[aarch64-port-dev ] Guarantee failures since 8144028: Use AArch64 bit-test instructions in C2

[Andrew Haley]

On 12/08/2015 06:22 PM, Edward Nevill wrote:

> The problem is that test and branch instructions only have a 14 bit
> offset giving a range of +/- 32Kb which is not sufficient for large
> C2 methods.
> 
> What can we do about this? It seems a shame to backout this
> optimization but I cannot see any easy way around it.

C2 does support branch length relaxation: we already know it makes a
couple of passes generating code.  We've never used it, and I don't
quite know how to use it, but I think some other ports do.

Since this is my mess, I guess I should clean it up, and I'm
interested to try this.  But feel free if you like...

Andrew.