strtod (and atof) on hex numbers

Jeff Johnston jjohnstn@redhat.com
Fri Jun 23 16:16:00 GMT 2006


I have integrated a newer version of strtod from David M. Gay's gdtoa 
FreeBSD code.  This code has the C99 support in question including nan 
and inf support.  I have tested on x86-linux and mn10300.

As usual, please run it through its paces on Cygwin and let me know if 
there are any problems.

-- Jeff J.

Jeff Johnston wrote:
> This is a C99 extension to strtod over original ANSI C90 which is what 
> newlib started with.  I'll start working on it, but don't expect 
> anything too quick.
> 
> -- Jeff J.
> 
> Corinna Vinschen wrote:
> 
>> This is a newlib issue.  I redirected this to the appropriate mailing
>> list newlib AT sourceware DOT org.
>>
>>
>> On Jun 20 13:00, Paul Biggar wrote:
>>
>>> Hi,
>>>
>>> atof (and hence strtod) on hexadecimal numbers results in 0.0 (errno
>>> of 0). This may be related to an old issue where NaN isnt correctly
>>> parsed. I believe it isnt correct behaviour:
>>>
>>> http://www.opengroup.org/onlinepubs/000095399/functions/atof.html
>>>
>>>
>>>
>>> I've tested it for integers in the range 0x8000000 to 0xFFFFFFFF. It
>>> works properly on
>>>
>>> ubuntu dapper, gcc 4.1 on i386;
>>> debian stable, gcc 3.3 on amd64
>>> sunos ?, gcc 3.4 on sparc
>>>
>>> I'm using standard cygwin distribution, which uses gcc 3.4.4 (cygming 
>>> special)
>>>
>>> Sample code:
>>>
>>> #include "limits.h"
>>> #include <iostream.h>
>>> #include "errno.h"
>>>
>>> int main()
>>>
>>> {
>>>       cout << ULONG_MAX << endl;
>>>       cout << 0xFFFFFFFF << endl;
>>>
>>>       errno = 0;
>>>       cout << atof("0xFFFFFFFF") << endl;
>>>       cout << errno << endl;
>>>
>>>       errno = 0;
>>>       cout << strtod("0xFFFFFFFF", NULL) << endl;
>>>       cout << errno << endl;
>>>
>>> }
>>>
>>>
>>> Is this being fixed? I could find a mention of it before. Does anyone
>>> know a simple workaround?
>>>
>>> Thanks
>>> Paul
>>
>>
>>
>> Corinna
>>
> 



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