diff --git a/Source/Core/Common/BitSet.h b/Source/Core/Common/BitSet.h
index c04fee8746..e43ecf9bc7 100644
--- a/Source/Core/Common/BitSet.h
+++ b/Source/Core/Common/BitSet.h
@@ -14,7 +14,7 @@
 #include <intrin.h>
 
 template <typename T>
-static inline int CountSetBits(T v)
+constexpr int CountSetBits(T v)
 {
   // from https://graphics.stanford.edu/~seander/bithacks.html
   // GCC has this built in, but MSVC's intrinsic will only emit the actual
@@ -24,60 +24,60 @@ static inline int CountSetBits(T v)
   v = (v + (v >> 4)) & (T) ~(T)0 / 255 * 15;
   return (T)(v * ((T) ~(T)0 / 255)) >> (sizeof(T) - 1) * 8;
 }
-static inline int LeastSignificantSetBit(u8 val)
+inline int LeastSignificantSetBit(u8 val)
 {
   unsigned long index;
   _BitScanForward(&index, val);
   return (int)index;
 }
-static inline int LeastSignificantSetBit(u16 val)
+inline int LeastSignificantSetBit(u16 val)
 {
   unsigned long index;
   _BitScanForward(&index, val);
   return (int)index;
 }
-static inline int LeastSignificantSetBit(u32 val)
+inline int LeastSignificantSetBit(u32 val)
 {
   unsigned long index;
   _BitScanForward(&index, val);
   return (int)index;
 }
-static inline int LeastSignificantSetBit(u64 val)
+inline int LeastSignificantSetBit(u64 val)
 {
   unsigned long index;
   _BitScanForward64(&index, val);
   return (int)index;
 }
 #else
-static inline int CountSetBits(u8 val)
+constexpr int CountSetBits(u8 val)
 {
   return __builtin_popcount(val);
 }
-static inline int CountSetBits(u16 val)
+constexpr int CountSetBits(u16 val)
 {
   return __builtin_popcount(val);
 }
-static inline int CountSetBits(u32 val)
+constexpr int CountSetBits(u32 val)
 {
   return __builtin_popcount(val);
 }
-static inline int CountSetBits(u64 val)
+constexpr int CountSetBits(u64 val)
 {
   return __builtin_popcountll(val);
 }
-static inline int LeastSignificantSetBit(u8 val)
+inline int LeastSignificantSetBit(u8 val)
 {
   return __builtin_ctz(val);
 }
-static inline int LeastSignificantSetBit(u16 val)
+inline int LeastSignificantSetBit(u16 val)
 {
   return __builtin_ctz(val);
 }
-static inline int LeastSignificantSetBit(u32 val)
+inline int LeastSignificantSetBit(u32 val)
 {
   return __builtin_ctz(val);
 }
-static inline int LeastSignificantSetBit(u64 val)
+inline int LeastSignificantSetBit(u64 val)
 {
   return __builtin_ctzll(val);
 }
@@ -116,9 +116,9 @@ public:
   class Ref
   {
   public:
-    Ref(Ref&& other) : m_bs(other.m_bs), m_mask(other.m_mask) {}
-    Ref(BitSet* bs, IntTy mask) : m_bs(bs), m_mask(mask) {}
-    operator bool() const { return (m_bs->m_val & m_mask) != 0; }
+    constexpr Ref(Ref&& other) : m_bs(other.m_bs), m_mask(other.m_mask) {}
+    constexpr Ref(BitSet* bs, IntTy mask) : m_bs(bs), m_mask(mask) {}
+    constexpr operator bool() const { return (m_bs->m_val & m_mask) != 0; }
     bool operator=(bool set)
     {
       m_bs->m_val = (m_bs->m_val & ~m_mask) | (set ? m_mask : 0);
@@ -134,14 +134,13 @@ public:
   class Iterator
   {
   public:
-    Iterator(const Iterator& other) : m_val(other.m_val), m_bit(other.m_bit) {}
-    Iterator(IntTy val, int bit) : m_val(val), m_bit(bit) {}
+    constexpr Iterator(const Iterator& other) : m_val(other.m_val), m_bit(other.m_bit) {}
+    constexpr Iterator(IntTy val, int bit) : m_val(val), m_bit(bit) {}
     Iterator& operator=(Iterator other)
     {
       new (this) Iterator(other);
       return *this;
     }
-    int operator*() { return m_bit; }
     Iterator& operator++()
     {
       if (m_val == 0)
@@ -156,21 +155,22 @@ public:
       }
       return *this;
     }
-    Iterator operator++(int _)
+    Iterator operator++(int)
     {
       Iterator other(*this);
       ++*this;
       return other;
     }
-    bool operator==(Iterator other) const { return m_bit == other.m_bit; }
-    bool operator!=(Iterator other) const { return m_bit != other.m_bit; }
+    constexpr int operator*() const { return m_bit; }
+    constexpr bool operator==(Iterator other) const { return m_bit == other.m_bit; }
+    constexpr bool operator!=(Iterator other) const { return m_bit != other.m_bit; }
   private:
     IntTy m_val;
     int m_bit;
   };
 
