Re: access to ld128 system

From: Steve Kargl <sgk_at_troutmask.apl.washington.edu>
Date: Mon, 01 Nov 2021 00:47:49 UTC 
On Thu, Oct 28, 2021 at 03:28:51PM -0700, Steve Kargl wrote:
> kib@ recently committed my implementations of cospi[fl],
> sinpi[fl], and tanpi[fl].  These functions have been
> extensively tested for float, double, and long double
> where long double is the Intel 80-bit long double (e.g.,
> msun/ld80/s_sinpil.c).  The 128-bit versions of these
> routines have not been tested (e.g., msun/ld128/s_sinpil.c)
> 
> kib pointed me to a system in the FreeBSD, which I have
> access to.  Unfortunately, that system has double ==
> long double, and can only test the support for the
> weak references.
> 
> Is there a system with 128-bit long double that I can
> have access for some testing?
>  

FYI.  An individual has provided access to an aarch64
system.  A patch has been submitted to fix the ld128
sinpi, cospi, and tanpi.  For the record, I did limited
testing to not overwhelm the system.

The observed max ULP for sinpi and cospi were less than
1.1 ULP, which is slight worse that the desired less than 
1 ULP target.  This has been traced to the kernel for 
computing cosl() in the interval [0,pi/4].  I suspect
the minmax polynomial coefficients need refinement.

-- 
Steve