Path: utzoo!attcan!uunet!quick!srg
From: srg@quick.COM (Spencer Garrett)
Newsgroups: comp.arch
Subject: Re: register save/restore
Message-ID: <292@quick.COM>
Date: 9 Nov 88 06:35:30 GMT
References: <3300037@m.cs.uiuc.edu> <5938@killer.DALLAS.TX.US> <234@taux02.UUCP>
Organization: Quicksilver Engineering, Seattle
Lines: 9

In article <234@taux02.UUCP>, amos@taux02.UUCP (Amos Shapir) writes:
- I haven't seen anyone mention the idea of mixing caller-saves and callee-saves
- methods: the caller hands to the callee a mask of live registers; the callee
- ANDs this with a mask of the registers it uses and saves the registers whose
- corresponding bits are set.  The mask the callee hands to the routines it calls
- is the OR of these two masks. (I hope that's clear).

Problem is, the mask thus generated quickly tends toward all 1's if
it's saving any stores, and is equivalent to callee-saves if it isn't.