Displaying 20 results from an estimated 193 matches for "undecidability".
2011 Jul 04
0
[LLVMdev] Deleting unused C++ code
.......
>
>> 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 general you will not be able to.
There are a number of static analysis to do things like class
hierarchy resolution which may be able to prove whic...
2011 Jul 04
2
[LLVMdev] Deleting unused C++ code
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
2012 Feb 29
0
controller code for access to params in radio button column
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.
2005 Jun 28
2
Windows or Linux
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.
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2006 Oct 31
4
Syntax Error in Rcmd check on Windows
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
2000 Nov 14
3
ODBC Connectivity
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
2011 Jul 04
2
[LLVMdev] Deleting unused C++ code
...lysis 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 general you will not be able to.
> There are a number of static analysis to do things like class
> hierarchy resolution wh...
2008 Nov 22
2
GetFinalPathNameByHandle for XP and earlier
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
2016 May 17
3
Interested in writing for the LLVM blog?
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,
2007 May 29
2
Binary_Packages/Debian
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
2009 Mar 25
3
[LLVMdev] pragmas
Hello
Is there a "generic" pragma that is supported by LLVM and is visible
by optimization passes? or any other way for a programmer to pass
meta-data information to the compiler?
I am writing an analysis pass that could benefit from user provided
information. At this stage, I could like to keep the kind of
information that the user can provide as general as possible.
2009 Mar 20
1
[LLVMdev] getTripCount and pointers
Hello,
I'm having some trouble with getTripCount() ... again. In particular
it fails in the first of the following two examples, although it works
for the second. By fails, I mean it returns NULL.
---------- example 1 ----------
test1(int *a, const int *ip) {
int k;
for (k = 0; k < ip[2]; ++k) {
a[k] = (k+11)/(k+2);
}
}
---------- example 2 ----------
test2(int
2010 Apr 21
0
[LLVMdev] determining the number of iteration of a loop
On Apr 21, 2010, at 7:31 AM, khaled 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
2010 Oct 29
2
[LLVMdev] Identify recursion in a call graph
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
2015 Jul 17
2
[LLVMdev] For a pointer to pointer ?How to fast get the pointee pointer?
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
2015 Sep 28
2
object storage
> 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
2007 Aug 16
1
stdio
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
2012 Nov 19
0
expand time period
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,
2006 Jul 18
3
[LLVMdev] Correctness of Optimization Phases
>> 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
2006 Jul 18
0
[LLVMdev] Correctness of Optimization Phases
> 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