[all-commits] [llvm/llvm-project] 39bb79: [SimplifyCFG] `switch`: Do Not Transform the Defau...

[Qiongsi Wu via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 39bb790b906f4921a5d9fc09e856abe53ae7a320
      https://github.com/llvm/llvm-project/commit/39bb790b906f4921a5d9fc09e856abe53ae7a320
  Author: Qiongsi Wu <274595+qiongsiwu at users.noreply.github.com>
  Date:   2024-01-12 (Fri, 12 Jan 2024)

  Changed paths:
    M llvm/lib/Transforms/Utils/SimplifyCFG.cpp
    M llvm/test/Transforms/SimplifyCFG/switch-dead-default.ll

  Log Message:
  -----------
  [SimplifyCFG] `switch`: Do Not Transform the Default Case if the Condition is Too Wide (#77831)

https://github.com/llvm/llvm-project/pull/76669 taught SimplifyCFG to
handle switches when `default` has only one case. When the `switch`'s
condition is wider than 64 bit, the current implementation can calculate
the wrong default value. This PR skips cases where the condition is too
wide.