[AArch64] Improve lowering for scalable masked deinterleaving loads (#154338)

For IR like this:

%mask = ... @llvm.vector.interleave2(<vscale x 16 x i1> %a, <vscale x 16
x i1> %a)
  %vec = ... @llvm.masked.load(..., <vscale x 32 x i1> %mask, ...)
  %dvec = ... @llvm.vector.deinterleave2(<vscale x 32 x i8> %vec)

where we're deinterleaving a wide masked load of the supported type
and with an interleaved mask we can lower this directly to a ld2b
instruction. Similarly we can also support other variants of ld2
and ld4.

This PR adds a DAG combine to spot such patterns and lower to ld2X
or ld4X variants accordingly, whilst being careful to ensure the
masked load is only used by the deinterleave intrinsic.

0 files changed, 0 insertions, 0 deletions