[all-commits] [llvm/llvm-project] 1e3c6f: [JumpThreading] Ignore free instructions

[Nikita Popov via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 1e3c6fc7cb9d2ee6a5328881f95d6643afeadbff
      https://github.com/llvm/llvm-project/commit/1e3c6fc7cb9d2ee6a5328881f95d6643afeadbff
  Author: Nikita Popov <nikita.ppv at gmail.com>
  Date:   2021-09-23 (Thu, 23 Sep 2021)

  Changed paths:
    M llvm/include/llvm/Transforms/Scalar/JumpThreading.h
    M llvm/lib/Transforms/Scalar/JumpThreading.cpp
    M llvm/test/Transforms/JumpThreading/free_instructions.ll
    M llvm/test/Transforms/PhaseOrdering/inlining-alignment-assumptions.ll

  Log Message:
  -----------
  [JumpThreading] Ignore free instructions

This is basically D108837 but for jump threading. Free instructions
should be ignored for the threading decision. JumpThreading already
skips some free instructions (like pointer bitcasts), but does not
skip various free intrinsics -- in fact, it currently gives them a
fairly large cost of 2.

Differential Revision: https://reviews.llvm.org/D110290