[all-commits] [llvm/llvm-project] 498f89: [LV] Collect dead induction truncates

[David Green via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 498f89d1887752a207568311a9e657025ed4eeea
      https://github.com/llvm/llvm-project/commit/498f89d1887752a207568311a9e657025ed4eeea
  Author: David Green <david.green at arm.com>
  Date:   2020-10-08 (Thu, 08 Oct 2020)

  Changed paths:
    M llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
    M llvm/test/Transforms/LoopVectorize/ARM/tail-folding-not-allowed.ll
    M llvm/test/Transforms/LoopVectorize/X86/pr36524.ll
    M llvm/test/Transforms/LoopVectorize/X86/tail_loop_folding.ll
    M llvm/test/Transforms/LoopVectorize/followup.ll
    M llvm/test/Transforms/LoopVectorize/if-pred-stores.ll

  Log Message:
  -----------
  [LV] Collect dead induction truncates

We currently collect the ICmp and Add from an induction variable,
marking them as dead so that vplan values are not created for them. This
extends that to include any single use trunk from the ICmp, which allows
the Add to more readily be removed too.

This can help with costing vplan nodes, as the ICmp and Add are more
reliably removed and are not double-counted.

Differential Revision: https://reviews.llvm.org/D88873