[aarch64-port-dev ] RFR: JDK-8203041 : AArch64: fix overflow in immediate cmp/cmn instruction

[White, Derek]

Looks good to me too.

 - Derek

> -----Original Message-----
> From: aarch64-port-dev [mailto:aarch64-port-dev-
> bounces at openjdk.java.net] On Behalf Of Andrew Haley
> Sent: Tuesday, May 22, 2018 5:12 AM
> To: Joshua Zhu <Joshua.Zhu at arm.com>; Dmitrij Pochepko
> <dmitrij.pochepko at bell-sw.com>; aarch64-port-dev at openjdk.java.net
> Cc: nd <nd at arm.com>
> Subject: Re: [aarch64-port-dev ] RFR: JDK-8203041 : AArch64: fix overflow in
> immediate cmp/cmn instruction
> 
> On 05/22/2018 08:49 AM, Joshua Zhu wrote:
> > I submit http://cr.openjdk.java.net/~zyao/8203041/webrev.02/ for review.
> > I think there will be another change to cover all rscratch alias issue
> mentioned by Andrew. Therefore I do not touch it.
> 
> Thanks very much.  Please add this comment before the first subs.
> No need for another review.
> 
>   // tmp6 is not used.  MacroAssembler::subs is used here (rather than
>   // cmp) because subs allows an unlimited range of immediate operand.
> 
> I had a look at using some C++ features to detect automagically when cmp is
> being used with a variable as its immediate operand, but it's very difficult to
> do.
> 
> --
> Andrew Haley
> Java Platform Lead Engineer
> Red Hat UK Ltd. <https://www.redhat.com>
> EAC8 43EB D3EF DB98 CC77 2FAD A5CD 6035 332F A671