Since C++11, the C++ standard has a forward progress guarantee
[intro.progress], so all such functions must have the `mustprogress`
requirement. In addition, from C11 and onwards, loops without a non-zero
constant conditional or no conditional are also required to make
progress (C11 6.8.5p6). This patch implements these attribute deductions
so they can be used by the optimization passes.
Differential Revision: https://reviews.llvm.org/D86841
Summary:
Make sure that loop metadata only is put on the backedge
when expanding a do-while loop.
Previously we added the loop metadata also on the branch
in the pre-header. That could confuse optimization passes
and result in the loop metadata being associated with the
wrong loop.
Fixes https://bugs.llvm.org/show_bug.cgi?id=38011
Committing on behalf of deepak2427 (Deepak Panickal)
Reviewers: #clang, ABataev, hfinkel, aaron.ballman, bjope
Reviewed By: bjope
Subscribers: bjope, rsmith, shenhan, zzheng, xbolva00, lebedev.ri, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D48721
llvm-svn: 336717
Atmn Patel