[RISCV] <vscale x 1 x *> masked.load crashes with Zve32

[topperc]

<vscale x 1 x *> types aren't legal with Zve32*. The type legalizer is unable to widen non-VP masked load. It currently asserts on a call getVectorNumElements which isn't valid for scalable vectors. Replacing that with getVectorElementCount crashes in legalizing concat_vectors due to the padding of the mask with 0 elements.

I don't think we can do the 0 element padding for scalable vectors. Probably the best thing to do is to widen using VP_LOAD and limit the VL instead of padding the mask.

CC: @preames @lukel97 @wangpc-pp

[llvmbot]

@llvm/issue-subscribers-backend-risc-v

Author: Craig Topper (topperc)

<vscale x 1 x *> types aren't legal with Zve32*. The type legalizer is unable to widen non-VP masked load. It currently asserts on a call getVectorNumElements which isn't valid for scalable vectors. Replacing that with getVectorElementCount crashes in legalizing concat_vectors due to the padding of the mask with 0 elements.

I don't think we can do the 0 element padding for scalable vectors. Probably the best thing to do is to widen using VP_LOAD and limit the VL instead of padding the mask.

CC: @preames @lukel97 @wangpc-pp

[alexey-bataev]

How it is related to SLP? SLP does not emit scalable vector types. Is there a reproducer?

[topperc]

It's not related to SLP since SLP doesn't use scalable vectors.