strat: split out common functionality for future meso use

stratosphere/libstratosphere/include/atmosphere/util/util_alignment.hpp

@@ -0,0 +1,75 @@
+/*
+ * Copyright (c) 2018-2019 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#include "../defines.hpp"
+
+namespace ams::util {
+
+    /* Utilities for alignment to power of two. */
+
+    template<typename T>
+    constexpr inline T AlignUp(T value, size_t alignment) {
+        using U = typename std::make_unsigned<T>::type;
+        const U invmask = static_cast<U>(alignment - 1);
+        return static_cast<T>((value + invmask) & ~invmask);
+    }
+
+    template<typename T>
+    constexpr inline T AlignDown(T value, size_t alignment) {
+        using U = typename std::make_unsigned<T>::type;
+        const U invmask = static_cast<U>(alignment - 1);
+        return static_cast<T>(value & ~invmask);
+    }
+
+    template<typename T>
+    constexpr inline bool IsAligned(T value, size_t alignment) {
+        using U = typename std::make_unsigned<T>::type;
+        const U invmask = static_cast<U>(alignment - 1);
+        return (value & invmask) == 0;
+    }
+
+    template<>
+    constexpr inline void *AlignUp<void *>(void *value, size_t alignment) {
+        return reinterpret_cast<void *>(AlignUp(reinterpret_cast<uintptr_t>(value), alignment));
+    }
+
+    template<>
+    constexpr inline const void *AlignUp<const void *>(const void *value, size_t alignment) {
+        return reinterpret_cast<const void *>(AlignUp(reinterpret_cast<uintptr_t>(value), alignment));
+    }
+
+    template<>
+    constexpr inline void *AlignDown<void *>(void *value, size_t alignment) {
+        return reinterpret_cast<void *>(AlignDown(reinterpret_cast<uintptr_t>(value), alignment));
+    }
+
+    template<>
+    constexpr inline const void *AlignDown<const void *>(const void *value, size_t alignment) {
+        return reinterpret_cast<void *>(AlignDown(reinterpret_cast<uintptr_t>(value), alignment));
+    }
+
+    template<>
+    constexpr inline bool IsAligned<void *>(void *value, size_t alignment) {
+        return IsAligned(reinterpret_cast<uintptr_t>(value), alignment);
+    }
+
+    template<>
+    constexpr inline bool IsAligned<const void *>(const void *value, size_t alignment) {
+        return IsAligned(reinterpret_cast<uintptr_t>(value), alignment);
+    }
+
+}