[libcxx-commits] [libcxx] [libc++] Refactor variant benchmarks (PR #174743)

[Nikolas Klauser via libcxx-commits]

https://github.com/philnik777 updated https://github.com/llvm/llvm-project/pull/174743

>From b9b34a99cc4c805a93551d77c82d5b5414ad48a0 Mon Sep 17 00:00:00 2001
From: Nikolas Klauser <nikolasklauser at berlin.de>
Date: Wed, 7 Jan 2026 11:55:24 +0100
Subject: [PATCH] [libc++] Refactor variant benchmarks

---
 ...{VariantBenchmarks.h => variant.bench.cpp} | 24 ++++++------
 .../test/benchmarks/variant_visit_1.bench.cpp | 37 -------------------
 .../test/benchmarks/variant_visit_2.bench.cpp | 32 ----------------
 .../test/benchmarks/variant_visit_3.bench.cpp | 30 ---------------
 4 files changed, 12 insertions(+), 111 deletions(-)
 rename libcxx/test/benchmarks/{VariantBenchmarks.h => variant.bench.cpp} (62%)
 delete mode 100644 libcxx/test/benchmarks/variant_visit_1.bench.cpp
 delete mode 100644 libcxx/test/benchmarks/variant_visit_2.bench.cpp
 delete mode 100644 libcxx/test/benchmarks/variant_visit_3.bench.cpp

diff --git a/libcxx/test/benchmarks/VariantBenchmarks.h b/libcxx/test/benchmarks/variant.bench.cpp
similarity index 62%
rename from libcxx/test/benchmarks/VariantBenchmarks.h
rename to libcxx/test/benchmarks/variant.bench.cpp
index bb0c714279150..e191aeeb00ae0 100644
--- a/libcxx/test/benchmarks/VariantBenchmarks.h
+++ b/libcxx/test/benchmarks/variant.bench.cpp
@@ -1,4 +1,3 @@
-// -*- C++ -*-
 //===----------------------------------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
@@ -7,21 +6,14 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef BENCHMARK_VARIANT_BENCHMARKS_H
-#define BENCHMARK_VARIANT_BENCHMARKS_H
+// UNSUPPORTED: c++03, c++11, c++14, c++17
 
 #include <array>
-#include <cstddef>
-#include <tuple>
-#include <type_traits>
 #include <variant>
 
 #include "benchmark/benchmark.h"
-
 #include "GenerateInput.h"
 
-namespace VariantBenchmarks {
-
 template <std::size_t I>
 struct S {
   static constexpr size_t v = I;
@@ -50,6 +42,14 @@ static void BM_Visit(benchmark::State& state) {
   }
 }
 
