[InstCombine]Avoid introduction of unaligned mem access

InstCombine is able to transform mem transfer instrinsic to alone store or store/load pair.
It might result in generation of unaligned atomic load/store which later in backend
will be transformed to libcall. It is not an evident gain and it is better to keep intrinsic as is
and handle it at backend.

Reviewers: reames, anna, apilipenko, mkazantsev
Reviewed By: reames
Subscribers: t.p.northover, jfb, llvm-commits
Differential Revision: https://reviews.llvm.org/D56582

llvm-svn: 351295
2 files changed
tree: c0b5ce0871627524316a708b7d01625387793bf6
  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. pstl/
  17. .arcconfig
  18. README.md
README.md

The LLVM Compiler Infrastructure

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