search for: multiply

...ode 991238, i_blocks is 56, should be 128. Fix? yes Restarting e2fsck from the beginning... /dev/sdb7 contains a file system with errors, check forced. Pass 1: Checking inodes, blocks, and sizes Running additional passes to resolve blocks claimed by more than one inode... Pass 1B: Rescanning for multiply-claimed blocks Multiply-claimed block(s) in inode 90119: 4685733 4685734 4685735 4685736 4685737 4685738 4685739 4685740 4685741 4685742 4685743 4685744 4685745 4685750 4685751 4685752 4685753 4127735 4127736 4127737 4127738 4688088 4688089 4688090 4688091 4688092 4688093 4688094 4688095 4688096 46...

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" > > set...

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, rS...

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 = matrix(rnorm(n.obs*n.param),nrow=n.param) In th...

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 Alternatively, would something like following get reduced to a single multiply and two stores on arch...

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 enough to wait for opt to finish :) ) So I suppose SCEV is lacking some protection, for instance degrading to "unknow" when an expression is above a given threshold, or stop flattening...

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). For flo...

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 0, > and sinks write...

...>> 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 enough to >> wait for opt to finish :) ) >> >> So I suppose SCEV is lacking some protection, for instance degrading >> to "unknow" when an expres...

...t 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 + inspection of the CC. As a quick fix, that isn't a bad solution for bignum arithmetic, but it doesn't deal with the upper bits from multiply, and it doesn't deal with floating point condition codes at all. shap

...it > > overflowed. Truncate to 32 bits to get the result. Probably codegen > > can be taught to implement this as a 32 bit add + inspection of the CC. > > As a quick fix, that isn't a bad solution for bignum arithmetic, but it > doesn't deal with the upper bits from multiply, and it doesn't deal with > floating point condition codes at all. can you really use condition codes for multiply and floating point? You can handle integer multiply by doing it in an integer twice as wide as the one you are interested in, so an i64 on a 32 bit machine. Is there hardware...

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

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 <-...

...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 anything that wasn't "empty", which broader than >> necessary) >> and updated the unit test to match, but I'm not completely confident >> that I understand ConstantRange and APInt and was hop...

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 to be generated. If I understand it correctly, this is undesirable given that multiply-and-add for targets like PPC (I am not sure about all the oth...

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 time (on...

...system elapsed 3.640 0.000 3.642 user system elapsed 7.950 0.000 7.953 The main issue here is again ISNAN. The R code doesn't trust the Fortran routine it calls to handle NA and NaN correctly, so it checks whether the arguments have any NAs or NaNs, and if so does the matrix multiply itself, with simple nested loops. For multiplies in which the number of elements in the result matrix is large, this check will take a negligible amount of time. But otherwise it can drastically slow things down. This is true in particular for dot products, of a 1xN times an Nx1 matrix, giving a...