[llvm-commits] [llvm] r49458 - /llvm/trunk/lib/Transforms/IPO/SimplifyLibCalls.cpp

[Bill Wendling]

On Apr 10, 2008, at 1:58 AM, Duncan Sands wrote:
>> +      // x    pow(x, 0.5)  sqrt(x)
>> +      // ---------------------------------------------
>> +      // -0.0    +0.0       -0.0
>> +      // -inf    +inf       NaN
>
> looks like pow is broken.  Is pow's behaviour documented
> anywhere?  On my machine the man page says:
>
>       The pow() function can return the following error:
>
>       EDOM   The  argument x is negative and y is not an integral  
> value.  This would result in a complex num‐
>              ber.
>
> Are you sure errno is not being set by pow in these cases?
>
This is what we have on Darwin:

...
	pow(x, y) returns a NaN and raises the "invalid" floating-point  
exception for finite x < 0 and finite non-integer y.
...

The man page says nothing about errno. It claims to follow this  
standard:

	The pow() function conforms to ISO/IEC 9899:1999(E).

-bw