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Re: [Question] How to deliver loop-related pragma information from TREE to RTL?

Hi Richard,

    Thank you for the suggestion. I see that your patch is merged into trunk. 
    But I am still not sure that if we can pass "ivdep" to RTL. Can you shed light on this please ? 
    For me, I want to do something on RTL with the loop pragma information. 


> On Mon, Mar 24, 2014 at 1:46 PM, Yangfei (Felix) <>
> wrote:
> > Hello everyone,
> >
> >     I'm thinking of the right way of adding some loop related pragmas to
> GCC.
> >     An example:
> >
> >     #pragma loop unroll = 2
> >     for (i = 0; i < n; i ++)
> >       {
> >         Whatever...
> >       }
> >
> >     Here I want the unroll factor of the loop to be 2 when doing RTL loop
> unrolling.
> >     But I find that it's kind of difficult to achieve this in GCC.
> >     The reason is that the loop structures are initialized and finalized at run
> time. Also the RTL expand phase is kind of complex and it does not care about
> loops.
> >     So how to deliver the pragma information to RTL loop unrolling pass?
> What the the elegant way of doing this?
> >     Can anyone give some suggestions on this please?
> Look at how we implement #pragma ivdep (see replace_loop_annotate () and
> fortran/trans-stmt.c where it builds ANNOTATE_EXPR).
> Richard.
> >     Many thanks.
> >

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