-} // namespace VariantBenchmarks
-
-#endif // BENCHMARK_VARIANT_BENCHMARKS_H
+BENCHMARK(BM_Visit<1, 1>)->Name("std::variant<1-alt>::visit() (1 variant)");
+BENCHMARK(BM_Visit<1, 8>)->Name("std::variant<8-alts>::visit() (1 variant)");
+BENCHMARK(BM_Visit<1, 100>)->Name("std::variant<100-alts>::visit() (1 variant)");
+BENCHMARK(BM_Visit<2, 1>)->Name("std::variant<1-alt>::visit() (2 variants)");
+BENCHMARK(BM_Visit<2, 8>)->Name("std::variant<8-alts>::visit() (2 variants)");
+BENCHMARK(BM_Visit<2, 50>)->Name("std::variant<50-alts>::visit() (2 variants)");
+BENCHMARK(BM_Visit<3, 1>)->Name("std::variant<1-alt>::visit() (3 variants)");
+BENCHMARK(BM_Visit<3, 8>)->Name("std::variant<8-alts>::visit() (3 variants)");
+BENCHMARK(BM_Visit<3, 20>)->Name("std::variant<20-alts>::visit() (3 variants)");
+
+BENCHMARK_MAIN();
diff --git a/libcxx/test/benchmarks/variant_visit_1.bench.cpp b/libcxx/test/benchmarks/variant_visit_1.bench.cpp
deleted file mode 100644
index f1b702530bed3..0000000000000
--- a/libcxx/test/benchmarks/variant_visit_1.bench.cpp
+++ /dev/null
@@ -1,37 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// 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 "benchmark/benchmark.h"
-
-#include "VariantBenchmarks.h"
-
-using namespace VariantBenchmarks;
-
-BENCHMARK(BM_Visit<1, 1>);
-BENCHMARK(BM_Visit<1, 2>);
-BENCHMARK(BM_Visit<1, 3>);
-BENCHMARK(BM_Visit<1, 4>);
-BENCHMARK(BM_Visit<1, 5>);
-BENCHMARK(BM_Visit<1, 6>);
-BENCHMARK(BM_Visit<1, 7>);
-BENCHMARK(BM_Visit<1, 8>);
-BENCHMARK(BM_Visit<1, 9>);
-BENCHMARK(BM_Visit<1, 10>);
-BENCHMARK(BM_Visit<1, 20>);
-BENCHMARK(BM_Visit<1, 30>);
-BENCHMARK(BM_Visit<1, 40>);
-BENCHMARK(BM_Visit<1, 50>);
-BENCHMARK(BM_Visit<1, 60>);
-BENCHMARK(BM_Visit<1, 70>);
-BENCHMARK(BM_Visit<1, 80>);
-BENCHMARK(BM_Visit<1, 90>);
-BENCHMARK(BM_Visit<1, 100>);
-
-BENCHMARK_MAIN();
diff --git a/libcxx/test/benchmarks/variant_visit_2.bench.cpp b/libcxx/test/benchmarks/variant_visit_2.bench.cpp
deleted file mode 100644
index 7dd8d02b358be..0000000000000
--- a/libcxx/test/benchmarks/variant_visit_2.bench.cpp
+++ /dev/null
@@ -1,32 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// 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 "benchmark/benchmark.h"
-
-#include "VariantBenchmarks.h"
-
-using namespace VariantBenchmarks;
-
-BENCHMARK(BM_Visit<2, 1>);
-BENCHMARK(BM_Visit<2, 2>);
-BENCHMARK(BM_Visit<2, 3>);
-BENCHMARK(BM_Visit<2, 4>);
-BENCHMARK(BM_Visit<2, 5>);
-BENCHMARK(BM_Visit<2, 6>);
-BENCHMARK(BM_Visit<2, 7>);
-BENCHMARK(BM_Visit<2, 8>);
-BENCHMARK(BM_Visit<2, 9>);
-BENCHMARK(BM_Visit<2, 10>);
-BENCHMARK(BM_Visit<2, 20>);
-BENCHMARK(BM_Visit<2, 30>);
-BENCHMARK(BM_Visit<2, 40>);
-BENCHMARK(BM_Visit<2, 50>);
-
-BENCHMARK_MAIN();
diff --git a/libcxx/test/benchmarks/variant_visit_3.bench.cpp b/libcxx/test/benchmarks/variant_visit_3.bench.cpp
deleted file mode 100644
index 0fe42b0d8e009..0000000000000
--- a/libcxx/test/benchmarks/variant_visit_3.bench.cpp
+++ /dev/null
@@ -1,30 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-// 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 "benchmark/benchmark.h"
-
-#include "VariantBenchmarks.h"
-
-using namespace VariantBenchmarks;
-
-BENCHMARK(BM_Visit<3, 1>);
-BENCHMARK(BM_Visit<3, 2>);
-BENCHMARK(BM_Visit<3, 3>);
-BENCHMARK(BM_Visit<3, 4>);
-BENCHMARK(BM_Visit<3, 5>);
-BENCHMARK(BM_Visit<3, 6>);
-BENCHMARK(BM_Visit<3, 7>);
-BENCHMARK(BM_Visit<3, 8>);
-BENCHMARK(BM_Visit<3, 9>);
-BENCHMARK(BM_Visit<3, 10>);
-BENCHMARK(BM_Visit<3, 15>);
-BENCHMARK(BM_Visit<3, 20>);
-
-BENCHMARK_MAIN();