[PATCH 1/2] Cost model: Add check for reverse shuffles to CostModel analysis

[Renato Golin]

LGTM.


On 9 February 2013 19:52, Arnold Schwaighofer <aschwaighofer at apple.com>wrote:

> They are related. This one is about modeling the cost of reverse shuffles
> correctly.
>
> I will update the cost of v8i16 and v16i8 when I commit this patch. It all
> depends which patch goes in first :).
>
> The code for checking is similar but not the same because they are at
> different stages of lowering.
>
> On Feb 9, 2013, at 1:37 PM, Renato Golin <renato.golin at linaro.org> wrote:
>
> I'm guessing this could be used in your other patch about detecting
> reverse stride, are they related or conflicting?
>
> --renato
>
>
> On 8 February 2013 18:40, Arnold Schwaighofer <aschwaighofer at apple.com>wrote:
>
>> Updated patch.
>>
>>
>>
>>
>> Thanks
>>
>> On Feb 8, 2013, at 11:44 AM, Nadav Rotem <nrotem at apple.com> wrote:
>>
>> > LGTM!  A few minor comments:
>> >
>> > There is an extra line break here.
>> >
>> > +
>> > +static bool isReverseVectorMask(SmallVector<int, 16> &Mask) {
>> > +  for (unsigned i = 0, MaskSize = Mask.size(); i < MaskSize; ++i)
>> > +    if (Mask[i] != (int)(MaskSize - 1 - i))
>> > +      return false;
>> > +  return true;
>> > +}
>> > +
>> >
>> > We should also check for -1's in the mask.
>> >
>> > +    if (NumVecElems == Mask.size() &&
>> > +        isReverseVectorMask(Mask))
>> >
>> >
>> > The expression above can fit in one line.
>> >
>> >
>> > Thanks,
>> > Nadav
>>
>>
>> _______________________________________________
>> llvm-commits mailing list
>> llvm-commits at cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
>>
>>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20130209/e5817157/attachment.html>