[all-commits] [llvm/llvm-project] 730df5: [Support] Add KnownBits::computeForSubBorrow (#67788)

[Christian Kissig via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 730df5a437914e66b292dd9cb7d5f3f47b73bab0
      https://github.com/llvm/llvm-project/commit/730df5a437914e66b292dd9cb7d5f3f47b73bab0
  Author: Christian Kissig <dev at kissig.fastmail.fm>
  Date:   2023-10-18 (Wed, 18 Oct 2023)

  Changed paths:
    M llvm/include/llvm/Support/KnownBits.h
    M llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
    M llvm/lib/Support/KnownBits.cpp
    M llvm/unittests/CodeGen/AArch64SelectionDAGTest.cpp
    M llvm/unittests/Support/KnownBitsTest.cpp

  Log Message:
  -----------
  [Support] Add KnownBits::computeForSubBorrow (#67788)

- [Support] Add KnownBits::computeForSubBorrow
- [CodeGen] Implement USUBC, USUBO_CARRY, and SSUBO_CARRY with
KnownBits::computeForSubBorrow
- [CodeGen] Compute unknown bits for Carry/Borrow for ADD/SUB
- [CodeGen] Compute known bits of Carry/Borrow for UADDO, SADDO, USUBO,
and SSUBO

Fixes #65893

---------

Co-authored-by: Shafik Yaghmour <shafik at users.noreply.github.com>