[llvm-commits] [llvm][commits] r162603

[Silviu Baranga]

Hi Jakob,

Do you have a testcase? I know it's been a while since the
commit but it would help anyone who might try to fix this.

Thanks,
Silviu

> -----Original Message-----
> From: Jakob Stoklund Olesen [mailto:stoklund at 2pi.dk]
> Sent: 12 November 2012 17:33
> To: Silviu Baranga
> Cc: llvm-commits at cs.uiuc.edu
> Subject: Re: [llvm][commits] r162603
> 
> 
> On Nov 12, 2012, at 2:31 AM, "Silviu Baranga" <silbar01 at arm.com> wrote:
> 
> > Hi Jakob,
> >
> > Why is the LEApcrel marked as having side effects?
> > This is preventing it from being hoisted by the MachineLICM pass.
> 
> Hi Silviu,
> 
> As the commit message says, hoisting the lea breaks the pass that forms
> tbb instructions for jump tables.
> 
> Patches welcome, it's the constant island pass IIRC.
> 
> /jakob
> 
> >> Explicitly mark LEApcrel pseudos with hasSideEffects.
> >>
> >> It's not clear that they should be marked as such, but tbb formation
> > fails if t2LEApcrelJT is hoisted of of a loop.
> >>
> >> This doesn't change the flags on these instructions,
> >> UnmodeledSideEffects was already inferred from the missing pattern.
> >
> >
> >
> 
>