[all-commits] [llvm/llvm-project] 179ed8: [AAPointerInfo] handle multiple offsets in PHI

[Sameer Sahasrabuddhe via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 179ed8871101cd197e0a719a3629cd5077b1a999
      https://github.com/llvm/llvm-project/commit/179ed8871101cd197e0a719a3629cd5077b1a999
  Author: Sameer Sahasrabuddhe <sameer.sahasrabuddhe at amd.com>
  Date:   2022-12-15 (Thu, 15 Dec 2022)

  Changed paths:
    M llvm/include/llvm/Analysis/CycleAnalysis.h
    M llvm/include/llvm/Transforms/IPO/Attributor.h
    M llvm/lib/Target/AMDGPU/AMDGPUAttributor.cpp
    M llvm/lib/Transforms/IPO/AttributorAttributes.cpp
    M llvm/test/CodeGen/AMDGPU/implicitarg-attributes.ll
    M llvm/test/CodeGen/AMDGPU/llc-pipeline.ll
    M llvm/test/Transforms/Attributor/multiple-offsets-pointer-info.ll

  Log Message:
  -----------
  [AAPointerInfo] handle multiple offsets in PHI

Previously reverted in 12696d302d146ffe616eecab3feceba9d29be2db

The arguments to a PHI may represent a recurrence by eventually using the output
of the PHI itself. This is now handled by checking for cycles in the control
flow. If a PHI is not in a recurrence, it is now able to report multiple offsets
instead of conservatively reporting unknown.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D138991