[all-commits] [llvm/llvm-project] bd1a4c: [ValueTracking] Teach isKnownNonZero that a vscale...

[David Green via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: bd1a4c8565ac7a48a5dc1e18b8ea07b29b93d213
      https://github.com/llvm/llvm-project/commit/bd1a4c8565ac7a48a5dc1e18b8ea07b29b93d213
  Author: David Green <david.green at arm.com>
  Date:   2022-06-23 (Thu, 23 Jun 2022)

  Changed paths:
    M llvm/lib/Analysis/ValueTracking.cpp
    A llvm/test/Transforms/InstCombine/vscale_zero.ll

  Log Message:
  -----------
  [ValueTracking] Teach isKnownNonZero that a vscale is never 0.

A llvm.vscale will always be at least 1, never zero. Teaching that to
isKnownNonZero can help fold away some statically known compares.

Differential Revision: https://reviews.llvm.org/D128217