search for: axiom

Displaying 20 results from an estimated 83 matches for "axiom".

2005 Feb 04
3
Server Criteria
I've been doing a lot of background reading/searching of this list, voip-info.org, and Google, looking to define a good candidate for a server platform. I'm very interested in thoughts from others! So here goes... Axiom 1: if you are not doing doing much transcoding (converting between codecs), the bottleneck for supporting high volumes of simultaneous calls is system bus speed, not CPU power ---> points to a 64 bit AMD Opteron system, and maybe just one of the two processor slots populated. Bus is twice a...
2011 Apr 07
2
[LLVMdev] GSoC 2011: Superoptimization for LLVM IR
...he original only better; but instead start from the original > code > sequence and repeatedly apply transformations that change code to > equivalent > code, looking to see if you can eventually get something better than the > original. Is that right? > > Exactly. If we can use axioms/transformations/identities which don't modify the code behavior, but just tries to interpret instruction semantics in a different way, so as to find another (and hopefully simpler) instructions to do the same job, the role of the SAT prover is no longer necessary, since the search space is con...
2008 Aug 12
7
New Ogg Dirac mapping draft
David Flynn has proposed a new Ogg Dirac mapping. The draft is here: http://davidf.woaf.net/dirac-mapping-ogg.pdf This is a much bigger break from other codecs than my draft (at http://wiki.xiph.org/index.php/OggDirac). We talked a bit about it on IRC today. Below is my summary; hopefully David can correct anything I got wrong or misleading. Comments? There are two main differences
2011 Apr 08
0
[LLVMdev] GSoC 2011: Superoptimization for LLVM IR
...inal only better; but instead start from the original code > sequence and repeatedly apply transformations that change code to equivalent > code, looking to see if you can eventually get something better than the > original. Is that right? > > > Exactly. If we can use axioms/transformations/identities which don't modify the > code behavior, but just tries to interpret instruction semantics in a different > way, so as to find another (and hopefully simpler) instructions to do the same > job, the role of the SAT prover is no longer necessary, since the sear...
2016 Jan 15
2
[cfe-dev] RFC: Extend UBSan with qsort checks
On Tue, Jan 12, 2016 at 10:27 PM, Yury Gribov via cfe-dev < cfe-dev at lists.llvm.org> wrote: > > As for C++11, it has for e.g. srtd::sort: > > "Requires: operator< (for the version with no arguments) or comp (for the > version with a comparison argument) defines a strict weak ordering (25.4)." > > which also sounds like UB. Exactly correct. If your
2011 Apr 06
7
[LLVMdev] GSoC 2011: Superoptimization for LLVM IR
...ossible code sequence optimizations. When successfully identified, these optimizations could be implemented directly as peephole optimizations for LLVM IR. Timeline This project is expected to last three months, as follows. • 1st month, 1st week - Study the LLVM IR in order to establish a list of axioms, that is, valid transformations that determine the search algorithm capability. There is an important trade-off to investigate here, since using fewer transformations will lead to faster searches, but several good optimizations may be missed. • 1st month, 2nd week - Thorough study of the current im...
2011 Apr 08
0
[LLVMdev] GSoC 2011: Superoptimization for LLVM IR
...instead start from the original >> code >> sequence and repeatedly apply transformations that change code to >> equivalent >> code, looking to see if you can eventually get something better than the >> original.  Is that right? >> > > Exactly. If we can use axioms/transformations/identities which don't modify > the code behavior, but just tries to interpret instruction semantics in a > different way, so as to find another (and hopefully simpler) instructions to > do the same job, the role of the SAT prover is no longer necessary, since > the...
2005 Jan 07
4
glm fit with no intercept
...th no intercept? Regards, Gudrun -- Gudrun Jonasdottir, M.Sc. Matematiska institutionen Stockholms Universitet SE- 106 91 Stockholm Work: +46 (0)8 16 45 56 Mobile: +46 (0)709 779 800 -------------------------------------------- "N?r inget annat hj?lper, l?s instruktionsboken." - Canns axiom
2004 Sep 10
4
SIP on Handhelds
Does anyone know if SIP will/is support on handheld PCs such as the iPaq or Axiom? With their integrated 802.11b and Bluetooth it seems like a solution to provide a wireless based sip phone for any user would be possible. Handoff between access points might be problematic but most users I know would be using their PDA phone in an airport with free wireless or at the local cafe...
2005 Jul 12
10
Computer algebra in R - would that be an idea??
