search for: undecidable

...aid, it would be interesting to add gcov to the testsuite to get a measure > of how many percent of the application we're exercising.... > >> A static analysis will not be able to see through things like virtual >> method calls. > > Not even in theory? It's provably undecidable to do so in general, because aliasing is statically undecidable. http://academic.research.microsoft.com/Publication/857191/the-undecidability-of-aliasing (and the more complicated paper it cites by Landi). This is not to say it's not possible to resolve any of them sometimes, it means in gener...

On Sun, Jul 3, 2011 at 10:34 PM, Reid Kleckner <reid.kleckner at gmail.com> wrote: > An easier way would be to use a coverage tool like gcov to see what's > actually *used* when the app is run normally.  Then you can ask the > question, what percentage of all lines of code are dead? We need something that can do this using static analysis... Otherwise we can just use Eclipse

I am new to Rails, and I thought I understood params, but I''m a little fuzzy on what goes into the controller to access a third value for a radio button. In my migration I defined the column as a string with a default value of nil. The column itself is actually a question(no question mark appears in the column though)with three choices in the radio button form: yes, no, and undecided.

We are undecided right now if we will be streaming through a linux based computer or through a windows computer. Any opinions out there? We have heard that windows presents a major problem with viruses, etc. when trying to stream. Also, can icecast be used with both linux and windows? Thanks. -------------- next part -------------- An HTML attachment was scrubbed... URL:

Dear R-developers, I am currently developing an R package called RLadyBug. When developing under Linux "R CMD check ." works fine without a warning. However, when I do "Rcmd check ." under Windows (version 2.4.0 and earlier) I get a ?syntax error" when checking the examples. This puzzles me somewhat, because a manual source("RLadyBug-Ex.R") on Windows works

Does anyone have any experience using R to pull/push data from an ODBC compliant database? I'm working on a small project and am undecided about whether to use just R or use some other software for extracting and transforming. TIA Samir. The information contained in this e-mail transmission is confidential and may be privileged. It is intended only for the addressee(s) stated above. If

...dd gcov to the testsuite to get a measure >> of how many percent of the application we're exercising.... >> >>> A static analysis will not be able to see through things like virtual >>> method calls. >> >> Not even in theory? > > It's provably undecidable to do so in general, because aliasing is > statically undecidable. > http://academic.research.microsoft.com/Publication/857191/the-undecidability-of-aliasing > (and the more complicated paper it cites by Landi). > > This is not to say it's not possible to resolve any of them some...

Hi all, How''s this look? I based it on http://msdn.microsoft.com/en-us/library/aa366789(VS.85).aspx. I''m undecided as to when I should raise an error versus when I should just let it fall through, but this is how it is for now. You''ll need the latest windows-pr from CVS, btw. Regards, Dan PS - Where should I put it? In Windows::File directly? In a separate helper

On Tue, May 17, 2016 at 2:46 PM, Renato Golin <renato.golin at linaro.org> wrote: > On 17 May 2016 at 22:41, Tanya Lattner via llvm-dev > <llvm-dev at lists.llvm.org> wrote: >> If you are interested in volunteering for this position OR if you are >> interested in writing a blog post, please send me an email. > > Why don't we communicate the releases,

Dear users, I have uploaded the new 3.0.25a packages compiled for sarge. At the same time I have removed older 2.2.x and 3.0.x packages for Woody. Support for back porting packages to Woody was already discontinued, but older packages were still provided. As these packages were not updated after the recent security issues, I decided to remove them to avoid pushing people to use outdated and

...as general as possible. Examples would be "x, y are (not) aliased", "loop trip count = x" (where x is either a static constant, or an expression", "branch cond. is true most of the time" (or x% of the time), and other information that might be statically undecidable, but the developer knows the answer to. thanks, Anthony

...for (k = 0; k < ip[2]; ++k) { a[k] = (k+11)/(k+2); } } ---------- example 2 ---------- test2(int *a) { int k, ip[4]; vbar(ip, 4, 7); for (k = 0; k < ip[2]; ++k) { a[k] = (k+11)/(k+2); } } However, in both cases the trip count is the same and equally undecidable, since "vbar()" is an external function. Note that in each example that is the only code in the file and I am running my pass as: opt -O1 -licm -load ... -mypass < test.bc > /dev/null Any suggestions? thanks, Anthony

...aled hamidouche wrote: > I'm wandring to know how many times a block is executed inside a > loop ? > knowing that I can't use getSmallConstantTripCount() because the > number is unkown "for (i=0;i<N;i++) for example" In general, the number of iterations is undecidable. For example: int main(char **argv, int N) { for (int i = 0; i < N; i++) { std::cout << "arg: " << argv[i] << std::endl; } return 0; } If you are parsing code whose iterations can be determined, please post it. Trevor

Hi, Is there any facility in LLVM to identify recursion in a call graph? I realize this is undecidable in the general case due to function pointers, but at least the static cases could be identified. I don't even care about whole-program recursion, just looking at a single module would suffice. But I don't see anything like this already in LLVM, so do I simply write some code to look...

Hi all, i am coding to analyze an IR with multi-level pointers, and i am eager to know whether there exists a way to find the pointee pointer directly, if only given an upper level pointer. For example, in the following demo, C code: int i = 10; int *p = &i; int **pp; *pp = &p; IR code: %i = alloca i32, align 4 %p = alloca i32*, align 8 %pp = alloca i32**, align 8 store

> Timo Sirainen wrote: > Our typical projects have several million user accounts. I think 100k > users is around the minimum. Interesting. So che choice for object storage is driven by the number of accounts rather than the amount of data stored? For example I am heading towards 10 TB online with "just" 10k users. It wouldn't be worth? Paolo

Hi, I have experimentally done a branch of klibc with buffered stdio support. It seems to add about 1.5K of code (for x86-64), which isn't so bad, except that it means that *every* program now pulls in stdio, which in turn depends on malloc() and some other pieces of code. I have not yet implemented fscanf(), however, which may cause additional bloat. As of this point, I'm a bit

I'd like to expand the following data to perform a daily time series. It should cover from '2012-07-01' to '2012-10-06' with the values I actually have being the mean from one point measurement to another. Does anyone has a clue to perform this task. structure(list(Date.beg = structure(c(15635, 15617, 15615, 15610, 15609, 15605, 15604, 15601, 15593, 15593, 15586, 15581,

>> I may sound stupid but can someone tell me that after applying >> optimization sequences randomly whether we can surely say that the >> final output is correct? > > Answering this question is equivalent to solving the Halting Problem. Prooving correctness of a compiler is really an NP problem. This goes for any compiler backend. All you can do is have enough test

> Prooving correctness of a compiler is really an NP problem. This goes for > any compiler backend. All you can do is have enough test cases. No. To be in NP it would be necessary for a Non-deterministic Polynomial algorithm to exist. There is no such algorithm. The problem is undecidable. It doesn't means that it is impossible to prove the correctness of a compiler. It means that no algorithm can do it. >From a practical point of view, I think that the original question was: Are the different optimizations "expected" to work in any order or do they have some int...