Intel® Cilk™ Plus

Optimizing Big Data processing with Haswell 256-bit Integer SIMD instructions

Big Data requires processing huge amounts of data. Intel Advanced Vector Extensions 2 (aka AVX2) promoted most Intel AVX 128-bits integer SIMD instruction sets to 256-bits. Intel AVX brought 256-bits floating-point SIMD instructions, but it didn't include 256-bits integer SIMD instructions. Intel AVX2 allows you to operate with the AVX 256-bits wide YMM register for integer data types. In this post, I’ll explain how developers can speedup big data processing with the new 256-bits integer SIMD instructions.

Less performance on 16 core than on 4 ?!

Hi there,

I evaluated my cilk application using "taskset -c 0-(x-1) MYPROGRAM) to analyze scaling behavior.


I was very suprised to see, that the performances increases up to a number of cores but decreases afterwards.

for 2 Cores, I gain a speedup of 1,85. for 4, I gain 3.15. for 8 4.34 - but with 12 cores the performance drops down
to a speedup close to the speedup gained by 2 cores (1.99).
16 cores performe slightly better (2.11)

Exception when run project at debug mode using cilk_for

Dear all,

I have used cilk_plus to make parallel processing into my source code with visual studio 2008 IDE.

But when I build it at debug mode, the project throw an exception below:

"Run-Time Check Failure #0 - The value of ESP was not properly saved across a function call. This is usually a result of calling a function pointer declared with a different calling convention"

How can  I resolve it to make debug mode operated ?

Thanks of all,

Tam Nguyen


Cilk Tools error while loading shared libraries

I have successfully compiled cilkplus for gcc (4.8 branch) on Ubuntu 14.04 LTS and compiled the example program fib on the cilkplus website.  I would like to run cilkview and cilkscreen on it, and so I downloaded cilk tools from the website as well.  However, when I try to run cilkview, I get the following error:

Cilkview: Generating scalability data
-t: error while loading shared libraries: -t: cannot open shared object file: No such file or directory

Submissions open: High Performance Parallelism Gems

We have all had our little discoveries and triumphs in identifying new and innovative approaches that increased the performance of our applications. Occasionally we find something more, something that could also help others, an innovative gem. You now have an opportunity to broadcast your successes more widely to the benefit of our community. You are invited to submit a proposal to a contribution-based book, working title, “High Performance Parallelism Gems – Successful Approaches for Multicore and Many-core Programming” that will focus on practical techniques for Intel® Xeon® processor and Intel® Xeon Phi™ coprocessor parallel computing. Submissions are due by May 29, 2014.

Internal compiler error 010101_239

Hi guys,

I condensed our project down to a piece of code that lets you reproduce the following issue.
When I compile this in Release configuration (Debug works), I get this compiler error:

1>------ Build started: Project: ng-gtest, Configuration: Release x64 ------
1> CilkTest.cpp
1>" : error : 010101_239
1> compilation aborted for General\CilkTest.cpp (code 4)
========== Build: 0 succeeded, 1 failed, 3 up-to-date, 0 skipped ==========

Cilk worker scheduling


I would like to understand better how Cilk scheduling works. 
I am not sure how to phrase this question so I give it my best.

I have downloaded the latest Intel Cilk runtime release (cilkplus-rtl-003365 -  released 3-May-2013).
I use the classical Fibonacci example in Cilk.

Iscriversi a Intel® Cilk™ Plus