[LLVMdev] dmb ishld in AArch64

Tim Northover t.p.northover at gmail.com
Tue Dec 9 15:32:39 PST 2014


On 9 December 2014 at 15:14, Chengyu Song <csong84 at gatech.edu> wrote:
> Errr. my fault. I patched the rcu_assign_pointer ... Let me try again.

It's looking closer now, but I still can't trigger the bug I'm afraid.
Even disabling the load/store optimiser and fiddling with CPUs (to try
different schedulers) just gives me what I'd expect:

        ldr     x8, [x21, #8]
        str      x21, [x19]
        str     x8, [x19, #8]
        dmb ishst
        ldr     x8, [x19, #8]
        str      x19, [x8]

I'm not aware of any big changes in this area recently. You don't have
any local LLVM patches or anything that could be causing the problem?
What revision of trunk did you get it to fail on? I could try checking
that one out.

Cheers.

Tim.



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