topic BLAS LAPACK Intel Compilers in Visual Studio 2005 IDE in Intel® oneAPI Math Kernel Library

BLAS LAPACK Intel Compilers in Visual Studio 2005 IDE

wolfee — Sun, 23 Nov 2008 21:08:35 GMT

Hello,

As a start, I'm just trying to run Example 7.2 from the Intel Math Kernal Library User Guide. It is an example of calling a complex BLAS Level 1 from C++. I am attempting to run the example in Visual Studio 2005. The example is listed at the very end of this entry for completeness.

Here is the problem - > For some reason I keep getting an error regarding duplication of the zdotc function. The exact error follows. Can anyone help?

------ Build started: Project: BLAS_EXAMPLE, Configuration: Debug Win32 ------
Compiling with Intel C++ 10.1.011 [IA-32]... (Intel C++ Environment)
BLAS_LEVEL_1.cpp
.\BLAS_LEVEL_1.cpp(3): error: more than one instance of overloaded function "zdotc" has "C" linkage
extern "C" void zdotc(complex16*, int *, complex16 *, int *, complex16*, int *);
^

compilation aborted for .\BLAS_LEVEL_1.cpp (code 2)
Build log was saved at "file://C:\CARL\DEVELOPMENT\RESEARCH\200811WORK\LEARN_INTEL_MTL\BLAS_EXAMPLE\BLAS_EXAMPLE\Debug\BuildLog.htm"
BLAS_EXAMPLE - 1 error(s), 0 warning(s)
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

code listing follows ------------------------------------

#include "mkl_blas.h"
typedef struct{ double re; double im; } complex16;
extern "C" void zdotc(complex16*, int *, complex16 *, int *, complex16*, int *);
#define N 5

int main()
{
int n, inca = 1, incb = 1, i;
complex16 a, b, c;
n = N;
for( i = 0; i < n; i++ ){
a.re = (double)i; a.im = (double)i * 2.0;
b.re = (double)(n - i); b.im = (double)i * 2.0;
}
zdotc(&c, &n, a, &inca, b, &incb );
//printf( "The complex dot product is: ( %6.2f, %6.2f)\n", c.re, c.im );
}

Re: BLAS LAPACK Intel Compilers in Visual Studio 2005 IDE

Andrey_Bespalov — Mon, 24 Nov 2008 15:19:05 GMT

Your declaration of zdotc (void zdotc(complex16*, int *, complex16 *, int *, complex16*, int *);) conflicts with declaration in mkl_blas.h (void zdotc(MKL_Complex16 *pres, const MKL_INT *n, const MKL_Complex16 *x, const MKL_INT *incx, const MKL_Complex16 *y, const MKL_INT *incy);)

Re: BLAS LAPACK Intel Compilers in Visual Studio 2005 IDE

Gennady_F_Intel — Mon, 24 Nov 2008 16:12:47 GMT

As an additional info, please pay attention the Note into mkl manual:

NOTE. Instead of calling BLAS directly from C programs, you might wish to use the

CBLAS interface; this is the supported way of calling BLAS from C. For more information

about CBLAS, see Appendix D , which presents CBLAS, the C interface to the Basic Linear

Algebra Subprograms (BLAS) implemented in Intel MKL.

And you can find the appropriate examples of using CBLAS Interface to the BLAS into

${MKLROOT}examplescblassource

--Gennady