Single precision floating point calcs?

[Grant Edwards]

On 2007-05-09, Terry Reedy <tjreedy at udel.edu> wrote:

>| I'm pretty sure the answer is "no", but before I give up on the
>| idea, I thought I'd ask...
>|
>| Is there any way to do single-precision floating point
>| calculations in Python?
>
> Make your own Python build from altered source.  And run it on
> an ancient processor/OS/C compiler combination that does not
> automatically convert C floats to double when doing any sort
> of calculation.

It wouldn't have to be that ancient.  The current version of
gcc supports 32-bit doubles on quite a few platforms -- though
it doesn't seem to for IA32 :/

Simply storing intermediate and final results as
single-precision floats would probably be sufficient.

> Standard CPython does not have C single-precision floats.

I know.

> The only point I can think of for doing this with single numbers, as 
> opposed to arrays of millions, is to show that there is no point.

I use Python to test algorithms before implementing them in C.
It's far, far easier to do experimentation/prototyping in
Python than in C.  I also like to have two sort-of independent
implementations to test against each other (it's a good way to
catch typos).

In the C implementations, the algorithms will be done
implemented in single precision, so doing my Python prototyping
in as close to single precision as possible would be "a good
thing".

> Or do you have something else in mind?

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