[all-commits] [llvm/llvm-project] 65f78e: [SimplifyCFG] Consider cost of combining predicates.

[Sam Parker via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 65f78e73ad574bb73bb625c787850acd261ba53a
      https://github.com/llvm/llvm-project/commit/65f78e73ad574bb73bb625c787850acd261ba53a
  Author: Sam Parker <sam.parker at arm.com>
  Date:   2020-09-07 (Mon, 07 Sep 2020)

  Changed paths:
    M llvm/include/llvm/Transforms/Utils/Local.h
    M llvm/lib/Transforms/Utils/SimplifyCFG.cpp
    M llvm/test/Transforms/SimplifyCFG/ARM/branch-fold-threshold.ll

  Log Message:
  -----------
  [SimplifyCFG] Consider cost of combining predicates.

Modify FoldBranchToCommonDest to consider the cost of inserting
instructions when attempting to combine predicates to fold blocks.
The threshold can be controlled via a new option:
-simplifycfg-branch-fold-threshold which defaults to '2' to allow
the insertion of a not and another logical operator.

Differential Revision: https://reviews.llvm.org/D86526