RFR: 8214377: ZGC: Don't use memset to initialize array of ZForwardingTableEntry

[Erik Österlund]

Hi Per,

Looks good.

Thanks
/Erik

On 2018-11-29 13:49, Per Liden wrote:
> Use placement new instead of memset() to avoid compiler warning/error 
> when using GCC 8 with -Werror=class-memaccess (memset to initialize 
> non-trivial object).
> 
> To avoid any undefined behavior I also added a loop to destruct the 
> objects properly, but this loop will be compiled down to nothing.
> 
> I ran SPECjbb2015 to see if the execution time for "Prepare Relocation 
> Set" was noticeably affected by this change (assuming memset does a 
> batter job than then loop), but I can't see any real difference. I'll 
> run a few more iterations over night just to make sure.
> 
> Bug: https://bugs.openjdk.java.net/browse/JDK-8214377
> Webrev: http://cr.openjdk.java.net/~pliden/8214377/webrev.0
> 
> /Per