Is super-accuracy matters?

[Albert Chan]

(10-13-2023 03:08 PM)dm319 Wrote:  

(10-11-2023 12:21 AM)Albert Chan Wrote:  lua> x = 1e308
lua> sin(x), dtoh(x)
0.4533964905016491             +0x1.1ccf385ebc8a0p+1023

BC isn't agreeing.

If we try hexfloat, which lua actually get, it matched.

bc s(x) internal use about scale*1.1 digits for pi/4
scale=308 should give us good FIX20 of sin(x = float(1e308))

bc Wrote:ibase = 16
x = 11CCF385EBC8A0
ibase = A
x = x * 2^(1023-52)
scale = 308
y = s(x)
scale = 20
y/1
.45339649050164911655