OK. It have been changed to sign-extended in the "processing of
Narrower Values" section of the new spec(version 1.0.0.rc) . I'll
fix this and update other nan-boxing processing in current
implementation.
Sorry. In the old spec(version 0.41), nanboxing is not totally
disabled, but "NaN-boxing is limited to XLEN
bits,
not FLEN
bits". Taking misa.mxl into acount, if
misa.mxl is RV32, and maximum is RV64, this should be
sign-extended. Is there any other new update for nanboxing to
the spec?
在 2021/12/26 上午6:00, Richard
Henderson 写道:
On
12/24/21 7:13 PM, liweiwei wrote:
In RV64 case, this should be nan-boxing
value( upper bits are all ones). However, zfinx will not
check nan-boxing of source, the upper 32 bits have no effect
on the final result. So I think both zero-extended or
sign-extended are OK.
There is no nanboxing in zfinx at all -- values are
sign-extended.
r~