newlib?: pow function can produce incorrect results.

Dave Korn
Tue Apr 24 02:24:00 GMT 2007

On 24 April 2007 03:14, Lev Bishop wrote:

> On 4/23/07, Dave Korn  wrote:
>> On 24 April 2007 00:53, Cary R. wrote:
>>> I had some more time to look into this and when the
>>> simple C program I mentioned earlier uses variables
>>> like the other program, incorrect results are
>>> produced. I have attached this C/C++ program. I
>>> certainly don't understand what is going on. I would
>>> have expected pow to be pass-by value which should
>>> make the two calls identical from a system standpoint,
>>> but the results imply something different. Any
>>> suggestions would be greatly appreciated.
>>   The notorious PR323.
> Nah, in this case it's just that gcc's __builtin_pow() is more
> standards-compliant than newlib's pow().

  Yeh, after a second reading through the assembly I figure you're right.

  Maybe I should sleep every now and againzzzzzzzzzzzzzzzz......

Can't think of a witty .sigline today....

Unsubscribe info:
Problem reports:

More information about the Cygwin mailing list