why not consfold sin(const)

[Dale Johannesen]

On Sep 19, 2004, at 5:31 PM, Robert Dewar wrote:

>> Yes; but someone (I forget who) early in this thread said it was 
>> "impossible" since you couldn't simulate target-specific elementary 
>> functions (presumably they were assuming that the target would have 
>> ill-defined or buggy routines).
>
> Ah, now I see the discussion. This thread is actually specifically
> about the possibility of doing this in -ffast-math mode. My
> "impossible" comment was a note about doing it without this
> mode being turned on, and yes it is impossible to simulate
> target routines and precompute at compile-time the exact
> values you will get at run-time (because the algorithms are
> not documented -- which is not quite the same as ill-defined :-)

Well, they *could* be reverse engineered, as there are a finite
number of possible inputs.  You'd have to want this an awful lot
to attempt it, though.