. Use integer literal constants instead of double literal constants.
* s_erff.c:
. Use integer literal constants instead of casting double literal
constants to float.
. Update the threshold values from those carried over from erf() to
values appropriate for float.
. New sets of polynomial coefficients for the rational approximations.
These coefficients have little, but positive, effect on the maximum
error in ULP in the four intervals, but do improve the overall
speed of execution.
. Remove redundant GET_FLOAT_WORD(ix,x) as hx already contained the
contents that is packed into ix.
. Update the mask that is used to zero-out lower-order bits in x in
the intervals [1.25, 2.857143] and [2.857143, 12]. In tests on
amd64, this change improves the maximum error in ULP from 6.27739
and 63.8095 to 3.16774 and 2.92095 on these intervals for erffc().
Reviewed by: bde
2a3910b931