similar to: [LLVMdev] Reversing a function's CFG?

Hi Justin, I take the fact that nobody has replied as a sign that nobody really understands what you are asking. > I was wondering if there was a quick way to reverse a function's CFG and, > in turn, all basic blocks within it. Assuming all variables are globals, is > there a quick way to generate a function's reversal? I highly doubt such > functionality exists but I

Forgot to CC the list. On Wed, Mar 23, 2011 at 12:51 PM, Joshua Warner <joshuawarner32 at gmail.com>wrote: > >> In large-scale parallel simulations, sometimes you process an event >> speculatively. If it turns out you should not have processed that event >> (and such situations can be detected by our system), you need to undo all of >> the changes you made in

This is in reply to the posting below. I am not a compiler writer type, so I am probably in over my head a bit. Several years ago I was a bit interested in something called code slicers. An example of one (probably no longer supported) is UNRAVEL (http://www.itl.nist.gov/div897/sqg/unravel/unravel.html ) Their basic idea is to identify the algorithm which serves to determine the value of

This maybe early, but is there an ext3fs patch for the 2.4.16 kernel -- also, in general where does one download the lastest ext3fs patches?? I found the 2.4.14 patch a few weeks ago on in the linux.org UK site, but all the patches appear to be taken off that site...Any help would be most appreciated... Thanks, Chris --------------------------------------------------------------------

Hi, I'm having a problem with spss.read reversing my factor input. Here is the input copied from the spss data editor: color cost 1 2.30 2 2.40 3 3.00 1 2.10 1 1.00 1 2.00 2 4.00 2 3.20 2 2.33 3 2.44 3 2.55 For color, red=1, blue=2, and green = 3. It's type is 'String' and >out=read.spss(file) >out $COLOR [1] green blue red green green green blue blue blue red red

Before I start down this road, has anyone done a breadcrumbs implementation they''d be happy to share? Thanks Chris T

> example (x+y)-x -> y. Here the right-hand side "y" is a particularly simple > subexpression of the original :) Yeah. We have not found a lot of this kind of thing-- it looks like you and others scooped up a lot of the low-hanging fruit! John

Dear all, I encounter some covariance matrix with quite small eigenvalues (around 1e-18), which are smaller than the machine precision. The dimension of my matrix is 17. Here I just fake some small matrix for illustration. a<-diag(c(rep(3,4),1e-18)) # a matrix with small eigenvalues b<-matrix(1:25,ncol=5) # define b to get an orthogonal matrix b<-b+t(b) bb<-eigen(b,symmetric=T)

Hi, On 23/07/15 19:11, Philip Reames wrote: > > > On 07/23/2015 07:24 AM, John Regehr wrote: >>> I guess another way to select interesting transformations could be to look >>> for sequences where the >>> result uses a "subset" of the input instruction sequence. >> >> Yeah, I had been noticing those subsets too. It sounds like it's

Hi; I am having problems inverting matrices using the function solve() For example R can not invert the following matrix [,1] [,2] [,3] [,4] [,5] [1,] 25 500 11250 275000 7.106250e+06 [2,] 500 11250 275000 7106250 1.906250e+08

In the next patch, we want to get rid of the requirement for the user to supply LD_LIBRARY_PATH pointing to vddk libs, if we can derive it ourselves from libdir. However, VDDK itself requires LD_LIBRARY_PATH to be set (because it tries to load libraries that in turn depend on a bare library name, which no manner of dlopen() hacking can work around, and implementing la_objsearch() is no better for

I have a box behind a firewall that I'd like to administer. The firewall allows outgoing connections, but blocks all incoming connection requests. Thus, behind the firewall I can ssh out to my server, but I can't do the reverse. I found Sebastian Krahmer's OpenSSH Reverse [1] which looks very promising, but it is a few revisions behind. I was wondering if anyone has considered

Dear R Users, I am executing the following command to produce a line graph: matplot(aggregate_1986[,1], aggregate_1986[,2:3], type="l", col=2:3) On the x-axis I have values of Latitude (in column 1) ranging from -60 to +80 (left to right on the x-axis). However, I wish to have these values shown in reverse on the x-axis, going from +80 to -60 (ie. North to South in terms of Latitude).

How about this: f <- function(a,wh){ ## a is the array; wh is the index to be reversed l<- lapply(dim(a),seq_len) l[[wh]]<- rev(l[[wh]]) do.call(`[`,c(list(a),l)) } ## test z <- array(1:120,dim=2:5) ## I omit the printouts f(z,2) f(z,3) Cheers, Bert Bert Gunter "The trouble with having an open mind is that people keep coming along and sticking things into

?? > z <- array(1:24,dim=2:4) > all.equal(f(z,3),f2(z,3)) [1] "Attributes: < Component ?dim?: Mean relative difference: 0.4444444 >" [2] "Mean relative difference: 0.6109091" In fact, > dim(f(z,3)) [1] 2 3 4 > dim(f2(z,3)) [1] 3 4 2 Have I made some sort of stupid error here? Or have I misunderstood what was wanted? Cheers, Bert Bert Gunter

Here is an alternative approach using apply(). Note that with apply() you are reversing rows or columns not indices of rows or columns so apply(junk, 2, rev) reverses the values in each column not the column indices. We actually need to use rev() on everything but the index we are interested in reversing: f2 <- function(a, wh) { dims <- seq_len(length(dim(a))) dims <-

Dear R-devel: I could use some advice about matrix calculations and steps that might make for faster computation of generalized inverses. It appears in some projects there is a bottleneck at the use of svd in calculation of generalized inverses. Here's some Rprof output I need to understand. > summaryRprof("Amelia.out") $by.self self.time self.pct

David, thanks for the response. In your response the quantile function (if I see correctly) runs on the columns versus I need to run it on the rows, which is an easy fix, but that is not exactly what I had in mind... essentially we can remove t() from my original code to make "res" look like this: res<-apply(z, 1, quantile, probs=c(0.3)) but after all maybe I did not explain

My error. Clearly I did not do enough testing. z <- array(1:24,dim=2:4) > all.equal(f(z,1),f2(z,1)) [1] TRUE > all.equal(f(z,2),f2(z,2)) [1] TRUE > all.equal(f(z,3),f2(z,3)) [1] "Attributes: < Component ?dim?: Mean relative difference: 0.4444444 >" [2] "Mean relative difference: 0.6109091" # Your earlier example > z <- array(1:120, dim=2:5) >

dear useRs, i created a distance matrix, of certain voltage values. unfortunately, i lost the original values. i am only left with the distance matrix that i created from those values. i wanted to ask that is there a way in R to reverse distance matrix for the original values? thanks in advance eliza [[alternative HTML version deleted]]