[all-commits] [llvm/llvm-project] 6042c2: [flang] use TBAAForest in TBAABuilder

[Tom Eccles via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 6042c2eb9edc5c5f743c209b37a72dca664864cb
      https://github.com/llvm/llvm-project/commit/6042c2eb9edc5c5f743c209b37a72dca664864cb
  Author: Tom Eccles <tom.eccles at arm.com>
  Date:   2023-10-11 (Wed, 11 Oct 2023)

  Changed paths:
    M flang/include/flang/Optimizer/CodeGen/TBAABuilder.h
    M flang/lib/Optimizer/CodeGen/TBAABuilder.cpp
    M flang/test/Fir/tbaa-codegen.fir
    A flang/test/Fir/tbaa-codegen2.fir
    M flang/test/Fir/tbaa.fir

  Log Message:
  -----------
  [flang] use TBAAForest in TBAABuilder

This is important to ensure that tags end up in the same trees that were
created in the FIR TBAA pass. If they are in different trees then
everything in one tree will be assumed to MayAlias with everything in the
other tree. This leads to poor performance.

@vzakhari requested that the old (not-per-function) trees are
maintained so I left the old test intact.

PR: https://github.com/llvm/llvm-project/pull/68437