[llvm-dev] invariant.load metadata semantics

Sanjoy Das via llvm-dev llvm-dev at lists.llvm.org
Thu Aug 25 16:47:55 PDT 2016


Hi Piotr,

Piotr Padlewski wrote:
 > I disagree. It's much easier to write fronted and use invariant load
 > when you can emit stores that store the same value.
 > For example with invariant.group used on vptrs optimizer can assume the
 > 2 loads load the same vtable, even when you can write code in c++ that
 > is valid that store vptr after calling virtual function (like placement
 > new(this) with the same type).

That's a good point -- I didn't have this use case in mind.

-- Sanjoy


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