Intel® C++ Compiler

Intel® Parallel Studio XE 2016 Beta program has begun

Hello everyone,

The Intel® Parallel Studio XE 2016 Beta program has just begun. We welcome you to participate. For the new features and improvements, you can find them under "Change History" section in the Intel C++ Compiler Release Notes:

Free webinar April 7 2015 9am PST "Further Vectorization Features of the Intel Compiler"

There is a free webinar “Further Vectorization Features of the Intel Compiler” coming next Tuesday talking specifically about getting more vectorizations from Intel Compilers. But you would benefit it more if you've watched/listened to the previous webinar Performance essentials using OpenMP* 4.0 vectorization with C/C++.

OS X 10.9 Xcode 5 error can't open "stdlib.h" OR ld: library not found for -lcrt1.10.6.o

Environment:  OS X 10.9 (Mavericks) and Xcode 5.0

Command line compilations/links fail with either:

"catastrophic error: cannot open source file "stdlib.h" OR with "ld: library not found for -lcrt1.10.6.o"

Affected compiler:  Intel Composer XE 2013 Update 1

Root cause:  Xcode 5.0 installation does not install all command line tools (include files, libraries, SDKs) need for the compiler to link user applications. 

IDB use under Mac OS* X 10.7 Lion

In order to debug applications built by the Intel Composer XE 2011 (
Updates 6, 7, 8, and possible future updates ) under Mac OS* X 10.7
Lion, the following options are required:

-g -save-temps -fpic -Wl,-no_pie

Further information can be found here:

This does not affect users running Mac OS* X 10.6 Snow Leopard or Mac OS* X 10.5 Leopard.

Memory leak caused or worsened by /Qipo?

I've made a DLL while I compile with /Qipo (Intel C++ Composer XE2015). If I call the constructor and destructor of the main class in it, the memory doesn't get released and after a few calls (32 bit mode) I'm out of memory. However, if I disable /Qipo, there doesn't seem to be a problem at all (I will run it for a longer period tonight, but I let it construct and deconstruct 1024 times earlier tonight and I didn't notice an increase in memory usage).

If I use /Qip mode, the leak is 8 MB per call. With /Qipo it's about 300 MB.

Parallelization of dyadic product


I have two vectors (they can address the same vector) and I need to perform the product x[i]*y[j] with i,j=1..n.

What is the best way to perform this operation in parallel? I've tried


but I guess it is only a naive tentative to do that. Indeed vec-report says it is uneffcient.




_mm_unpackhi_epi8 and _mm_unpacklo_epi8 to convert 16 signed chars into 2 signed short vectors

I am using the _mm_unpacklo_epi16 and _mm_unpackhi_epi16 with second argumet vector of 0s to convert signed/unsigned short vectors into 2 signed/unsigned integer vectors. i.e.:

__m128i lowVec  = _mm_unpacklo_epi16(vecA vec0);
__m128i highVec = _mm_unpackhi_epi16(vecA,vec0);

This works fine with 16 unsigned chars vector into 2 unsigned short  vectors using  _mm_unpacklo_epi8 and _mm_unpackhi_epi8, yet when the input vector is of 16 signed chars the 2 short values in result vectors are all 127+original values. 

Unresolved references in MSVCRT.lib with Visual Studio 2015 RC

I installed Intel Parallel Studio XE 2016 Beta Update 1 with Visual Studio Community 2015 RC and I'm getting unresolved references in MSVCRT.lib when I try to build a default Win32 console project in x64 mode:

simple vector addition



I have a question w.r.t below scenario on Intel Sandy Bridge,

For simple vector addition code in C,

If I do dynamic memory allocation it vectorizes the main addition loop

    C[i] = A[i] + B[i]

even if I do not use any restrict keyword (icc 13)

But if I statically allocate arrays, it does not vectorize loop nor it specifies something about it in vectorization report.

Even if I do allocation using declspec(align) it does not vectorize.

What can be the causes ?

Thanks in advance,



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