[all-commits] [llvm/llvm-project] f8045b: Recommit "[SCCP] Remove forcedconstant, go to over...

[Florian Hahn via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: f8045b250d80ccdb2ae5f46d3aa02137fe475907
      https://github.com/llvm/llvm-project/commit/f8045b250d80ccdb2ae5f46d3aa02137fe475907
  Author: Florian Hahn <flo at fhahn.com>
  Date:   2020-02-15 (Sat, 15 Feb 2020)

  Changed paths:
    M llvm/lib/Transforms/Scalar/SCCP.cpp
    M llvm/test/Transforms/IPConstantProp/PR16052.ll
    M llvm/test/Transforms/IPConstantProp/PR26044.ll
    M llvm/test/Transforms/SCCP/2006-12-19-UndefBug.ll
    M llvm/test/Transforms/SCCP/apint-bigint2.ll
    M llvm/test/Transforms/SCCP/apint-ipsccp3.ll
    M llvm/test/Transforms/SCCP/apint-select.ll
    M llvm/test/Transforms/SCCP/ip-constant-ranges.ll
    M llvm/test/Transforms/SCCP/ipsccp-basic.ll
    M llvm/test/Transforms/SCCP/logical-nuke.ll
    A llvm/test/Transforms/SCCP/resolvedundefsin-tracked-fn.ll
    M llvm/test/Transforms/SCCP/switch-multiple-undef.ll
    M llvm/test/Transforms/SCCP/ub-shift.ll
    M llvm/test/Transforms/SCCP/undef-resolve.ll

  Log Message:
  -----------
  Recommit "[SCCP] Remove forcedconstant, go to overdefined instead"

This includes a fix for cases where things get marked as overdefined in
ResolvedUndefsIn, but we later discover a constant. To avoid crashing,
we consistently bail out on overdefined values in the visitors. This is
similar to the previous behavior with forcedconstant.

This reverts the revert commit 02b72f564c8be0b4f4337d5c4a3fcf7e8018a818.