[all-commits] [llvm/llvm-project] ee31a4: [ARM] IselLowering unsigned overflow to crash usin...

[Peter Rong via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: ee31a4a7029f2f6fda5f416e7eb67ca3907d9e36
      https://github.com/llvm/llvm-project/commit/ee31a4a7029f2f6fda5f416e7eb67ca3907d9e36
  Author: Peter Rong <PeterRong96 at gmail.com>
  Date:   2022-12-06 (Tue, 06 Dec 2022)

  Changed paths:
    M llvm/lib/Target/ARM/ARMISelLowering.cpp
    A llvm/test/CodeGen/ARM/pr59317.ll

  Log Message:
  -----------
  [ARM] IselLowering unsigned overflow to crash using APInt in PerformSHLSimplify

This diff fixes issue https://github.com/llvm/llvm-project/issues/59317

We should check if bitwidth is lower than the shift amount before we subtract them to avoid unsigned overflow.

Reviewed By: dmgreen

Differential Revision: https://reviews.llvm.org/D139238