[all-commits] [llvm/llvm-project] 99809f: [SCCP] Do not mark unknown loads as overdefined.

[Florian Hahn via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 99809f98d7bb18dbe3be543942a4b467dff7e92e
      https://github.com/llvm/llvm-project/commit/99809f98d7bb18dbe3be543942a4b467dff7e92e
  Author: Florian Hahn <flo at fhahn.com>
  Date:   2020-02-20 (Thu, 20 Feb 2020)

  Changed paths:
    M llvm/lib/Transforms/Scalar/SCCP.cpp
    M llvm/test/Transforms/IPConstantProp/PR26044.ll
    M llvm/test/Transforms/SCCP/apint-bigint2.ll
    M llvm/test/Transforms/SCCP/loadtest.ll
    A llvm/test/Transforms/SCCP/loadtest2.ll

  Log Message:
  -----------
  [SCCP] Do not mark unknown loads as overdefined.

For tracked globals that are unknown after solving, we expect all
non-store uses to be replaced.

This is a follow-up to f8045b250d80, which removed forcedconstant.

We should not mark unknown loads as overdefined, as they either load
from an unknown pointer or an undef global. Restore the original logic
for loads.