[LLVMdev] Question on Fence Instruction

[陳韋任 (Wei-Ren Chen)]

On Tue, Oct 16, 2012 at 01:44:57PM +0000, Duan, Yue Lu wrote:
> Hi, 
> 
> I have a question with the latest released LLVM which supports Fence
> Instruction as IR. Say if I intentionally place a Sequentially Consistent Fence
> Instruction somewhere in the code, then would the other transformation passes
> that applied later respect the Fence and do not perform any reordering across
> it?

  In theory, all optimization passes should respect sc. If you find any
counter example, I think it's a bug.

HTH,
chenwj

-- 
Wei-Ren Chen (陳韋任)
Computer Systems Lab, Institute of Information Science,
Academia Sinica, Taiwan (R.O.C.)
Tel:886-2-2788-3799 #1667
Homepage: http://people.cs.nctu.edu.tw/~chenwj