+++ /dev/null
- SUBROUTINE CGETRI( N, A, LDA, IPIV, WORK, LWORK, INFO )
-*
-* -- LAPACK routine (version 3.0) --
-* Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,
-* Courant Institute, Argonne National Lab, and Rice University
-* June 30, 1999
-*
-* .. Scalar Arguments ..
- INTEGER INFO, LDA, LWORK, N
-* ..
-* .. Array Arguments ..
- INTEGER IPIV( * )
- COMPLEX A( LDA, * ), WORK( * )
-* ..
-*
-* Purpose
-* =======
-*
-* CGETRI computes the inverse of a matrix using the LU factorization
-* computed by CGETRF.
-*
-* This method inverts U and then computes inv(A) by solving the system
-* inv(A)*L = inv(U) for inv(A).
-*
-* Arguments
-* =========
-*
-* N (input) INTEGER
-* The order of the matrix A. N >= 0.
-*
-* A (input/output) COMPLEX array, dimension (LDA,N)
-* On entry, the factors L and U from the factorization
-* A = P*L*U as computed by CGETRF.
-* On exit, if INFO = 0, the inverse of the original matrix A.
-*
-* LDA (input) INTEGER
-* The leading dimension of the array A. LDA >= max(1,N).
-*
-* IPIV (input) INTEGER array, dimension (N)
-* The pivot indices from CGETRF; for 1<=i<=N, row i of the
-* matrix was interchanged with row IPIV(i).
-*
-* WORK (workspace/output) COMPLEX array, dimension (LWORK)
-* On exit, if INFO=0, then WORK(1) returns the optimal LWORK.
-*
-* LWORK (input) INTEGER
-* The dimension of the array WORK. LWORK >= max(1,N).
-* For optimal performance LWORK >= N*NB, where NB is
-* the optimal blocksize 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.
-*
-* INFO (output) INTEGER
-* = 0: successful exit
-* < 0: if INFO = -i, the i-th argument had an illegal value
-* > 0: if INFO = i, U(i,i) is exactly zero; the matrix is
-* singular and its inverse could not be computed.
-*
-* =====================================================================
-*
-* .. Parameters ..
- COMPLEX ZERO, ONE
- PARAMETER ( ZERO = ( 0.0E+0, 0.0E+0 ),
- $ ONE = ( 1.0E+0, 0.0E+0 ) )
-* ..
-* .. Local Scalars ..
- LOGICAL LQUERY
- INTEGER I, IWS, J, JB, JJ, JP, LDWORK, LWKOPT, NB,
- $ NBMIN, NN
-* ..
-* .. External Functions ..
- INTEGER ILAENV
- EXTERNAL ILAENV
-* ..
-* .. External Subroutines ..
- EXTERNAL CGEMM, CGEMV, CSWAP, CTRSM, CTRTRI, XERBLA
-* ..
-* .. Intrinsic Functions ..
- INTRINSIC MAX, MIN
-* ..
-* .. Executable Statements ..
-*
-* Test the input parameters.
-*
- INFO = 0
- NB = ILAENV( 1, 'CGETRI', ' ', N, -1, -1, -1 )
- LWKOPT = N*NB
- WORK( 1 ) = LWKOPT
- LQUERY = ( LWORK.EQ.-1 )
- IF( N.LT.0 ) THEN
- INFO = -1
- ELSE IF( LDA.LT.MAX( 1, N ) ) THEN
- INFO = -3
- ELSE IF( LWORK.LT.MAX( 1, N ) .AND. .NOT.LQUERY ) THEN
- INFO = -6
- END IF
- IF( INFO.NE.0 ) THEN
- CALL XERBLA( 'CGETRI', -INFO )
- RETURN
- ELSE IF( LQUERY ) THEN
- RETURN
- END IF
-*
-* Quick return if possible
-*
- IF( N.EQ.0 )
- $ RETURN
-*
-* Form inv(U). If INFO > 0 from CTRTRI, then U is singular,
-* and the inverse is not computed.
