--- /dev/null
+*> \brief \b CHETRF_ROOK computes the factorization of a complex Hermitian indefinite matrix using the bounded Bunch-Kaufman ("rook") diagonal pivoting method (blocked algorithm, calling Level 3 BLAS).
+*
+* =========== DOCUMENTATION ===========
+*
+* Online html documentation available at
+* http://www.netlib.org/lapack/explore-html/
+*
+*> \htmlonly
+*> Download CHETRF_ROOK + dependencies
+*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/chetrf_rook.f">
+*> [TGZ]</a>
+*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/chetrf_rook.f">
+*> [ZIP]</a>
+*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/chetrf_rook.f">
+*> [TXT]</a>
+*> \endhtmlonly
+*
+* Definition:
+* ===========
+*
+* SUBROUTINE CHETRF_ROOK( UPLO, N, A, LDA, IPIV, WORK, LWORK, INFO )
+*
+* .. Scalar Arguments ..
+* CHARACTER UPLO
+* INTEGER INFO, LDA, LWORK, N
+* ..
+* .. Array Arguments ..
+* INTEGER IPIV( * )
+* COMPLEX A( LDA, * ), WORK( * )
+* ..
+*
+*
+*> \par Purpose:
+* =============
+*>
+*> \verbatim
+*>
+*> CHETRF_ROOK computes the factorization of a comlex Hermitian matrix A
+*> using the bounded Bunch-Kaufman ("rook") diagonal pivoting method.
+*> The form of the factorization is
+*>
+*> A = U*D*U**T or A = L*D*L**T
+*>
+*> where U (or L) is a product of permutation and unit upper (lower)
+*> triangular matrices, and D is Hermitian and block diagonal with
+*> 1-by-1 and 2-by-2 diagonal blocks.
+*>
+*> This is the blocked version of the algorithm, calling Level 3 BLAS.
+*> \endverbatim
+*
+* Arguments:
+* ==========
+*
+*> \param[in] UPLO
+*> \verbatim
+*> UPLO is CHARACTER*1
+*> = 'U': Upper triangle of A is stored;
+*> = 'L': Lower triangle of A is stored.
+*> \endverbatim
+*>
+*> \param[in] N
+*> \verbatim
+*> N is INTEGER
+*> The order of the matrix A. N >= 0.
+*> \endverbatim
+*>
+*> \param[in,out] A
+*> \verbatim
+*> A is COMPLEX array, dimension (LDA,N)
+*> On entry, the Hermitian matrix A. If UPLO = 'U', the leading
+*> N-by-N upper triangular part of A contains the upper
+*> triangular part of the matrix A, and the strictly lower
+*> triangular part of A is not referenced. If UPLO = 'L', the
+*> leading N-by-N lower triangular part of A contains the lower
+*> triangular part of the matrix A, and the strictly upper
+*> triangular part of A is not referenced.
+*>
+*> On exit, the block diagonal matrix D and the multipliers used
+*> to obtain the factor U or L (see below for further details).
+*> \endverbatim
+*>
+*> \param[in] LDA
+*> \verbatim
+*> LDA is INTEGER
+*> The leading dimension of the array A. LDA >= max(1,N).
+*> \endverbatim
+*>
+*> \param[out] IPIV
+*> \verbatim
+*> IPIV is INTEGER array, dimension (N)
+*> Details of the interchanges and the block structure of D.
+*>
+*> If UPLO = 'U':
+*> Only the last KB elements of IPIV are set.
+*>
+*> If IPIV(k) > 0, then rows and columns k and IPIV(k) were
+*> interchanged and D(k,k) is a 1-by-1 diagonal block.
+*>
+*> If IPIV(k) < 0 and IPIV(k-1) < 0, then rows and
+*> columns k and -IPIV(k) were interchanged and rows and
+*> columns k-1 and -IPIV(k-1) were inerchaged,
+*> D(k-1:k,k-1:k) is a 2-by-2 diagonal block.
+*>
+*> If UPLO = 'L':
+*> Only the first KB elements of IPIV are set.
+*>
+*> If IPIV(k) > 0, then rows and columns k and IPIV(k)
+*> were interchanged and D(k,k) is a 1-by-1 diagonal block.
