[libcxx-commits] [libcxx] [libc++] Merge the two swap_ranges benchmarks into one (PR #214712)

[Nikolas Klauser via libcxx-commits]

================
@@ -55,6 +58,36 @@ int main(int argc, char** argv) {
     bm.operator()<std::list<int>>("std::swap_ranges(list<int>)", std_swap_ranges);
   }
 
+  // {std,ranges}::swap_ranges(vector<bool>)
+  {
+    auto bm = []<bool Aligned>(std::string name, auto swap_ranges) {
+      benchmark::RegisterBenchmark(
+          name,
+          [swap_ranges](auto& st) {
+            std::size_t const size = st.range(0);
+            std::vector<bool> c1(size, true);
+            std::vector<bool> c2(Aligned ? size : size + 8, false);
+            auto first1 = c1.begin();
+            auto last1  = c1.end();
+            auto first2 = Aligned ? c2.begin() : c2.begin() + 4;
+            auto last2  = Aligned ? c2.end() : c2.end() - 4;
+
+            for ([[maybe_unused]] auto _ : st) {
+              benchmark::DoNotOptimize(c1);
+              benchmark::DoNotOptimize(c2);
+              auto result = swap_ranges(first1, last1, first2, last2);
+              benchmark::DoNotOptimize(result);
+            }
+          })
+          ->Arg(50) // non power-of-two
+          ->Range(64, 1 << 20);
+    };
+    bm.operator()<true>("std::swap_ranges(vector<bool>) (aligned)", std_swap_ranges);
+    bm.operator()<false>("std::swap_ranges(vector<bool>) (unaligned)", std_swap_ranges);
+    bm.operator()<true>("rng::swap_ranges(vector<bool>) (aligned)", ranges_swap_ranges);
+    bm.operator()<false>("rng::swap_ranges(vector<bool>) (unaligned)", ranges_swap_ranges);
----------------
philnik777 wrote:

We've dropped the `ranges::` benchmarks elsewhere if they don't provide any additional coverage (which I think is the case here).

https://github.com/llvm/llvm-project/pull/214712