-*
- CALL CTRTRI( 'Upper', 'Non-unit', N, A, LDA, INFO )
- IF( INFO.GT.0 )
- $ RETURN
-*
- NBMIN = 2
- LDWORK = N
- IF( NB.GT.1 .AND. NB.LT.N ) THEN
- IWS = MAX( LDWORK*NB, 1 )
- IF( LWORK.LT.IWS ) THEN
- NB = LWORK / LDWORK
- NBMIN = MAX( 2, ILAENV( 2, 'CGETRI', ' ', N, -1, -1, -1 ) )
- END IF
- ELSE
- IWS = N
- END IF
-*
-* Solve the equation inv(A)*L = inv(U) for inv(A).
-*
- IF( NB.LT.NBMIN .OR. NB.GE.N ) THEN
-*
-* Use unblocked code.
-*
- DO 20 J = N, 1, -1
-*
-* Copy current column of L to WORK and replace with zeros.
-*
- DO 10 I = J + 1, N
- WORK( I ) = A( I, J )
- A( I, J ) = ZERO
- 10 CONTINUE
-*
-* Compute current column of inv(A).
-*
- IF( J.LT.N )
- $ CALL CGEMV( 'No transpose', N, N-J, -ONE, A( 1, J+1 ),
- $ LDA, WORK( J+1 ), 1, ONE, A( 1, J ), 1 )
- 20 CONTINUE
- ELSE
-*
-* Use blocked code.
-*
- NN = ( ( N-1 ) / NB )*NB + 1
- DO 50 J = NN, 1, -NB
- JB = MIN( NB, N-J+1 )
-*
-* Copy current block column of L to WORK and replace with
-* zeros.
-*
- DO 40 JJ = J, J + JB - 1
- DO 30 I = JJ + 1, N
- WORK( I+( JJ-J )*LDWORK ) = A( I, JJ )
- A( I, JJ ) = ZERO
- 30 CONTINUE
- 40 CONTINUE
-*
-* Compute current block column of inv(A).
-*
- IF( J+JB.LE.N )
- $ CALL CGEMM( 'No transpose', 'No transpose', N, JB,
- $ N-J-JB+1, -ONE, A( 1, J+JB ), LDA,
- $ WORK( J+JB ), LDWORK, ONE, A( 1, J ), LDA )
- CALL CTRSM( 'Right', 'Lower', 'No transpose', 'Unit', N, JB,
- $ ONE, WORK( J ), LDWORK, A( 1, J ), LDA )
- 50 CONTINUE
- END IF
-*
-* Apply column interchanges.
-*
- DO 60 J = N - 1, 1, -1
- JP = IPIV( J )
- IF( JP.NE.J )
- $ CALL CSWAP( N, A( 1, J ), 1, A( 1, JP ), 1 )
- 60 CONTINUE
-*
- WORK( 1 ) = IWS
- RETURN
-*
-* End of CGETRI
-*
- END
+++ /dev/null
- SUBROUTINE DGETRI( N, A, LDA, IPIV, WORK, LWORK, INFO )
-*
-* -- LAPACK routine (version 3.0) --
-* Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,
-* Courant Institute, Argonne National Lab, and Rice University
-* June 30, 1999
-*
-* .. Scalar Arguments ..
- INTEGER INFO, LDA, LWORK, N
-* ..
-* .. Array Arguments ..
- INTEGER IPIV( * )
- DOUBLE PRECISION A( LDA, * ), WORK( * )
-* ..
-*
-* Purpose
-* =======
-*
-* DGETRI computes the inverse of a matrix using the LU factorization
-* computed by DGETRF.
-*
-* This method inverts U and then computes inv(A) by solving the system
-* inv(A)*L = inv(U) for inv(A).
-*
-* Arguments
-* =========
-*
-* N (input) INTEGER
-* The order of the matrix A. N >= 0.
