[PATCH] D75601: [AArch64][SVE] Add intrinsics for non-temporal scatters/gathers

Thu Mar 5 06:01:53 PST 2020

andwar marked an inline comment as done.
andwar added a comment.

In D75601#1906202 <https://reviews.llvm.org/D75601#1906202>, @efriedma wrote:

> If I'm following correctly, you don't actually create any SSTNT1_INDEX nodes?  You're just using it as a placeholder in the call to performScatterStoreCombine?  I guess that's not a big deal.

Correct. Same for `LDNT1_INDEX`. I'm only using these nodes to uniquely identify scatters/gathers that:

- are non-temporal
- use the  "scalar + vector of indices" addressing mode.

It's not great, but I think it's the least intrusive way of identifying these cases.

================
Comment at: llvm/test/CodeGen/AArch64/sve2-intrinsics-nt-gather-loads-64bit-scaled-offset.ll:12
+; CHECK-LABEL: gldnt1h_index
+; CHECK:          mul z0.d, z0.d, #2
+; CHECK-NEXT:     ldnt1h  { z0.d }, p0/z, [z0.d, x0]
----------------
efriedma wrote:
> "mul"?  Can we make a shift instead?
Sadly there are no patterns for `lsl` yet, so I'd have to add a call to `@llvm.aarch64.sve.lsl` for this to wok. It's an option, but I'd prefer to leave a  TODO instead (e.g. `// TODO Replace MUL with SHL once patterns for lsl are added)`.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D75601/new/

https://reviews.llvm.org/D75601