Failure to hoist loop invariant #23587
Description
| Bugzilla Link | 23213 |
| Version | trunk |
| OS | All |
| Attachments | Original C++ Code, Unoptimized IR |
| CC | @Bigcheese,@chandlerc,@hfinkel |
Extended Description
LLVM fails to properly optimize the attached code from Mike Acton's talk "How to Write Code the Compiler Can Actually Optimize".
The issue is that Foo::Bar is inlined into Foo::Baz before Foo::Bar has been optimized, and LICM/SCEV can't handle the resulting double loop.