-*
-* A (input/output) DOUBLE PRECISION array, dimension (LDA,N)
-* On entry, the factors L and U from the factorization
-* A = P*L*U as computed by DGETRF.
-* On exit, if INFO = 0, the inverse of the original matrix A.
-*
-* LDA (input) INTEGER
-* The leading dimension of the array A. LDA >= max(1,N).
-*
-* IPIV (input) INTEGER array, dimension (N)
-* The pivot indices from DGETRF; for 1<=i<=N, row i of the
-* matrix was interchanged with row IPIV(i).
-*
-* WORK (workspace/output) DOUBLE PRECISION array, dimension (LWORK)
-* On exit, if INFO=0, then WORK(1) returns the optimal LWORK.
-*
-* LWORK (input) INTEGER
-* The dimension of the array WORK. LWORK >= max(1,N).
-* For optimal performance LWORK >= N*NB, where NB is
-* the optimal blocksize 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.
-*
-* INFO (output) INTEGER
-* = 0: successful exit
-* < 0: if INFO = -i, the i-th argument had an illegal value
-* > 0: if INFO = i, U(i,i) is exactly zero; the matrix is
-* singular and its inverse could not be computed.
-*
-* =====================================================================
-*
-* .. Parameters ..
- DOUBLE PRECISION ZERO, ONE
- PARAMETER ( ZERO = 0.0D+0, ONE = 1.0D+0 )
-* ..
-* .. Local Scalars ..
- LOGICAL LQUERY
- INTEGER I, IWS, J, JB, JJ, JP, LDWORK, LWKOPT, NB,
- $ NBMIN, NN
-* ..
-* .. External Functions ..
- INTEGER ILAENV
- EXTERNAL ILAENV
-* ..
-* .. External Subroutines ..
- EXTERNAL DGEMM, DGEMV, DSWAP, DTRSM, DTRTRI, XERBLA
-* ..
-* .. Intrinsic Functions ..
- INTRINSIC MAX, MIN
-* ..
-* .. Executable Statements ..
-*
-* Test the input parameters.
-*
- INFO = 0
- NB = ILAENV( 1, 'DGETRI', ' ', N, -1, -1, -1 )
- LWKOPT = N*NB
- WORK( 1 ) = LWKOPT
- LQUERY = ( LWORK.EQ.-1 )
- IF( N.LT.0 ) THEN
- INFO = -1
- ELSE IF( LDA.LT.MAX( 1, N ) ) THEN
- INFO = -3
- ELSE IF( LWORK.LT.MAX( 1, N ) .AND. .NOT.LQUERY ) THEN
- INFO = -6
- END IF
- IF( INFO.NE.0 ) THEN
- CALL XERBLA( 'DGETRI', -INFO )
- RETURN
- ELSE IF( LQUERY ) THEN
- RETURN
- END IF
-*
-* Quick return if possible
-*
- IF( N.EQ.0 )
- $ RETURN
-*
-* Form inv(U). If INFO > 0 from DTRTRI, then U is singular,
-* and the inverse is not computed.
-*
- CALL DTRTRI( 'Upper', 'Non-unit', N, A, LDA, INFO )
- IF( INFO.GT.0 )
- $ RETURN
-*
- NBMIN = 2
- LDWORK = N
- IF( NB.GT.1 .AND. NB.LT.N ) THEN
- IWS = MAX( LDWORK*NB, 1 )
- IF( LWORK.LT.IWS ) THEN
- NB = LWORK / LDWORK
- NBMIN = MAX( 2, ILAENV( 2, 'DGETRI', ' ', N, -1, -1, -1 ) )
- END IF
- ELSE
- IWS = N
- END IF
-*
-* Solve the equation inv(A)*L = inv(U) for inv(A).
-*
- IF( NB.LT.NBMIN .OR. NB.GE.N ) THEN
-*
-* Use unblocked code.
-*
- DO 20 J = N, 1, -1
-*
-* Copy current column of L to WORK and replace with zeros.
