search for: _correctness_

...e TBAA. > but the point is that valid but > naive optimizations can cause them to be actively misleading ... but not cause mis-compilation. Note, optimization passes are free to update info conveyed through MDNodes, if they want to. The "optional to update" while still preserving _correctness_ of the program is a key property of MDNodes. Regarding, TBAA you say that this optionality is not optional. If you insist that all transformation passes in pipeline _must_ ensure correctness of alias info conveyed by front end as part of TBAA then I guess you need an explicit mechanism anyway. In...

On Jan 27, 2012, at 3:40 PM, Devang Patel wrote: > [ removing cfe-dev from the cc list ] > > On Jan 27, 2012, at 1:31 PM, Dan Gohman wrote: > >> On Jan 27, 2012, at 11:20 AM, Devang Patel wrote: >> >>> >>> On Jan 26, 2012, at 2:10 PM, Dan Gohman wrote: >>> >>>> On Jan 26, 2012, at 12:54 PM, Devang Patel wrote:

...Wednesday, January 7, 2004, 9:37:19 PM, you wrote: > > Well, Chris, let's forget about traditions (finally LLVM is > tradition-breaking thing!). At which level the optimization like i've > meant *should* be implemented?.. Ok, I thought you were concerned about LLVM breaking the _correctness_ of distributed programs, sorry. :) > If a priori optimization is restricted to a one host, then nothing to > discuss. But just imagine that you say: "OK, let's make a basic > support for code eval distributed to multiple hosts" :) > 2. LLVM could bring a *lot* to distr...

Hello Chris, Wednesday, January 7, 2004, 9:37:19 PM, you wrote: CL> Typically distributed computing like this is performed at a much higher CL> level than things like LLVM. almost right, if you mean "distributed computing is usually implemented as some compiled libs". But if it is a part of the language then it is not as you say :) Well, Chris, let's forget about traditions

On Wed, 7 Jan 2004, Valery A.Khamenya wrote: > just imagine, that we have Linux cluster, and we have two functions in > one module (`f' and `g'). If they are about to be executed at one host, > then one is allowed to do very aggressive interprocedural > optimizations between these `f' and `g'. However if `g' should be > "outsourced to" (i.e.

...37:19 PM, you wrote: > > > > Well, Chris, let's forget about traditions (finally LLVM is > > tradition-breaking thing!). At which level the optimization like i've > > meant *should* be implemented?.. > > Ok, I thought you were concerned about LLVM breaking the _correctness_ of > distributed programs, sorry. :) > > > If a priori optimization is restricted to a one host, then nothing to > > discuss. But just imagine that you say: "OK, let's make a basic > > support for code eval distributed to multiple hosts" :) > > 2. LLV...

...but the point is that valid but >> naive optimizations can cause them to be actively misleading > > ... but not cause mis-compilation. Note, optimization passes are free to update info conveyed through MDNodes, if they want to. The "optional to update" while still preserving _correctness_ of the program is a key property of MDNodes. Even if we single out TBAA, recall that TBAA was one of the main motivations for the design of MDNodes -- it's in the second sentance, and most of the last paragraph, of http://blog.llvm.org/2010/04/extensible-metadata-in-llvm-ir.html > Regardin...

...finite looping or by calling exit(0) - Have memory synchronization operations, like fences, atomic loads, stores etc. - Have side effects like IO, volatile writes If an intrinsic's behavior can be explained by some subset of the above, then you should not need to edit any pass to preserve _correctness_ -- all optimization passes (today) conservatively assume that calls that they don't understand have all of the behaviors outlined above. However, if to preserve *correctness* you have to edit optimization passes and teach them that certain intrinsic calls have behavior *outside* the set mentio...

...finite looping or by calling exit(0) - Have memory synchronization operations, like fences, atomic loads, stores etc. - Have side effects like IO, volatile writes If an intrinsic's behavior can be explained by some subset of the above, then you should not need to edit any pass to preserve _correctness_ -- all optimization passes (today) conservatively assume that calls that they don't understand have all of the behaviors outlined above. However, if to preserve *correctness* you have to edit optimization passes and teach them that certain intrinsic calls have behavior *outside* the set mentio...

Hi Sanjoy, Yes, that's exactly what we have been looking at recently here, but the region tags seem to make it possible to express the control flow as well, so I think we could start with reg ions+metadata, as Hal and Xinmin proposed, and then figure out what needs to be first class instructions. --Vikram Adve > On Jan 19, 2017, at 11:03 PM, Sanjoy Das <sanjoy at