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From: jim@ism780b.UUCP
Newsgroups: net.lang.c
Subject: Re: Re: setjmp: read the manual
Message-ID: <71@ism780b.UUCP>
Date: Thu, 18-Oct-84 00:33:36 EDT
Article-I.D.: ism780b.71
Posted: Thu Oct 18 00:33:36 1984
Date-Received: Fri, 19-Oct-84 06:39:12 EDT
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Nf-ID: #R:sun:-173500:ism780b:25500044:000:683
Nf-From: ism780b!jim    Oct 16 19:54:00 1984

>I am afraid I don't follow Sun's logic.  All that is required is to
>unravel the call stack frames by following the back-pointers.  The
>VAX built-in support for this stuff is not used on any UNIXes I am
>familiar with.  When someone does a longjmp the odds are very good
>that it is not in the inside of a tight loop, so the extra time
>taken to unwind the stack frame to fix up clobbered registers should
>not be an efficiency issue, unless your call frames have a variable
>amount of information and no internal clue about how much.

The VAX built-in stuff used is the indication on the stack of which register
variables were saved.

-- Jim Balter, INTERACTIVE Systems (ima!jim)