+*>
+*> If IPIV(k) < 0 and IPIV(k+1) < 0, then rows and
+*> columns k and -IPIV(k) were interchanged and rows and
+*> columns k+1 and -IPIV(k+1) were inerchaged,
+*> D(k:k+1,k:k+1) is a 2-by-2 diagonal block.
+*> \endverbatim
+*>
+*> \param[out] WORK
+*> \verbatim
+*> WORK is COMPLEX array, dimension (MAX(1,LWORK)).
+*> On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
+*> \endverbatim
+*>
+*> \param[in] LWORK
+*> \verbatim
+*> LWORK is INTEGER
+*> The length of WORK. LWORK >=1. For best performance
+*> LWORK >= N*NB, where NB is the block size returned by ILAENV.
+*>
+*> If LWORK = -1, then a workspace query is assumed; the routine
+*> only calculates the optimal size of the WORK array, returns
+*> this value as the first entry of the WORK array, and no error
+*> message related to LWORK is issued by XERBLA.
+*> \endverbatim
+*>
+*> \param[out] INFO
+*> \verbatim
+*> INFO is INTEGER
+*> = 0: successful exit
+*> < 0: if INFO = -i, the i-th argument had an illegal value
+*> > 0: if INFO = i, D(i,i) is exactly zero. The factorization
+*> has been completed, but the block diagonal matrix D is
+*> exactly singular, and division by zero will occur if it
+*> is used to solve a system of equations.
+*> \endverbatim
+*
+* Authors:
+* ========
+*
+*> \author Univ. of Tennessee
+*> \author Univ. of California Berkeley
+*> \author Univ. of Colorado Denver
+*> \author NAG Ltd.
+*
+*> \date November 2011
+*
+*> \ingroup complexHEcomputational
+*
+*> \par Further Details:
+* =====================
+*>
+*> \verbatim
+*>
+*> If UPLO = 'U', then A = U*D*U**T, where
+*> U = P(n)*U(n)* ... *P(k)U(k)* ...,
+*> i.e., U is a product of terms P(k)*U(k), where k decreases from n to
+*> 1 in steps of 1 or 2, and D is a block diagonal matrix with 1-by-1
+*> and 2-by-2 diagonal blocks D(k). P(k) is a permutation matrix as
+*> defined by IPIV(k), and U(k) is a unit upper triangular matrix, such
+*> that if the diagonal block D(k) is of order s (s = 1 or 2), then
+*>
+*> ( I v 0 ) k-s
+*> U(k) = ( 0 I 0 ) s
+*> ( 0 0 I ) n-k
+*> k-s s n-k
+*>
+*> If s = 1, D(k) overwrites A(k,k), and v overwrites A(1:k-1,k).
+*> If s = 2, the upper triangle of D(k) overwrites A(k-1,k-1), A(k-1,k),
+*> and A(k,k), and v overwrites A(1:k-2,k-1:k).
+*>
+*> If UPLO = 'L', then A = L*D*L**T, where
+*> L = P(1)*L(1)* ... *P(k)*L(k)* ...,
+*> i.e., L is a product of terms P(k)*L(k), where k increases from 1 to
+*> n in steps of 1 or 2, and D is a block diagonal matrix with 1-by-1
+*> and 2-by-2 diagonal blocks D(k). P(k) is a permutation matrix as
+*> defined by IPIV(k), and L(k) is a unit lower triangular matrix, such
+*> that if the diagonal block D(k) is of order s (s = 1 or 2), then
+*>
+*> ( I 0 0 ) k-1
+*> L(k) = ( 0 I 0 ) s
+*> ( 0 v I ) n-k-s+1
+*> k-1 s n-k-s+1
+*>
+*> If s = 1, D(k) overwrites A(k,k), and v overwrites A(k+1:n,k).
+*> If s = 2, the lower triangle of D(k) overwrites A(k,k), A(k+1,k),
+*> and A(k+1,k+1), and v overwrites A(k+2:n,k:k+1).
+*> \endverbatim
+*
+*> \par Contributors:
+* ==================
+*>
+*> \verbatim
+*>
+*> November 2012, Igor Kozachenko,
+*> Computer Science Division,
+*> University of California, Berkeley
+*>
+*> September 2007, Sven Hammarling, Nicholas J. Higham, Craig Lucas,
+*> School of Mathematics,
+*> University of Manchester
+*>
+*> \endverbatim
+*
+* =====================================================================
+ SUBROUTINE CHETRF_ROOK( UPLO, N, A, LDA, IPIV, WORK, LWORK, INFO )
+*
+* -- LAPACK computational routine (version 3.4.0) --
+* -- LAPACK is a software package provided by Univ. of Tennessee, --
+* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
+* November 2011
+*
+* .. Scalar Arguments ..
