llvm dev - Feb 2017 - Post-register allocation MachineLICM does not optimize loops

Hello.
     I want to avoid running the pre-register allocation (pre-RA) MachineLICM
pass, since
it can "destroy" some sequences of instructions that should be bundled
together (and it
seems LLVM, by design, does NOT allow to bundle MachineInstr instructions before
the
pre-RA MachineLICM pass).
     So I disabled the pre-RA LICM by always giving llc -disable-machine-licm.

     I've also applied all possible passes subarguments for the
post-register allocation
(post-RA) MachineLICM pass without any success:
         -hoist-cheap-insts - MachineLICM should hoist even cheap instructions
         -disable-licm-promotion - Disable memory promotion in LICM pass
         -sink-insts-to-avoid-spills - MachineLICM should sink instructions into
loops to
avoid register spills
         -avoid-speculation - MachineLICM should avoid speculation
     (Note that llc has some other arguments related to hoisting that I did not
yet use.)

     With any of these arguments I always obtain the following UNoptimized loop
assembly code:
         REPEAT_X_TIMES(numRowsCols)
             R(3) = 1 ;; this instruction is a loop invariant and should be
moved before
the loop
             R(5) = LS[R(0)]
             ...
             R(1) = R(1) + R(3)
         END_REPEAT

     Could you please tell me if I can optimize this kind of loops with the
post-RA
MachineLICM?

   Thank you very much,
     Alex