bug-gnulib
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: m4-1.4.9b on HP-UX 11


From: Albert Chin-A-Young
Subject: Re: m4-1.4.9b on HP-UX 11
Date: Sun, 3 Jun 2007 08:59:49 -0500
User-agent: Mutt/1.5.6i

On Sun, Jun 03, 2007 at 02:53:22PM +0100, Gary V. Vaughan wrote:
> [[Cc:ing Albert Chin:  Albert, why do we need +Onofltacc in the  
> standard hpux11.23
>   flags, when it clearly causes NaN regressions?]]

>From the cc(1) man page:
           +O[no]fltacc   Disable [enable] floating-point optimizations that
                          can result in numerical differences.
                          +Ofltacc is the same as +Ofltacc=strict.
                          +Onofltacc is the same as +Ofltacc=relaxed.

So, +Onofltacc disables floating-point optimizations. Seems like the
correct decision to me.

I'm fine leaving it off if it fixes something but it seems odd.

> On 3 Jun 2007, at 01:48, Bruno Haible wrote:
> 
> >Gary V. Vaughan wrote in
> >  http://lists.gnu.org/archive/html/bug-gnulib/2007-06/msg00005.html
> >[For some reason, I can see your last 3 mails on gmane and on  
> >lists.gnu.org,
> >but they don't came into my mailbox. And I have no spam filter.]
> >
> >>With CC=cc CFLAGS="-z +O2 +Onofltacc +Olit=all +Oentrysched  
> >>+Odataprefetch \
> >>+Onolimit" LDFLAGS="-Wl,+nodefaultrpath":
> >>
> >>1.000000 33
> >>test-vasprintf-posix.c:1239: assertion failed
> >>/opt/fsw/bash30/bin/bash: line 1: 12683 ABORT instruction (core  
> >>dumped) EXEEXT='' EXEEXT='' EXEEXT='' srcdir='.' EXEEXT=''  
> >>srcdir='.' EXEEXT='' srcdir='.' ${dir}$tst
> >>FAIL: test-vasprintf-posix
> >>
> >>With CC=cc CFLAGS="-z +O2 +Olit=all +Oentrysched +Odataprefetch  
> >>+Onolimit" \
> >>LDFLAGS="-Wl,+nodefaultrpath":
> >>
> >>  -nan 33
> >>  -nan 33
> >>  PASS: test-vasprintf-posix
> >
> >This makes it pretty clear that +Onofltacc is the culprit.
> >
> >>Do you think the test is at fault here?
> >
> >No; dividing zero by zero *must* give a NaN according to IEEE 754.  
> >This is
> >not the kind of "undefined behaviour" that may be optimized  
> >randomly by
> >the compilers.
> >
> >>Or is it an hpux compiler bug?
> >
> >Whether it's an HP-UX compiler bug or whether it's you who are  
> >willfully
> >choosing a non-IEEE-754-compliant compiler by using the option  
> >+Onofltacc,
> >depends on the HP compiler's documentation. I can not judge it by  
> >the small
> >snippet you posted.
> 
> The fact that it breaks this test only on hpux11.23 when the same  
> flags do
> not break it on hpux11.11 and hpux11.00 makes me think it is a  
> compiler bug.
> 
> >>we've made it a standard flag for compilations on hpux in order for
> >>other FLOSS projects to build correctly
> >
> >It sounds surprising that some projects _require_ a particular  
> >optimization
> >in order to build correctly?! But it any case, I'm more inclined to  
> >adapt
> >source code so that it compiles with default flags, more than for some
> >pretty aggressive vendor-specific optimization flags. (Here for HP- 
> >UX cc
> >I consider "cc -Ae" the default.)
> 
> ACK.  Thanks for your input.
> 
> Cheers,
>       Gary
> -- 
>   ())_.              Email me: address@hidden
>   ( '/           Read my blog: http://blog.azazil.net
>   / )=         ...and my book: http://sources.redhat.com/autobook
> `(_~)_ Join my AGLOCO Network: http://www.agloco.com/r/BBBS7912
> 
> 
> 
> 



-- 
albert chin (address@hidden)




reply via email to

[Prev in Thread] Current Thread [Next in Thread]