Is i686 the minimum required for HotSpot on x86?

[Dr Andrew John Hughes]

On 12:27 Thu 31 Mar     , Christian Thalinger wrote:
> On Mar 30, 2011, at 10:33 AM, Christian Thalinger wrote:
> > On Mar 30, 2011, at 12:44 AM, Dr Andrew John Hughes wrote:
> >> On 17:31 Tue 29 Mar     , Christian Thalinger wrote:
> >>> On Mar 29, 2011, at 4:35 PM, Christian Thalinger wrote:
> >>>> On Mar 29, 2011, at 4:26 PM, Dr Andrew John Hughes wrote:
> >>>>> We've just had a bug report for IcedTea which suggests that
> >>>>> HotSpot fails on any x86 platform below i686.
> >>>>> 
> >>>>> The report is:
> >>>>> 
> >>>>> http://icedtea.classpath.org/bugzilla/show_bug.cgi?id=682
> >>>>> 
> >>>>> and shows a failure caused by an attempt by the JIT to emit
> >>>>> an instruction which isn't present on i586.
> >>>>> 
> >>>>> Does HotSpot require i686 as a minimum? Or is there something
> >>>>> else at fault here?
> >>>> 
> >>>> There is a switch -XX:+Use486InstrsOnly but I have an open bug for that one:
> >>>> 
> >>>> 6808665: Use486InstrsOnly aborts 32-bit VM
> >>> 
> >>> Looking a little closer this could actually be my fault.  I added unguarded cmov instructions to C1 with:
> >>> 
> >>> 6919934: JSR 292 needs to support x86 C1
> >>> 
> >>> http://hg.openjdk.java.net/jdk7/hotspot-comp/hotspot/rev/3cf667df43ef
> >>> 
> >>> And that was delivered in HS18b01.  I will fix that.
> >>> 
> >>> -- Christian
> >> 
> >> Ah thanks for finding the issue!  I await the fix.
> > 
> > 7032388: guarantee(VM_Version::supports_cmov()) failed: illegal instruction on i586 after 6919934
> 
> I case you haven't seen it:
> 
> http://hg.openjdk.java.net/jdk7/hotspot-comp/hotspot/rev/09f96c3ff1ad
> 
> Can you apply that patch to IcedTea and ask the bug submitter to try again?
> 

First part is already done :-)

I'll try and get it approved for the 1.10.1 release on Monday, then it can
get out in the distros.

> -- Christian

-- 
Andrew :)

Free Java Software Engineer
Red Hat, Inc. (http://www.redhat.com)

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