1 /*
2
3 Copyright (C) 2014, The University of Texas at Austin
4
5 This file is part of libflame and is available under the 3-Clause
6 BSD license, which can be found in the LICENSE file at the top-level
7 directory, or at http://opensource.org/licenses/BSD-3-Clause
8
9 */
10
11 #include "FLAME.h"
12
13 #ifdef FLA_ENABLE_NON_CRITICAL_CODE
14
FLA_LU_nopiv_unb_var3(FLA_Obj A)15 FLA_Error FLA_LU_nopiv_unb_var3( FLA_Obj A )
16 {
17 FLA_Obj ATL, ATR, A00, a01, A02,
18 ABL, ABR, a10t, alpha11, a12t,
19 A20, a21, A22;
20
21 FLA_Part_2x2( A, &ATL, &ATR,
22 &ABL, &ABR, 0, 0, FLA_TL );
23
24 while ( FLA_Obj_length( ATL ) < FLA_Obj_length( A ) &&
25 FLA_Obj_width( ATL ) < FLA_Obj_width( A )){
26
27 FLA_Repart_2x2_to_3x3( ATL, /**/ ATR, &A00, /**/ &a01, &A02,
28 /* ************* */ /* ************************** */
29 &a10t, /**/ &alpha11, &a12t,
30 ABL, /**/ ABR, &A20, /**/ &a21, &A22,
31 1, 1, FLA_BR );
32
33 /*------------------------------------------------------------*/
34
35 // a01 = trilu( A00 ) \ a10
36 FLA_Trsv_external( FLA_LOWER_TRIANGULAR, FLA_NO_TRANSPOSE, FLA_UNIT_DIAG, A00, a01 );
37
38 // alpha11 = alpha11 - a10t * a01
39 FLA_Dots_external( FLA_MINUS_ONE, a10t, a01, FLA_ONE, alpha11 );
40
41 // a21 = a21 - A20 * a01
42 FLA_Gemv_external( FLA_NO_TRANSPOSE, FLA_MINUS_ONE, A20, a01, FLA_ONE, a21 );
43
44 // a21 = a21 / alpha11
45 FLA_Inv_scal_external( alpha11, a21 );
46
47 /*------------------------------------------------------------*/
48
49 FLA_Cont_with_3x3_to_2x2( &ATL, /**/ &ATR, A00, a01, /**/ A02,
50 a10t, alpha11, /**/ a12t,
51 /* ************** */ /* ************************ */
52 &ABL, /**/ &ABR, A20, a21, /**/ A22,
53 FLA_TL );
54
55 }
56
57 if ( FLA_Obj_width( ATR ) > 0 )
58 // ATR = trilu( ATL ) \ ATR
59 FLA_Trsm_external( FLA_LEFT, FLA_LOWER_TRIANGULAR,
60 FLA_NO_TRANSPOSE, FLA_UNIT_DIAG,
61 FLA_ONE, ATL, ATR );
62
63 return FLA_SUCCESS;
64 }
65
66 #endif
67