RFR(S): 8213538: VM crashes when MaxVectorSize is set to 0, 1 or 2

[Vladimir Kozlov]

Hi Nils,

Fix and refactoring looks good.

The only complain I have is names of locals. Can you use full names: max_vector_size and min_vector_size?

Please, add testing results link to bug report.

Thanks,
Vladimir

On 11/12/18 3:14 AM, Nils Eliasson wrote:
> Hi,
> 
> This patch add the requirement that MaxVectorSize must be at least 4 on x64.
> 
> The background is that we crash in startup when testing when setting it to 0, 1 or 2. When MaxVectorSize is less than 4, 
> the XMM reg types won't be initialized, and then we crash in intrinsics that unconditionally use XMM regs. Since SSE2 is 
> the required minimum on x64, the assumption that you can use XMM regs is always valid. This adds the requirement that 
> MaxVectorSize is at least 4.
> 
> I had to do a little refactoring to make the code more readable, but the essence is the same.
> 
> Bug: https://bugs.openjdk.java.net/browse/JDK-8213538
> 
> Webrev: http://cr.openjdk.java.net/~neliasso/8213538/webrev/
> 
> Testing is running.
> 
> Please review,
> 
> // Nils
>