[all-commits] [llvm/llvm-project] 907a75: [NFC][InstCombine] Add test for PR49778

[Roman Lebedev via All-commits]

  Branch: refs/heads/release/12.x
  Home:   https://github.com/llvm/llvm-project
  Commit: 907a751a38fff8d05b288ab52b19ba4e2cc1fc38
      https://github.com/llvm/llvm-project/commit/907a751a38fff8d05b288ab52b19ba4e2cc1fc38
  Author: Roman Lebedev <lebedev.ri at gmail.com>
  Date:   2021-05-03 (Mon, 03 May 2021)

  Changed paths:
    A llvm/test/Transforms/InstCombine/redundant-left-shift-input-masking-pr49778.ll

  Log Message:
  -----------
  [NFC][InstCombine] Add test for PR49778

(cherry picked from commit 5352490ce613f1bdedaf478765b089b1f0a8be0d)


  Commit: 4a4b1c75a1ea3f1ca90ef45470c42debb81ffc90
      https://github.com/llvm/llvm-project/commit/4a4b1c75a1ea3f1ca90ef45470c42debb81ffc90
  Author: Roman Lebedev <lebedev.ri at gmail.com>
  Date:   2021-05-03 (Mon, 03 May 2021)

  Changed paths:
    M llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp

  Log Message:
  -----------
  [NFC][InstCombine] Extract canTryToConstantAddTwoShiftAmounts() as helper

(cherry picked from commit dceb3e599668496420d41b993100d23eeb7c0ada)


  Commit: c27ad80507bfea35da07681fd4ec9972ca698015
      https://github.com/llvm/llvm-project/commit/c27ad80507bfea35da07681fd4ec9972ca698015
  Author: Roman Lebedev <lebedev.ri at gmail.com>
  Date:   2021-05-03 (Mon, 03 May 2021)

  Changed paths:
    M llvm/lib/Transforms/InstCombine/InstCombineShifts.cpp
    M llvm/test/Transforms/InstCombine/redundant-left-shift-input-masking-pr49778.ll

  Log Message:
  -----------
  [InstCombine] dropRedundantMaskingOfLeftShiftInput(): check that adding shift amounts doesn't overflow (PR49778)

This is identical to 781d077afb0ed9771c513d064c40170c1ccd21c9,
but for the other function.

For certain shift amount bit widths, we must first ensure that adding
shift amounts is safe, that the sum won't have an unsigned overflow.

Fixes https://bugs.llvm.org/show_bug.cgi?id=49778

(cherry picked from commit 2760a808b9916a2839513b7fd7314a464f52481e)


Compare: https://github.com/llvm/llvm-project/compare/0cbbf06b6256...c27ad80507bf