[cfe-dev] __builtin_shufflevector question

[Craig Topper]

And another question, should -1 be a valid index to specify undef?


On Thu, Jul 18, 2013 at 9:58 PM, Craig Topper <craig.topper at gmail.com>wrote:

> What are the supported forms of __builtin_shufflevector supposed to be?
>
> Comments in SemaChecking.cpp indicates these
>   // 1) unary, vector mask: (lhs, mask)
>   // 2) binary, vector mask: (lhs, rhs, mask)
>   // 3) binary, scalar mask: (lhs, rhs, index, ..., index)
>
> But the actual code in SemaChecking.cpp only implements 1 and 3. I tried
> to use 2 and it fails with "index for __builtin_shufflevector must be a
> constant integer" on the 3rd argument.
>
>
> Additionally, official documentation indicates only form 3 is supported.
> http://clang.llvm.org/docs/LanguageExtensions.html
>
> --
> ~Craig
>



-- 
~Craig
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/cfe-dev/attachments/20130718/1dc6cd6e/attachment.html>