[all-commits] [llvm/llvm-project] 8cba99: [ARM][MVE] Tail-Predication: rematerialise iterati...

[sjoerdmeijer via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 8cba99e2aa937b8459e74e2d22d4e2c9d4bdc5d5
      https://github.com/llvm/llvm-project/commit/8cba99e2aa937b8459e74e2d22d4e2c9d4bdc5d5
  Author: Sjoerd Meijer <sjoerd.meijer at arm.com>
  Date:   2020-01-20 (Mon, 20 Jan 2020)

  Changed paths:
    M llvm/lib/Target/ARM/MVETailPredication.cpp
    M llvm/test/CodeGen/Thumb2/LowOverheadLoops/cond-vector-reduce-mve-codegen.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/vector-arith-codegen.ll
    M llvm/test/CodeGen/Thumb2/LowOverheadLoops/vector-reduce-mve-tail.ll

  Log Message:
  -----------
  [ARM][MVE] Tail-Predication: rematerialise iteration count in exit blocks

This patch uses helper function rewriteLoopExitValues that is refactored in
D72602 to rematerialise the iteration count in exit blocks, so that we can
clean-up loop update expressions inside the hardware-loops later in
ARMLowOverheadLoops, which is necessary to get actual performance gains for
tail-predicated loops.

Differential Revision: https://reviews.llvm.org/D72714