[libc++] Add benchmarks for is_permutation and its std::ranges counte… #130387
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@llvm/pr-subscribers-libcxx Author: Imad Aldij (imdj) ChangesAdd benchmarks for is_permutation. Related to:
Full diff: https://github.com/llvm/llvm-project/pull/130387.diff 1 Files Affected:
diff --git a/libcxx/test/benchmarks/algorithms/is_permutation.bench.cpp b/libcxx/test/benchmarks/algorithms/is_permutation.bench.cpp
new file mode 100644
index 0000000000000..d77896cb8ce6c
--- /dev/null
+++ b/libcxx/test/benchmarks/algorithms/is_permutation.bench.cpp
@@ -0,0 +1,112 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14, c++17
+
+#include <algorithm>
+#include <random>
+#include <vector>
+#include <numeric>
+#include <benchmark/benchmark.h>
+
+void BenchmarkSizes(benchmark::internal::Benchmark* Benchmark) {
+ Benchmark->DenseRange(1, 8);
+ for (size_t i = 16; i != 1 << 20; i *= 2) {
+ Benchmark->Arg(i - 1);
+ Benchmark->Arg(i);
+ Benchmark->Arg(i + 1);
+ }
+}
+
+// Test std::is_permutation when sequences are identical
+static void bm_std_is_permutation_same(benchmark::State& state) {
+ std::vector<int> vec1(state.range(), 1);
+ std::vector<int> vec2(state.range(), 1);
+
+ for (auto _ : state) {
+ benchmark::DoNotOptimize(vec1);
+ benchmark::DoNotOptimize(vec2);
+ benchmark::DoNotOptimize(std::is_permutation(vec1.begin(), vec1.end(), vec2.begin()));
+ }
+}
+BENCHMARK(bm_std_is_permutation_same)->Apply(BenchmarkSizes);
+
+// Test std::ranges::is_permutation when sequences are identical
+static void bm_ranges_is_permutation_same(benchmark::State& state) {
+ std::vector<int> vec1(state.range(), 1);
+ std::vector<int> vec2(state.range(), 1);
+
+ for (auto _ : state) {
+ benchmark::DoNotOptimize(vec1);
+ benchmark::DoNotOptimize(vec2);
+ benchmark::DoNotOptimize(std::ranges::is_permutation(vec1, vec2));
+ }
+}
+BENCHMARK(bm_ranges_is_permutation_same)->Apply(BenchmarkSizes);
+
+// Test std::is_permutation when sequences are permutations
+static void bm_std_is_permutation_shuffled(benchmark::State& state) {
+ std::vector<int> vec1(state.range());
+ std::iota(vec1.begin(), vec1.end(), 0);
+ auto vec2 = vec1;
+ std::mt19937 gen(42);
+ std::shuffle(vec2.begin(), vec2.end(), gen);
+
+ for (auto _ : state) {
+ benchmark::DoNotOptimize(vec1);
+ benchmark::DoNotOptimize(vec2);
+ benchmark::DoNotOptimize(std::is_permutation(vec1.begin(), vec1.end(), vec2.begin()));
+ }
+}
+BENCHMARK(bm_std_is_permutation_shuffled)->Apply(BenchmarkSizes);
+
+// Test std::ranges::is_permutation when sequences are permutations
+static void bm_ranges_is_permutation_shuffled(benchmark::State& state) {
+ std::vector<int> vec1(state.range());
+ std::iota(vec1.begin(), vec1.end(), 0);
+ auto vec2 = vec1;
+ std::mt19937 gen(42);
+ std::shuffle(vec2.begin(), vec2.end(), gen);
+
+ for (auto _ : state) {
+ benchmark::DoNotOptimize(vec1);
+ benchmark::DoNotOptimize(vec2);
+ benchmark::DoNotOptimize(std::ranges::is_permutation(vec1, vec2));
+ }
+}
+BENCHMARK(bm_ranges_is_permutation_shuffled)->Apply(BenchmarkSizes);
+
+// Test std::is_permutation when sequences differ in last element
+static void bm_std_is_permutation_diff_last(benchmark::State& state) {
+ std::vector<int> vec1(state.range(), 1);
+ std::vector<int> vec2(state.range(), 1);
+ vec2.back() = 2;
+
+ for (auto _ : state) {
+ benchmark::DoNotOptimize(vec1);
+ benchmark::DoNotOptimize(vec2);
+ benchmark::DoNotOptimize(std::is_permutation(vec1.begin(), vec1.end(), vec2.begin()));
+ }
+}
+BENCHMARK(bm_std_is_permutation_diff_last)->Apply(BenchmarkSizes);
+
+// Test std::ranges::is_permutation when sequences differ in last element
+static void bm_ranges_is_permutation_diff_last(benchmark::State& state) {
+ std::vector<int> vec1(state.range(), 1);
+ std::vector<int> vec2(state.range(), 1);
+ vec2.back() = 2;
+
+ for (auto _ : state) {
+ benchmark::DoNotOptimize(vec1);
+ benchmark::DoNotOptimize(vec2);
+ benchmark::DoNotOptimize(std::ranges::is_permutation(vec1, vec2));
+ }
+}
+BENCHMARK(bm_ranges_is_permutation_diff_last)->Apply(BenchmarkSizes);
+
+BENCHMARK_MAIN();
\ No newline at end of file
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Did you copy this from @ldionne's PR? |
No, I looked for benchmarks that target |
There was a problem hiding this comment.
Thanks for the patch! Unfortunately it looks like we raced a bit here, I already had #128206 up which added similar benchmarks for {std,ranges}::is_permutation.
I had a look to make sure that both had similar coverage and I think that's the case. You do have different benchmarks for the following cases
- both sequences are identical
- both sequences differ only in the last element
However, I don't think the performance profile of the algorithm would change much between those two -- it would only change whether the answer is true or false. Therefore, I think the benchmarks for is_permutation I checked in recently probably supersede the ones added in this PR.
I am happy to work with you on getting #129565 reviewed, though.
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My bad, I swear I scanned that PR earlier based on Mark's recommendation but I still somehow missed that |
Add benchmarks for is_permutation. Related to:
std::is_permutation#129324