From b73895df0afd525dbfdc2c8ef27030fb49742a2d Mon Sep 17 00:00:00 2001
From: Michael Scire <SciresM@gmail.com>
Date: Wed, 8 Apr 2020 08:39:36 -0700
Subject: [PATCH] util: add bitflagset

---
 libraries/libvapours/include/vapours/util.hpp |   1 +
 .../include/vapours/util/util_bitflagset.hpp  | 196 ++++++++++++++++++
 2 files changed, 197 insertions(+)
 create mode 100644 libraries/libvapours/include/vapours/util/util_bitflagset.hpp

diff --git a/libraries/libvapours/include/vapours/util.hpp b/libraries/libvapours/include/vapours/util.hpp
index f3dbdb62d..f6d8a68c2 100644
--- a/libraries/libvapours/include/vapours/util.hpp
+++ b/libraries/libvapours/include/vapours/util.hpp
@@ -25,6 +25,7 @@
 #include <vapours/util/util_specialization_of.hpp>
 #include <vapours/util/util_bitpack.hpp>
 #include <vapours/util/util_bitset.hpp>
+#include <vapours/util/util_bitflagset.hpp>
 #include <vapours/util/util_bitutil.hpp>
 #include <vapours/util/util_typed_storage.hpp>
 #include <vapours/util/util_fourcc.hpp>
diff --git a/libraries/libvapours/include/vapours/util/util_bitflagset.hpp b/libraries/libvapours/include/vapours/util/util_bitflagset.hpp
new file mode 100644
index 000000000..2c421afd6
--- /dev/null
+++ b/libraries/libvapours/include/vapours/util/util_bitflagset.hpp
@@ -0,0 +1,196 @@
+/*
+ * Copyright (c) 2018-2020 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 <vapours/common.hpp>
+#include <vapours/assert.hpp>
+#include <vapours/util/util_alignment.hpp>
+#include <vapours/util/util_bitutil.hpp>
+
+namespace ams::util {
+
+    namespace impl {
+
+        template<size_t Count, typename Storage>
+        constexpr void NegateImpl(Storage arr[]) {
+            for (size_t i = 0; i < Count; i++) {
+                arr[i] = ~arr[i];
+            }
+        }
+
+        template<size_t Count, typename Storage>
+        constexpr void AndImpl(Storage dst[], const Storage src[]) {
+            for (size_t i = 0; i < Count; i++) {
+                dst[i] &= src[i];
+            }
+        }
+
+        template<size_t Count, typename Storage>
+        constexpr void OrImpl(Storage dst[], const Storage src[]) {
+            for (size_t i = 0; i < Count; i++) {
+                dst[i] |= src[i];
+            }
+        }
+
+        template<size_t Count, typename Storage>
+        constexpr void XorImpl(Storage dst[], const Storage src[]) {
+            for (size_t i = 0; i < Count; i++) {
+                dst[i] ^= src[i];
+            }
+        }
+
+        template<size_t Count, typename Storage>
+        constexpr bool IsEqual(const Storage lhs[], const Storage rhs[]) {
+            for (size_t i = 0; i < Count; i++) {
+                if (lhs[i] != rhs[i]) {
+                    return false;
+                }
+            }
+            return true;
+        }
+
+        template<size_t Count, typename Storage>
+        constexpr bool IsAnySet(const Storage arr[]) {
+            for (size_t i = 0; i < Count; i++) {
+                if (arr[i]) {
+                    return true;
+                }
+            }
+            return false;
+        }
+
+        template<size_t Count, typename Storage>
+        constexpr int PopCount(const Storage arr[]) {
+            int count = 0;
+            for (size_t i = 0; i < Count; i++) {
+                count += PopCount(arr[i]);
+            }
+            return count;
+        }
+
+    }
+
+    template<size_t N, typename T = void>
+    struct BitFlagSet {
+        static_assert(N > 0);
+        using Storage = typename std::conditional<N <= BITSIZEOF(u32), u32, u64>::type;
+        static constexpr size_t StorageBitCount = BITSIZEOF(Storage);
+        static constexpr size_t StorageCount    = util::AlignUp(N, StorageBitCount) / StorageBitCount;
+        Storage _storage[StorageCount];
+        private:
+            constexpr BitFlagSet<N, T> &SetImpl(s32 idx, Storage mask, bool en) {
+                if (en) {
+                    this->_storage[idx] |= mask;
+                } else {
+                    this->_storage[idx] &= ~mask;
+                }
+                return *this;
+            }
+
+            constexpr bool TestImpl(s32 idx, Storage mask) const { return (this->_storage[idx] & mask) != 0; }
+            constexpr void Truncate() { TruncateIf(std::integral_constant<bool, N % StorageBitCount != 0>{}); }
+            constexpr void TruncateIf(std::true_type) { this->_storage[StorageCount - 1] &= MakeStorageMask(N) - 1; }
+            constexpr void TruncateIf(std::false_type) { /* ... */ }
+
+            static constexpr s32 GetStorageIndex(s32 idx) { return idx / StorageBitCount; }
+            static constexpr Storage MakeStorageMask(s32 idx) { return static_cast<Storage>(1) << (idx % StorageBitCount); }
+        public:
+            class Reference {
+                friend struct BitFlagSet<N, T>;
+                private:
+                    BitFlagSet<N, T> *set;
+                    s32 idx;
+                private:
+                    constexpr Reference() : set(nullptr), idx(0) { /* ... */ }
+                    constexpr Reference(BitFlagSet<N, T> &s, s32 i) : set(std::addressof(s)), idx(i) { /* ... */ }
+                public:
