[common] replace Common::BitSet with std::bitset (#2576)

Signed-off-by: lizzie <lizzie@eden-emu.dev>
Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/2576
Reviewed-by: crueter <crueter@eden-emu.dev>
Co-authored-by: lizzie <lizzie@eden-emu.dev>
Co-committed-by: lizzie <lizzie@eden-emu.dev>

3 files changed, 18 insertions, 98 deletions

diff --git a/src/common/CMakeLists.txt b/src/common/CMakeLists.txt
index 7759ea6a21..96ea429e5a 100644
--- a/src/common/CMakeLists.txt
+++ b/src/common/CMakeLists.txt
@@ -32,7 +32,6 @@ add_library(
   atomic_ops.h
   bit_cast.h
   bit_field.h
-  bit_set.h
   bit_util.h
   bounded_threadsafe_queue.h
   cityhash.cpp
diff --git a/src/common/bit_set.h b/src/common/bit_set.h
deleted file mode 100644
index 74754504be..0000000000
--- a/src/common/bit_set.h
+++ /dev/null
@@ -1,86 +0,0 @@
-// SPDX-FileCopyrightText: Copyright 2020 yuzu Emulator Project
-// SPDX-License-Identifier: GPL-2.0-or-later
-
-#pragma once
-
-#include <array>
-#include <bit>
-
-#include "common/alignment.h"
-#include "common/bit_util.h"
-#include "common/common_types.h"
-
-namespace Common {
-
-namespace impl {
-
-template <typename Storage, size_t N>
-class BitSet {
-
-public:
-    constexpr BitSet() = default;
-
-    constexpr void SetBit(size_t i) {
-        this->words[i / FlagsPerWord] |= GetBitMask(i % FlagsPerWord);
-    }
-
-    constexpr void ClearBit(size_t i) {
-        this->words[i / FlagsPerWord] &= ~GetBitMask(i % FlagsPerWord);
-    }
-
-    constexpr size_t CountLeadingZero() const {
-        for (size_t i = 0; i < NumWords; i++) {
-            if (this->words[i]) {
-                return FlagsPerWord * i + CountLeadingZeroImpl(this->words[i]);
-            }
-        }
-        return FlagsPerWord * NumWords;
-    }
-
-    constexpr size_t GetNextSet(size_t n) const {
-        for (size_t i = (n + 1) / FlagsPerWord; i < NumWords; i++) {
-            Storage word = this->words[i];
-            if (!IsAligned(n + 1, FlagsPerWord)) {
-                word &= GetBitMask(n % FlagsPerWord) - 1;
-            }
-            if (word) {
-                return FlagsPerWord * i + CountLeadingZeroImpl(word);
-            }
-        }
-        return FlagsPerWord * NumWords;
-    }
-
-private:
-    static_assert(std::is_unsigned_v<Storage>);
-    static_assert(sizeof(Storage) <= sizeof(u64));
-
-    static constexpr size_t FlagsPerWord = BitSize<Storage>();
-    static constexpr size_t NumWords = AlignUp(N, FlagsPerWord) / FlagsPerWord;
-
-    static constexpr auto CountLeadingZeroImpl(Storage word) {
-        return std::countl_zero(static_cast<unsigned long long>(word)) -
-               (BitSize<unsigned long long>() - FlagsPerWord);
-    }
-
-    static constexpr Storage GetBitMask(size_t bit) {
-        return Storage(1) << (FlagsPerWord - 1 - bit);
-    }
-
-    std::array<Storage, NumWords> words{};
-};
-
-} // namespace impl
-
-template <size_t N>
-using BitSet8 = impl::BitSet<u8, N>;
-
-template <size_t N>
-using BitSet16 = impl::BitSet<u16, N>;
-
-template <size_t N>
-using BitSet32 = impl::BitSet<u32, N>;
-
-template <size_t N>
-using BitSet64 = impl::BitSet<u64, N>;
-
-} // namespace Common
diff --git a/src/core/hle/kernel/k_priority_queue.h b/src/core/hle/kernel/k_priority_queue.h
index 26677ec65c..0ef6bcc32c 100644
--- a/src/core/hle/kernel/k_priority_queue.h
+++ b/src/core/hle/kernel/k_priority_queue.h
@@ -1,3 +1,6 @@
+// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
 // SPDX-FileCopyrightText: Copyright 2020 yuzu Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
@@ -5,10 +8,11 @@
 
 #include <array>
 #include <bit>
+#include <bitset>
 #include <concepts>
+#include <cstddef>
 
 #include "common/assert.h"
-#include "common/bit_set.h"
 #include "common/common_types.h"
 #include "common/concepts.h"
 
@@ -159,7 +163,7 @@ public:
             }
 
             if (m_queues[priority].PushBack(core, member)) {
-                m_available_priorities[core].SetBit(priority);
+                m_available_priorities[core].set(std::size_t(priority));
             }
         }
 
@@ -172,7 +176,7 @@ public:
             }
 
             if (m_queues[priority].PushFront(core, member)) {
-                m_available_priorities[core].SetBit(priority);
+                m_available_priorities[core].set(std::size_t(priority));
             }
         }
 
@@ -185,14 +189,14 @@ public:
             }
 
             if (m_queues[priority].Remove(core, member)) {
-                m_available_priorities[core].ClearBit(priority);
+                m_available_priorities[core].reset(std::size_t(priority));
             }
         }
 
         constexpr Member* GetFront(s32 core) const {
             ASSERT(IsValidCore(core));
 
-            const s32 priority = static_cast<s32>(m_available_priorities[core].CountLeadingZero());
+            const s32 priority = s32((~m_available_priorities[core]).count());
             if (priority <= LowestPriority) {
                 return m_queues[priority].GetFront(core);
             } else {
@@ -216,11 +220,14 @@ public:
 
             Member* next = member->GetPriorityQueueEntry(core).GetNext();
             if (next == nullptr) {
-                const s32 priority = static_cast<s32>(
-                    m_available_priorities[core].GetNextSet(member->GetPriority()));
-                if (priority <= LowestPriority) {
-                    next = m_queues[priority].GetFront(core);
-                }
+                s32 priority = member->GetPriority() + 1;
+                do {
+                    if (m_available_priorities[core][priority]) {
+                        next = m_queues[priority].GetFront(core);
+                        break;
+                    }
+                    ++priority;
+                } while (priority <= LowestPriority && priority < s32(m_available_priorities[core].size()));
             }
             return next;
         }
@@ -250,7 +257,7 @@ public:
 
     private:
         std::array<KPerCoreQueue, NumPriority> m_queues{};
-        std::array<Common::BitSet64<NumPriority>, NumCores> m_available_priorities{};
+        std::array<std::bitset<NumPriority>, NumCores> m_available_priorities{};
     };
 
 private: