d3d12: CMP vertex format has 4 members.

Fix 1878

rpcs3/Emu/RSX/D3D12/D3D12Formats.cpp

@@ -455,10 +455,10 @@ DXGI_FORMAT get_vertex_attribute_format(rsx::vertex_base_type type, u8 size)
 	{
 		switch (size)
 		{
-		case 1: return DXGI_FORMAT_R16G16B16A16_SNORM;
+		case 1:
 		case 2:
-		case 3:
-		case 4: fmt::throw_exception("Unsupported CMP vertex format with size > 1" HERE);
+		case 3: fmt::throw_exception("Unsupported CMP vertex format with size > 1" HERE);
+		case 4: return DXGI_FORMAT_R16G16B16A16_SNORM;
 		}
 		break;
 	}

rpcs3/Emu/RSX/rsx_vertex_data.h

@@ -38,6 +38,8 @@ public:
 
 	u8 size() const
 	{
+		if (decode_reg().type() == rsx::vertex_base_type::cmp)
+			return 4;
 		return decode_reg().size();
 	}