+ CHARACTER UPLO
+ INTEGER INFO, LDA, LWORK, N
+* ..
+* .. Array Arguments ..
+ INTEGER IPIV( * )
+ COMPLEX A( LDA, * ), WORK( * )
+* ..
+*
+* =====================================================================
+*
+* .. Local Scalars ..
+ LOGICAL LQUERY, UPPER
+ INTEGER IINFO, IWS, J, K, KB, LDWORK, LWKOPT, NB, NBMIN
+* ..
+* .. External Functions ..
+ LOGICAL LSAME
+ INTEGER ILAENV
+ EXTERNAL LSAME, ILAENV
+* ..
+* .. External Subroutines ..
+ EXTERNAL CLAHEF_ROOK, CHETF2_ROOK, XERBLA
+* ..
+* .. Intrinsic Functions ..
+ INTRINSIC MAX
+* ..
+* .. Executable Statements ..
+*
+* Test the input parameters.
+*
+ INFO = 0
+ UPPER = LSAME( UPLO, 'U' )
+ LQUERY = ( LWORK.EQ.-1 )
+ IF( .NOT.UPPER .AND. .NOT.LSAME( UPLO, 'L' ) ) THEN
+ INFO = -1
+ ELSE IF( N.LT.0 ) THEN
+ INFO = -2
+ ELSE IF( LDA.LT.MAX( 1, N ) ) THEN
+ INFO = -4
+ ELSE IF( LWORK.LT.1 .AND. .NOT.LQUERY ) THEN
+ INFO = -7
+ END IF
+*
+ IF( INFO.EQ.0 ) THEN
+*
+* Determine the block size
+*
+ NB = ILAENV( 1, 'CHETRF_ROOK', UPLO, N, -1, -1, -1 )
+ LWKOPT = N*NB
+ WORK( 1 ) = LWKOPT
+ END IF
+*
+ IF( INFO.NE.0 ) THEN
+ CALL XERBLA( 'CHETRF_ROOK', -INFO )
+ RETURN
+ ELSE IF( LQUERY ) THEN
+ RETURN
+ END IF
+*
+ NBMIN = 2
+ LDWORK = N
+ IF( NB.GT.1 .AND. NB.LT.N ) THEN
+ IWS = LDWORK*NB
+ IF( LWORK.LT.IWS ) THEN
+ NB = MAX( LWORK / LDWORK, 1 )
+ NBMIN = MAX( 2, ILAENV( 2, 'CHETRF_ROOK',
+ $ UPLO, N, -1, -1, -1 ) )
+ END IF
+ ELSE
+ IWS = 1
+ END IF
+ IF( NB.LT.NBMIN )
+ $ NB = N
+*
+ IF( UPPER ) THEN
+*
+* Factorize A as U*D*U**T using the upper triangle of A
+*
+* K is the main loop index, decreasing from N to 1 in steps of
+* KB, where KB is the number of columns factorized by CLAHEF_ROOK;
+* KB is either NB or NB-1, or K for the last block
+*
+ K = N
+ 10 CONTINUE
+*
+* If K < 1, exit from loop
+*
+ IF( K.LT.1 )
+ $ GO TO 40
+*
+ IF( K.GT.NB ) THEN
+*
+* Factorize columns k-kb+1:k of A and use blocked code to
+* update columns 1:k-kb
+*
+ CALL CLAHEF_ROOK( UPLO, K, NB, KB, A, LDA,
+ $ IPIV, WORK, LDWORK, IINFO )
+ ELSE
+*
+* Use unblocked code to factorize columns 1:k of A
+*
+ CALL CHETF2_ROOK( UPLO, K, A, LDA, IPIV, IINFO )
+ KB = K
+ END IF
+*
+* Set INFO on the first occurrence of a zero pivot
+*
+ IF( INFO.EQ.0 .AND. IINFO.GT.0 )
+ $ INFO = IINFO
+*
+* No need to adjust IPIV
+*
+* Decrease K and return to the start of the main loop
+*
+ K = K - KB
+ GO TO 10
+*
+ ELSE
+*
+* Factorize A as L*D*L**T using the lower triangle of A
+*
+* K is the main loop index, increasing from 1 to N in steps of
+* KB, where KB is the number of columns factorized by CLAHEF_ROOK;
+* KB is either NB or NB-1, or N-K+1 for the last block
