[LLVMdev] proposal to add MVT::vAny type

[Dan Gohman]

Hi Bob,

An alternative would be to model the operations as regular shuffle,  
load, and store operators, combined to describe the actual  
instructions.  This would make them easier for target-independent code  
to understand.

Dan

On Aug 8, 2009, at 11:47 PM, Bob Wilson <bob.wilson at apple.com> wrote:

> The ARM Neon load, store and shuffle operations that I've been
> implementing recently with LLVM intrinsics do not care about the
> distinction between vectors with i32 and f32 elements -- only the size
> matters.  But, because we have only MVT::fAny and MVT::iAny types,
> I've been having to define separate intrinsics for the operations with
> floating-point vector elements.  It didn't bother me when there were
> only a few intrinsics like this, but now there are more, and I
> realized this weekend that I still need to add more for the load/store
> lane operations.
>
> I had been thinking about trying to bitcast my way out of this, but it
> struck me that it would make a lot more sense to have a new MVT::vAny
> type that TableGen would match to any vector type.  That would more
> accurately reflect the type constraints on these intrinsics.
>
> It seems like since these "*Any" types are confined to TableGen, it
> should be pretty easy to add another one.  I looked at the places
> using iAny and fAny and they seem pretty easy to extend to handle a
> new vAny type.  Does this seem like a good idea?  Any objections?
>
> I'd like to get the Neon intrinsics finalized before the 2.6 release,
> since it may be harder to change them later.
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