[BranchFolding] Allow hoisting to block with a single conditional branch.

Summary:
The BranchFolding pass is currently missing opportunities to hoist
common code if the hoisted-to block contains a single conditional branch
that has register uses.  This occurs somewhat frequently on AArch64 with
CBZ/TBZ opcodes.

This change also eliminates some code differences when debug info is
present since the presence of e.g. DBG_VALUE instructions in the
hoisted-to block can enable hoisting that wouldn't have occurred without
them.

Reviewers: MatzeB, rnk, kparzysz, twoh, aprantl, javed.absar

Subscribers: kristof.beyls, JDevlieghere, mcrosier, llvm-commits

Differential Revision: https://reviews.llvm.org/D46324

llvm-svn: 332265
2 files changed
tree: f2ea82ffd78bf8ded706e71f90883b1b255eaa0e
  1. clang/
  2. clang-tools-extra/
  3. compiler-rt/
  4. debuginfo-tests/
  5. libclc/
  6. libcxx/
  7. libcxxabi/
  8. libunwind/
  9. lld/
  10. lldb/
  11. llgo/
  12. llvm/
  13. openmp/
  14. parallel-libs/
  15. polly/
  16. README.md
README.md

Low Level Virtual Machine (LLVM)

This directory and its subdirectories contain source code for LLVM, a toolkit for the construction of highly optimized compilers, optimizers, and runtime environments.