GPU/Software: Ensure commands are always aligned to 4 bytes

src/core/gpu_backend.cpp

@@ -1,4 +1,5 @@
 #include "gpu_backend.h"
+#include "common/align.h"
 #include "common/log.h"
 #include "common/state_wrapper.h"
 #include "settings.h"
@@ -44,71 +45,59 @@ void GPUBackend::Shutdown()
 
 GPUBackendFillVRAMCommand* GPUBackend::NewFillVRAMCommand()
 {
-  GPUBackendFillVRAMCommand* cmd =
-    static_cast<GPUBackendFillVRAMCommand*>(AllocateCommand(sizeof(GPUBackendFillVRAMCommand)));
-  cmd->type = GPUBackendCommandType::FillVRAM;
-  cmd->size = cmd->Size();
-  return cmd;
+  return static_cast<GPUBackendFillVRAMCommand*>(
+    AllocateCommand(GPUBackendCommandType::FillVRAM, sizeof(GPUBackendFillVRAMCommand)));
 }
 
 GPUBackendUpdateVRAMCommand* GPUBackend::NewUpdateVRAMCommand(u32 num_words)
 {
   const u32 size = sizeof(GPUBackendUpdateVRAMCommand) + (num_words * sizeof(u16));
-  GPUBackendUpdateVRAMCommand* cmd = static_cast<GPUBackendUpdateVRAMCommand*>(AllocateCommand(size));
-  cmd->type = GPUBackendCommandType::UpdateVRAM;
-  cmd->size = size;
+  GPUBackendUpdateVRAMCommand* cmd =
+    static_cast<GPUBackendUpdateVRAMCommand*>(AllocateCommand(GPUBackendCommandType::UpdateVRAM, size));
   return cmd;
 }
 
 GPUBackendCopyVRAMCommand* GPUBackend::NewCopyVRAMCommand()
 {
-  GPUBackendCopyVRAMCommand* cmd =
-    static_cast<GPUBackendCopyVRAMCommand*>(AllocateCommand(sizeof(GPUBackendCopyVRAMCommand)));
-  cmd->type = GPUBackendCommandType::CopyVRAM;
-  cmd->size = cmd->Size();
-  return cmd;
+  return static_cast<GPUBackendCopyVRAMCommand*>(
+    AllocateCommand(GPUBackendCommandType::CopyVRAM, sizeof(GPUBackendCopyVRAMCommand)));
 }
 
 GPUBackendSetDrawingAreaCommand* GPUBackend::NewSetDrawingAreaCommand()
 {
-  GPUBackendSetDrawingAreaCommand* cmd =
-    static_cast<GPUBackendSetDrawingAreaCommand*>(AllocateCommand(sizeof(GPUBackendSetDrawingAreaCommand)));
-  cmd->type = GPUBackendCommandType::SetDrawingArea;
-  cmd->size = cmd->Size();
-  return cmd;
+  return static_cast<GPUBackendSetDrawingAreaCommand*>(
+    AllocateCommand(GPUBackendCommandType::SetDrawingArea, sizeof(GPUBackendSetDrawingAreaCommand)));
 }
 
 GPUBackendDrawPolygonCommand* GPUBackend::NewDrawPolygonCommand(u32 num_vertices)
 {
   const u32 size = sizeof(GPUBackendDrawPolygonCommand) + (num_vertices * sizeof(GPUBackendDrawPolygonCommand::Vertex));
-  GPUBackendDrawPolygonCommand* cmd = static_cast<GPUBackendDrawPolygonCommand*>(AllocateCommand(size));
-  cmd->type = GPUBackendCommandType::DrawPolygon;
-  cmd->size = size;
+  GPUBackendDrawPolygonCommand* cmd =
+    static_cast<GPUBackendDrawPolygonCommand*>(AllocateCommand(GPUBackendCommandType::DrawPolygon, size));
   cmd->num_vertices = Truncate16(num_vertices);
   return cmd;
 }
 
 GPUBackendDrawRectangleCommand* GPUBackend::NewDrawRectangleCommand()
 {
-  GPUBackendDrawRectangleCommand* cmd =
-    static_cast<GPUBackendDrawRectangleCommand*>(AllocateCommand(sizeof(GPUBackendDrawRectangleCommand)));
-  cmd->type = GPUBackendCommandType::DrawRectangle;
-  cmd->size = cmd->Size();
-  return cmd;
+  return static_cast<GPUBackendDrawRectangleCommand*>(
+    AllocateCommand(GPUBackendCommandType::DrawRectangle, sizeof(GPUBackendDrawRectangleCommand)));
 }
 
 GPUBackendDrawLineCommand* GPUBackend::NewDrawLineCommand(u32 num_vertices)
 {
   const u32 size = sizeof(GPUBackendDrawLineCommand) + (num_vertices * sizeof(GPUBackendDrawLineCommand::Vertex));
-  GPUBackendDrawLineCommand* cmd = static_cast<GPUBackendDrawLineCommand*>(AllocateCommand(size));
-  cmd->type = GPUBackendCommandType::DrawLine;
-  cmd->size = size;
+  GPUBackendDrawLineCommand* cmd =
+    static_cast<GPUBackendDrawLineCommand*>(AllocateCommand(GPUBackendCommandType::DrawLine, size));
   cmd->num_vertices = Truncate16(num_vertices);
   return cmd;
 }
 
