputs gen)23 void BM_Hash(benchmark::State& st, HashFn fn, GenInputs gen) {
24 auto in = gen(st.range(0));
25 const auto end = in.data() + in.size();
26 std::size_t last_hash = 0;
27 benchmark::DoNotOptimize(&last_hash);
28 while (st.KeepRunning()) {
29 for (auto it = in.data(); it != end; ++it) {
30 benchmark::DoNotOptimize(last_hash += fn(*it));
31 }
32 benchmark::ClobberMemory();
33 }
34 }
35
36 BENCHMARK_CAPTURE(BM_Hash, uint32_random_std_hash, std::hash<uint32_t>{}, getRandomIntegerInputs<uint32_t>)
37 ->Arg(TestNumInputs);
38
39 BENCHMARK_CAPTURE(BM_Hash, uint32_top_std_hash, std::hash<uint32_t>{}, getSortedTopBitsIntegerInputs<uint32_t>)
40 ->Arg(TestNumInputs);
41
42 BENCHMARK_MAIN();
43