[SVE] Add new VectorType subclasses

[ctetreau]

Summary

Introduce new types for fixed width and scalable vectors.

Does not remove getNumElements yet so as to not break code during transition
period.

[ctetreau]

Move getMinNumElements to ScalableVectorType. There's no reason for it to be in base VectorType

[efriedma]

Looks right, generally.

llvm/include/llvm-c/Core.h

178

The C API is officially not ABI-stable anymore across versions, No reason to have a gap like this.

llvm/lib/ExecutionEngine/ExecutionEngine.cpp

1011

?

llvm/lib/Target/AMDGPU/AMDGPUPrintfRuntimeBinding.cpp

480

Please fix this to use isa<> while you're here.

[ctetreau]

llvm/lib/ExecutionEngine/ExecutionEngine.cpp

1011

clang-format-diff must have done this.

[sdesmalen]

Thanks for this patch @ctetreau! Overall looks great to me, just two little nits.

llvm/include/llvm/IR/DerivedTypes.h

436

Do you need the method on line 432 if you have this one (that takes a const VectorType *Other) ?

llvm/lib/ExecutionEngine/ExecutionEngine.cpp

1109

This code doesn't really work for scalable vectors. Assuming you don't want to change that in this patch, Is it worth putting a FIXME here?

[ctetreau]

llvm/include/llvm/IR/DerivedTypes.h

436

It shouldn't be needed, I'll remove it.

llvm/lib/ExecutionEngine/ExecutionEngine.cpp

1109

This will have to be changed when getNumElements() moves into FixedVectorType. I'll get it then.

Likely, the plan will be to just have the scalable vector branch assert. My overall strategy is to just assume all calls to getNumElements are correct, cast to FixedVectorType instead of VectorType, and just fix enough to make the tests pass.

There's a lot of code that calls getNumElements, and the overall goal is to force everybody to clean their own houses.

[ctetreau]

address code review issues

[ctetreau]

rebase

[ctetreau]

llvm/include/llvm/IR/DerivedTypes.h

432

In this example, "getElementType" should be "getElementCount", but I assume you get the idea...

[sdesmalen]

llvm/lib/Target/AMDGPU/AMDGPUPrintfRuntimeBinding.cpp

411

should this be !isa<FixedVectorType>(ArgType) (i.e. negated)?

[ctetreau]

address code review issues

[sdesmalen]

Thanks for all the changes, this patch LGTM!

[ctetreau]

Fixup canLosslesslyBitCastTo to use FixedVectorType again

[ctetreau]

rebase

[ctetreau]

remove unused variable

[ctetreau]

Catch stragglers in C api

[ctetreau]

split C api stuff into separate commit. Do bare minimum here