[8u] RFR + RFA: 8213419: "C2 may hang in MulLNode::Ideal()/MulINode::Ideal() with gcc 8.2.1" and follow up 8214206

[Aleksey Shipilev]

On 2/6/19 5:54 PM, Roland Westrelin wrote:
> 
> I'd like to backport 8213419 and follow up 8214206 to 8u as they can
> cause c2 to enter an infinite loop in some corner cases when compiled
> with a recent version of gcc.
> 
> Neither changes apply cleanly. In particular I dropped the
> STATIC_ASSERT() from the globalDefinitions.hpp function. My
> understanding is that keeping them requires a backport of 8181449: "Fix
> debug.hpp / globalDefinitions.hpp dependency inversion", a big and
> complicated change.
> 
> Webrevs:
> 
> http://cr.openjdk.java.net/~roland/8213419.8u/webrev.00/

Changes look good.

Where's the regression test? MultiplyByIntegerMinHang.java is in original change.

> http://cr.openjdk.java.net/~roland/8214206.8u/webrev.00/

Changes look good.

Let me build it on a few platforms (e.g. 32-bits) to check everything is fine.

Thanks,
-Aleksey