Link MKL Library

[mohanmuthu]

Hello,

I am trying to use the MKL library function GEMM in my code by adding the line INCLUDE "mkl.fi" and compliling with option /Qmkl in commandline. I am getting the error LNK2019: unresolved external symbol _GEMM. Am I missing anything? However, I tried to use VSCBRT function with appropriate include file, and it works. Please help.

[TimP]

For lapack95 support, you need use lapack95 to accomplish the substitutions of specific MKL functions for generic ones such as gemm. I suppose this might conflict with mkl.fi, but the latter would not handle the lapack95 calls.

[mohanmuthu]

I tried to replace "mkl.fi" with "blas.f90", but it throws many errors since blas.f90 is the collection of interfaces alone. I use the command line of IA-32, Version 12.1.5.344 [Visual Studio 2005]. ?gemm page of MKL user manual says: Include Files: Fortran : mkl.fi Fortran 95 : blas.f90

[mecej4 · Accepted solution]

You have to follow the prescribed way of telling the compiler and linker that your code uses BLAS95 routines such as DGEMM. See the example driver dgemx.f90 in the .../mkl/examples/blas95/source directory. To call DGEMM using the F9x interface, you need "USE mkl95_blas" before the declarations section of your program, and link to mkl_blas95.lib.

[mohanmuthu]

Thanks mecej4. I tried it and found working with sgemm, not GEMM alone as indicated in manual. However, while running, I get error: forrtl: severe (157): Program Exception - access violation. Not sure what I miss. test.f90************ PROGRAM test use mkl95_blas real*4 :: a(10,10),b(10,10),c(10,10) a=1.0 b=1.0 call sgemm(a,b,c) END PROGRAM test

[mecej4]

The access violation was a result of your "fixing" something that was not broken. You called the F77 SGEMM routine with an incorrect argument list. Try this: [fortran]PROGRAM test use mkl95_blas real*4 :: a(5,3),b(3,4),c(5,4) a=1.0 b=2.0 call gemm(a,b,c) write(*,10)(c(i,:),i=1,5) 10 format(1x,4ES12.4) END PROGRAM test [/fortran] [bash]ifort /MD /Qmkl gemx.f90 mkl_blas95.lib[/bash]