[Bug target/34261] Directed rounding doesn't work on MacOS X

["j dot d dot pryce at ntlworld dot com" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #4 from j dot d dot pryce at ntlworld dot com  2007-12-02 16:17 -------
Subject: Re:  Directed rounding doesn't work on MacOS X

Dear Pinskia

-----------------
I did not realise that GCC does not provide these libraries. Thank  
you for explaining.

On 30 Nov 2007, at 22:20, pinskia at gcc dot gnu dot org wrote:
> ------- Comment #3 from pinskia at gcc dot gnu dot org  2007-11-30  
> 22:20 -------
> (In reply to comment #2)
> ...
> Lets put it this way.  If fprintf failed, it does not mean it is a  
> GCC bug as
> GCC does not provide the fprintf library function.  Yes GCC could  
> have an ABI
> bug but that would mean everything else would be broken but since  
> just fprintf
> is broken, it is most likely a bug in fprintf.

Does that mean, for instance, that every C compiler on this  
particular machine uses the same fprintf function? And it was written  
by Apple?

-----------------
> Well since fesetround is not provided by GCC, it is provided by the  
> system.
> Also are you using Apple's provided GCC, if so please file a bug  
> with them.  We
> cannot support their modified version anyways.

I got this in a Terminal window
> johnpryce 43$which g++
> /usr/bin/g++
>
> johnpryce 44$which gcc
> /usr/bin/gcc
>
> johnpryce 45$gcc --version
> i686-apple-darwin8-gcc-4.0.1 (GCC) 4.0.1 (Apple Computer, Inc.  
> build 5367)
> Copyright (C) 2005 Free Software Foundation, Inc.
> This is free software; see the source for copying conditions.   
> There is NO
> warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR  
> PURPOSE.


I see there is a folder /Developer/SDKs/MacOSX10.3.9.sdk/usr/lib/gcc/  
but don't know if this is used by the above gcc command, or is  
something separate.

How do I file a bug with Apple? I consulted Apple Help and found a  
page with these instructions
> To submit a bug report to Apple:
> Connect to the Internet.
> In the dialog that appeared when the application crashed, click the  
> submit button. ...
Which doesn't help, as it's not about crashes.

-----------------
>> This violates the IEEE754 standard, which of course mandates  
>> rounding to
>> nearest as the default.
>
> Of course x87 violates it anyways.
>
> When I ran the test on a x86 machine, I get:...

This stuff about x86 versus x87 was quite new to me.

> Please read bug 323.

Thanks. I have done so, and read the "floating-point-article.pdf".  
Very useful.

> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34261
>
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John Pryce
j.d.pryce@ntlworld.com


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34261