C2: fix zeroing elimination with heap allocated value types

[Tobias Hartmann]

Hi Roland,

On 03.01.2017 11:29, Roland Westrelin wrote:
> Tobias noticed zeroing elimination doesn't trigger when value types are
> heap allocated.
> 
> http://cr.openjdk.java.net/~roland/valhalla/zeroingelim/webrev.00/
> 
> With this change initialization stores are captured by the allocation
> and some of them show up as raw memory stores: that's why test9 had to
> be tweaked.

This looks good to me! Do we still need the call to set_complete_with_arraycopy() in ValueTypeNode::store_to_memory() that I tried to add in my value type array prototype [1]?

Thanks,
Tobias

[1] http://cr.openjdk.java.net/~thartmann/valhalla/vt_prototype/webrev.05/src/share/vm/opto/valuetypenode.cpp.sdiff.html

> 
> Roland.
>