[PATCH] D76359: [ARM,MVE] Add intrinsics for the VQDMLAD family.

[Simon Tatham via Phabricator via cfe-commits]

simon_tatham created this revision.
simon_tatham added reviewers: dmgreen, MarkMurrayARM, miyuki, ostannard.
Herald added subscribers: cfe-commits, hiraditya, kristof.beyls.
Herald added a project: clang.

This is another set of instructions too complicated to be sensibly
expressed in IR by anything short of a target-specific intrinsic.
Given input vectors a,b, the instruction generates intermediate values
2*(a[0]*b[0]+a[1]+b[1]), 2*(a[2]*b[2]+a[3]+b[3]), etc; takes the high
half of each double-width values, and overwrites half the lanes in the
output vector c, which you therefore have to provide the input value
of. Optionally you can swap the elements of b so that the are things
like a[0]*b[1]+a[1]*b[0]; optionally you can round to nearest when
taking the high half; and optionally you can take the difference
rather than sum of the two products. Finally, saturation is applied
when converting back to a single-width vector lane.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D76359

Files:
  clang/include/clang/Basic/arm_mve.td
  clang/test/CodeGen/arm-mve-intrinsics/vqdmlad.c
  llvm/include/llvm/IR/IntrinsicsARM.td
  llvm/lib/Target/ARM/ARMInstrMVE.td
  llvm/test/CodeGen/Thumb2/mve-intrinsics/vqdmlad.ll

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