Request for reviews (S): 7192965: assert(is_aligned_sets(size)) failed: mask is not aligned, adjacent sets

[John Rose]

On Aug 22, 2012, at 3:20 PM, Vladimir Kozlov wrote:

> http://cr.openjdk.java.net/~kvn/7192965/webrev
> 
> 7192965: assert(is_aligned_sets(size)) failed: mask is not aligned, adjacent sets
> 
> Bias coloring in RA does not work for vectors with size > 64 bits, it only works for pairs (64 bits).
> Change pair check to vector check. I did small refactoring and added comment.
> 
> Tested with failing test.
> 
> Thanks,
> Vladimir

It is a good cleanup as well as a bug fix.

Suggestion:  Make the new function static, to encourage inlining and keep the global name space tidier.

I suppose this logic applies to stack slot coloring.  If so, will there be similar problems with overlapping allocations of spill slots?  For example, stack[20..21] might be allocated for a double spill, while stack[20..23] is allocated for a quad spill.  I hope we detect interference between those allocations by setting all four bits 20..23 when building interference bit-masks.

— John