search for: invartianess

Hi Piotr, On Thu, May 4, 2017 at 6:44 AM, Piotr Padlewski <piotr.padlewski at gmail.com> wrote: > Also, Sanjoy proposed to mark invariant.group features as experimental, so > we will not be afraid to break behavior of frontends that already use it. > > Right now I am pretty sure that clang is the only one that curently uses it > (and not by default). Firstly, yes, I think we

...the transitions being > explicitly > marked. There's no way to extend the TBAA idea to make that work. > The other reason why similar scheme doesn't work for !invariant.group is that we rely on a calls to launder/strip being present for some constructs to preserve information about invartianess of an object (like in the example from RFC). > On 12/4/18 11:24 AM, John McCall via llvm-dev wrote: > > Note that IPO is generally permitted to partially inline or outline code, > and so good-faith optimizations that e.g. require two instructions to be > moved > in tandem or not...

Skimming along, apologies if I'm repeating something which already got said. If I understand this correctly, the basic problem we're trying to solve is to use a local hint (the invariant.group) to make a global assumption about other code which might exist elsewhere outside the function.  The attribute proposed can basically be phrased as describing a universe of functions within