https://bugs.freedesktop.org/show_bug.cgi?id=84232
--- Comment #3 from Matt Arsenault arsenm2@gmail.com --- (In reply to Vitaliy Filippov from comment #2)
Unhandled loop condition! UNREACHABLE executed at /var/home/vitali/setup/llvm-toolchain-3.5-3.5/lib/Target/R600/ SIAnnotateControlFlow.cpp:259!
This is probably related to bugpoint replacing the branch conditions with constants, which makes conditional branches effectively unconditional :) and SIAnnotateControlFlow::handleLoopCondition also doesn't handle this case.
Looks like an easy to fix problem?
The StructurizeCFG pass can actually create branches on constants, although it shouldn't, which I've seen several times before. I've had a partial fix for SIAnnotateControlFlow handling branches on constants for a while, but I've been putting off fixing it until the less noticeable StructurizeCFG problem is fixed.