[llvm] r228027 - Fixed signed/unsigned comparison warning.

[Chad Rosier]

> On Tue, Feb 3, 2015 at 1:10 PM, Chad Rosier <mcrosier at codeaurora.org>
> wrote:
>
>> Hi Simon,
>> MVT::getVectorNumElements() has an 'unsigned' return type.
>>
>> Would it make more sense to change NumElements to unsigned and fix the
>> induction variables for those loops that compare NumElements, rather
>> than
>> using a cast in the assert?
>>
>
> I strongly prefer not to.
>
> We are often doing subtraction and other things, and in fact using them
> with values which can be -1. Using unsigned anywhere in this code is just
> wrong.
>
> The nice thing about casting to an int is that UBSan can throw an error if
> it is out-of-range.
>

Good to know!  Thanks, Chandler.