openmp

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: Disclaimer: I'm quite certain that this has been answered somewhere, but myself and another person have been searching quite hard to no avail. I've got a code that looks something like this: PROGRAM main !$omp parallel do !$omp private(somestuff) shared(otherstuff) DO i=1,n ... CALL mysubroutine(args) ... a=myfunction(moreargs) ... ENDDO !$omp end parallel do END PROGRAM SUBROUTINE mysubroutine(things) ... END SUBROUTINE FUNCTION myfunction(morethings) ... END FUNCTION I cannot determine where/how to handle private, shared, reduction, etc.

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I have the following class: Class L{ public: bool foo(vector<bool> & data); private: C** cArray; } and would like to parallelize the for loop in the function foo which is called somtime after an object of L is created and all the elements in cArray are initialized. bool L::foo(vector<int> & data){ int row, col; #pragma omp parallel shared(SIZE, cArray, data) private(row, col) for (row=0, row<SIZE; ++row) { for (col=0; col<SIZE; ++col) { cArray[row][col].computeScore(data); } } } But this gives an error: error C3028: 'L::cArray' : only a

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I am trying to turn a C project of mine from sequential into parallel programming. Although most of the code has now been redesigned from scratch for this purpose, the generation of random numbers is still at its core. Thus, bad performance of the random number generator (RNG) affects very badly the overall performance of the program. I wrote some code lines (see below) to show the problem I am facing without much verbosity. The problem is the following: everytime the number of threads nt increases, the performance gets singnificantly worse.

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: Is there a way I can compile code with OpenMP to C code (With OpenMP part translated to plain C), so that I can know what kind of code is being generated by OpenMP. I am using gcc 4.4 compiler. 回答1: There is at least http://www2.cs.uh.edu/~openuh/ OpenUH (even listed at http://openmp.org/wp/openmp-compilers/ ), which can emit optimized C or Fortran 77 code that may be compiled by a native compiler on other platforms. Also there are: http://www.cs.uoi.gr/~ompi/ OMPi: The OMPi compiler takes C source code with OpenMP #pragmas and produces

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I am trying to learn OMP library task based programming and as an example I copied and pasted the code below taken from a book and it outputs errors 'task' : expected an OpenMP directive name and 'taskwait' : expected an OpenMP directive name I can run omp parallel for loops but not tasks. Do you know whether omp tasking needs any further adjustments in visual studio? #include "stdafx.h" #include <omp.h> int fib(int n) { int i, j; if (n<2) return n; else { #pragma omp task shared(i) firstprivate(n) i=fib(n-1); #pragma omp task shared(j)

Cython starter here. I am trying to speed up a calculation of a certain pairwise statistic (in several bins) by using multiple threads. In particular, I am using prange from cython.parallel, which internally uses openMP. The following minimal example illustrates the problem (compilation via Jupyter notebook Cython magic). Notebook setup: %load_ext Cython import numpy as np Cython code: %%cython --compile-args=-fopenmp --link-args=-fopenmp -a from cython cimport boundscheck import numpy as np from cython.parallel cimport prange, parallel @boundscheck(False) def my_parallel_statistic(double[:] X

可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试): 问题: I am using the newest CMake (3.9.3) from Homebrew along with LLVM 5.0.0 also from Brew, because Clang here has OpenMP support. This worked in CMake 3.8.2 with LLVM 5. In my CMakeLists.txt I have find_package( OpenMP ) and later I want to do if( OpenMP_CXX_FOUND ) However CMake doesn't seem to pick up on the find_package directive. I run CMake with cmake .. -DCMAKE_BUILD_TYPE=Debug -DCMAKE_CXX_COMPILER=clang++ -DCMAKE_C_COMPILER=clang -DUSE_WERROR=ON where I have checked that clang and clang++ points correctly to /usr/local/opt/llvm/bin/clang

I am using OpenMP in my Visual Studio projects and currently thinking very seriously in changing to QT creator. (Doesn't Visual Studio suck?,I expect much more from Microsoft) But anyway... Does QT creator support OpenMP? In case of that, what should I do to enable it? Or maybe is enabled by default? Do I need to do something special? Thanks for your advices. Ignacio. Does QT creator support OpenMP? As someone else mentioned, it's not Qt itself that support OpenMP but the compiler. What should I do to enable it? If you have installed a recent Qt 4.6.x SDK (hint: latest QtCreator 1.3 is

I've been struggling a weird problem the last few days. We create some libraries using GCC 4.8 which link some of their dependencies statically - eg. log4cplus or boost. For these libraries we have created Python bindings using boost-python. Every time such a library used TLS (like log4cplus does in it's static initialization or stdlibc++ does when throwing an exception - not only during initialization phase) the whole thing crashed in a segfault - and every time the address of the thread local variable has been 0. I tried everything like recompiling, ensuring -fPIC is used, ensuring -tls