>From time to time people request symbolic computations beyond what D() and deriv() etc can provide. A brief look at the internet shows that there are many more or less developed computer algebra packages freely available. Therefore, I wondered if it would be an idea to try to 'integrate' one of these packages in R, which I guess can be done in more or less elegant ways... I do not know
2007 Apr 09
2
[LLVMdev] New automated decision procedure for path-sensitive analysis
...e operators like MUL ( as they rely on linear arithmetic solvers, like simplex ). Spear takes a different approach - it is bit-precise, handles all operators, but currently doesn't handle arrays directly. However, the other mentioned thm provers handle arrays by encoding them as UIFs + several axioms. As UIFs can be encoded to SAT, I think that the theory of arrays could be as well. So, with a bit of effort, you should be able to use Spear for reasoning about arrays. Cheers, Domagoj Babic
2014 Mar 02
2
[LLVMdev] Stub LLVM backend wanted
...Cpu0 architecture' (which is unfinished), I'd be really interested...) -- ┌─── dg@cowlark.com ───── http://www.cowlark.com ───── │ "There does not now, nor will there ever, exist a programming │ language in which it is the least bit hard to write bad programs." --- │ Flon's Axiom -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 828 bytes Desc: OpenPGP digital signature URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20140302/c225c3de/attachment.sig>
2005 Oct 26
4
symbolic math
Hi all! Does anyone knows if it exists a "symbolic math" package in R, that allows to compute derivatives, integrals, etc.? Does exist a freeware version of Maple? Cheers, Marco [[alternative HTML version deleted]]
2016 Jan 11
2
RFC: Extend UBSan with qsort checks
...tizer currently does not check for undefined behaviors which result from improper usage of standard library functions. One notorious instance of such errors is invalid usage of qsort or bsearch routines (or std::sort and friends in case of C++): * using comparison function that violates ordering axioms (reflexivity, symmetry, transitivity) * returning unstable results from comparison function * passing unsorted array to bsearch * etc. Errors like this will usually result in slightly invalid output (not fully sorted arrays, rare failed bsearches, etc.) but may as well cause aborts on some sys...
1999 Aug 05
1
cbind is not generic as claimed, omits labels where S has them (PR#240)
On 5 Aug 1999, Peter Dalgaard BSA wrote: > (1) The docs are clearly wrong (or perhaps rather, wishful thinking) Sorry, but always the docs are right and the implementation wrong. That's an axiom of professional computer programming (so I am told by several ex-professional computer programmers.) > (2) Cbind should be generic as in Splus > > (3) For the labels, one needs essentially to implement deparse.level > or face the horrors of > eval(substitute(cbind(a,b,depar...
2017 Jul 22
3
GEP with a null pointer base
...to prove that induction variable widening is safe (overflow cannot happen). > > There is nothing special about induction variable widening with respect to UB. It is justified by applying the same principles as all other UB-related transformations. > > > Briefly, there is only one axiom in the compiler writer's toolbox w.r.t. UB and that is "the input program does not execute UB". Everything else is derived from that by pure logical reasoning. Does that make sense? Can you see how all the descriptions I gave above are derivable from that axiom? > > The common...
2017 Jul 21
3
GEP with a null pointer base
> On Jul 20, 2017, at 11:22 AM, David Blaikie <dblaikie at gmail.com> wrote: > > > > On Wed, Jul 19, 2017 at 10:17 AM Peter Lawrence via llvm-dev <llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>> wrote: > Chandler, > The only thing David made clear that wasn’t already clear > is that he believes UB to be “comparatively
1998 Sep 15
7
Samba and NIS
...I can get Samba to access the NIS maps? SMB.CONF ========= [global] auto services = homes printers dead time = 5 guest account = nobody load printers = yes mangled map = (*.html *.htm) printer name = lp printcap name = /usr/local/samba/printcap public = yes workgroup = AXIOM [root] comment = Home Directories path = / writable = yes create mode = 0750 [homes] comment = Home Directories writable = yes create mode = 0750 [printers] comment = All Printers path = /tmp printable = yes create mode = 0700 browseable = no All suggestion...
2016 Jan 12
4
RFC: Extend UBSan with qsort checks
...> overflow bugs in sanitizers). > > [1] -fsanitize=vptr is an only notable exception > > One notorious instance of such errors is invalid usage of qsort or bsearch >> routines (or std::sort and friends in case of C++): >> * using comparison function that violates ordering axioms (reflexivity, >> symmetry, transitivity) >> * returning unstable results from comparison function >> * passing unsorted array to bsearch >> * etc. >> >> Errors like this will usually result in slightly invalid output (not >> fully sorted arrays, rare faile...
2016 Jan 13
2
RFC: Extend UBSan with qsort checks
...>>> [1] -fsanitize=vptr is an only notable exception >>> >>> One notorious instance of such errors is invalid usage of qsort or >>>> bsearch routines (or std::sort and friends in case of C++): >>>> * using comparison function that violates ordering axioms (reflexivity, >>>> symmetry, transitivity) >>>> * returning unstable results from comparison function >>>> * passing unsorted array to bsearch >>>> * etc. >>>> >>>> Errors like this will usually result in slightly invalid outp...