Path: utzoo!censor!geac!torsqnt!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!decwrl!uunet!nih-csl!lhc!adm!smoke!gwyn
From: gwyn@smoke.brl.mil (Doug Gwyn)
Newsgroups: comp.lang.c
Subject: Re: scope of malloc
Message-ID: <14448@smoke.brl.mil>
Date: 13 Nov 90 06:57:54 GMT
References: <3729@skye.ed.ac.uk> <14413@smoke.brl.mil> <3739@skye.ed.ac.uk>
Organization: U.S. Army Ballistic Research Laboratory, APG, MD.
Lines: 9

In article <3739@skye.ed.ac.uk> richard@aiai.UUCP (Richard Tobin) writes:
>Are there *any* widely-used processors that can't implement alloca()
>reasonably efficiently even with compiler support?

It can't be implemented correctly (except by the compiler turning it into
malloc()/free() calls that you could have coded yourself) on any system
that doesn't provide separate frame and stack pointers.  Just consider
the effects of an interrupt.  It also cannot be reasonably implemented on
a system that uses linked stack frames, such as on the IBM System/370.