[all-commits] [llvm/llvm-project] 4ad1ed: [ConstraintElimination] Add test from PR54228.

[Florian Hahn via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 4ad1ed3a2ea9c25b2a69a560c22ee09961b5248a
      https://github.com/llvm/llvm-project/commit/4ad1ed3a2ea9c25b2a69a560c22ee09961b5248a
  Author: Florian Hahn <flo at fhahn.com>
  Date:   2022-03-07 (Mon, 07 Mar 2022)

  Changed paths:
    A llvm/test/Transforms/ConstraintElimination/pr54228-variable-name-order.ll

  Log Message:
  -----------
  [ConstraintElimination] Add test from PR54228.

Test for https://github.com/llvm/llvm-project/issues/54228


  Commit: 542c335159d45f4650383a2bdfb337d9f9b4d1f1
      https://github.com/llvm/llvm-project/commit/542c335159d45f4650383a2bdfb337d9f9b4d1f1
  Author: Florian Hahn <flo at fhahn.com>
  Date:   2022-03-07 (Mon, 07 Mar 2022)

  Changed paths:
    M llvm/include/llvm/Analysis/ConstraintSystem.h
    M llvm/lib/Transforms/Scalar/ConstraintElimination.cpp
    M llvm/test/Transforms/ConstraintElimination/pr54228-variable-name-order.ll

  Log Message:
  -----------
  [ConstraintElimination] Remove dead variables when dropping constraints.

This patch extends ConstraintElimination to also remove dead variables
when removing a constraint. When a constraint is removed because it is
out of scope, all new variables added for this constraint can also be
removed.

This keeps the total size of the systems much smaller, because it
reduces the number of variables drastically.

It also fixes a bug where variables where removed incorrectly.

Fixes https://github.com/llvm/llvm-project/issues/54228


Compare: https://github.com/llvm/llvm-project/compare/be85f55b2dcb...542c335159d4