Displaying 2 results from an estimated 2 matches for "x86punpcklbw".
2011 Apr 09
0
[LLVMdev] Long-Term ISel Design
...fle masks through the compiler which is a marginal speedup.
To me, there are two missing pieces here:
1. The x86 backend is half way converted over to the new model.
2. We *really really* want a way to express shuffle masks in .td files, and tblgen should generate the Legalize code. The "def X86Punpcklbw" should include a (per cpu) cost for the shuffle as well as the mask that it matches, or a predicate to run if it the mask isn't constant.
>> I think that this is just because the current code is in a half
>> converted state. Bruno can say more, but the ultimate goal is to ma...
2011 Mar 27
2
[LLVMdev] Long-Term ISel Design
Chris Lattner <clattner at apple.com> writes:
>> We would still keep the existing pre-table-driven-isel passes so we'd
>> still have a chance to do some cleanup before the main table-driven
>> isel.
>>
>> Obviously a lot of details have to be worked out.
>
> I'm not seeing how this is useful for shuffles. Since tblgen doesn't
> generate