Extended Description

llc -march=ppc32 -mcpu=440 -filetype=obj -o test.o

crashes on

define void @​f() {
fence acquire
ret void
}

The PowerPC backend has a pretty complete MC support, so the fix should be trivial, but it is probably better if someone familiar with the ISA looks at it.

My guess from the existing code is that is most cpus msync is as alias for "sync 0", but on "book E" versions there is not "sync 0" and msync is a proper instruction.