Sort benchmarks

1 files changed, 35 insertions, 0 deletions

diff --git a/sort-benchmark/pairs/sort_parallel.cpp b/sort-benchmark/pairs/sort_parallel.cpp
new file mode 100644
index 0000000..ef9ee05
--- /dev/null
+++ b/sort-benchmark/pairs/sort_parallel.cpp
@@ -0,0 +1,35 @@
+/* Requires Thread Building Blocks (libtbb-dev on Debian) */
+
+#include <algorithm>
+#include <cstdlib>
+#include <ctime>
+#include <execution>
+#include <iostream>
+
+typedef struct { int a, b; } pair_t;
+pair_t a[ARRAYSIZE];
+
+int main(void) {
+        srand(time(NULL));
+        for (auto &x : a) {
+                x.a = rand() % 1000000;
+                x.b = rand() % 1000000;
+        }
+
+        struct timespec begin;
+        clock_gettime(CLOCK_MONOTONIC, &begin);
+
+        std::sort(std::execution::par, a, a+ARRAYSIZE,
+                [](const pair_t &x, const pair_t &y) {
+                        int d = x.a - y.a;
+                        return d < 0 || (d == 0 && x.b > y.b);
+                });
+
+        struct timespec end;
+        clock_gettime(CLOCK_MONOTONIC, &end);
+        double time = end.tv_sec - begin.tv_sec +
+                (end.tv_nsec - begin.tv_nsec) / 1000000000.0;
+
+        std::cout << "(" << a[ARRAYSIZE/2].a << ") C++ time for " << ARRAYSIZE
+                << " pairs (parallel): " << time << "s\n";
+}