Intel® Parallel Composer

Оптимизировали, оптимизировали, да не выоптимизировали!

Оптимизация? Конечно, каждый сталкивался с данной задачей при разработке своих, сколь-нибудь значительных, требующих определённых вычислений, приложений. При этом способов оптимизировать код существует огромное множество, и, как следствие, различных путей сделать это в автоматическом режиме с помощью опций компилятора. Вот здесь и возникает проблема – как выбрать то, что нужно нам и не запутаться?

Slides from May 4th Webinar on Cilk

Hi all,

We did a webinar this morning at 8am Pacific time on changes and new updates in Cilk in the Intel Parallel Composer beta. I am posting the slides here. Let me know if there's any interest to do another webinar on this around 5pm or so Pacific time - I want to see if there's anyone that couldn't attend due to the time that would have liked to attend. Thanks everyone, and I really enjoyed the questions in today's session.

Problem in Cilkview and Cilkscreen 4225

Hello,

I am new in Cilk plus. I am facing problem in Cilkview and Cilkscreen 4225. Please help/ guide me ...

I am working on Ubuntu 14.04 LTS with GCC 4.9.2. I install Intel Cilk Plus SDK by synaptic manager.

=> libcilkrts5, libcilkrts5-dbg, libx32cilkrts5, libx32cilkrts5-dbg

I wrote the following code

/**********************/

#include <iostream>
#include <cilk/cilk.h>

using namespace std;

How is the user worker thread returned when returning from cilk runtime?

Hi

In the Binary Interface Specification, it says when the last user thread calls __cilkrts_leave_frame() with a __cilkrts_stack_frame which has CILK_FRAME_LAST set in the flags field, the runtime will suspend all of the worker threads it created."

I have a question about when the stack frame set as CILK_FRAME_LAST gets stolen by the system worker.

gcc 5.1 -mfpmath=387 Floating point exception

It appears that the compiler option -mfpmath=387 immediately causes floating point exceptions on Intel architecture processors in cilk_spawn routines compiled with gcc-5.1 cilk.  This seems to be a regression as gcc-4.9 with the cilk patches works fine.  Note that -mfpmath=sse works on 64-bit machines, however, this option is not available for 32-bit Intel machines.  As far as I can tell, most floating point code is affected.  Does anyone know of patches or workarounds for this, especially as this appears to be a show-stopper on 32-bit Intel.

Cilkplus port to Raspberry Pi 2B

I compiled the new release of gcc-5.1 with the Cilkplus parallel processing extensions and runtime library for ARMv7 architecture on the Raspberry Pi 2B single board computer.  Two changes were needed.

The first change corrects a typo in generic/cilk-abi-vla.c by changing the second to the last line of the file from

vla_internal_heap_free(t, full_size);

to

vla_internal_heap_free(p, full_size);

the second change was to generic/os-fence.c and ARM specific. Comment out the line

COMMON_SYSDEP void __cilkrts_fence(void); ///< MFENCE instruction

changes in CEAN implications re vectorization in next release?

I note that premier.intel.com is open for submissions for the first time in months, so I submitted a ticket.  It still looks like setting up premier for beta 16 has not been completed, as the form requires choosing compiler version 15.0 or earlier from the pull-down.

I'm curious whether Cilk(tm) Plus is under deprecation, in view of the comments at IDF last year that Intel would not sponsor publications on it, and the lack of follow-through to make gcc -fcilkplus viable.

As to changes in behavior in the beta test:

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