+*
+ K = 1
+ 20 CONTINUE
+*
+* If K > N, exit from loop
+*
+ IF( K.GT.N )
+ $ GO TO 40
+*
+ IF( K.LE.N-NB ) THEN
+*
+* Factorize columns k:k+kb-1 of A and use blocked code to
+* update columns k+kb:n
+*
+ CALL CLAHEF_ROOK( UPLO, N-K+1, NB, KB, A( K, K ), LDA,
+ $ IPIV( K ), WORK, LDWORK, IINFO )
+ ELSE
+*
+* Use unblocked code to factorize columns k:n of A
+*
+ CALL CHETF2_ROOK( UPLO, N-K+1, A( K, K ), LDA, IPIV( K ),
+ $ IINFO )
+ KB = N - K + 1
+ END IF
+*
+* Set INFO on the first occurrence of a zero pivot
+*
+ IF( INFO.EQ.0 .AND. IINFO.GT.0 )
+ $ INFO = IINFO + K - 1
+*
+* Adjust IPIV
+*
+ DO 30 J = K, K + KB - 1
+ IF( IPIV( J ).GT.0 ) THEN
+ IPIV( J ) = IPIV( J ) + K - 1
+ ELSE
+ IPIV( J ) = IPIV( J ) - K + 1
+ END IF
+ 30 CONTINUE
+*
+* Increase K and return to the start of the main loop
+*
+ K = K + KB
+ GO TO 20
+*
+ END IF
+*
+ 40 CONTINUE
+ WORK( 1 ) = LWKOPT
+ RETURN
+*
+* End of CHETRF_ROOK
+*
+ END
--- /dev/null
+*> \brief \b ZHETRF_ROOK computes the factorization of a complex Hermitian indefinite matrix using the bounded Bunch-Kaufman ("rook") diagonal pivoting method (blocked algorithm, calling Level 3 BLAS).
+*
+* =========== DOCUMENTATION ===========
+*
+* Online html documentation available at
+* http://www.netlib.org/lapack/explore-html/
+*
+*> \htmlonly
+*> Download ZHETRF_ROOK + dependencies
+*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/zhetrf_rook.f">
+*> [TGZ]</a>
+*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/zhetrf_rook.f">
+*> [ZIP]</a>
+*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/zhetrf_rook.f">
+*> [TXT]</a>
+*> \endhtmlonly
+*
+* Definition:
+* ===========
+*
+* SUBROUTINE ZHETRF_ROOK( UPLO, N, A, LDA, IPIV, WORK, LWORK, INFO )
+*
+* .. Scalar Arguments ..
+* CHARACTER UPLO
+* INTEGER INFO, LDA, LWORK, N
+* ..
+* .. Array Arguments ..
+* INTEGER IPIV( * )
+* COMPLEX*16 A( LDA, * ), WORK( * )
+* ..
+*
+*
+*> \par Purpose:
+* =============
+*>
+*> \verbatim
+*>
+*> ZHETRF_ROOK computes the factorization of a complex Hermitian matrix A
+*> using the bounded Bunch-Kaufman ("rook") diagonal pivoting method.
+*> The form of the factorization is
+*>
+*> A = U*D*U**T or A = L*D*L**T
+*>
+*> where U (or L) is a product of permutation and unit upper (lower)
+*> triangular matrices, and D is Hermitian and block diagonal with
+*> 1-by-1 and 2-by-2 diagonal blocks.
+*>
+*> This is the blocked version of the algorithm, calling Level 3 BLAS.
+*> \endverbatim
+*
+* Arguments:
+* ==========
+*
+*> \param[in] UPLO
+*> \verbatim
+*> UPLO is CHARACTER*1
+*> = 'U': Upper triangle of A is stored;
+*> = 'L': Lower triangle of A is stored.
