[Gambas-user] JIT bug 4

[Jussi Lahtinen]

OK, I didn't know that kind of optimization is done...
That explains also why "imMatr[10, 10] += x" was needed.

Jussi



On 10 July 2012 22:22, Emil Lenngren <emil.lenngren at ...626...> wrote:

> Because if you only write "x = 0.6 ^ x", that statement is completely
> optimized away, because x is never used later on.
> If you write "Print 0.6 ^ x", the result of the operation is printed, i.e.
> used.
>
> If you write "Print 0.6 ^ 2", that is optimized to "Print 0.36".
>
> /Emil
>
> 2012/7/10 Jussi Lahtinen <jussi.lahtinen at ...626...>
>
> > Yes it works now.
> > But "Print 0.6 ^ x" did crash, but "x = 0.6 ^ x" alone did not crash
> > ("imMatr[10, 10] += x" was needed)!
> > So I wonder was "0.6 ^ x" culprit alone?
> >
> > Jussi
> >
> >
> >
> >
> > On 10 July 2012 18:13, Emil Lenngren <emil.lenngren at ...626...> wrote:
> >
> > > It should work now in revision #4934!
> > >
> > > /Emil
> > >
> > > 2012/7/9 Emil Lenngren <emil.lenngren at ...626...>
> > >
> > > > From gdb I disassemble the jit function to this:
> > > > ...
> > > >    0x00007ffff7e3f05c:  movabs $0x0,%rax
> > > >    0x00007ffff7e3f066:  callq  *%rax
> > > > ...
> > > >
> > > > You can see that llvm replaced the llvm.powi.f64 to a null function
> :/
> > > >
> > > > 2012/7/9 Emil Lenngren <emil.lenngren at ...626...>
> > > >
> > > >> Public Sub Button1_Click()
> > > >>   test(19)
> > > >> End
> > > >>
> > > >>
> > > >> Fast Private Sub test(x As Integer)
> > > >>   Print 0.6 ^ x
> > > >> End
> > > >>
> > > >> Does this crash for you as well?
> > > >>
> > > >> I think there is a bug in llvm or something. It doesn't seem to like
> > > that
> > > >> I call llvm.powi.f64.
> > > >>
> > > >> I shall see what I can do about it ...
> > > >>
> > > >> /Emil
> > > >>
> > > >> 2012/7/9 Jussi Lahtinen <jussi.lahtinen at ...626...>
> > > >>
> > > >>> In fact the function can be further reduced to:
> > > >>> c = CInt((0.6 ^ iEta) / sngCached[iEta])
> > > >>>
> > > >>> Jussi
> > > >>>
> > > >>>
> > > >>>
> > > >>> On 9 July 2012 21:02, Jussi Lahtinen <jussi.lahtinen at ...626...>
> > wrote:
> > > >>>
> > > >>> > Finally, here it is isolated. See attachment.
> > > >>> > I don't know why I didn't get it in first try, and yet, I'm not
> > sure
> > > >>> what
> > > >>> > is going on...
> > > >>> >
> > > >>> > Gambas 3 rev 4921 @ Xubuntu 12.04 64bit
> > > >>> >
> > > >>> > Jussi
> > > >>> >
> > > >>>
> > > >>>
> > >
> >
> ------------------------------------------------------------------------------
> > > >>> Live Security Virtual Conference
> > > >>> Exclusive live event will cover all the ways today's security and
> > > >>> threat landscape has changed and how IT managers can respond.
> > > Discussions
> > > >>> will include endpoint security, mobile security and the latest in
> > > malware
> > > >>> threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
> > > >>> _______________________________________________
> > > >>> Gambas-user mailing list
> > > >>> Gambas-user at lists.sourceforge.net
> > > >>> https://lists.sourceforge.net/lists/listinfo/gambas-user
> > > >>>
> > > >>
> > > >>
> > > >
> > >
> > >
> >
> ------------------------------------------------------------------------------
> > > Live Security Virtual Conference
> > > Exclusive live event will cover all the ways today's security and
> > > threat landscape has changed and how IT managers can respond.
> Discussions
> > > will include endpoint security, mobile security and the latest in
> malware
> > > threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
> > > _______________________________________________
> > > Gambas-user mailing list
> > > Gambas-user at lists.sourceforge.net
> > > https://lists.sourceforge.net/lists/listinfo/gambas-user
> > >
> >
> >
> ------------------------------------------------------------------------------
> > Live Security Virtual Conference
> > Exclusive live event will cover all the ways today's security and
> > threat landscape has changed and how IT managers can respond. Discussions
> > will include endpoint security, mobile security and the latest in malware
> > threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
> > _______________________________________________
> > Gambas-user mailing list
> > Gambas-user at lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/gambas-user
> >
>
> ------------------------------------------------------------------------------
> Live Security Virtual Conference
> Exclusive live event will cover all the ways today's security and
> threat landscape has changed and how IT managers can respond. Discussions
> will include endpoint security, mobile security and the latest in malware
> threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
> _______________________________________________
> Gambas-user mailing list
> Gambas-user at lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/gambas-user
>