-*
- DO 10 I = J + 1, N
- WORK( I ) = A( I, J )
- A( I, J ) = ZERO
- 10 CONTINUE
-*
-* Compute current column of inv(A).
-*
- IF( J.LT.N )
- $ CALL DGEMV( 'No transpose', N, N-J, -ONE, A( 1, J+1 ),
- $ LDA, WORK( J+1 ), 1, ONE, A( 1, J ), 1 )
- 20 CONTINUE
- ELSE
-*
-* Use blocked code.
-*
- NN = ( ( N-1 ) / NB )*NB + 1
- DO 50 J = NN, 1, -NB
- JB = MIN( NB, N-J+1 )
-*
-* Copy current block column of L to WORK and replace with
-* zeros.
-*
- DO 40 JJ = J, J + JB - 1
- DO 30 I = JJ + 1, N
- WORK( I+( JJ-J )*LDWORK ) = A( I, JJ )
- A( I, JJ ) = ZERO
- 30 CONTINUE
- 40 CONTINUE
-*
-* Compute current block column of inv(A).
-*
- IF( J+JB.LE.N )
- $ CALL DGEMM( 'No transpose', 'No transpose', N, JB,
- $ N-J-JB+1, -ONE, A( 1, J+JB ), LDA,
- $ WORK( J+JB ), LDWORK, ONE, A( 1, J ), LDA )
- CALL DTRSM( 'Right', 'Lower', 'No transpose', 'Unit', N, JB,
- $ ONE, WORK( J ), LDWORK, A( 1, J ), LDA )
- 50 CONTINUE
- END IF
-*
-* Apply column interchanges.
-*
- DO 60 J = N - 1, 1, -1
- JP = IPIV( J )
- IF( JP.NE.J )
- $ CALL DSWAP( N, A( 1, J ), 1, A( 1, JP ), 1 )
- 60 CONTINUE
-*
- WORK( 1 ) = IWS
- RETURN
-*
-* End of DGETRI
-*
- END
+++ /dev/null
- SUBROUTINE SGETRI( N, A, LDA, IPIV, WORK, LWORK, INFO )
-*
-* -- LAPACK routine (version 3.0) --
-* Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,
-* Courant Institute, Argonne National Lab, and Rice University
-* June 30, 1999
-*
-* .. Scalar Arguments ..
- INTEGER INFO, LDA, LWORK, N
-* ..
-* .. Array Arguments ..
- INTEGER IPIV( * )
- REAL A( LDA, * ), WORK( * )
-* ..
-*
-* Purpose
-* =======
-*
-* SGETRI computes the inverse of a matrix using the LU factorization
-* computed by SGETRF.
-*
-* This method inverts U and then computes inv(A) by solving the system
-* inv(A)*L = inv(U) for inv(A).
-*
-* Arguments
-* =========
-*
-* N (input) INTEGER
-* The order of the matrix A. N >= 0.
-*
-* A (input/output) REAL array, dimension (LDA,N)
-* On entry, the factors L and U from the factorization
-* A = P*L*U as computed by SGETRF.
-* On exit, if INFO = 0, the inverse of the original matrix A.
-*
-* LDA (input) INTEGER
-* The leading dimension of the array A. LDA >= max(1,N).
-*
-* IPIV (input) INTEGER array, dimension (N)
-* The pivot indices from SGETRF; for 1<=i<=N, row i of the
-* matrix was interchanged with row IPIV(i).
-*
-* WORK (workspace/output) REAL array, dimension (LWORK)
-* On exit, if INFO=0, then WORK(1) returns the optimal LWORK.
-*
-* LWORK (input) INTEGER
-* The dimension of the array WORK. LWORK >= max(1,N).
-* For optimal performance LWORK >= N*NB, where NB is
-* the optimal blocksize 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.
-*
-* INFO (output) INTEGER
-* = 0: successful exit
-* < 0: if INFO = -i, the i-th argument had an illegal value
-* > 0: if INFO = i, U(i,i) is exactly zero; the matrix is
-* singular and its inverse could not be computed.
