Request for reviews (XL): 7119644: Increase superword's vector size up to 256 bits

[Vladimir Kozlov]

I found few issues in superword code during testing on SB, the rest changes 
seems fine. I will send updated webrev after I resolve issues.

Vladimir

Vladimir Kozlov wrote:
> http://cr.openjdk.java.net/~kvn/7119644/webrev
> 
> 7119644: Increase superword's vector size up to 256 bits
> 
> Increase superword's vector size up to 256-bits for YMM AVX registers on 
> x86. Added generation of different vector sizes for different types of 
> arrays in the same loop. Allow to generate small (4 bytes) vectors for 
> loops which were unrolled small number of iterations.
> Add new C2 types for vectors and rework VectorNode implementation. Used 
> MachTypeNode as base node for vector mach nodes to keep vector type.
> Moved XMM registers definition and vector instructions into one file 
> x86.ad (have to rename eRegI to rRegI in x86_32.ad).
> 
> Tested with full CTW, NSK, C2 regression tests, JPRT and added new test.
> 
> Thanks,
> Vladimir