[libcxx-commits] [libcxx] 0646941 - [libc++] Rewrite the std::pop_heap benchmark (#179911)

[via libcxx-commits]

Author: Nikolas Klauser
Date: 2026-02-11T12:47:33+01:00
New Revision: 064694160fcb255d014c7b1cedeeb4d42e8392ff

URL: https://github.com/llvm/llvm-project/commit/064694160fcb255d014c7b1cedeeb4d42e8392ff
DIFF: https://github.com/llvm/llvm-project/commit/064694160fcb255d014c7b1cedeeb4d42e8392ff.diff

LOG: [libc++] Rewrite the std::pop_heap benchmark (#179911)

Testing a bunch of random types has relatively little value. This
reduces the number of benchmarks so we can run them on a regular basis.
This saves ~90 seconds when running the benchmarks.

Added: 
    libcxx/test/benchmarks/algorithms/sorting/pop_heap.bench.cpp

Modified: 
    libcxx/test/benchmarks/GenerateInput.h

Removed: 
    libcxx/test/benchmarks/algorithms/pop_heap.bench.cpp


################################################################################
diff  --git a/libcxx/test/benchmarks/GenerateInput.h b/libcxx/test/benchmarks/GenerateInput.h
index d07cb8857579d..516ea77b93e12 100644
--- a/libcxx/test/benchmarks/GenerateInput.h
+++ b/libcxx/test/benchmarks/GenerateInput.h
@@ -40,6 +40,12 @@ inline IntT getRandomInteger(IntT Min, IntT Max) {
   return static_cast<IntT>(dist(getRandomEngine()));
 }
 
+template <class FloatT>
+inline FloatT getRandomFloat(FloatT Min, FloatT Max) {
+  std::uniform_real_distribution<FloatT> dist(Min, Max);
+  return static_cast<FloatT>(dist(getRandomEngine()));
+}
+
 inline std::string getRandomString(std::size_t Len) {
   std::string str(Len, 0);
   std::generate_n(str.begin(), Len, &getRandomChar);
@@ -194,6 +200,15 @@ struct Generate<T> {
   static T random() { return getRandomInteger<T>(std::numeric_limits<T>::min(), std::numeric_limits<T>::max()); }
 };
 
+template <class T>
+  requires std::floating_point<T>
+struct Generate<T> {
+  static T arbitrary() { return 42; }
+  static T cheap() { return 42; }
+  static T expensive() { return 42; }
+  static T random() { return getRandomFloat<T>(std::numeric_limits<T>::min(), std::numeric_limits<T>::max()); }
+};
+
 template <>
 struct Generate<std::string> {
   static std::string arbitrary() { return "hello world"; }

diff  --git a/libcxx/test/benchmarks/algorithms/pop_heap.bench.cpp b/libcxx/test/benchmarks/algorithms/pop_heap.bench.cpp
deleted file mode 100644
index e4b96a0ae48c7..0000000000000
--- a/libcxx/test/benchmarks/algorithms/pop_heap.bench.cpp
+++ /dev/null
@@ -1,38 +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 <algorithm>
-
-#include "common.h"
-
-namespace {
-template <class ValueType>
-struct PopHeap {
-  size_t Quantity;
-
-  void run(benchmark::State& state) const {
-    runOpOnCopies<ValueType>(state, Quantity, Order(), BatchSize::CountElements, [](auto& Copy) {
-      for (auto B = Copy.begin(), I = Copy.end(); I != B; --I) {
-        std::pop_heap(B, I);
-      }
-    });
-  }
-
-  std::string name() const { return "BM_PopHeap" + ValueType::name() + "_" + std::to_string(Quantity); };
-};
-} // namespace
-
-int main(int argc, char** argv) {
-  benchmark::Initialize(&argc, argv);
-  if (benchmark::ReportUnrecognizedArguments(argc, argv))
-    return 1;
-  makeCartesianProductBenchmark<PopHeap, AllValueTypes>(Quantities);
-  benchmark::RunSpecifiedBenchmarks();
-}

diff  --git a/libcxx/test/benchmarks/algorithms/sorting/pop_heap.bench.cpp b/libcxx/test/benchmarks/algorithms/sorting/pop_heap.bench.cpp
new file mode 100644
index 0000000000000..d545daa1241d2
--- /dev/null
+++ b/libcxx/test/benchmarks/algorithms/sorting/pop_heap.bench.cpp
@@ -0,0 +1,59 @@
+//===----------------------------------------------------------------------===//
+//
+// 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 <deque>
+#include <iterator>
+#include <vector>
+
+#include "benchmark/benchmark.h"
+#include "../../GenerateInput.h"
+
+int main(int argc, char** argv) {
+  auto bm = []<class Container>(std::type_identity<Container>, std::string name) {
+    benchmark::RegisterBenchmark(
+        name,
+        [](benchmark::State& state) {
+          std::size_t size = state.range(0);
+
+          Container c;
+          std::generate_n(std::back_inserter(c), size, [] {
+            return Generate<typename Container::value_type>::random();
+          });
+
+          while (state.KeepRunningBatch(size)) {
+            state.PauseTiming();
+            std::make_heap(c.begin(), c.end());
+            state.ResumeTiming();
+
+            for (auto first = c.begin(), last = c.end(); last != first; --last) {
+              std::pop_heap(first, last);
+            }
+          }
+        })
+        ->Arg(8)
+        ->Arg(1024)
+        ->Arg(8192);
+  };
+
+  bm(std::type_identity<std::vector<int>>{}, "std::pop_heap(vector<int>)");
+  bm(std::type_identity<std::vector<float>>{}, "std::pop_heap(vector<float>)");
+  bm(std::type_identity<std::vector<size_t>>{}, "std::pop_heap(vector<size_t>)");
+  bm(std::type_identity<std::vector<std::string>>{}, "std::pop_heap(vector<std::string>)");
+  bm(std::type_identity<std::deque<int>>{}, "std::pop_heap(deque<int>)");
+  bm(std::type_identity<std::deque<float>>{}, "std::pop_heap(deque<float>)");
+  bm(std::type_identity<std::deque<size_t>>{}, "std::pop_heap(deque<size_t>)");
+  bm(std::type_identity<std::deque<std::string>>{}, "std::pop_heap(deque<std::string>)");
+
+  benchmark::Initialize(&argc, argv);
+  benchmark::RunSpecifiedBenchmarks();
+  benchmark::Shutdown();
+  return 0;
+}