Re: [PATCH] Implement range-op entry for sin/cos.

[Siddhesh Poyarekar <siddhesh@gotplt.org>]

On 2023-04-20 13:57, Siddhesh Poyarekar wrote:
> For bounds that aren't representable, one could get error bounds from 
> libm-test-ulps data in glibc, although I reckon those won't be 
> exhaustive.  From a quick peek at the sin/cos data, the arc target seems 
> to be among the worst performers at about 7ulps, although if you include 
> the complex routines we get close to 13 ulps.  The very worst 
> imprecision among all math routines (that's gamma) is at 16 ulps for 
> power in glibc tests, so maybe allowing about 25-30 ulps error in bounds 
> might work across the board.

I was thinking about this a bit more and it seems like limiting ranges 
to targets that can generate sane results (i.e. error bounds within, 
say, 5-6 ulps) and for the rest, avoid emitting the ranges altogether. 
Emitting a bad range for all architectures seems like a net worse 
solution again.

Thanks,
Sid