intel Mkl Oneapi (library usage)

[sedsil]

Dear All,
I used to use Turbo Pascal. I am a new user of Lazarus 4.0. I can not resolve to add the Intel MKL library to Lazarus. On the windows 10, I have defined PATH  "C:\Program Files (x86)\Intel\oneAPI\mkl\latest\bin". This folder contains mkl_rt.2.dll and mkl_rt.dll. my code is like that: ********************************************
program MKLEigenSolver;
{$mode objfpc}{$H+}
{$APPTYPE CONSOLE}

uses
  Windows, SysUtils;

type
  TLAPACKE_dsyev = function(layout: Integer; jobz, uplo: Char;
                           n: Integer; a: PDouble; lda: Integer;
                           w: PDouble): Integer; cdecl;

const
  MKL_PATH = 'C:\Program Files (x86)\Intel\oneAPI\mkl\latest\bin\';
  LAPACK_ROW_MAJOR = 101;

var
  hMKL: HMODULE;
  dsyevFunc: TLAPACKE_dsyev;
  A: array[0..8] of Double = (
    4.0, 1.0, 0.5,
    1.0, 3.0, 1.0,
    0.5, 1.0, 2.0
  );
  W: array[0..2] of Double;
  i: Integer;

begin
  try
    // Load only the main MKL DLL
    WriteLn('Loading MKL runtime...');

    // Try loading in preferred order
    hMKL := LoadLibrary(PChar(MKL_PATH + 'mkl_rt.2.dll'));
    if hMKL = 0 then
      hMKL := LoadLibrary(PChar(MKL_PATH + 'mkl_rt.dll'));

    if hMKL = 0 then
    begin
      WriteLn('ERROR: Failed to load MKL runtime library');
      WriteLn('Please ensure either mkl_rt.2.dll or mkl_rt.dll exists in:');
      WriteLn(MKL_PATH);
      ReadLn;
      Exit;
    end;

    // Get function pointer
    WriteLn('Locating dsyev function...');
    dsyevFunc := TLAPACKE_dsyev(GetProcAddress(hMKL, 'LAPACKE_dsyev'));
    if not Assigned(dsyevFunc) then
    begin
      WriteLn('ERROR: Failed to find required function');
      FreeLibrary(hMKL);
      ReadLn;
      Exit;
    end;

    // Compute eigenvalues
    WriteLn('Calculating eigenvalues...');
    if dsyevFunc(LAPACK_ROW_MAJOR, 'N', 'U', 3, @A[0], 3, @W[0]) = 0 then
    begin
      WriteLn(#13#10'RESULTS:');
      for i := 0 to 2 do
        WriteLn(Format('λ%d = %.6f', [i+1, W]));
    end
    else
      WriteLn('ERROR: Eigenvalue computation failed');

  except
    on E: Exception do
      WriteLn('FATAL ERROR: ', E.ClassName, ' -> ', E.Message);
  end;

  if hMKL <> 0 then
    FreeLibrary(hMKL);

  WriteLn(#13#10'Press Enter to exit...');
  ReadLn;
end.
***************************************
the output for the error message is attached. Could you direct me to solve this matter?

[marcov]

Maybe the library needs some initializer? Some exception occurs in the DLL.

[Zvoni]

C:\Program Files (x86)\Intel\oneAPI\mkl\latest\bin

32-Bit vs. 64-Bit?
What's the Compile-Target?

EDIT: Ignore the above. Just saw his LoadLibrary-Call, which apparently works.
So my money is on wrong native FreePascal-Types used.
Maybe use ctypes-unit and its types?

[marcov]

C:\Program Files (x86)\Intel\oneAPI\mkl\latest\bin

32-Bit vs. 64-Bit?
What's the Compile-Target?

No, then the library wouldn't load and loadlibrary and getprocaddress calls would fail

[Zvoni]

C:\Program Files (x86)\Intel\oneAPI\mkl\latest\bin

32-Bit vs. 64-Bit?
What's the Compile-Target?

No, then the library wouldn't load and loadlibrary and getprocaddress calls would fail

Yeah, see my edit above. Noticed that, too

I've found this in the lapacke_config.h-file

Code: C  [Select][+][-]

1. #ifndef lapack_int
2.    #if defined(LAPACK_ILP64)
3.    #define lapack_int              long
4.    #else
5.    #define lapack_int              int
6. #endif

[marcov]

ILP64 targets are rare. Windows is LLP64 and open source Unix is usually LP64.   In both of them integer is 32-bit on 64-bit targets.