+                    constexpr Reference &operator=(bool en) { this->set->Set(this->idx, en); return *this; }
+                    constexpr Reference &operator=(const Reference &r) { this->set->Set(this->idx, r); return *this; }
+                    constexpr Reference &Negate() { this->set->Negate(this->idx); return *this; }
+                    constexpr operator bool() const { return this->set->Test(this->idx); }
+                    constexpr bool operator~() const { return !this->set->Test(this->idx); }
+            };
+
+            template<s32 _Index>
+            struct Flag {
+                static_assert(_Index < static_cast<s32>(N));
+                friend struct BitFlagSet<N, T>;
+                static constexpr s32 Index = _Index;
+                static const BitFlagSet<N, T> Mask;
+                private:
+                    static constexpr s32 StorageIndex = Index / StorageBitCount;
+                    static constexpr Storage StorageMask = static_cast<Storage>(1) << (Index % StorageBitCount);
+
+                    template<size_t StorageCount>
+                    struct SingleStorageTrait {
+                        static_assert(StorageCount == 1);
+                        using Type = Storage;
+                    };
+            };
+
+            template<typename FlagType>
+            constexpr bool Test()       const { return this->TestImpl(FlagType::StorageIndex, FlagType::StorageMask); }
+            constexpr bool Test(s32 idx) const { return this->TestImpl(GetStorageIndex(idx), MakeStorageMask(idx)); }
+
+            template<typename FlagType>
+            constexpr BitFlagSet<N, T> &Set(bool en = true) { return this->SetImpl(FlagType::StorageIndex, FlagType::StorageMask, en); }
+            constexpr BitFlagSet<N, T> &Set(s32 idx, bool en = true) { return this->SetImpl(GetStorageIndex(idx), MakeStorageMask(idx), en); }
+            constexpr BitFlagSet<N, T> &Set() { std::memset(this->_storage, ~0, sizeof(this->_storage)); this->Truncate(); return *this; }
+
+            template<typename FlagType>
+            constexpr BitFlagSet<N, T> &Reset() { return this->Set<FlagType>(false); }
+            constexpr BitFlagSet<N, T> &Reset(s32 idx) { return this->Set(idx, false); }
+            constexpr BitFlagSet<N, T> &Reset() { std::memset(this->_storage, 0, sizeof(this->_storage)); this->Truncate(); return *this; }
+
+            template<typename FlagType>
+            constexpr BitFlagSet<N, T> &Negate() { return this->Set<FlagType>(!this->Test<FlagType>()); }
+            constexpr BitFlagSet<N, T> &Negate(s32 idx) { return this->Set(idx, !this->Test(idx)); }
+            constexpr BitFlagSet<N, T> &Negate() { ams::util::impl::NegateImpl<StorageCount>(this->_storage); this->Truncate(); return *this; }
+
+            constexpr int GetCount()  const { return static_cast<int>(N); }
+            constexpr bool IsAnySet() const { return ams::util::impl::IsAnySet<StorageCount>(this->_storage); }
+            constexpr int  PopCount() const { return ams::util::impl::PopCount<StorageCount>(this->_storage); }
+            constexpr bool IsAllSet() const { return this->PopCount() == this->GetCount(); }
+            constexpr bool IsAllOff() const { return !this->IsAnySet(); }
+
+            constexpr bool operator[](s32 idx) const { return this->Test(idx); }
+            constexpr Reference operator[](s32 idx) { return Reference(*this, idx); }
+
+            constexpr bool operator==(const BitFlagSet<N, T> &rhs) const { return ams::util::impl::IsEqual<StorageCount>(this->_storage, rhs._storage); }
+            constexpr bool operator!=(const BitFlagSet<N, T> &rhs) const { return !(*this == rhs); }
+
+            constexpr BitFlagSet<N, T> operator~() const { BitFlagSet<N, T> tmp = *this; return tmp.Negate(); }
+
+            constexpr BitFlagSet<N, T> operator&(const BitFlagSet<N, T> &rhs) const { BitFlagSet<N, T> v = *this; v &= rhs; return v; }
+            constexpr BitFlagSet<N, T> operator^(const BitFlagSet<N, T> &rhs) const { BitFlagSet<N, T> v = *this; v ^= rhs; return v; }
+            constexpr BitFlagSet<N, T> operator|(const BitFlagSet<N, T> &rhs) const { BitFlagSet<N, T> v = *this; v |= rhs; return v; }
+
+            constexpr BitFlagSet<N, T> &operator&=(const BitFlagSet<N, T> &rhs) const { ams::util::impl::AndImpl<StorageCount>(this->_storage, rhs._storage); return *this; }
+            constexpr BitFlagSet<N, T> &operator^=(const BitFlagSet<N, T> &rhs) const { ams::util::impl::XorImpl<StorageCount>(this->_storage, rhs._storage); return *this; }
+            constexpr BitFlagSet<N, T> &operator|=(const BitFlagSet<N, T> &rhs) const { ams::util::impl::OrImpl<StorageCount>(this->_storage, rhs._storage); return *this; }
+    };
+
+    template<size_t N, typename T>
+    template<s32 Index>
+    constexpr inline const BitFlagSet<N, T> BitFlagSet<N, T>::Flag<Index>::Mask = { { static_cast<typename SingleStorageTrait<BitFlagSet<N, T>::StorageCount>::Type>(1) << Index } };
+
+    template<size_t N, typename T>
+    constexpr BitFlagSet<N, T> MakeBitFlagSet() { return BitFlagSet<N, T>{}; }
+
+    template<size_t N>
+    constexpr BitFlagSet<N, void> MakeBitFlagSet() { return MakeBitFlagSet<N, void>(); }
+
+}