-*
-* =====================================================================
-*
-* .. Parameters ..
- REAL ZERO, ONE
- PARAMETER ( ZERO = 0.0E+0, ONE = 1.0E+0 )
-* ..
-* .. Local Scalars ..
- LOGICAL LQUERY
- INTEGER I, IWS, J, JB, JJ, JP, LDWORK, LWKOPT, NB,
- $ NBMIN, NN
-* ..
-* .. External Functions ..
- INTEGER ILAENV
- EXTERNAL ILAENV
-* ..
-* .. External Subroutines ..
- EXTERNAL SGEMM, SGEMV, SSWAP, STRSM, STRTRI, XERBLA
-* ..
-* .. Intrinsic Functions ..
- INTRINSIC MAX, MIN
-* ..
-* .. Executable Statements ..
-*
-* Test the input parameters.
-*
- INFO = 0
- NB = ILAENV( 1, 'SGETRI', ' ', N, -1, -1, -1 )
- LWKOPT = N*NB
- WORK( 1 ) = LWKOPT
- LQUERY = ( LWORK.EQ.-1 )
- IF( N.LT.0 ) THEN
- INFO = -1
- ELSE IF( LDA.LT.MAX( 1, N ) ) THEN
- INFO = -3
- ELSE IF( LWORK.LT.MAX( 1, N ) .AND. .NOT.LQUERY ) THEN
- INFO = -6
- END IF
- IF( INFO.NE.0 ) THEN
- CALL XERBLA( 'SGETRI', -INFO )
- RETURN
- ELSE IF( LQUERY ) THEN
- RETURN
- END IF
-*
-* Quick return if possible
-*
- IF( N.EQ.0 )
- $ RETURN
-*
-* Form inv(U). If INFO > 0 from STRTRI, then U is singular,
-* and the inverse is not computed.
-*
- CALL STRTRI( 'Upper', 'Non-unit', N, A, LDA, INFO )
- IF( INFO.GT.0 )
- $ RETURN
-*
- NBMIN = 2
- LDWORK = N
- IF( NB.GT.1 .AND. NB.LT.N ) THEN
- IWS = MAX( LDWORK*NB, 1 )
- IF( LWORK.LT.IWS ) THEN
- NB = LWORK / LDWORK
- NBMIN = MAX( 2, ILAENV( 2, 'SGETRI', ' ', N, -1, -1, -1 ) )
- END IF
- ELSE
- IWS = N
- END IF
-*
-* Solve the equation inv(A)*L = inv(U) for inv(A).
-*
- IF( NB.LT.NBMIN .OR. NB.GE.N ) THEN
-*
-* Use unblocked code.
-*
- DO 20 J = N, 1, -1
-*
-* Copy current column of L to WORK and replace with zeros.
-*
- DO 10 I = J + 1, N
- WORK( I ) = A( I, J )
- A( I, J ) = ZERO
- 10 CONTINUE
-*
-* Compute current column of inv(A).
-*
- IF( J.LT.N )
- $ CALL SGEMV( 'No transpose', N, N-J, -ONE, A( 1, J+1 ),
- $ LDA, WORK( J+1 ), 1, ONE, A( 1, J ), 1 )
- 20 CONTINUE
- ELSE
-*
-* Use blocked code.
-*
- NN = ( ( N-1 ) / NB )*NB + 1
- DO 50 J = NN, 1, -NB
- JB = MIN( NB, N-J+1 )
-*
-* Copy current block column of L to WORK and replace with
-* zeros.
-*
- DO 40 JJ = J, J + JB - 1
- DO 30 I = JJ + 1, N
- WORK( I+( JJ-J )*LDWORK ) = A( I, JJ )
- A( I, JJ ) = ZERO
- 30 CONTINUE
- 40 CONTINUE
-*
-* Compute current block column of inv(A).
