llvm dev - Jul 2010 - [LLVMdev] APFloat::convertToDouble asserts

>>
>> I wonder why APFloat::convertToDouble asserts if it is not an
>> APFloat::IEEEdouble while the name "convertToDouble" suggests
that it
>> converts when it is not a double.
>
> The conversion is to (host) double, as the name implies.  Among 
> APFloat types, that is only implemented for APFloat::IEEEdouble.
>
yes, it's to host double ("convert this APFloat to double"),
therefore I
hoped that it works for any APFloat type (otherwise I would suggest a 
name such as getIfIEEEdouble() ).
Is there a reason against it or would it be accepted if it would work 
for any type?

On Jul 9, 2010, at 12:59 PMPDT, Jochen Wilhelmy wrote:
>>> I wonder why APFloat::convertToDouble asserts if it is not an
>>> APFloat::IEEEdouble while the name "convertToDouble"
suggests that
>>> it
>>> converts when it is not a double.
>>
>> The conversion is to (host) double, as the name implies.  Among  
>> APFloat types, that is only implemented for APFloat::IEEEdouble.
>>
>
> yes, it's to host double ("convert this APFloat to double"),
> therefore I hoped that it works for any APFloat type (otherwise I  
> would suggest a name such as getIfIEEEdouble() ).
> Is there a reason against it or would it be accepted if it would  
> work for any type?
I'd rather not.  The functionality you want is there, feed another  
APFloat type through APFloat::convert first.

Using host FP is not something that should be encouraged; the main  
point of APFloat is so people don't have to do that.  Why do you want  
to, btw?

> I'd rather not.  The functionality you want is there, feed another 
> APFloat type through APFloat::convert first.
>
> Using host FP is not something that should be encouraged; the main 
> point of APFloat is so people don't have to do that.  Why do you want 
> to, btw?
>
Yes, i got it working using APFloat::convert. I need host float to 
output to my backend which is similar
to the c-backend, but generates if/else instead of goto. I do not use 
APFloat::toString since it can
generate "1" for 1.0 which is not useful for me since I append
"f" for
float and "1f" is not a valid float.

-Jochen