Note I have two more tests with the same assertion, 186.crafty.llvm.bc and 464.h264ref.llvm.bc. They are pretty big, so I won't attach.

They both crash bugpoint, so I can't reduce them: UNREACHABLE executed at /d/g/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp:904!

Devang/Dale, this is dying in:

MachineLocation
X86AsmPrinter::getDebugValueLocation(const MachineInstr *MI) const {
MachineLocation Location;
assert (MI->getNumOperands() == 7 && "Invalid no. of machine operands!");
// Frame address. Currently handles register +- offset only.
assert(MI->getOperand(0).isReg() && MI->getOperand(3).isImm());
Location.set(MI->getOperand(0).getReg(), MI->getOperand(3).getImm());
return Location;
}

The DBG_VALUE is actually:

(gdb) call MI->dump()
DBG_VALUE %RIP, 1, %reg0, ga:@C.9.2167, %reg0, 0, !"find_strings"; dbg:pbmsrch.c:73

causing the crash. Please investigate, I assume the assert just needs to be loosened up or something.

Fixed the crash. r107678.
File PR 7577 to track missing debug info.