RFR: 8240615: is_power_of_2() has Undefined Behaviour and is inconsistent

[Stefan Karlsson]

On 2020-03-09 11:54, Andrew Haley wrote:
> So, my plan is to push http://cr.openjdk.java.net/~aph/8240615-1/ and
> subsequently patch a few AArch64 cases plus the x86_64 immL_Pow2 and
> immL_NotPow2 cases that we already identified.
> 
> I do not intend to do bulk changes to any other clients of
> is_power_of_2() because it's often unclear exactly what behaviour is
> required, and I'd risk breaking something.
> 
> OK?

I would prefer if the x86_64 and aarch64 patches were pushed first, or 
folded into this patch. Otherwise, we knowingly introduce a regression 
by pushing the proposed patch above. However, I'll leave it up to the 
compiler devs/maintainers to decide if this is OK.

StefanK

>