-  BitSet() : m_val(0) {}
-  explicit BitSet(IntTy val) : m_val(val) {}
+  constexpr BitSet() : m_val(0) {}
+  constexpr explicit BitSet(IntTy val) : m_val(val) {}
   BitSet(std::initializer_list<int> init)
   {
     m_val = 0;
@@ -178,36 +178,32 @@ public:
       m_val |= (IntTy)1 << bit;
   }
 
-  static BitSet AllTrue(size_t count)
+  constexpr static BitSet AllTrue(size_t count)
   {
     return BitSet(count == sizeof(IntTy) * 8 ? ~(IntTy)0 : (((IntTy)1 << count) - 1));
   }
 
   Ref operator[](size_t bit) { return Ref(this, (IntTy)1 << bit); }
-  const Ref operator[](size_t bit) const { return (*const_cast<BitSet*>(this))[bit]; }
-  bool operator==(BitSet other) const { return m_val == other.m_val; }
-  bool operator!=(BitSet other) const { return m_val != other.m_val; }
-  bool operator<(BitSet other) const { return m_val < other.m_val; }
-  bool operator>(BitSet other) const { return m_val > other.m_val; }
-  BitSet operator|(BitSet other) const { return BitSet(m_val | other.m_val); }
-  BitSet operator&(BitSet other) const { return BitSet(m_val & other.m_val); }
-  BitSet operator^(BitSet other) const { return BitSet(m_val ^ other.m_val); }
-  BitSet operator~() const { return BitSet(~m_val); }
+  constexpr const Ref operator[](size_t bit) const { return (*const_cast<BitSet*>(this))[bit]; }
+  constexpr bool operator==(BitSet other) const { return m_val == other.m_val; }
+  constexpr bool operator!=(BitSet other) const { return m_val != other.m_val; }
+  constexpr bool operator<(BitSet other) const { return m_val < other.m_val; }
+  constexpr bool operator>(BitSet other) const { return m_val > other.m_val; }
+  constexpr BitSet operator|(BitSet other) const { return BitSet(m_val | other.m_val); }
+  constexpr BitSet operator&(BitSet other) const { return BitSet(m_val & other.m_val); }
+  constexpr BitSet operator^(BitSet other) const { return BitSet(m_val ^ other.m_val); }
+  constexpr BitSet operator~() const { return BitSet(~m_val); }
+  constexpr explicit operator bool() const { return m_val != 0; }
   BitSet& operator|=(BitSet other) { return *this = *this | other; }
   BitSet& operator&=(BitSet other) { return *this = *this & other; }
   BitSet& operator^=(BitSet other) { return *this = *this ^ other; }
-  explicit operator bool() const { return m_val != 0; }
   // Warning: Even though on modern CPUs this is a single fast instruction,
   // Dolphin's official builds do not currently assume POPCNT support on x86,
   // so slower explicit bit twiddling is generated.  Still should generally
   // be faster than a loop.
-  unsigned int Count() const { return CountSetBits(m_val); }
-  Iterator begin() const
-  {
-    Iterator it(m_val, 0);
-    return ++it;
-  }
-  Iterator end() const { return Iterator(m_val, -1); }
+  constexpr unsigned int Count() const { return CountSetBits(m_val); }
+  constexpr Iterator begin() const { return ++Iterator(m_val, 0); }
+  constexpr Iterator end() const { return Iterator(m_val, -1); }
   IntTy m_val;
 };
 }