[aarch64-port-dev ] RFR: 8129426: aarch64: add support for PopCount in C2

[Andrew Haley]

On 06/22/2015 04:29 PM, Andrew Dinn wrote:
> So, it seems Ed is right to use iRegI and rely on an l2i conversion to
> zero the top word if the incoming value is long.

I don't think that's safe.  I certainly don't think it's a good
tradeoff.  I think it'd be the only place in our entire code base
where we assume that the high bits of a jint are zero.  If it really
wants zeros in the top bits we'd better put them there.

Andrew.