From a5e3f163a5b352482ced2fe1cf659835105df80e Mon Sep 17 00:00:00 2001
From: Stenzek <stenzek@gmail.com>
Date: Sun, 13 Jul 2025 20:16:59 +1000
Subject: [PATCH] Misc: Make bitfield unions trivially copyable

---
 src/common/bitfield.h |  3 ---
 src/util/cd_image.h   | 18 ------------------
 src/util/gpu_device.h | 25 +++++++++----------------
 3 files changed, 9 insertions(+), 37 deletions(-)

diff --git a/src/common/bitfield.h b/src/common/bitfield.h
index 73aff18c4..29b2d2f08 100644
--- a/src/common/bitfield.h
+++ b/src/common/bitfield.h
@@ -12,9 +12,6 @@ struct BitField
 {
   static_assert(!std::is_same_v<DataType, bool> || BitCount == 1, "Boolean bitfields should only be 1 bit");
 
-  // We have to delete the copy assignment operator otherwise we can't use this class in anonymous structs/unions.
-  BitField& operator=(const BitField& rhs) = delete;
-
   ALWAYS_INLINE constexpr BackingDataType GetMask() const
   {
     return ((static_cast<BackingDataType>(~0)) >> (8 * sizeof(BackingDataType) - BitCount)) << BitIndex;
diff --git a/src/util/cd_image.h b/src/util/cd_image.h
index 85de1bdb5..2cc792b5b 100644
--- a/src/util/cd_image.h
+++ b/src/util/cd_image.h
@@ -156,14 +156,6 @@ public:
       Control() = default;
 
       Control(u8 bits_) : bits(bits_) {}
-
-      Control(const Control& rhs) : bits(rhs.bits) {}
-
-      Control& operator=(const Control& rhs)
-      {
-        bits = rhs.bits;
-        return *this;
-      }
     };
 
     struct
@@ -189,16 +181,6 @@ public:
     bool IsData() const { return GetControl().data; }
 
     bool IsCRCValid() const;
-
-    SubChannelQ() = default;
-
-    SubChannelQ(const SubChannelQ& q) : data(q.data) {}
-
-    SubChannelQ& operator=(const SubChannelQ& q)
-    {
-      data = q.data;
-      return *this;
-    }
   };
   static_assert(sizeof(SubChannelQ) == SUBCHANNEL_BYTES_PER_FRAME, "SubChannelQ is correct size");
 
diff --git a/src/util/gpu_device.h b/src/util/gpu_device.h
index 40f6dc1a8..05f0e6ee6 100644
--- a/src/util/gpu_device.h
+++ b/src/util/gpu_device.h
@@ -278,8 +278,8 @@ public:
 
     // clang-format off
     ALWAYS_INLINE VertexAttribute() = default;
-    ALWAYS_INLINE constexpr VertexAttribute(const VertexAttribute& rhs) : key(rhs.key) {}
-    ALWAYS_INLINE VertexAttribute& operator=(const VertexAttribute& rhs) { key = rhs.key; return *this; }
+    ALWAYS_INLINE constexpr VertexAttribute(const VertexAttribute& rhs) = default;
+    ALWAYS_INLINE VertexAttribute& operator=(const VertexAttribute& rhs) = default;
     ALWAYS_INLINE bool operator==(const VertexAttribute& rhs) const { return key == rhs.key; }
     ALWAYS_INLINE bool operator!=(const VertexAttribute& rhs) const { return key != rhs.key; }
     ALWAYS_INLINE bool operator<(const VertexAttribute& rhs) const { return key < rhs.key; }
@@ -369,13 +369,11 @@ public:
   // TODO: purge this?
   union RasterizationState
   {
-    BitField<u8, CullMode, 0, 2> cull_mode;
     u8 key;
 
+    BitField<u8, CullMode, 0, 2> cull_mode;
+
     // clang-format off
-    ALWAYS_INLINE RasterizationState() = default;
-    ALWAYS_INLINE RasterizationState(const RasterizationState& rhs) : key(rhs.key) {}
-    ALWAYS_INLINE RasterizationState& operator=(const RasterizationState& rhs) { key = rhs.key; return *this; }
     ALWAYS_INLINE bool operator==(const RasterizationState& rhs) const { return key == rhs.key; }
     ALWAYS_INLINE bool operator!=(const RasterizationState& rhs) const { return key != rhs.key; }
     ALWAYS_INLINE bool operator<(const RasterizationState& rhs) const { return key < rhs.key; }
@@ -386,14 +384,12 @@ public:
 
   union DepthState
   {
-    BitField<u8, DepthFunc, 0, 3> depth_test;
-    BitField<u8, bool, 4, 1> depth_write;
     u8 key;
 
+    BitField<u8, DepthFunc, 0, 3> depth_test;
+    BitField<u8, bool, 4, 1> depth_write;
+
     // clang-format off
-    ALWAYS_INLINE DepthState() = default;
-    ALWAYS_INLINE DepthState(const DepthState& rhs) : key(rhs.key) {}
-    ALWAYS_INLINE DepthState& operator=(const DepthState& rhs) { key = rhs.key; return *this; }
     ALWAYS_INLINE bool operator==(const DepthState& rhs) const { return key == rhs.key; }
     ALWAYS_INLINE bool operator!=(const DepthState& rhs) const { return key != rhs.key; }
     ALWAYS_INLINE bool operator<(const DepthState& rhs) const { return key < rhs.key; }
@@ -405,6 +401,8 @@ public:
 
   union BlendState
   {
+    u64 key;
+
     BitField<u64, bool, 0, 1> enable;
     BitField<u64, BlendFunc, 1, 4> src_blend;
     BitField<u64, BlendFunc, 5, 4> src_alpha_blend;
@@ -422,12 +420,7 @@ public:
     BitField<u64, u16, 1, 16> blend_factors;
     BitField<u64, u8, 17, 6> blend_ops;
 
-    u64 key;
-
     // clang-format off
-    ALWAYS_INLINE BlendState() = default;
-    ALWAYS_INLINE BlendState(const BlendState& rhs) : key(rhs.key) {}
-    ALWAYS_INLINE BlendState& operator=(const BlendState& rhs) { key = rhs.key; return *this; }
     ALWAYS_INLINE bool operator==(const BlendState& rhs) const { return key == rhs.key; }
     ALWAYS_INLINE bool operator!=(const BlendState& rhs) const { return key != rhs.key; }
     ALWAYS_INLINE bool operator<(const BlendState& rhs) const { return key < rhs.key; }