+*> \endverbatim
+*>
+*> \param[in] N
+*> \verbatim
+*> N is INTEGER
+*> The order of the matrix A. N >= 0.
+*> \endverbatim
+*>
+*> \param[in,out] A
+*> \verbatim
+*> A is COMPLEX*16 array, dimension (LDA,N)
+*> On entry, the Hermitian matrix A. If UPLO = 'U', the leading
+*> N-by-N upper triangular part of A contains the upper
+*> triangular part of the matrix A, and the strictly lower
+*> triangular part of A is not referenced. If UPLO = 'L', the
+*> leading N-by-N lower triangular part of A contains the lower
+*> triangular part of the matrix A, and the strictly upper
+*> triangular part of A is not referenced.
+*>
+*> On exit, the block diagonal matrix D and the multipliers used
+*> to obtain the factor U or L (see below for further details).
+*> \endverbatim
+*>
+*> \param[in] LDA
+*> \verbatim
+*> LDA is INTEGER
+*> The leading dimension of the array A. LDA >= max(1,N).
+*> \endverbatim
+*>
+*> \param[out] IPIV
+*> \verbatim
+*> IPIV is INTEGER array, dimension (N)
+*> Details of the interchanges and the block structure of D.
+*>
+*> If UPLO = 'U':
+*> Only the last KB elements of IPIV are set.
+*>
+*> If IPIV(k) > 0, then rows and columns k and IPIV(k) were
+*> interchanged and D(k,k) is a 1-by-1 diagonal block.
+*>
+*> If IPIV(k) < 0 and IPIV(k-1) < 0, then rows and
+*> columns k and -IPIV(k) were interchanged and rows and
+*> columns k-1 and -IPIV(k-1) were inerchaged,
+*> D(k-1:k,k-1:k) is a 2-by-2 diagonal block.
+*>
+*> If UPLO = 'L':
+*> Only the first KB elements of IPIV are set.
+*>
+*> If IPIV(k) > 0, then rows and columns k and IPIV(k)
+*> were interchanged and D(k,k) is a 1-by-1 diagonal block.
+*>
+*> If IPIV(k) < 0 and IPIV(k+1) < 0, then rows and
+*> columns k and -IPIV(k) were interchanged and rows and
+*> columns k+1 and -IPIV(k+1) were inerchaged,
+*> D(k:k+1,k:k+1) is a 2-by-2 diagonal block.
+*> \endverbatim
+*>
+*> \param[out] WORK
+*> \verbatim
+*> WORK is COMPLEX*16 array, dimension (MAX(1,LWORK)).
+*> On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
+*> \endverbatim
+*>
+*> \param[in] LWORK
+*> \verbatim
+*> LWORK is INTEGER
+*> The length of WORK. LWORK >=1. For best performance
+*> LWORK >= N*NB, where NB is the block size returned by ILAENV.
+*>
+*> If LWORK = -1, then a workspace query is assumed; the routine
+*> only calculates the optimal size of the WORK array, returns
+*> this value as the first entry of the WORK array, and no error
+*> message related to LWORK is issued by XERBLA.
+*> \endverbatim
+*>
+*> \param[out] INFO
+*> \verbatim
+*> INFO is INTEGER
+*> = 0: successful exit
+*> < 0: if INFO = -i, the i-th argument had an illegal value
+*> > 0: if INFO = i, D(i,i) is exactly zero. The factorization
+*> has been completed, but the block diagonal matrix D is
+*> exactly singular, and division by zero will occur if it
+*> is used to solve a system of equations.
+*> \endverbatim
+*
+* Authors:
+* ========
+*
+*> \author Univ. of Tennessee
+*> \author Univ. of California Berkeley
+*> \author Univ. of Colorado Denver
+*> \author NAG Ltd.
+*
+*> \date November 2011
+*
+*> \ingroup complex16HEcomputational
+*
+*> \par Further Details:
+* =====================
+*>
+*> \verbatim
+*>
+*> If UPLO = 'U', then A = U*D*U**T, where
+*> U = P(n)*U(n)* ... *P(k)U(k)* ...,
+*> i.e., U is a product of terms P(k)*U(k), where k decreases from n to
+*> 1 in steps of 1 or 2, and D is a block diagonal matrix with 1-by-1
+*> and 2-by-2 diagonal blocks D(k). P(k) is a permutation matrix as
+*> defined by IPIV(k), and U(k) is a unit upper triangular matrix, such
+*> that if the diagonal block D(k) is of order s (s = 1 or 2), then
+*>
+*> ( I v 0 ) k-s
+*> U(k) = ( 0 I 0 ) s
+*> ( 0 0 I ) n-k
+*> k-s s n-k
+*>
+*> If s = 1, D(k) overwrites A(k,k), and v overwrites A(1:k-1,k).
