---

Stack Areas: How to name stack locations before laying out the stack

The current conversion from STG to CMM leaves stack management completely implicit. The consequence is that a number of things must happen all at once:

• The stack is laid out.
• CopyIn and CopyOut nodes are converted to the appropriate moves, loads and stores, as required by the calling conventions.
• The stack pointer is adjusted to conventional locations before and after function calls.
• The return address is pushed on the stack at call sites.

And of course, none of the argument-passing or stack-adjusting instructions are available during optimization, before the stack layout is fixed.

A much better approach is to give symbolic names to locations on the stack, lower all the argument passing and stack adjusting to the actual data-movement instructions, and replace the names later when the final stack layout is fixed.