[all-commits] [llvm/llvm-project] b0e600: [InstCombine] Add additional tests for known non z...

[Nikita Popov via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: b0e6007c8254811a5828c1a253a615e45359c653
      https://github.com/llvm/llvm-project/commit/b0e6007c8254811a5828c1a253a615e45359c653
  Author: Nikita Popov <nikita.ppv at gmail.com>
  Date:   2020-12-25 (Fri, 25 Dec 2020)

  Changed paths:
    M llvm/test/Transforms/InstCombine/known-non-zero.ll

  Log Message:
  -----------
  [InstCombine] Add additional tests for known non zero (NFC)

Check conditions that imply non-zero, even if they are not literally
"x != 0".

Using ctlz for testing, as explicit comparison might get folded by
other reasoning.


  Commit: 35676a4f9a536a2aab768af63ddbb15bc722d7f9
      https://github.com/llvm/llvm-project/commit/35676a4f9a536a2aab768af63ddbb15bc722d7f9
  Author: Nikita Popov <nikita.ppv at gmail.com>
  Date:   2020-12-25 (Fri, 25 Dec 2020)

  Changed paths:
    M llvm/lib/Analysis/ValueTracking.cpp
    M llvm/test/Transforms/Attributor/nonnull.ll
    M llvm/test/Transforms/InstCombine/known-non-zero.ll

  Log Message:
  -----------
  [InstCombine] Generalize icmp handling in isKnownNonZero()

The dominating condition handling in isKnownNonZero() currently
only takes into account conditions of the form "x != 0" or "x == 0".
However, there are plenty of other conditions that imply non-zero,
a common one being "x s> 0".

Peculiarly, the handling for assumes was already dealing with more
general non-zero-ness conditions, so this just reuses the same
logic for the dominating condition case.


Compare: https://github.com/llvm/llvm-project/compare/a3614a31c46a...35676a4f9a53