Usage Examples for the Memory Functions

Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

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ID 766686

Date 3/22/2024

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Usage Examples for the Memory Functions

Usage Example for 1-dimensional Arrays

      PROGRAM FOO
      INCLUDE 'mkl.fi'
 
      DOUBLE PRECISION     A,B,C
      POINTER    (A_PTR,A(1)), (B_PTR,B(1)), (C_PTR,C(1))
      INTEGER    N, I
      REAL*8     ALPHA, BETA
      INTEGER*8  ALLOCATED_BYTES
      INTEGER*8  PEAK_MEMORY
      INTEGER*4  ALLOCATED_BUFFERS
 
#ifdef _SYSTEM_BITS32
        INTEGER*4 MKL_MALLOC, MKL_CALLOC, MKL_REALLOC
        INTEGER*4 ALLOC_SIZE, NUM, SIZE
#else
        INTEGER*8 MKL_MALLOC, MKL_CALLOC, MKL_REALLOC
        INTEGER*8 ALLOC_SIZE, NUM, SIZE
#endif
 
      EXTERNAL   MKL_MALLOC, MKL_FREE, MKL_CALLOC, MKL_REALLOC

      ALPHA = 1.1; BETA = -1.2
      N = 1000
      SIZE = 8
      NUM = N*N
      ALLOC_SIZE = SIZE*NUM
      PEAK_MEMORY = MKL_PEAK_MEM_USAGE(MKL_PEAK_MEM_ENABLE)
      A_PTR = MKL_MALLOC(ALLOC_SIZE,64)
      B_PTR = MKL_MALLOC(ALLOC_SIZE,64)
      C_PTR = MKL_CALLOC(NUM,SIZE,64)
      DO I=1,N*N
        A(I) = I
        B(I) = -I
      END DO
 
      CALL DGEMM('N','N',N,N,N,ALPHA,A,N,B,N,BETA,C,N);
 
      ALLOCATED_BYTES = MKL_MEM_STAT(ALLOCATED_BUFFERS)
      PRINT *,'DGEMM uses ',ALLOCATED_BYTES,' bytes in ',
     $  ALLOCATED_BUFFERS,' buffers '
 
      CALL MKL_FREE_BUFFERS
      CALL MKL_FREE(A_PTR)
      CALL MKL_FREE(B_PTR)
      CALL MKL_FREE(C_PTR)

      ALLOCATED_BYTES = MKL_MEM_STAT(ALLOCATED_BUFFERS)
      IF (ALLOCATED_BYTES > 0) THEN
       PRINT *,'MKL MEMORY LEAK!'
       PRINT *,'AFTER MKL_FREE_BUFFERS there are ',
     $    ALLOCATED_BYTES,' bytes in ',
     $    ALLOCATED_BUFFERS,' buffers'
      END IF

      PEAK_MEMORY = MKL_PEAK_MEM_USAGE(MKL_PEAK_MEM_RESET)
      PRINT *,'Peak memory allocated by Intel MKL memory allocator ',
     $  PEAK_MEMORY,' bytes. ',
     $  'Start to count new memory peak'

      A_PTR = MKL_MALLOC(ALLOC_SIZE,64)
      A_PTR = MKL_REALLOC(A_PTR,ALLOC_SIZE*SIZE)
      CALL MKL_FREE(A_PTR)
      PEAK_MEMORY = MKL_PEAK_MEM_USAGE(MKL_PEAK_MEM)
      PRINT *,'After reset of peak memory counter',
     $  'Peak memory allocated by Intel MKL memory allocator ',
     $  PEAK_MEMORY,' bytes'

      STOP
      END

Usage Example for 2-dimensional Arrays

      PROGRAM FOO
      INTEGER    N
      PARAMETER  (N=100)
      DOUBLE PRECISION     A,B,C
      POINTER    (A_PTR,A(N,*)), (B_PTR,B(N,*)), (C_PTR,C(N,*))
      INTEGER    I,J
      REAL*8     ALPHA, BETA
      INTEGER*8  ALLOCATED_BYTES
      INTEGER*4  ALLOCATED_BUFFERS

#ifdef _SYSTEM_BITS32
        INTEGER*4 MKL_MALLOC
        INTEGER*4 ALLOC_SIZE
#else
        INTEGER*8 MKL_MALLOC
        INTEGER*8 ALLOC_SIZE
#endif

      INTEGER    MKL_MEM_STAT
      EXTERNAL   MKL_MALLOC, MKL_FREE, MKL_MEM_STAT

      ALPHA = 1.1; BETA = -1.2
      ALLOC_SIZE = 8*N*N
      A_PTR = MKL_MALLOC(ALLOC_SIZE,64)
      B_PTR = MKL_MALLOC(ALLOC_SIZE,64)
      C_PTR = MKL_MALLOC(ALLOC_SIZE,64)
      DO I=1,N
        DO J=1,N
           A(I,J) = I
           B(I,J) = -I
           C(I,J) = 0.0
        END DO
      END DO

      CALL DGEMM('N','N',N,N,N,ALPHA,A,N,B,N,BETA,C,N);

      ALLOCATED_BYTES = MKL_MEM_STAT(ALLOCATED_BUFFERS)
      PRINT *,'DGEMM uses ',ALLOCATED_BYTES,' bytes in ',
     $  ALLOCATED_BUFFERS,' buffers '

      CALL MKL_FREE_BUFFERS
      CALL MKL_FREE(A_PTR)
      CALL MKL_FREE(B_PTR)
      CALL MKL_FREE(C_PTR)

      ALLOCATED_BYTES = MKL_MEM_STAT(ALLOCATED_BUFFERS)
      IF (ALLOCATED_BYTES > 0) THEN
        PRINT *,'MKL MEMORY LEAK!'
        PRINT *,'AFTER MKL_FREE_BUFFERS there are ',
     $    ALLOCATED_BYTES,' bytes in ',
     $    ALLOCATED_BUFFERS,' buffers'
      END IF

      STOP
      END

Parent topic: Memory Management

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Developer Reference for Intel® oneAPI Math Kernel Library for Fortran

Usage Examples for the Memory Functions