RFR(XS): 8193518: C2: Vector registers sometimes corrupted at safepoint

[Vladimir Kozlov]

Nice find. Looks good. Why you changed type to uint?

Thanks,
Vladimir

On 12/14/17 8:00 AM, Roland Westrelin wrote:
> 
> http://cr.openjdk.java.net/~roland/8193518/webrev.00/
> 
> If a method has several vectorized loops, the logic that keep tracks of
> Compile::_max_vector_size sets it to the max vector size of the last
> loop (and not to the max vector size of all
> loops). Compile::_max_vector_size is then used to mark nmethods that
> need vector registers to be saved on a safepoint. If the last loop uses
> small vectors but other loops in the method use large vectors, registers
> are not saved correctly at a safepoint in one of the other loops and can
> be corrupted.
> 
> The test case only fails with Serial GC AFAICT but I saw that failure
> with G1 running some other applications.
> 
> Roland.
>