intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 70 insertions, 0 deletions

diff --git a/library/cpp/pop_count/popcount_ut.cpp b/library/cpp/pop_count/popcount_ut.cpp
new file mode 100644
index 0000000000..5cd6605411
--- /dev/null
+++ b/library/cpp/pop_count/popcount_ut.cpp
@@ -0,0 +1,70 @@
+#include "popcount.h"
+
+#include <library/cpp/testing/unittest/registar.h>
+
+#include <util/random/random.h>
+
+Y_UNIT_TEST_SUITE(TestPopCount) {
+    template <class T>
+    static inline ui32 SlowPopCount(T t) {
+        ui32 ret = 0;
+
+        while (t) {
+            if (t & T(1)) {
+                ++ret;
+            }
+
+            t = t >> 1;
+        }
+
+        return ret;
+    }
+
+    template <class T>
+    static inline void Test() {
+        for (size_t i = 0; i < 10000; ++i) {
+            const T rndv = RandomNumber<T>();
+
+            UNIT_ASSERT_VALUES_EQUAL(SlowPopCount(rndv), PopCount(rndv));
+        }
+    }
+
+    Y_UNIT_TEST(Test8) {
+        Test<ui8>();
+    }
+
+    Y_UNIT_TEST(Test16) {
+        Test<ui16>();
+    }
+
+    Y_UNIT_TEST(Test32) {
+        Test<ui32>();
+    }
+
+    Y_UNIT_TEST(Test64) {
+        Test<ui64>();
+    }
+
+    Y_UNIT_TEST(TestPopCount) {
+        UNIT_ASSERT_VALUES_EQUAL(PopCount(0), 0);
+        UNIT_ASSERT_VALUES_EQUAL(PopCount(1), 1);
+        UNIT_ASSERT_VALUES_EQUAL(PopCount(1 << 10), 1);
+        UNIT_ASSERT_VALUES_EQUAL(PopCount((1 << 10) + 1), 2);
+        UNIT_ASSERT_VALUES_EQUAL(PopCount(0xFFFF), 16);
+        UNIT_ASSERT_VALUES_EQUAL(PopCount(0xFFFFFFFF), 32);
+        UNIT_ASSERT_VALUES_EQUAL(PopCount(0x55555555), 16);
+
+        UNIT_ASSERT_VALUES_EQUAL(0, PopCount(0ULL));
+        UNIT_ASSERT_VALUES_EQUAL(1, PopCount(1ULL));
+        UNIT_ASSERT_VALUES_EQUAL(16, PopCount(0xAAAAAAAAULL));
+        UNIT_ASSERT_VALUES_EQUAL(32, PopCount(0xFFFFFFFFULL));
+        UNIT_ASSERT_VALUES_EQUAL(32, PopCount(0xAAAAAAAAAAAAAAAAULL));
+        UNIT_ASSERT_VALUES_EQUAL(64, PopCount(0xFFFFFFFFFFFFFFFFULL));
+
+        ui64 v = 0;
+
+        for (int i = 0; i < 64; v |= 1ULL << i, ++i) {
+            UNIT_ASSERT_VALUES_EQUAL(i, PopCount(v));
+        }
+    }
+}