[cfarm-users] cfarm26 FP inaccuracies

[Jacob Bachmeyer]

On 8/30/26 05:37, Bruno Haible wrote:
> [...]
>
> Btw, on x86_64 you have this problem as well, if you use the gcc option
> "-mfpmath=387". Fortunately this option is not the default, which is why
> this problem with the 387 is not seen in practice on x86_64 systems.

I would not necessarily call it a problem as long as you know it is 
there---presumably there are applications where the 80-bit format is useful.

The other catch is that I am fairly sure the SSE unit is faster and 
capable of concurrent operations, while there is probably only a single 
x87 pipeline.  Since the SSE unit is both faster and "good enough" for 
64-bit double (i.e. most uses)---and always available on x86_64---it is 
generally preferred.


-- Jacob