[LLVMdev] ifconversion before register allocation

[mahdi hamzeh]

Andy,

I have already enabled EarlyIfConversion but as you said, it does not
predicate instruction (only works for exception safe instructions).

Thanks
Mahdi


On Wed, Feb 12, 2014 at 5:29 PM, Andrew Trick <atrick at apple.com> wrote:

>
> On Feb 12, 2014, at 3:38 PM, mahdi hamzeh <mahdy.hamzeh at gmail.com> wrote:
>
> > Hi all,
> >
> > I am using llvm backend to generate binary for a specific accelerator. I
> would like to convert instructions into predicated form when instructions
> are still in SSA form. It looks like that ifconversion execution flow is
> different when instructions are in SSA form. However, I am encountering
> many problems (specially with registers) when I use it before register
> allocation. I was wondering if anybody could confirm that if-conversion can
> be used before register allocation? Any suggestion is really appreciated.
>
> EarlyIfConverter is the pass designed to run before RA. It is not enabled
> by default. It is quite different from the post-ra if-converter. It works
> on SSA and does not actually predicate instructions. It generates CMOVs.
> --Andy
>
> >
> > Thanks
> > _______________________________________________
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> > LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>
>
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