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From: archer%segin4.segin.fr@prime.com (Vincent Archer)
Newsgroups: comp.os.minix
Subject: Problems with C68
Message-ID: <21058@nigel.udel.EDU>
Date: 5 Jun 90 07:06:28 GMT
Sender: usenet@udel.EDU
Lines: 28


    I've found C68 to be very useful... But I've also found that it's not
reliable :-( Try compiling the lib/ansi/strcpy.c; the construction:

    while ((*dest++ = *src++) != 0) continue;

is compiled as:

_0:
    move.l    a2,a0
    add.l     #1,a2
    move.b    (a3)+,(a0)
    tst.b     (a3)+               <==== Uh? A second increment
    bne       _0

Aside from the optimisation problem of dst++, there's a problem in the
reduction of the expression (a=b)op => (a=b),(b op), which is safe as long as
b is safe to evaluate more than once.

No wonder you get 1018 dhrystones/sec. that way! :-) I lack the time to fix it,
so, CvW, you're notified of the problem...


    Vincent


Vincent Archer                   | Email:archer%segin4.segin.fr@prime.com
"People that are good at finding excuses are never good at anything else"