llvm dev - Jul 2017 - Avoid generating COPY instructions with TwoAddressInstructionPass for a region of MachineInstr

Hello.
     Is there a way to avoid generating register-COPY instructions with 
TwoAddressInstructionPass (the one that does "REWRITING TWO-ADDR
INSTRS") for a region of
my MachineBasicBlock? (It seems that the RegisterCoalescer is not removing every
possible
COPY?)
     If I use bundles or I predicate the instructions in the respective region
(they are
actually predicated instructions) would it help?

   Thank you,
     Alex

Hello.
     I come back to say that it seems that indeed bundling several instructions
helps -
the TwoAddressInstructionPass is not generating COPY instructions in the bundle.
     Following the discussion at 
http://lists.llvm.org/pipermail/llvm-dev/2017-June/113727.html I created a
bundle and set
the InternalRead flag to true for all operands that are uses of defined operands
inside
the bundle (I can provide the code for doing this). (This allowed me to avoid
the error
that I got before with bundles "Bad machine code: Virtual register defs
don't dominate all
uses." at a pass after TwoAddressInstructionPass).

     But, I get an error from RegisterCoalescer due to one bundle (or several
bundles):
       <<llc: /llvm/lib/CodeGen/RegisterCoalescer.cpp:2258: void 
{anonymous}::JoinVals::computeAssignment(unsigned int,
{anonymous}::JoinVals&): Assertion
`Other.Vals[V.OtherVNI->id].isAnalyzed() && "Missing
recursion"' failed.>>
     The bundles from the program that generate this error seem well formed.

     Did someone already encounter this error? It's difficult for me to
understand exactly
what is this error.

   Thank you,
     Alex

On 7/4/2017 5:11 PM, Alex Susu wrote:
>   Hello.
>     Is there a way to avoid generating register-COPY instructions with
> TwoAddressInstructionPass (the one that does "REWRITING TWO-ADDR
INSTRS") for a region of
> my MachineBasicBlock? (It seems that the RegisterCoalescer is not removing
every possible
> COPY?)
>     If I use bundles or I predicate the instructions in the respective
region (they are
> actually predicated instructions) would it help?
>
>   Thank you,
>     Alex