[Zvoni]

Found this example: https://www.intel.com/content/www/us/en/docs/onemkl/code-samples-lapack/2024-1/lapacke-dsyev-example-c-column.html

The only thing i see is

Code: C  [Select][+][-]

1. /* Solve eigenproblem */
2.         info = LAPACKE_dsyev( LAPACK_COL_MAJOR, 'V', 'U', n, a, lda, w );

is in the example 'V' as second Argument (as opposed to 'N' in TS code)
Maybe the dll chokes on that?
The C-code basically transfers work to
https://netlib.org/lapack/explore-html-3.6.1/de/ddd/lapacke_8h_a6fe2a100c43ce81b43ae242f9763e3ec.html#a6fe2a100c43ce81b43ae242f9763e3ec

Code: C  [Select][+][-]

1. void LAPACK_dsyev       (       char *          jobz,
2.                 char *          uplo,
3.                 lapack_int *    n,
4.                 double *        a,
5.                 lapack_int *    lda,
6.                 double *        w,
7.                 double *        work,
8.                 lapack_int *    lwork,
9.                 lapack_int *    info
10.         )              

But i couldn't find the implementation file

EDIT: Looking further into this:
In ctypes-unit:
a c-"char" is a typedef for a cint8, which is a typedef for shortint
a c-"int" is a typedef for cint32, which is a TypeDef for longint

so my money is still on wrong types in his Prototype

[Thaddy]

I suspect it is the olden exception mask that needs to be set:

Code: Pascal  [Select][+][-]

1. SetExceptionMask(GetExceptionMask + [exOverflow,exZeroDivide,exInvalidOp]);

(By coincedense I ran into the same issue using python4lazarus today: on Windows, that also needs the exception mask set properly.)

Or the deprecated:

Code: Pascal  [Select][+][-]

1.  Set8087CW($1331);

[LV]

Place libiomp5md.dll in the project folder. 

Code: Pascal  [Select][+][-]

1. program MKLEigenSolver;
2. {$mode objfpc}{$H+}
3. {$APPTYPE CONSOLE}
4.  
5. uses
6.   Windows, SysUtils;
7.  
8. type
9.   TLAPACKE_dsyev = function(layout: Integer; jobz, uplo: Char;
10.                            n: Integer; a: PDouble; lda: Integer;
11.                            w: PDouble): Integer; cdecl;
12.  
13. const
14.   MKL_PATH = 'C:\Program Files (x86)\Intel\oneAPI\mkl\latest\bin\';
15.   LAPACK_ROW_MAJOR = 101;
16.  
17. var
18.   hMKL: HMODULE;
19.   dsyevFunc: TLAPACKE_dsyev;
20.   A: array[0..8] of Double = (
21.     4.0, 1.0, 0.5,
22.     1.0, 3.0, 1.0,
23.     0.5, 1.0, 2.0
24.   );
25.   W: array[0..2] of Double;
26.   i: Integer;
27.  
28. begin
29.   try
30.     // Load only the main MKL DLL
31.     WriteLn('Loading MKL runtime...');
32.  
33.     // Try loading in preferred order
34.     hMKL := LoadLibrary(PChar(MKL_PATH + 'mkl_rt.2.dll'));
35.     if hMKL = 0 then
36.       hMKL := LoadLibrary(PChar(MKL_PATH + 'mkl_rt.dll'));
37.  
38.     if hMKL = 0 then
39.     begin
40.       WriteLn('ERROR: Failed to load MKL runtime library');
41.       WriteLn('Please ensure either mkl_rt.2.dll or mkl_rt.dll exists in:');
42.       WriteLn(MKL_PATH);
43.       ReadLn;
44.       Exit;
45.     end;
46.  
47.     // Get function pointer
48.     WriteLn('Locating dsyev function...');
49.     dsyevFunc := TLAPACKE_dsyev(GetProcAddress(hMKL, 'LAPACKE_dsyev'));
50.     if not Assigned(dsyevFunc) then
51.     begin
52.       WriteLn('ERROR: Failed to find required function');
53.       FreeLibrary(hMKL);
54.       ReadLn;
55.       Exit;
56.     end;
57.  
58.     // Compute eigenvalues
59.     WriteLn('Calculating eigenvalues...');
60.     if dsyevFunc(LAPACK_ROW_MAJOR, 'N', 'U', 3, @A[0], 3, @W[0]) = 0 then
61.     begin
62.       WriteLn(#13#10'RESULTS:');
63.       for i := 0 to 2 do
64.         WriteLn(Format('λ%d = %.6f', [i+1, W[i]]));
65.     end
66.     else
67.       WriteLn('ERROR: Eigenvalue computation failed');
68.  
69.   except
70.     on E: Exception do
71.       WriteLn('FATAL ERROR: ', E.ClassName, ' -> ', E.Message);
72.   end;
73.  
74.   if hMKL <> 0 then
75.     FreeLibrary(hMKL);
76.  
77.   WriteLn(#13#10'Press Enter to exit...');
78.   ReadLn;
79. end.
80.  

Get the result you want 

Code: Text  [Select][+][-]

1. Loading MKL runtime...
2. Locating dsyev function...
3. Calculating eigenvalues...
4.  
5. RESULTS:
6. О>1 = 1,377095
7. О>2 = 2,682456
8. О>3 = 4,940450
9.  
10. Press Enter to exit...
11.  

Enjoy 

[PascalDragon]

my code is like that:

Please use [code][/code]-tags to avoid the forum software interpreting your code.

[Zvoni]

Place libiomp5md.dll in the project folder. 

*groan*
Did we actually forgot it might be a dependant dll missing?

[sedsil]

Place libiomp5md.dll in the project folder. 

Dear friend, I have tested the proposal you advised me on. YES, it works very well. Thank you for your help. Thank you all for the help.