To test the conclusions of the last post i modified the field order of some LCL classes to group together Boolean fields.
Here's the return value of the InstanceSize property:
TButton
before: 874 bytes
after: 829 bytes (saved 24, 16 and 5 bytes in TControl, TWinControl and TCustomButton respectively)
TMenuItem
before: 152 bytes
after: 136 bytes
In an application with 100 controls and 20 menu items you save 2400 (considering only TControl memory) and 320 bytes respectively.
Maybe be this is negligible in computers with 1GB or more of RAM, but for mobile platforms it makes a difference.
The patch is here. Have fun!
