[all-commits] [llvm/llvm-project] 6c989d: [BasicAA] Fix aliasGEP/DecomposeGEPExpression for ...

[huihzhang via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 6c989d024862f1d0a7a7f700f94adcbab76489a2
      https://github.com/llvm/llvm-project/commit/6c989d024862f1d0a7a7f700f94adcbab76489a2
  Author: Huihui Zhang <huihuiz at quicinc.com>
  Date:   2020-04-10 (Fri, 10 Apr 2020)

  Changed paths:
    M llvm/include/llvm/Analysis/BasicAliasAnalysis.h
    M llvm/lib/Analysis/BasicAliasAnalysis.cpp
    A llvm/test/Analysis/BasicAA/vscale.ll

  Log Message:
  -----------
  [BasicAA] Fix aliasGEP/DecomposeGEPExpression for scalable type.

Summary:
Don't attempt to analyze the decomposed GEP for scalable type.
GEP index scale is not compile-time constant for scalable type.
Be conservative, return MayAlias.

Explicitly call TypeSize::getFixedSize() to assert on places where
scalable type doesn't make sense.

Add unit tests to check functionality of -basicaa for scalable type.

This patch is needed for D76944.

Reviewers: sdesmalen, efriedma, spatel, bjope, ctetreau

Reviewed By: efriedma

Subscribers: tschuett, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D77828