similar to: [LLVMdev] Pointer aliasing issue

Hi Artiom, > I have following C code: > > void factorial(float **a, float **b) > { > b[2][2] = a[0][2]; > b[2][2] = a[0][1]; > } ... > Assuming that a and b arrays contains pointers that are not aliased, > is it possible to remove the first store by using some C or LLVM IR specific > declarations? try this: void factorial(float **

Unfortunately since in this example function arguments are array of pointers, __restrict doesn't help. Yes, using 2 stores into same location is intentional. On Mon, Oct 11, 2010 at 12:20 PM, Duncan Sands <baldrick at free.fr> wrote: > Hi Artiom, > > > I have following C code: > > > > void factorial(float **a, float **b) > > { > >

Hi, I have a question regarding pointer aliasing. I have following C code: void factorial(float **a, float **b) { b[2][2] = a[0][2]; b[2][2] = a[0][1]; } Which is converted to following LLVM IR: define void @factorial(float** nocapture %a, float** nocapture %b) nounwind{ entry: %0 = getelementptr inbounds float** %b, i64 2 ; <float**> [#uses=2] %1 = load float** %0, align 8

I configured a domU to access to the physical serial port of the dom0 (/dev/ttyS0) typing this in the domU configuration file: irq = [ 4 ] ioports = [ "3f8-3ff" ] The domU starts without any error, but the serial port isn''t recognised. The /dev/ttyS0 device exists on the domU, and I blacklisted the serial_core, the 8250 and 8250_pnp modules on the dom0. What is the problem?

Peter Cooper wrote: > I think the problem here is that the IR doesn't have any way to attach restrict information to loads/stores/pointers. I think we do now, actually. Now that the loads and stores have TBAA metadata, I think the restrict attribute can go there. It needs to be attached to every use of a restrict pointer, but that's similar to how TBAA already works. > It works

I think the problem here is that the IR doesn't have any way to attach restrict information to loads/stores/pointers. It works on arguments because they can be given the 'noalias' attribute, and then the alias analyzer must understand what that means. Pete On Jan 24, 2012, at 7:47 AM, Roel Jordans wrote: > I have no clue, I didn't have time to look into that example yet.

On Jun 17, 2010, at 9:42 AM, Pierre C wrote: > >>> Consider a case like the following: >>> struct X { int a; int b[10]; }; >>> int f(struct X* a) { a->b[-1] = 1; return a->a; } >>> >>> This is technically illegal code, but various programs depend on >>> constructs like this working. >>> > > Actually if you want to

Hi Brent, Looking at your code I can see at least one reason why some of the store operations remain in the output since you are (through x, y, and z) writing in memory which exists outside of your function (p). Constant propagation also seems to work in the first few lines, *y = *x +1 (%3) is stored directly. The strange thing to me is that the same doesn't happen for *z = *x + 2. Here

Hi, Rusers: Thanks for answering my last questions. I am frustrated in plotting a trinomial pmf function f(x,y | n, pa, pb) = factorial(n)/ (factorial(x) * factorial(y) * factorial (n-x-y))* pa^x * pb^y * ((1-pa-pb)^(n-x-y)) obviously it is a bivariate function of x and y. But I have put a lot of time on this. ********************************** x <- seq(0, n, len = n/2+1) # for now I set

Hi Brent, I think this is a problem in the easy-cse transform. In this transform load operations can be replaced by their subexpression, in this case the propagated constant, based on the value of the 'CurrentGeneration' of memory writes. This implies that any store operation invalidates the knowledge about previously stored subexpressions. In general, this is a safe assumption but

I have no clue, I didn't have time to look into that example yet. How does the IR (before optimization) differ from the other version? Roel On 01/24/2012 04:45 PM, Brent Walker wrote: > Can you explain please why it works for this version of the function: > > double f(double *__restrict__ x, double *__restrict__ y, double > *__restrict__ z); > > What is different here?

Hi, I tried to calculate the formula for the birthday problem (the probability that at least two people out of a group of n people share the same birthday) But the factorial-function allows me only to calculate factorials up to 170. So is there a way to push that limit? to solve this formula: (factorial(365) / factorial((365-23))) / (365^23) (n=23)

Caching computation in rails? Simple example: factorial modulus a large number input: integer x output: factorial( x ) % 12345678901234567 I want it so that if it computes factorial of N once, it will not have to compute for N again. code: class SiteController < ApplicationController caches_action :factorial, :inv def examine @inv = @params[''inv''] @outv =

Interestingly, the <<- operator is also a lot faster than using a namespace explicitly, and only slightly slower than using <- with local variables, see below. But, surely, both must at some point insert values in a given environment ? either the local one, for <-, or an enclosing one, for <<- ? so I guess I am asking if there is a more low-level assignment operation I can get my

I am working on a project that requires me to do very large factorial evaluations. On R the built in factorial function and the one I created both are not able to do factorials over 170. The first gives an error and mine return Inf. Is there a way to have R do these larger calculations (the calculator in accessories can do 10000 factorial and Maple can do even larger) -- View this message in

Following up on this attempt of implementing the tail-recursion optimisation ? now that I?ve finally had the chance to look at it again ? I find that non-local return implemented with callCC doesn?t actually incur much overhead once I do it more sensibly. I haven?t found a good way to handle parallel assignments that isn?t vastly slower than simply introducing extra variables, so I am going with

No clue, but see ?assign perhaps if you have not done so already. -- Bert Bert Gunter "The trouble with having an open mind is that people keep coming along and sticking things into it." -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip ) On Tue, Feb 27, 2018 at 6:51 AM, Thomas Mailund <thomas.mailund at gmail.com> wrote: > Interestingly, the

Dear all, I wanted to create the mean using a algebra matrix. so I tried this one: > meanAnimals <- new3%*%factorial (Calculates the matrix multiplication of the new3 * factorial). But I get the following error message: Error in new3 %*% factorial : non-conformable arguments These are my matrices: > new3 [,1] [,2] [1,] 1.350 8.1 [2,] 465.000 423.0

Hi guys, I am working on some code for automatically translating recursive functions into looping functions to implemented tail-recursion optimisations. See https://github.com/mailund/tailr As a toy-example, consider the factorial function factorial <- function(n, acc = 1) { if (n <= 1) acc else factorial(n - 1, acc * n) } I can automatically translate this into the loop-version

> On Feb 11, 2018, at 7:48 AM, Thomas Mailund <thomas.mailund at gmail.com> wrote: > > Hi guys, > > I am working on some code for automatically translating recursive functions into looping functions to implemented tail-recursion optimisations. See https://github.com/mailund/tailr > > As a toy-example, consider the factorial function > > factorial <-