+*> If s = 2, the upper triangle of D(k) overwrites A(k-1,k-1), A(k-1,k),
+*> and A(k,k), and v overwrites A(1:k-2,k-1:k).
+*>
+*> If UPLO = 'L', then A = L*D*L**T, where
+*> L = P(1)*L(1)* ... *P(k)*L(k)* ...,
+*> i.e., L is a product of terms P(k)*L(k), where k increases from 1 to
+*> n in steps of 1 or 2, and D is a block diagonal matrix with 1-by-1
+*> and 2-by-2 diagonal blocks D(k). P(k) is a permutation matrix as
+*> defined by IPIV(k), and L(k) is a unit lower triangular matrix, such
+*> that if the diagonal block D(k) is of order s (s = 1 or 2), then
+*>
+*> ( I 0 0 ) k-1
+*> L(k) = ( 0 I 0 ) s
+*> ( 0 v I ) n-k-s+1
+*> k-1 s n-k-s+1
+*>
+*> If s = 1, D(k) overwrites A(k,k), and v overwrites A(k+1:n,k).
+*> If s = 2, the lower triangle of D(k) overwrites A(k,k), A(k+1,k),
+*> and A(k+1,k+1), and v overwrites A(k+2:n,k:k+1).
+*> \endverbatim
+*
+*> \par Contributors:
+* ==================
+*>
+*> \verbatim
+*>
+*> November 2012, Igor Kozachenko,
+*> Computer Science Division,
+*> University of California, Berkeley
+*>
+*> September 2007, Sven Hammarling, Nicholas J. Higham, Craig Lucas,
+*> School of Mathematics,
+*> University of Manchester
+*>
+*> \endverbatim
+*
+* =====================================================================
+ SUBROUTINE ZHETRF_ROOK( UPLO, N, A, LDA, IPIV, WORK, LWORK, INFO )
+*
+* -- LAPACK computational routine (version 3.4.0) --
+* -- LAPACK is a software package provided by Univ. of Tennessee, --
+* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
+* November 2011
+*
+* .. Scalar Arguments ..
+ CHARACTER UPLO
+ INTEGER INFO, LDA, LWORK, N
+* ..
+* .. Array Arguments ..
+ INTEGER IPIV( * )
+ COMPLEX*16 A( LDA, * ), WORK( * )
+* ..
+*
+* =====================================================================
+*
+* .. Local Scalars ..
+ LOGICAL LQUERY, UPPER
+ INTEGER IINFO, IWS, J, K, KB, LDWORK, LWKOPT, NB, NBMIN
+* ..
+* .. External Functions ..
+ LOGICAL LSAME
+ INTEGER ILAENV
+ EXTERNAL LSAME, ILAENV
+* ..
+* .. External Subroutines ..
+ EXTERNAL ZLAHEF_ROOK, ZHETF2_ROOK, XERBLA
+* ..
+* .. Intrinsic Functions ..
+ INTRINSIC MAX
+* ..
+* .. Executable Statements ..
+*
+* Test the input parameters.
