[PATCH] [AArch64] Support ISD::SIGN_EXTEND_INREG

[Jiangning Liu]

committed as r199296.


2014/1/13 Jiangning Liu <liujiangning1 at gmail.com>

> Hi
> Ana,
>
> I have two reasons for handling this situation in "combine"
> stage.
>
> 1) If we customize lowering sext_inreg, we would probably missing the case
> of explicitly using shl/ashr in LLVM IR. I added three more cases with
> suffix "_2" to cover this kind of test. If we want to cover all in
> legalization, we would have to write more codes, I think.
> 2) LLVM documentation says "Subsequent runs of the pass clean up the messy
> code generated by the Legalize passes, which allows Legalize to be very
> simple (it can focus on making code legal instead of focusing on generating
> good and legal code)."
>
> Kevin already upstreamed the improvement of generating permutation
> instructions, so now I'm uploading new patches by
> 1) Checking uzip1 in the test
> 2) Adding three more cases for explicity shl/ashr pair.
>
> Thanks,
> -Jiangning
>
>


-- 
Thanks,
-Jiangning
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