[all-commits] [llvm/llvm-project] 099e4b: [InstCombine] Remove invariant group intrinsincs w...

[aeubanks via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 099e4bcd5d069a744cf6df114f4e412755c4e59f
      https://github.com/llvm/llvm-project/commit/099e4bcd5d069a744cf6df114f4e412755c4e59f
  Author: Arthur Eubanks <aeubanks at google.com>
  Date:   2021-08-29 (Sun, 29 Aug 2021)

  Changed paths:
    M llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
    M llvm/test/Transforms/InstCombine/invariant.group.ll

  Log Message:
  -----------
  [InstCombine] Remove invariant group intrinsincs when comparing against null

We cannot leak any equivalency information by comparing against null
since null never has virtual metadata associated with it (when null is
not a valid dereferenceable pointer).

Instcombine seems to make sure that a null will be on the RHS, so we
don't have to check both operands.

This fixes a missed optimization in llvm-test-suite's MultiSource lambda
benchmark under -fstrict-vtable-pointers.

Reviewed By: Prazek

Differential Revision: https://reviews.llvm.org/D108734