-*
- IF( J+JB.LE.N )
- $ CALL SGEMM( 'No transpose', 'No transpose', N, JB,
- $ N-J-JB+1, -ONE, A( 1, J+JB ), LDA,
- $ WORK( J+JB ), LDWORK, ONE, A( 1, J ), LDA )
- CALL STRSM( 'Right', 'Lower', 'No transpose', 'Unit', N, JB,
- $ ONE, WORK( J ), LDWORK, A( 1, J ), LDA )
- 50 CONTINUE
- END IF
-*
-* Apply column interchanges.
-*
- DO 60 J = N - 1, 1, -1
- JP = IPIV( J )
- IF( JP.NE.J )
- $ CALL SSWAP( N, A( 1, J ), 1, A( 1, JP ), 1 )
- 60 CONTINUE
-*
- WORK( 1 ) = IWS
- RETURN
-*
-* End of SGETRI
-*
- END
+++ /dev/null
- SUBROUTINE ZGETRI( N, A, LDA, IPIV, WORK, LWORK, INFO )
-*
-* -- LAPACK routine (version 3.0) --
-* Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,
-* Courant Institute, Argonne National Lab, and Rice University
-* June 30, 1999
-*
-* .. Scalar Arguments ..
- INTEGER INFO, LDA, LWORK, N
-* ..
-* .. Array Arguments ..
- INTEGER IPIV( * )
- COMPLEX*16 A( LDA, * ), WORK( * )
-* ..
-*
-* Purpose
-* =======
-*
-* ZGETRI computes the inverse of a matrix using the LU factorization
-* computed by ZGETRF.
-*
-* This method inverts U and then computes inv(A) by solving the system
-* inv(A)*L = inv(U) for inv(A).
-*
-* Arguments
-* =========
-*
-* N (input) INTEGER
-* The order of the matrix A. N >= 0.
-*
-* A (input/output) COMPLEX*16 array, dimension (LDA,N)
-* On entry, the factors L and U from the factorization
-* A = P*L*U as computed by ZGETRF.
-* On exit, if INFO = 0, the inverse of the original matrix A.
-*
-* LDA (input) INTEGER
-* The leading dimension of the array A. LDA >= max(1,N).
-*
-* IPIV (input) INTEGER array, dimension (N)
-* The pivot indices from ZGETRF; for 1<=i<=N, row i of the
-* matrix was interchanged with row IPIV(i).
-*
-* WORK (workspace/output) COMPLEX*16 array, dimension (LWORK)
-* On exit, if INFO=0, then WORK(1) returns the optimal LWORK.
-*
-* LWORK (input) INTEGER
-* The dimension of the array WORK. LWORK >= max(1,N).
-* For optimal performance LWORK >= N*NB, where NB is
-* the optimal blocksize 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.
-*
-* INFO (output) INTEGER
-* = 0: successful exit
-* < 0: if INFO = -i, the i-th argument had an illegal value
-* > 0: if INFO = i, U(i,i) is exactly zero; the matrix is
-* singular and its inverse could not be computed.
-*
-* =====================================================================
-*
-* .. Parameters ..
- COMPLEX*16 ZERO, ONE
- PARAMETER ( ZERO = ( 0.0D+0, 0.0D+0 ),
- $ ONE = ( 1.0D+0, 0.0D+0 ) )
-* ..
-* .. Local Scalars ..
- LOGICAL LQUERY
- INTEGER I, IWS, J, JB, JJ, JP, LDWORK, LWKOPT, NB,
- $ NBMIN, NN
-* ..
-* .. External Functions ..
- INTEGER ILAENV
- EXTERNAL ILAENV
-* ..
-* .. External Subroutines ..
- EXTERNAL XERBLA, ZGEMM, ZGEMV, ZSWAP, ZTRSM, ZTRTRI
-* ..
-* .. Intrinsic Functions ..
- INTRINSIC MAX, MIN
-* ..
-* .. Executable Statements ..
-*
-* Test the input parameters.
