[llvm] r322125 - [IPSCCP] Remove calls without side effects

[Davide Italiano via llvm-commits]

On Wed, Jan 10, 2018 at 3:36 PM, Philip Reames
<listmail at philipreames.com> wrote:
> I think this is wrong.  In particular, an ordered memory operation is NOT
> safe to remove during constant propagation, even if it's result is known.
> The ordered load has a side effect of ordering other loads which is not safe
> to remove.  The entire *point* of having side effects is that there's an
> effect other than the result of the instruction.
>


Hmm, on a second thought, I think you're correct. Chris, can you
please take a look?