libflame  revision_anchor
Functions
FLA_LU_nopiv_blk_var4.c File Reference

(r)

Functions

FLA_Error FLA_LU_nopiv_blk_var4 (FLA_Obj A, fla_lu_t *cntl)

Function Documentation

References FLA_Cont_with_3x3_to_2x2(), FLA_Determine_blocksize(), FLA_Gemm_internal(), FLA_LU_nopiv_internal(), FLA_MINUS_ONE, FLA_Obj_length(), FLA_Obj_width(), FLA_ONE, FLA_Part_2x2(), FLA_Repart_2x2_to_3x3(), and FLA_Trsm_internal().

Referenced by FLA_LU_nopiv_internal().

{
  FLA_Obj ATL,   ATR,      A00, A01, A02, 
          ABL,   ABR,      A10, A11, A12,
                           A20, A21, A22;

  dim_t b;


  FLA_Part_2x2( A,    &ATL, &ATR,
                      &ABL, &ABR,     0, 0, FLA_TL );

  while ( FLA_Obj_length( ATL ) < FLA_Obj_length( A ) &&
          FLA_Obj_width( ATL ) < FLA_Obj_width( A )){

    b = FLA_Determine_blocksize( ABR, FLA_BR, FLA_Cntl_blocksize( cntl ) );

    FLA_Repart_2x2_to_3x3( ATL, /**/ ATR,       &A00, /**/ &A01, &A02,
                        /* ************* */   /* ******************** */
                                                &A10, /**/ &A11, &A12,
                           ABL, /**/ ABR,       &A20, /**/ &A21, &A22,
                           b, b, FLA_BR );

    /*------------------------------------------------------------*/

    // A11 = LU( A11 - A10 * A01 )
    FLA_Gemm_internal( FLA_NO_TRANSPOSE, FLA_NO_TRANSPOSE,
                       FLA_MINUS_ONE, A10, A01, FLA_ONE, A11,
                       FLA_Cntl_sub_gemm1( cntl ) );

    // A11 = LU_nopiv( A11 )
    FLA_LU_nopiv_internal( A11, FLA_Cntl_sub_lu( cntl ) );

    // A12 = A12 - A10 * A02
    FLA_Gemm_internal( FLA_NO_TRANSPOSE, FLA_NO_TRANSPOSE,
                       FLA_MINUS_ONE, A10, A02, FLA_ONE, A12,
                       FLA_Cntl_sub_gemm2( cntl ) );

    // A12 = trilu( A11 ) \ A12
    FLA_Trsm_internal( FLA_LEFT, FLA_LOWER_TRIANGULAR, 
                       FLA_NO_TRANSPOSE, FLA_UNIT_DIAG,
                       FLA_ONE, A11, A12,
                       FLA_Cntl_sub_trsm1( cntl ) );

    // A21 = A21 - A20 * A01
    FLA_Gemm_internal( FLA_NO_TRANSPOSE, FLA_NO_TRANSPOSE,
                       FLA_MINUS_ONE, A20, A01, FLA_ONE, A21,
                       FLA_Cntl_sub_gemm3( cntl ) );

    // A21 = A21 / triu( A11 )
    FLA_Trsm_internal( FLA_RIGHT, FLA_UPPER_TRIANGULAR, 
                       FLA_NO_TRANSPOSE, FLA_NONUNIT_DIAG,
                       FLA_ONE, A11, A21,
                       FLA_Cntl_sub_trsm2( cntl ) );

    /*------------------------------------------------------------*/

    FLA_Cont_with_3x3_to_2x2( &ATL, /**/ &ATR,       A00, A01, /**/ A02,
                                                     A10, A11, /**/ A12,
                            /* ************** */  /* ****************** */
                              &ABL, /**/ &ABR,       A20, A21, /**/ A22,
                              FLA_TL );
  }

  return FLA_SUCCESS;
}