Editing Register allocation (section)

{{Short description|Computer compiler optimization technique}}
{{use dmy dates|cs1-dates=ly|date=October 2021}}
In [[compiler optimization]], '''register allocation''' is the process of assigning local [[automatic variable]]s and [[Expression (computer science)|expression]] results to a limited number of [[processor register]]s.

Register allocation can happen over a [[basic block]] (''local register allocation''), over a whole function/[[Subroutine|procedure]] (''global register allocation''), or across function boundaries traversed via call-graph (''interprocedural register allocation''). When done per function/procedure the [[calling convention]] may require insertion of save/restore around each [[Call site|call-site]].