[all-commits] [llvm/llvm-project] 4530f0: [ARM] Improve reduction fadd/fmul costs

[David Green via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 4530f029166408f545ca87c86fd4079f317508c7
      https://github.com/llvm/llvm-project/commit/4530f029166408f545ca87c86fd4079f317508c7
  Author: David Green <david.green at arm.com>
  Date:   2023-09-04 (Mon, 04 Sep 2023)

  Changed paths:
    M llvm/lib/Target/ARM/ARMTargetTransformInfo.cpp
    M llvm/test/Analysis/CostModel/ARM/reduce-fp.ll

  Log Message:
  -----------
  [ARM] Improve reduction fadd/fmul costs

This adds some basic fadd/fmul reduction costs for MVE/NEON. It reduces by
halving the vector size until it it gets scalarized, with some additional costs
for fp16 which may require extracting the top lanes.

Differential Revision: https://reviews.llvm.org/D159367