Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!uunet!mcsun!sunic!sics.se!uplog!uplog.uplog.se!thomas From: thomas@uplog.se (Thomas Hameenaho) Newsgroups: comp.sys.m88k Subject: Re: Register Allocation (was Re: Info about 88open & standards) Message-ID: Date: 28 Nov 89 09:05:12 GMT References: <1989Nov16.212149.9770@paris.ics.uci.edu> <100050002@hpcuhc.HP.COM> Sender: thomas@uplog.UUCP Organization: TeleLOGIC Uppsala AB Lines: 16 In-reply-to: edwardm@hpcuhc.HP.COM's message of 27 Nov 89 19:14:50 GMT I have followed the debate about caller vs. callee saves registers with great interest. I have an idea that perhaps could be a bit of both worlds: What about having the caller supply a mask of live registers to the callee, ie. registers that must not be clobbered to the callee? This mask should be ANDed with a mask of the registers that the callee clobbers and handed to the equivalent of MOVEM (68k) or CALLx (VAX). The save/restore should of course be handled by microcode/hardware to make it fast. This way there would never be unnecessary saves. -- Real life: Thomas Hameenaho Email: thomas@uplog.se Snail mail: TeleLOGIC Uppsala AB Phone: +46 18 189406 Box 1218 Fax: +46 18 132039 S - 751 42 Uppsala, Sweden