This article describes a parallel merge sort code, and why it is more scalable than parallel quicksort or parallel samplesort. The code relies on the C++11 “move” semantics. It also points out a scalability trap to watch out for with C++. The attached code has implementations in Intel® Threading Building Blocks (Intel® TBB), Intel® Cilk™ Plus, and OpenMP*.
Is cilk_sort functions parallel drop in replacements for the C qsort function?
I read on the doc that array notation can be used for array indicies in both cases :
C[:] = A[B[:]] and A[B[:]] = C[:]
I try to use this notation for left & right operands at the same time but it gives me wrong results.
Here is my problem:
In my search application there are globally variables defined outside any function that I would like to use the cilk reducers on.
Specifically I have code like this:
#include "search.h" static int total_users = 0; static int total_matches = 0;
These total_x variables are incremented throughout the application on different functions.
I tried adding the following for total_users and received the following error:
I have a C search application on a centos 6.x 64 bit linux server that I just installed the cilkplus compiler on to take advantage of more cpu/cores. I've added the cilk_spawn function to some recursive scanning functions in my program. After re-compiling the search application with the cilkplus gcc compiler, the search program is working as intended without any seg faults or any other errors.
My question is how do I use the cilkview analyzer? I want to if cilkplus/spawning is helping my search application and if so by how much?
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Explicit Vector Programming – Best Known Methods
Why do we care about vectorizing applications? The simple answer: Vectorizing improves performance, and achieving high performance can save power. The faster an application can compute CPU-intensive regions, the faster the CPU can be set to a lower power state.
First I would like to thank you all for the awesome cilk plus tools you have open source in GCC and LLVM.
I am trying to study the runtime library and finding it a bit difficult to follow the execution in a sample application.
Are there any developer documents available? A wiki perhaps.
Specifically, I am trying to trace the execution path for cilk_spawn which is a key word. Any helpful links to get me started would be really great!
What I understood about steal-continuation is, that every idle thread does not actually steal work, but the continuation which generates a new working item.
Does that mean, that inter-spawn execution time is crucial? If 2 threads are idle at the same time, from what I understand only one can steal the continuation and create its working unit, the other thread stays idle during that time?!
As a debugging artefact, I had a global counter incremented on every function call of a function used within every working item.
I'm new to cilk, and i wanted to ask if it has an implicit threshold for the task creation, in recursive computations like fib?
If so, is it based on the number of tasks created, or in the depth of the computation?