search for: multipliers

Hi all, Apologies but this is going to be a long post. I get a corruption sometime when I do a $sudo shutdown -r now This is on an ubuntu 8.10 machine. The only way to resolve the same I know is to do a sudo fsck -y /dev/sdb7 This is the output I got when I ran fsck through the Live CD $ sudo fsck -y /dev/sdb7 fsck 1.41.3 (12-Oct-2008) e2fsck 1.41.3 (12-Oct-2008) /dev/sdb7 contains a file

In the following code, 'multiply' doesn't multiply a at x by 2. I'm wondering how to define a method that can change the slot of a class. $ Rscript setGeneric.R > setClass( + Class='A', + representation=representation( + x='numeric' + ) + ) [1] "A" > > setMethod( + f='initialize', +

Hi all, llvm-test fails on me in the first test (and many subsequent tests, but I hope that fixing the first test will allow me to continue). I see syntax errors from the C compiler and core dumps from llc. Is any of this supposed to happen? This is still on my amd64 machine. However, the build process is using the right incantation to compile (gcc-4.2 -m32 -Wl,-melf_i386). The llvm-gcc

The only multiplication instruction on my target CPU is multiply-and-accumulate. The result goes into a special register that can destructively read at the end of a sequence of multiply-adds. The following sequence is required to so a simple multiply: acc r0 # clear accumulator, discarding its value (r0 reads as 0, and sinks writes) mac rSRC1, rSRC2 # multiply sources, store

Dear R-users, I am working on a problem that I am currently not able to solve efficiently. It is about multiplying one column of a matrix with only a certain number of rows of another matrix. Let me illustrate my problem with an example: n.obs = 800 n.rowsperobs = 300 n.param = 23 Designmat = matrix(rnorm(n.obs*n.rowsperobs*n.param),ncol=n.param) Betamat =

I've been playing around with llvm lately and I was wondering something about the bitcode instructions for basic arithmetic. Is there any plan to provide instructions that perform widening multiply, or add with carry? It might be written as: mulw i32 %lhs %rhs -> i64 ; widening multiply addw i32 %lhs %rhs -> i33 ; widening add addc i32 %lhs, i32 %rhs, i1 %c -> i33 ; add with carry

Hi, I was looking at some bugs to play with, and I started with http://llvm.org/bugs/show_bug.cgi?id=18606 As I commented there, a loop is unrolled and exhibit this pattern: %mul.1 = mul i32 %mul, %mul %mul.2 = mul i32 %mul.1, %mul.1 .... With an unroll factor of 32, the last multiply has 2^32 terms in its SCEV expression. (I mean I expect it would have those terms if I was patient

On Wed, 2008-03-26 at 15:47 +0100, Duncan Sands wrote: > can you really use condition codes for multiply and floating point? For scalar multiply, not really. What you *can* do is use the native multiply instruction that does (32x32)->(lower,upper), and then decide based on the upper 32 bits of the result whether you had a multiply-carry. Similarly for i-divide 64->(quotient,remainder).

Hi, I am trying to complete the hardware multiplier option for MSP430 backend. As the hardware multiplier in most of the MSP430 devices is for i8 and i16 operands, with i16 and i32 result, I am lowering MUL_i8 and MUL_I16. However, the front-end promotes the i8 argument to i32, executes 32-bit multiplier and truncates to 16-bit, so I never lower MUL_I8 nor MUL_I16 but MUL_I32, wchich is lowered

On Apr 16, 2009, at 2:19 PM, Greg McGary wrote: > The only multiplication instruction on my target CPU is > multiply-and-accumulate. The result goes into a special register that > can destructively read at the end of a sequence of multiply-adds. The > following sequence is required to so a simple multiply: > > acc r0 # clear accumulator, discarding its value (r0 reads as

On 2/7/14, 10:24 AM, Andrew Trick wrote: > > On Feb 5, 2014, at 12:54 AM, Mehdi Amini <mehdi.amini at silkan.com > <mailto:mehdi.amini at silkan.com>> wrote: > >> Hi, >> >> I was looking at some bugs to play with, and I started with >> http://llvm.org/bugs/show_bug.cgi?id=18606 >> >> As I commented there, a loop is unrolled and exhibit

On Wed, 2008-03-26 at 15:07 +0100, Duncan Sands wrote: > 4. Do arithmetic in a type with one more bit. For example, suppose you > want to know if an i32 add "x+y" will overflow. Extend x and y to 33 > bit integers, and do an i33 add. Inspect the upper bit to see if it > overflowed. Truncate to 32 bits to get the result. Probably codegen > can be taught to implement

Hi Shap, > > 4. Do arithmetic in a type with one more bit. For example, suppose you > > want to know if an i32 add "x+y" will overflow. Extend x and y to 33 > > bit integers, and do an i33 add. Inspect the upper bit to see if it > > overflowed. Truncate to 32 bits to get the result. Probably codegen > > can be taught to implement this as a 32 bit add +

I have tried many permutations of search terms in google and I haven't been able to find any confirmation that the megaraid* modules in centos4 supports port multipliers/multiplexers. Here is a link to the controller I have in mind at newegg: http://www.newegg.com/product/product.asp?item=N82E16816118032 In case anyone is interested, here is what my research has turned up when looking for external JBOD SATA enclosures: I'm just looking for a hot swap JBOD en...

I apologize for what seems like it should be a straighforward query. I am trying to multiply a list by a numeric and thought there would be a straightforward way to do this, but the best solution I found so far has a for loop. Everything else I try seems to throw an error "non-numeric argument to binary operator" Consider the example: a <- 1 b <- 1:2 c <- 1:3 abc <-

On Fri, Jul 10, 2009 at 8:35 PM, Dan Gohman<gohman at apple.com> wrote: > > > On Jul 10, 2009, at 2:03 PM, Ryan Flynn <parseerror at gmail.com> wrote: > >> I've addressed a "TODO" in ConstantRange and several in its unit test >> by implementing a stricter "multiply" method (it had been returning a >> "full" set for

Hey, just bought an eSATA/USB dual drive docking station and my CentOS 5 can only see one drive at a time... Any one knows if there are specific parameters to set somewhere? Or do I need a more recent kernel (like upgrading to CentOS 6?) The docking is a Sharkoon Quickport Duo v2 + 2 drives + 1 eSATA cable... http://www.sharkoon.com/?q=en/content/sata-quickport-duo-v2 The eSATA controller is an

Hi all, The AllowFPOpFusion option passed to a target can currently take 3 different values, Fast, Standard or Strict (TargetOptions.h), being Standard the default. In the DAGCombiner, during the combination of mul and add/subtract into multiply-and-add/subtract, this option is expected to be Fast in order to enable the combine. This means, that by default no multiply-and-add opcodes are going

Suppose x <- array(c(1,1,1,1,2,2,2,2), dim = c(2,2,2)) y <- c(5, 10) Now I would like to multiply x[, , 1] with y[1] and x[, , 2] with y[2]. Possible solution is a for-loop: for (i in 1:2) { x[, , i] * y[i] } Another possible solution is this construction: as.vector(t(replicate(nrow(x) * ncol(x), y))) * x I find that these two solutions have a relatively large computation

I've looked at the code for matrix multiplies in R, and found that it can speeded up quite a bit, for multiplies that are really vector dot products, and for other multiplies in which the result matrix is small. Here's my test program: u <- seq(0,1,length=1000) v <- seq(0,2,length=1000) A2 <- matrix(2.1,2,1000) A5 <- matrix(2.1,5,1000) B3 <- matrix(3.2,1000,3) A4 <-