+*
+ INFO = 0
+ UPPER = LSAME( UPLO, 'U' )
+ LQUERY = ( LWORK.EQ.-1 )
+ IF( .NOT.UPPER .AND. .NOT.LSAME( UPLO, 'L' ) ) THEN
+ INFO = -1
+ ELSE IF( N.LT.0 ) THEN
+ INFO = -2
+ ELSE IF( LDA.LT.MAX( 1, N ) ) THEN
+ INFO = -4
+ ELSE IF( LWORK.LT.1 .AND. .NOT.LQUERY ) THEN
+ INFO = -7
+ END IF
+*
+ IF( INFO.EQ.0 ) THEN
+*
+* Determine the block size
+*
+ NB = ILAENV( 1, 'ZHETRF_ROOK', UPLO, N, -1, -1, -1 )
+ LWKOPT = N*NB
+ WORK( 1 ) = LWKOPT
+ END IF
+*
+ IF( INFO.NE.0 ) THEN
+ CALL XERBLA( 'ZHETRF_ROOK', -INFO )
+ RETURN
+ ELSE IF( LQUERY ) THEN
+ RETURN
+ END IF
+*
+ NBMIN = 2
+ LDWORK = N
+ IF( NB.GT.1 .AND. NB.LT.N ) THEN
+ IWS = LDWORK*NB
+ IF( LWORK.LT.IWS ) THEN
+ NB = MAX( LWORK / LDWORK, 1 )
+ NBMIN = MAX( 2, ILAENV( 2, 'ZHETRF_ROOK',
+ $ UPLO, N, -1, -1, -1 ) )
+ END IF
+ ELSE
+ IWS = 1
+ END IF
+ IF( NB.LT.NBMIN )
+ $ NB = N
+*
+ IF( UPPER ) THEN
+*
+* Factorize A as U*D*U**T using the upper triangle of A
+*
+* K is the main loop index, decreasing from N to 1 in steps of
+* KB, where KB is the number of columns factorized by ZLAHEF_ROOK;
+* KB is either NB or NB-1, or K for the last block
+*
+ K = N
+ 10 CONTINUE
+*
+* If K < 1, exit from loop
+*
+ IF( K.LT.1 )
+ $ GO TO 40
+*
+ IF( K.GT.NB ) THEN
+*
+* Factorize columns k-kb+1:k of A and use blocked code to
+* update columns 1:k-kb
+*
+ CALL ZLAHEF_ROOK( UPLO, K, NB, KB, A, LDA,
+ $ IPIV, WORK, LDWORK, IINFO )
+ ELSE
+*
+* Use unblocked code to factorize columns 1:k of A
+*
+ CALL ZHETF2_ROOK( UPLO, K, A, LDA, IPIV, IINFO )
+ KB = K
+ END IF
+*
+* Set INFO on the first occurrence of a zero pivot
+*
+ IF( INFO.EQ.0 .AND. IINFO.GT.0 )
+ $ INFO = IINFO
+*
+* No need to adjust IPIV
+*
+* Decrease K and return to the start of the main loop
+*
+ K = K - KB
+ GO TO 10
+*
+ ELSE
+*
+* Factorize A as L*D*L**T using the lower triangle of A
+*
+* K is the main loop index, increasing from 1 to N in steps of
+* KB, where KB is the number of columns factorized by ZLAHEF_ROOK;
+* KB is either NB or NB-1, or N-K+1 for the last block
+*
+ K = 1
+ 20 CONTINUE
+*
+* If K > N, exit from loop
+*
+ IF( K.GT.N )
+ $ GO TO 40
+*
+ IF( K.LE.N-NB ) THEN
+*
+* Factorize columns k:k+kb-1 of A and use blocked code to
+* update columns k+kb:n
+*
+ CALL ZLAHEF_ROOK( UPLO, N-K+1, NB, KB, A( K, K ), LDA,
+ $ IPIV( K ), WORK, LDWORK, IINFO )
+ ELSE
+*
+* Use unblocked code to factorize columns k:n of A
+*
+ CALL ZHETF2_ROOK( UPLO, N-K+1, A( K, K ), LDA, IPIV( K ),
+ $ IINFO )
+ KB = N - K + 1
+ END IF
+*
+* Set INFO on the first occurrence of a zero pivot
+*
+ IF( INFO.EQ.0 .AND. IINFO.GT.0 )
+ $ INFO = IINFO + K - 1
+*
+* Adjust IPIV
+*
+ DO 30 J = K, K + KB - 1
+ IF( IPIV( J ).GT.0 ) THEN
+ IPIV( J ) = IPIV( J ) + K - 1
+ ELSE
+ IPIV( J ) = IPIV( J ) - K + 1
+ END IF
+ 30 CONTINUE
+*
+* Increase K and return to the start of the main loop
+*
+ K = K + KB
+ GO TO 20
+*
+ END IF
+*
+ 40 CONTINUE
+ WORK( 1 ) = LWKOPT
+ RETURN
+*
+* End of ZHETRF_ROOK
+*
+ END
projects / platform / upstream / lapack.git / commitdiff