-*
- INFO = 0
- NB = ILAENV( 1, 'ZGETRI', ' ', N, -1, -1, -1 )
- LWKOPT = N*NB
- WORK( 1 ) = LWKOPT
- LQUERY = ( LWORK.EQ.-1 )
- IF( N.LT.0 ) THEN
- INFO = -1
- ELSE IF( LDA.LT.MAX( 1, N ) ) THEN
- INFO = -3
- ELSE IF( LWORK.LT.MAX( 1, N ) .AND. .NOT.LQUERY ) THEN
- INFO = -6
- END IF
- IF( INFO.NE.0 ) THEN
- CALL XERBLA( 'ZGETRI', -INFO )
- RETURN
- ELSE IF( LQUERY ) THEN
- RETURN
- END IF
-*
-* Quick return if possible
-*
- IF( N.EQ.0 )
- $ RETURN
-*
-* Form inv(U). If INFO > 0 from ZTRTRI, then U is singular,
-* and the inverse is not computed.
-*
- CALL ZTRTRI( 'Upper', 'Non-unit', N, A, LDA, INFO )
- IF( INFO.GT.0 )
- $ RETURN
-*
- NBMIN = 2
- LDWORK = N
- IF( NB.GT.1 .AND. NB.LT.N ) THEN
- IWS = MAX( LDWORK*NB, 1 )
- IF( LWORK.LT.IWS ) THEN
- NB = LWORK / LDWORK
- NBMIN = MAX( 2, ILAENV( 2, 'ZGETRI', ' ', N, -1, -1, -1 ) )
- END IF
- ELSE
- IWS = N
- END IF
-*
-* Solve the equation inv(A)*L = inv(U) for inv(A).
-*
- IF( NB.LT.NBMIN .OR. NB.GE.N ) THEN
-*
-* Use unblocked code.
-*
- DO 20 J = N, 1, -1
-*
-* Copy current column of L to WORK and replace with zeros.
-*
- DO 10 I = J + 1, N
- WORK( I ) = A( I, J )
- A( I, J ) = ZERO
- 10 CONTINUE
-*
-* Compute current column of inv(A).
-*
- IF( J.LT.N )
- $ CALL ZGEMV( 'No transpose', N, N-J, -ONE, A( 1, J+1 ),
- $ LDA, WORK( J+1 ), 1, ONE, A( 1, J ), 1 )
- 20 CONTINUE
- ELSE
-*
-* Use blocked code.
-*
- NN = ( ( N-1 ) / NB )*NB + 1
- DO 50 J = NN, 1, -NB
- JB = MIN( NB, N-J+1 )
-*
-* Copy current block column of L to WORK and replace with
-* zeros.
-*
- DO 40 JJ = J, J + JB - 1
- DO 30 I = JJ + 1, N
- WORK( I+( JJ-J )*LDWORK ) = A( I, JJ )
- A( I, JJ ) = ZERO
- 30 CONTINUE
- 40 CONTINUE
-*
-* Compute current block column of inv(A).
-*
- IF( J+JB.LE.N )
- $ CALL ZGEMM( 'No transpose', 'No transpose', N, JB,
- $ N-J-JB+1, -ONE, A( 1, J+JB ), LDA,
- $ WORK( J+JB ), LDWORK, ONE, A( 1, J ), LDA )
- CALL ZTRSM( 'Right', 'Lower', 'No transpose', 'Unit', N, JB,
- $ ONE, WORK( J ), LDWORK, A( 1, J ), LDA )
- 50 CONTINUE
- END IF
-*
-* Apply column interchanges.
-*
- DO 60 J = N - 1, 1, -1
- JP = IPIV( J )
- IF( JP.NE.J )
- $ CALL ZSWAP( N, A( 1, J ), 1, A( 1, JP ), 1 )
- 60 CONTINUE
-*
- WORK( 1 ) = IWS
- RETURN
-*
-* End of ZGETRI
-*
- END
projects / platform / upstream / openblas.git / commitdiff