ppc: Fix xscvdpspn for SNAN
The xscvdpspn instruction implements a non-arithmetic conversion.
In particular, NaNs are not silenced and rounding is not performed.
Rewrite to match the pseudocode for ConvertDPtoSP_NS() in the
Power 3.0B manual.
Signed-off-by: Paul A. Clarke <pc@us.ibm.com>
Message-Id: <
1566321964-1447-1-git-send-email-pc@us.ibm.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
[dwg: Replaced description with clearer version from rth]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>