[all-commits] [llvm/llvm-project] c352e7: [ARM][MVE] Tail-predication: remove the BTC + 1 ov...

[sjoerdmeijer via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: c352e7fbda2f48c285eca61d2509780f648443ee
      https://github.com/llvm/llvm-project/commit/c352e7fbda2f48c285eca61d2509780f648443ee
  Author: Sjoerd Meijer <sjoerd.meijer at arm.com>
  Date:   2020-08-25 (Tue, 25 Aug 2020)

  Changed paths:
    M llvm/lib/Target/ARM/MVETailPredication.cpp
    M llvm/test/CodeGen/Thumb2/LowOverheadLoops/basic-tail-pred.ll
    M llvm/test/CodeGen/Thumb2/LowOverheadLoops/clear-maskedinsts.ll
    M llvm/test/CodeGen/Thumb2/LowOverheadLoops/cond-vector-reduce-mve-codegen.ll
    M llvm/test/CodeGen/Thumb2/LowOverheadLoops/extending-loads.ll
    M llvm/test/CodeGen/Thumb2/LowOverheadLoops/fast-fp-loops.ll
    M llvm/test/CodeGen/Thumb2/LowOverheadLoops/mve-tail-data-types.ll
    M llvm/test/CodeGen/Thumb2/LowOverheadLoops/nested.ll
    M llvm/test/CodeGen/Thumb2/LowOverheadLoops/reductions.ll
    M llvm/test/CodeGen/Thumb2/LowOverheadLoops/tail-pred-const.ll
    M llvm/test/CodeGen/Thumb2/LowOverheadLoops/tail-pred-intrinsic-add-sat.ll
    M llvm/test/CodeGen/Thumb2/LowOverheadLoops/tail-pred-intrinsic-fabs.ll
    M llvm/test/CodeGen/Thumb2/LowOverheadLoops/tail-pred-intrinsic-round.ll
    M llvm/test/CodeGen/Thumb2/LowOverheadLoops/tail-pred-intrinsic-sub-sat.ll
    M llvm/test/CodeGen/Thumb2/LowOverheadLoops/tail-pred-widen.ll
    M llvm/test/CodeGen/Thumb2/LowOverheadLoops/tail-reduce.ll
    M llvm/test/CodeGen/Thumb2/LowOverheadLoops/varying-outer-2d-reduction.ll
    M llvm/test/CodeGen/Thumb2/LowOverheadLoops/vector-arith-codegen.ll
    M llvm/test/CodeGen/Thumb2/LowOverheadLoops/vector-reduce-mve-tail.ll
    M llvm/test/CodeGen/Thumb2/mve-fma-loops.ll
    M llvm/test/CodeGen/Thumb2/mve-gather-scatter-tailpred.ll
    M llvm/test/CodeGen/Thumb2/mve-vecreduce-loops.ll

  Log Message:
  -----------
  [ARM][MVE] Tail-predication: remove the BTC + 1 overflow checks

This adapts tail-predication to the new semantics of get.active.lane.mask as
defined in D86147. This means that:
- we can remove the BTC + 1 overflow checks because now the loop tripcount is
  passed in to the intrinsic,
- we can immediately use that value to setup a counter for the number of
  elements processed by the loop and don't need to materialize BTC + 1.

Differential Revision: https://reviews.llvm.org/D86303