Strange behavior of mpf_inp_str

Ronald Bruck bruck at
Fri Feb 19 17:46:30 CET 2010

Roger Golliver wrote:
> Date: Thu, 18 Feb 2010 09:28:47 -0800
> From: "Golliver, Roger A" <roger.a.golliver at>
> Subject: Re: Strange behavior of mpf_inp_str
> To: "gmp-bugs at" <gmp-bugs at>
> Message-ID:
> <ADDEBCD9C145E542A8688C29F1FBDCB95DD13DCB at 
> >
> Content-Type: text/plain; charset="us-ascii"
> You might want to try gcc and if it works file a bug against icc.
> Roger

I have tried that, but the behavior continues.  I also recompiled  
gmp-5.0.1 (using defaults, including gcc, except I configured with -- 
enable-cxx).  On the i7, the behavior continues, despite passing  
"make check".

Now I also have a laptop, using a core2 processor and the same  
release of SuSE Linux.  When I installed gcc-5.0.1, the bug did NOT  
manifest itself.  I'm incredulous that it could be the i7.  I'm not  
sure what to try now.

I can work around the bug.  Most of my programs are running under the  
direction of scripts anyway; all I have to do is insert a "sed 's/e+/ 
e/g'" right after the file with the e+ is created.  Or I can figure  
out which instruction is writing the e+ in the first place (I think  
it's gmp_fprintf) and fix that (IIRC there's a format to suppress the  
+).  But the feeling I'm having is similar to the one I had when I  
went deaf in my left ear:  from onset of ringing to total deafness  
took half-an-hour, and my worry ever since has been, What ELSE might  
suddenly fall off?  ;-)  What if something happens that I DON'T  
notice, and my programs suddenly change and begin producing incorrect  
output?  We reassure our children there's no monster under the bed,  
but is that always true?

If someone else is using an i7, I'd appreciate hearing verification  
that mpf_inp_str works on YOUR configuration.  To repeat the  
problem:  MY mpf_inp_str doesn't recognize an explicit + sign in the  
exponent, e.g. 1.234e+2.  I'm puzzled why the installation passes the  
"make check".

My i7 is mildly overclocked, but I have the best MB and memory money  
could buy, and when overclocking causes problems it's not usually  
something this specific (just general flakiness).  Still, I'll turn  
that off.  Next I'll try starting in failsafe mode.  Ultimately I  
could reinstall the system, but that's draconian.

Ron Bruck

More information about the gmp-bugs mailing list