Date: Wed, 27 Aug 2003 14:06:02 -0500
From: Eric Rudd <rudd AT cyberoptics DOT com>
Subject: Re: Arithmetic Exceptions in C99
In-reply-to: <9003-Wed27Aug2003201417+0300-eliz@elta.co.il>
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Eli Zaretskii wrote:

>In particular, do we really intend to
>change all our math functions to trigger SIGFPE when the standard
>says ``should raise an exceptions''?
>
I'm having trouble reconciling Annex F with the following clause from 
the main body of C99:

    |7.12.1 Treatment of error conditions

    ||1 The behavior of each of the functions in <math.h> is specified
    for all representable ||values of its input arguments, except where
    stated otherwise. Each function shall execute ||as if it were a
    single operation without generating any externally visible
    exceptional ||conditions.|

||||||which suggests to me that SIGFPE should not be set by the math 
functions under any conditions.  If I am missing something, please 
straighten me out, but I thought that "exception" in the context of C99 
had to do with setting errno, rather than a low-level processor state, 
as it seems to imply in Annex F.  Perhaps this would be a good question 
for comp.std.c.

To cause the math functions to set SIGFPE, where they previously did 
not, could break existing code.

Question: Has it already been decided that DJGPP will be IEC 60559 
compliant (that is, comply with Annex F)?

-Eric Rudd
rudd AT cyberoptics DOT com

    ||