similar to: [LLVMdev] [RFC] Defining Infinite Loops

----- Original Message ----- > From: "Chandler Carruth" <chandlerc at google.com> > To: "Hal Finkel" <hfinkel at anl.gov>, "LLVM Dev" <llvmdev at cs.uiuc.edu> > Sent: Thursday, July 16, 2015 1:00:05 AM > Subject: Re: [LLVMdev] [RFC] Defining Infinite Loops > > > FWIW, I'm very much in favor of having a firm and clear answer

----- Original Message ----- > From: "Chandler Carruth" <chandlerc at google.com> > To: "Hal Finkel" <hfinkel at anl.gov> > Cc: "LLVM Dev" <llvmdev at cs.uiuc.edu> > Sent: Thursday, July 16, 2015 2:33:21 AM > Subject: Re: [LLVMdev] [RFC] Defining Infinite Loops > > > > > On Thu, Jul 16, 2015 at 12:27 AM Hal Finkel

> You dropped some context... > A daemon program wouldn't be readonly. An infinite loop can be. Right. To prevent miscommunication, here is a quick analysis of a problematic (IMO) example: We start with ``` define void @infloop(i1 %c) { entry: br i1 %c, label %l, label %e l: br label %l e: ret void } define void @main_func() { entry: call void @infloop(i1 1) ret

On Sat, Jun 27, 2015 at 2:16 PM, Nuno Lopes <nunoplopes at sapo.pt> wrote: > At least in C/C++ that's UB, yes. So you cannot map every turing machine to a valid C/C++ program then. :) Also, does this mean that "daemon" programs that run continuously till they're killed by the OS (using a mechanism that is not visible in C) are effectively undefined? -- Sanjoy >

Running -early-cse on declare void @rn() readnone nounwind define void @f() { entry: call void @rn() ret void } removes the call to @rn(). But @rn() could have had an infinite loop in it in which case @f() went from being a non-terminating program to an terminating no-op. Is this intentional? The only way I can see this transform being legal is if infinite loops are declared to have

On 11/25/2010 12:59 PM, Andrew Clinton wrote: > On 11/24/2010 06:55 PM, Owen Anderson wrote: >> On Nov 23, 2010, at 9:22 AM, Andrew Clinton wrote: >> >> >>> Most of my programs contain loops that the LoopDeletion pass is unable >>> to remove. It appears that the following code in LoopDeletion.cpp:152 >>> is the culprit: >>> >>>

On 11/24/2010 06:55 PM, Owen Anderson wrote: > On Nov 23, 2010, at 9:22 AM, Andrew Clinton wrote: > > >> Most of my programs contain loops that the LoopDeletion pass is unable >> to remove. It appears that the following code in LoopDeletion.cpp:152 >> is the culprit: >> >> ScalarEvolution& SE = getAnalysis<ScalarEvolution>(); >>

Andrew Clinton wrote: > On 11/25/2010 12:59 PM, Andrew Clinton wrote: >> On 11/24/2010 06:55 PM, Owen Anderson wrote: >>> On Nov 23, 2010, at 9:22 AM, Andrew Clinton wrote: >>> >>> >>>> Most of my programs contain loops that the LoopDeletion pass is unable >>>> to remove. It appears that the following code in LoopDeletion.cpp:152

Does 'nounwind' have semantics that inform optimization passes? It seems to in some cases, but not consistently. For example... int32_t foo(int32_t* ptr) { int i = 0; int result; do { bar(ptr); result = *ptr; bar(ptr); } while (i++ < *ptr); return result; } Say we have a front end that declares bar as... declare void @bar(i32*) readonly; So 'bar' is

Dear all! I'd like to do multiple imputation of missing values with s-plus libraries that are provided by Shafer (http://www.stat.psu.edu/~jls/misoftwa.html). I wonder, whether these libraries are compatible or somehow convertible to R (because I don't have S-plus), so that I can use this functions using the R Program. I would be happy if you could tell me, -if it is possible to use

I have the following setup: DS3 -> Cisco AS5400 -> H.323 (ooh323) -> Asterisk Inbound calls work great but outbound calls fail. So to check and make sure we have outbound calling ability on the DS3 we setup a Cisco Call Manager Express and it can make outbound calls both local and long distance with no problems. The failure code is Cause i = 0x8381 - Unallocated/unassigned number. We

On 04/25/2014 10:12 AM, Eric Christopher wrote: > Hi Andrew, > > Replying in both places because this mail is a pretty good summary of > issues and so it's worth replying to... my apologies for continuing in > both places. Responding to LLVMDev - I for one had missed this part of the thread. > >> The only language aspect under discussion is integer division. Every

----- Original Message ----- > From: "Nuno Lopes" <nunoplopes at sapo.pt> > To: "Sanjoy Das" <sanjoy at playingwithpointers.com>, "Jeremy Lakeman" <Jeremy.Lakeman at gmail.com>, nlewycky at google.com > Cc: "LLVM Developers Mailing List" <llvmdev at cs.uiuc.edu> > Sent: Sunday, June 28, 2015 6:08:52 AM > Subject: Re:

I'm not sure I understand why it's blocked on that, by the way. Even if we can't apply the attribute ourselves, I don't see why we wouldn't expose that ability to frontends. I'm not entirely sure "halting" is the right attribute either, by the way. What I, personally, would like to see is a way to specify a function call is safe to speculatively execute. That

Greetings folks, Shafer's S-plus package "norm" for multiple imputation of missing values in multivariate normal data has been most kindly and usefully ported to R by Alvaro A. Novo. Shafer's website http://www.stat.psu.edu/~jls/ lists four S-plus packages in all: NORM - multiple imputation of multivariate continuous data CAT - multiple imputation of multivariate

----- Original Message ----- > From: "Nuno Lopes" <nunoplopes at sapo.pt> > To: "Hal Finkel" <hfinkel at anl.gov> > Cc: "LLVM Developers Mailing List" <llvmdev at cs.uiuc.edu>, "Sanjoy Das" <sanjoy at playingwithpointers.com>, "Jeremy > Lakeman" <Jeremy.Lakeman at gmail.com>, nlewycky at google.com >

Andrew Trick wrote: > Does 'nounwind' have semantics that inform optimization passes? It seems to in some cases, but not consistently. For example... > > int32_t foo(int32_t* ptr) { > int i = 0; > int result; > do { > bar(ptr); > result = *ptr; > bar(ptr); > } while (i++< *ptr); > return result; > } > > Say we have

EFI booting may hang indefinitely when no keyboard is present on a machine (or when UEFI has chosen to not init USB due to fast boot). Reproducible at least with "EFI v2.31 by American Megatrends" on an Asrock H81M-ITX board. Reason is the input draining loop near the end in efi/main.c; it calls ReadKeyStroke() as long as EFI_NOT_READY is not returned. On machines without keyboard,

Of course frontends are free to put attributes, but it would be nice if optimizations actually used them. ;-) My use case is that of proprietary frontend that happens to know some library function calls - which are only resolved at link time - have no side effects and are safe to execute speculatively, and wants to tell the optimizer it can move them around however it likes. I'll gladly submit

Kuperstein, Michael M wrote: > I'm not sure I understand why it's blocked on that, by the way. It blocks our ability to automatically deduce the halting attribute in the optimizer, which was necessary for the use case I had at the time. If you have a use case of your own, feel free to propose the patch! (Technically it's not *blocked* -- see how my patch does it! -- but the