Document results of sin/cos a bit more.
@@ -7,11 +7,15 @@ use "sum-impl"
use "util"
/*
- This implmentation of sin and cos uses the "Highly Accurate
- Tables" method of [GB91]. The idea is to tabulate [0, pi/4] at
- 256 slightly irregular intervals xi, with the lucky property
- that the infinite binary expansions of significands of sin(xi)
- and cos(xi) look like
+ This implementation of sin and cos uses the "Highly Accurate
+ Tables" method of [GB91]. It's not as fast as it could be (the
+ sorting and excessive summation really takes a toll), however
+ we seem to be consistently within +/-1 ulp of the correct result
+ in flt64 case. In flt32 case we are correctly rounded.
+
+ The idea is to tabulate [0, pi/4] at 256 slightly irregular
+ intervals xi, with the lucky property that the infinite binary
+ expansions of significands of sin(xi) and cos(xi) look like
/ 53 bits \ / many '0's \ / noise \
1.bbbbbb...bb00000000000...0???????????...
