COMPUTER SYSTEM AND METHOD OF ADAPTING A COMPUTER SYSTEM TO SUPPORT A REGISTER WINDOW ARCHITECTURE

A target computing system (10) is adapted to support a register window architecture, particularly for use when converting non-native subject code (17) instead into target code (21) executed by a target processor (13). A subject register stack data structure (an ''SR stack'') (400) in memory has a plurality of frames (410) each containing a set of entries (401) corresponding to a subset of subject registers (502) of one register window (510) in a subject processor (3). The SR (10) stack (400) is accessed by the target code (21) executing on the target processor (13). The SR stack (400) stores a large plurality of such frames 410 and thereby avoids overhead such as modelling automatic spill and fill operations from the windowed register file of the subject architecture. In one embodiment, a target computing system (10) having sixteen general purpose working registers is adapted to support a register window architecture reliant upon a (15) register file containing tens or hundreds of subject registers (502). ® KIPO & WIPO 2009