[LLVMdev] Implementing llvm.memory.barrier on PowerPC

[Gary Benson]

Hi all,

I want to implement llvm.memory.barrier on PowerPC.  The
implementation would be the single instruction "sync", but
currently it's defined with:

 setOperationAction(ISD::MEMBARRIER, MVT::Other, Expand)

in lib/Target/PowerPC/PPCISelLowering.cpp, which causes it
to be a noop.  I replaced the "Expand" with "Legal" in the
hope I'd get an error message that'd point me to where I
need to start adding stuff, but I just got the cryptic:

  Cannot yet select: 0x10fc0500: ch = MemBarrier 0x10fc0368, 0x10fc0698, 0x10fc0610, 0x10fc0698, 0x10fc0698, 0x10fc0698".

Can anyone point me in the right direction?

Cheers,
Gary

-- 
http://gbenson.net/