[K/N][Runtime] Support equality and hashcode for stacktraces

kotlin-native/runtime/src/main/cpp/Utils.cpp

@@ -0,0 +1,71 @@
+/*
+ * Copyright 2010-2022 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the LICENSE file.
+ */
+
+#include "Utils.hpp"
+
+#include <climits>
+#include <cstdint>
+
+namespace {
+
+// Hash combine functions derived from boost ones.
+// Copyright 2005-2014 Daniel James.
+
+template <typename X, typename R>
+constexpr auto rotl32(X x, R r) noexcept { return (x << r) | (x >> (32 - r)); }
+
+template<size_t Bits>
+struct HashCompineImpl {
+    template <typename SizeT>
+    constexpr static SizeT fn(SizeT seed, SizeT value) {
+        seed ^= value + 0x9e3779b9 + (seed<<6) + (seed>>2);
+        return seed;
+    }
+};
+
+template<>
+struct HashCompineImpl<32> {
+    constexpr static uint32_t fn(uint32_t h1, uint32_t k1) {
+        const uint32_t c1 = 0xcc9e2d51;
+        const uint32_t c2 = 0x1b873593;
+
+        k1 *= c1;
+        k1 = rotl32(k1,15);
+        k1 *= c2;
+
+        h1 ^= k1;
+        h1 = rotl32(h1,13);
+        h1 = h1*5+0xe6546b64;
+
+        return h1;
+    }
+};
+
+template<>
+struct HashCompineImpl<64> {
+    constexpr static uint64_t fn(uint64_t h, uint64_t k) {
+        const uint64_t m = (uint64_t(0xc6a4a793) << 32) + 0x5bd1e995;
+        const int r = 47;
+
+        k *= m;
+        k ^= k >> r;
+        k *= m;
+
+        h ^= k;
+        h *= m;
+
+        // Completely arbitrary number, to prevent 0's
+        // from hashing to 0.
+        h += 0xe6546b64;
+
+        return h;
+    }
+};
+
+} // namespace
+
+size_t kotlin::CombineHash(size_t seed, size_t value) {
+    return HashCompineImpl<sizeof(std::size_t) * CHAR_BIT>::fn(seed, value);
+}