-void* GPUBackend::AllocateCommand(u32 size)
+void* GPUBackend::AllocateCommand(GPUBackendCommandType command, u32 size)
 {
+  // Ensure size is a multiple of 4 so we don't end up with an unaligned command.
+  size = Common::AlignUpPow2(size, 4);
+
   for (;;)
   {
     u32 read_ptr = m_command_fifo_read_ptr.load();
@@ -138,7 +127,10 @@ void* GPUBackend::AllocateCommand(u32 size)
       }
     }
 
-    return &m_command_fifo_data[write_ptr];
+    GPUBackendCommand* cmd = reinterpret_cast<GPUBackendCommand*>(&m_command_fifo_data[write_ptr]);
+    cmd->type = command;
+    cmd->size = size;
+    return cmd;
   }
 }
 
@@ -200,9 +192,8 @@ void GPUBackend::Sync()
   if (!m_use_gpu_thread)
     return;
 
-  GPUBackendSyncCommand* cmd = static_cast<GPUBackendSyncCommand*>(AllocateCommand(sizeof(GPUBackendSyncCommand)));
-  cmd->type = GPUBackendCommandType::Sync;
-  cmd->size = sizeof(GPUBackendSyncCommand);
+  GPUBackendSyncCommand* cmd =
+    static_cast<GPUBackendSyncCommand*>(AllocateCommand(GPUBackendCommandType::Sync, sizeof(GPUBackendSyncCommand)));
   PushCommand(cmd);
   WakeGPUThread();
 

src/core/gpu_backend.h

@@ -41,7 +41,7 @@ public:
   void RunGPULoop();
 
 protected:
-  void* AllocateCommand(u32 size);
+  void* AllocateCommand(GPUBackendCommandType command, u32 size);
   u32 GetPendingCommandSize() const;
   void WakeGPUThread();
   void StartGPUThread();

src/core/gpu_types.h

@@ -262,14 +262,13 @@ union GPUBackendCommandParameters
 
 struct GPUBackendCommand
 {
+  u32 size;
   GPUBackendCommandType type;
   GPUBackendCommandParameters params;
-  u32 size;
 };
 
 struct GPUBackendSyncCommand : public GPUBackendCommand
 {
-  ALWAYS_INLINE u32 Size() const { return sizeof(GPUBackendSyncCommand); }
 };
 
 struct GPUBackendFillVRAMCommand : public GPUBackendCommand
@@ -279,8 +278,6 @@ struct GPUBackendFillVRAMCommand : public GPUBackendCommand
   u16 width;
   u16 height;
   u32 color;
-
-  ALWAYS_INLINE u32 Size() const { return sizeof(GPUBackendFillVRAMCommand); }
 };
 
 struct GPUBackendUpdateVRAMCommand : public GPUBackendCommand
@@ -290,8 +287,6 @@ struct GPUBackendUpdateVRAMCommand : public GPUBackendCommand
   u16 width;
   u16 height;
   u16 data[0];
-
-  ALWAYS_INLINE u32 Size() const { return sizeof(GPUBackendUpdateVRAMCommand) + (sizeof(u16) * width * height); }
 };
 
 struct GPUBackendCopyVRAMCommand : public GPUBackendCommand
@@ -302,21 +297,17 @@ struct GPUBackendCopyVRAMCommand : public GPUBackendCommand
   u16 dst_y;
   u16 width;
   u16 height;
-
-  ALWAYS_INLINE u32 Size() const { return sizeof(GPUBackendCopyVRAMCommand); }
 };
 
 struct GPUBackendSetDrawingAreaCommand : public GPUBackendCommand
 {
   Common::Rectangle<u32> new_area;
-
-  ALWAYS_INLINE u32 Size() const { return sizeof(GPUBackendSetDrawingAreaCommand); }
 };
 
 struct GPUBackendDrawCommand : public GPUBackendCommand
 {
-  GPURenderCommand rc;
   GPUDrawModeReg draw_mode;
+  GPURenderCommand rc;
   GPUTexturePaletteReg palette;
   GPUTextureWindow window;
 
@@ -349,8 +340,6 @@ struct GPUBackendDrawPolygonCommand : public GPUBackendDrawCommand
   };
 
   Vertex vertices[0];
-
-  ALWAYS_INLINE u32 Size() const { return sizeof(GPUBackendDrawPolygonCommand) + sizeof(Vertex) * num_vertices; }
 };
 
 struct GPUBackendDrawRectangleCommand : public GPUBackendDrawCommand
@@ -359,8 +348,6 @@ struct GPUBackendDrawRectangleCommand : public GPUBackendDrawCommand
   u16 width, height;
   u16 texcoord;
   u32 color;
-
-  ALWAYS_INLINE u32 Size() const { return sizeof(GPUBackendDrawRectangleCommand); }
 };
 
 struct GPUBackendDrawLineCommand : public GPUBackendDrawCommand
@@ -381,8 +368,6 @@ struct GPUBackendDrawLineCommand : public GPUBackendDrawCommand
   };
 
   Vertex vertices[0];
-
-  ALWAYS_INLINE u32 Size() const { return sizeof(GPUBackendDrawLineCommand) + sizeof(Vertex) * num_vertices; }
 };
 
 #ifdef _MSC_VER