Intel® C++ Compiler

Imperfect Loop Unroll-Jammed by 2 (pre-vector)

Hi, I am optimizing an application. I am facing the below warning message in xxx.optrpt file.

(I gave -qopt-report=5 option.)

      remark #25461: Imperfect Loop Unroll-Jammed by 2   (pre-vector)

What would be the general requirements of perfect loop unroll-jamming?

I don't see any kinds of explanations about this warning in icc reference manual.

Also, what is the meaning of (pre-vector)? 

I am using icc 15.0.2 and unfortunately, I cannot upload the code here because it is very complex and large code.



icc 15.0.3 cannot compile std::vector<double> constructor with headers from gcc 5.1.1

The following simple program doesn't compile with icc 15.0.3 on Fedora 22.  It does work on Fedora 20.  I think the main difference is that Fedora 22 is using gcc 5.1.1, which is where the header files come from.  In contrast Fedora 20 uses gcc 4.8.3.


I don't know how to interpret the error message.


$ cat
#include <vector>

stringstream bug


In my program writing in C++, I use a few functions that use stringstream classes.

I do not have any problems with compilation of  my program by Visual Studio 2013 and Intel Parallel Studio 2013.

The same program I tried using  Visual Studio 2015 and Intel Parallel Studio 2015 XE Update 4.

I do not have any problems with compilation of  my program by MS compiler but when try to use Intel C++ compiler I get only one error:

1>": : error : ** The compiler has encountered an unexpected problem.

Missing links from to composer_xe - Parallel Studio 2015 update 3


I've installed the latest version of the Intel Parallel Studio XE -Cluster-Edition- 2015 Update 3 and found a minor bug:
After installation I've tried to source the which worked for all features (Vtune, Amplifier, etc,) except the Intel compilers and MPI-Variables.

The reason: tries to load the (see attached extract of source code)

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