GPU/SW: Use no_unique_address for potentially-unused varyings

src/common/types.h

@@ -100,6 +100,13 @@ char (&__countof_ArraySizeHelper(T (&array)[N]))[N];
 #define RESTRICT __restrict__
 #endif
 
+// msvc requires a different attribute, of course
+#ifdef _MSC_VER
+#define NO_UNIQUE_ADDRESS [[msvc::no_unique_address]]
+#else
+#define NO_UNIQUE_ADDRESS [[no_unique_address]]
+#endif
+
 // disable warnings that show up at warning level 4
 // TODO: Move to build system instead
 #ifdef _MSC_VER

src/core/gpu_sw_rasterizer.inl

@@ -477,12 +477,12 @@ struct PixelVectors
   GSVectorNi mask_and;
   GSVectorNi mask_or;
 
-  typename std::conditional_t<texture_enable, GSVectorNi, UnusedField> texture_window_and_x;
-  typename std::conditional_t<texture_enable, GSVectorNi, UnusedField> texture_window_or_x;
-  typename std::conditional_t<texture_enable, GSVectorNi, UnusedField> texture_window_and_y;
-  typename std::conditional_t<texture_enable, GSVectorNi, UnusedField> texture_window_or_y;
-  typename std::conditional_t<texture_enable, GSVectorNi, UnusedField> texture_base_x;
-  typename std::conditional_t<texture_enable, GSVectorNi, UnusedField> texture_base_y;
+  NO_UNIQUE_ADDRESS typename std::conditional_t<texture_enable, GSVectorNi, UnusedField> texture_window_and_x;
+  NO_UNIQUE_ADDRESS typename std::conditional_t<texture_enable, GSVectorNi, UnusedField> texture_window_or_x;
+  NO_UNIQUE_ADDRESS typename std::conditional_t<texture_enable, GSVectorNi, UnusedField> texture_window_and_y;
+  NO_UNIQUE_ADDRESS typename std::conditional_t<texture_enable, GSVectorNi, UnusedField> texture_window_or_y;
+  NO_UNIQUE_ADDRESS typename std::conditional_t<texture_enable, GSVectorNi, UnusedField> texture_base_x;
+  NO_UNIQUE_ADDRESS typename std::conditional_t<texture_enable, GSVectorNi, UnusedField> texture_base_y;
 
   PixelVectors(const GPUBackendDrawCommand* cmd)
   {