101 SUBROUTINE zpotrf ( UPLO, N, A, LDA, INFO )
113 COMPLEX*16 A( lda, * )
121 parameter ( one = 1.0d+0, cone = ( 1.0d+0, 0.0d+0 ) )
130 EXTERNAL lsame, ilaenv
143 upper = lsame( uplo,
'U' )
144 IF( .NOT.upper .AND. .NOT.lsame( uplo,
'L' ) )
THEN
146 ELSE IF( n.LT.0 )
THEN
148 ELSE IF( lda.LT.max( 1, n ) )
THEN
152 CALL xerbla(
'ZPOTRF', -info )
163 nb = ilaenv( 1,
'ZPOTRF', uplo, n, -1, -1, -1 )
164 IF( nb.LE.1 .OR. nb.GE.n )
THEN
168 CALL zpotf2( uplo, n, a, lda, info )
182 jb = min( nb, n-j+1 )
184 CALL zpotf2(
'Upper', jb, a( j, j ), lda, info )
193 CALL ztrsm(
'Left',
'Upper',
'Conjugate Transpose',
194 $
'Non-unit', jb, n-j-jb+1, cone, a( j, j ),
195 $ lda, a( j, j+jb ), lda )
196 CALL zherk(
'Upper',
'Conjugate transpose', n-j-jb+1,
197 $ jb, -one, a( j, j+jb ), lda,
198 $ one, a( j+jb, j+jb ), lda )
211 jb = min( nb, n-j+1 )
213 CALL zpotf2(
'Lower', jb, a( j, j ), lda, info )
222 CALL ztrsm(
'Right',
'Lower',
'Conjugate Transpose',
223 $
'Non-unit', n-j-jb+1, jb, cone, a( j, j ),
224 $ lda, a( j+jb, j ), lda )
226 CALL zherk(
'Lower',
'No Transpose', n-j-jb+1, jb,
227 $ -one, a( j+jb, j ), lda,
228 $ one, a( j+jb, j+jb ), lda )
subroutine zpotrf(UPLO, N, A, LDA, INFO)
ZPOTRF VARIANT: right looking block version of the algorithm, calling Level 3 BLAS.
subroutine zgemm(TRANSA, TRANSB, M, N, K, ALPHA, A, LDA, B, LDB, BETA, C, LDC)
ZGEMM
subroutine xerbla(SRNAME, INFO)
XERBLA
subroutine zherk(UPLO, TRANS, N, K, ALPHA, A, LDA, BETA, C, LDC)
ZHERK
subroutine ztrsm(SIDE, UPLO, TRANSA, DIAG, M, N, ALPHA, A, LDA, B, LDB)
ZTRSM
subroutine zpotf2(UPLO, N, A, LDA, INFO)
ZPOTF2 computes the Cholesky factorization of a symmetric/Hermitian positive definite matrix (unblock...