[all-commits] [llvm/llvm-project] 5672ae: [SCCP] Use constant ranges for select, if cond is ...

[Florian Hahn via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 5672ae8d868bbe8ddb33c23c2d2b8eadf8bf2a7f
      https://github.com/llvm/llvm-project/commit/5672ae8d868bbe8ddb33c23c2d2b8eadf8bf2a7f
  Author: Florian Hahn <flo at fhahn.com>
  Date:   2020-03-18 (Wed, 18 Mar 2020)

  Changed paths:
    M llvm/lib/Transforms/Scalar/SCCP.cpp
    M llvm/test/Transforms/SCCP/ip-ranges-select.ll
    M llvm/test/Transforms/SCCP/select.ll

  Log Message:
  -----------
  [SCCP] Use constant ranges for select, if cond is overdefined.

For selects with an unknown condition, we can approximate the result by
merging the state of both options. This automatically takes care of
the case where on operand is undef.

Reviewers: davide, efriedma, mssimpso

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D71935