[cfe-dev] [llvm-dev] generate vectorized code

[Rail Shafigulin via cfe-dev]

On Fri, Mar 18, 2016 at 1:53 PM, Mehdi Amini <mehdi.amini at apple.com> wrote:

>
> On Mar 18, 2016, at 1:47 PM, Rail Shafigulin <rail at esenciatech.com> wrote:
>
> Yes this IR does not build or shuffle any vector. Try to write a function
>> that takes 8 ints and a pointer to a <4xi32>, builds two vectors with the 8
>> ints,
>>
>
> This might sound like a dumb question, but how does one build a vector of
> ints out of regular ints in IR?
>
>
> See: http://llvm.org/docs/LangRef.html#vector-operations
>
> In short, the IR has "insertelement", which maps to "INSERT_VECTOR_ELT" in
> SDAG and "extractelement", which maps to "EXTRACT_VECTOR_ELT" in SDAG.
>
> I usually find good example by grepping in the lit tests. Another way is
> to write the function in clang, and run it with -O3 -emit-llvm -S to get a
> good starting point.
>
I tried using clang test.c -O3 -emit-llvm -S, but the only I didn't see any
of the insertvectorelt or extractvectorelt. I'm wondering how does one
trigger vector operations?

Below is the test.c file. It seemed to me like a good candidate for
vectorization, however nothing happened. I would really appreciate  if you
could point me in the right
direction with respect to vector generation.

Any help is appreciated.


>
> --
> Mehdi
>



-- 
Rail Shafigulin
Software Engineer
Esencia Technologies
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