Intel® Cilk™ Plus

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);


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 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:

Using Cilk reducer inside Cilker shared function

Hi I am trying to offload some parallel work to MIC using _Cilk_Shared and _Cilk_offload. 

I declare a Cilk shared function:

_Cilk_shared void somefun(int count)


In main I call this function using 

_Cilk_offload somefun(12) ;

inside this function everything is expected to be offloaded to MIC;

I want to declare a Cilk reducer inside somefun, so I can then use cilk_for and append to a cilk reducer list, 

but I get error:

Unable to Compile GCC

I was following the instructions from, and I consistently got an error saying that "tm.h": no file or directory was found. I'm not sure what tm.h is, or what package it is included with.

I installed the following packages: GNAT (probably doesn't help), GMP, MPFR, MPC, ISL, Flex, Bison.

My configuration options were `./configure --prefix=/usr/lib/gcc/cilkplus --enable-languages="c,c++" --disable-multilib`

On Ubuntu 14.10. 

Is cilk slower on Linux than on Windows?

Currently, I am getting decent results with Intel 15 Cilk on Windows. However, the results is not nearly as good on Linux. My feeling is the overhead of a spawn is bigger on Linux. Any suggestions/comments?

I had expected the opposite results i.e. better results on Linux. 

I am using fairly new hardware and have tried to disable hyperthreading. Disabling hypertreading improves the result a bit but not much.


cilkview and gcc 4.9 cilkplus branch on 64 bit linux

Hello, I've downloaded the latest (I think) version fo cilkview from the cilkplus website. For some reason it is not working (even if I try to run it from the same folder, it doesn't find the program...) I'm thinking it has to do with some 32 vs 64-bit library. I exported the lib64 to no avail. Is there any kind of support for cilkview? If not, will you guys just release the source, so we can patch it? This would be great. Same with cilkprof.

Thanks for your time.

Assine o Intel® Cilk™ Plus