[LLVMdev] AVX Status?

[Ralf Karrenberg]

Hi David,

>> The last time the AVX backend was mentioned on this list seems to be
>> from November 2010, so I would like to ask about the current status. Is
>> anybody (e.g. at Cray?) still actively working on it?
>
> Yes, we are!  I am doing a lot of tuning work at the moment.  We have
> been rather swamped with work for new products and I am now just getting
> out from under that.  Expect to see more patches flowing in over the
> next several weeks.  There's a LOT left to send up.

> We have a full implementation.  I just have to get enough time to get it
> merged.  :-/

This sounds great!

For my case, I only require some basic support, so I am optimistic that 
your next few patches will provide everything I need.

> It's a problem with integer code.  There are no 256-bit integer bitwise
> instructions in AVX.  There are no 256-bit integer instructions period.
> What's missing is the legalize code to handle this.  I have it in our
> tree.
>
>> There seems to be some code for this because
>> xor<8 x i32>  %m, %m
>> works, probably because it can get rid of all bitcasts.
>
> And it can use xorps to implement the operation.

Yes, that makes sense. But why does the same not work with "and" and 
"or" (-> VANDPS/VORPS) ?
Anyway, I am looking forward to testing your patches.

Would it be possible to send around a notification when the stuff goes 
upstream?
Thanks a lot :).

Best,
Ralf