[llvm-dev] rol/ror IR support question

[Aliaksei Zasenka via llvm-dev]

Hi James,

Thanks a lot for you answer!

Best regards,
Aleksey

On Thu, Nov 19, 2015 at 1:58 PM, James Molloy <james at jamesmolloy.co.uk>
wrote:

> Hi Aleksey,
>
> Rotations are not first-level constructs in the IR, but they can be
> expressed as a combination of shifts, ands and ors.
>
> The general principle in LLVM is to have a simple basic set of
> instructions that can be combined to produce higher level functions; in the
> case of rotate, there are several places in LLVM that detect rotation
> idioms and optimize them, and they will be selected correctly in the
> backend to optimized instructions if they are available in the target
> architecture.
>
> Cheers,
>
> James
>
> On Thu, 19 Nov 2015 at 09:13 Aliaksei Zasenka via llvm-dev <
> llvm-dev at lists.llvm.org> wrote:
>
>> Hi all,
>>
>> Is it planned to add support of rotations to IR?
>>
>>
>> Thanks,
>> Aleksey Zasenko
>> _______________________________________________
>> LLVM Developers mailing list
>> llvm-dev at lists.llvm.org
>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>>
>
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