[LLVMdev] Adding multiples-of-8 integer types to MVT

Chris Lattner
Thu, 03 Dec 2009 00:09:23 -0000

On Dec 2, 2009, at 12:32 PM, Ken Dyck wrote:

> Would there be any interest/opposition to extending the set of simple
> integer types in MVT to include the missing multiples of 8 (up to 64
> bits)? That is: i24, i40, i48, i56?
>
> Adding the types to MVT (and ValueTypes.td) would allow LLVM to be
> targeted to architectures that have registers and operations of these
> sizes (for example, a 24-bit DSP that I'd like to develop a back end
> for
> has 24-, 48- and 56-bit native integer types). Back ends are currently
> limited to using power-of-2 types in their TableGen descriptions.

I'm fine with doing this, but please only add the MVT types you
actually need.  Don't bother adding i40 unless you support i40.  If
someone needs it in the future, we can add it at that point.

Thanks Ken,

-Chris