101 SUBROUTINE sgetrf ( M, N, A, LDA, IPIV, INFO)
109 INTEGER INFO, LDA, M, N
120 parameter ( one = 1.0e+0 )
123 INTEGER I, IINFO, J, JB, NB
142 ELSE IF( n.LT.0 )
THEN
144 ELSE IF( lda.LT.max( 1, m ) )
THEN
148 CALL xerbla(
'SGETRF', -info )
154 IF( m.EQ.0 .OR. n.EQ.0 )
159 nb = ilaenv( 1,
'SGETRF',
' ', m, n, -1, -1 )
160 IF( nb.LE.1 .OR. nb.GE.min( m, n ) )
THEN
164 CALL sgetf2( m, n, a, lda, ipiv, info )
169 DO 20 j = 1, min( m, n ), nb
170 jb = min( min( m, n )-j+1, nb )
174 CALL sgemm(
'No transpose',
'No transpose',
175 $ m-j+1, jb, j-1, -one,
176 $ a( j, 1 ), lda, a( 1, j ), lda, one,
183 CALL sgetf2( m-j+1, jb, a( j, j ), lda, ipiv( j ), iinfo )
187 IF( info.EQ.0 .AND. iinfo.GT.0 )
188 $ info = iinfo + j - 1
189 DO 10 i = j, min( m, j+jb-1 )
190 ipiv( i ) = j - 1 + ipiv( i )
195 CALL slaswp( j-1, a, lda, j, j+jb-1, ipiv, 1 )
197 IF ( j+jb.LE.n )
THEN
201 CALL slaswp( n-j-jb+1, a( 1, j+jb ), lda, j, j+jb-1,
204 CALL sgemm(
'No transpose',
'No transpose',
205 $ jb, n-j-jb+1, j-1, -one,
206 $ a( j, 1 ), lda, a( 1, j+jb ), lda, one,
207 $ a( j, j+jb ), lda )
211 CALL strsm(
'Left',
'Lower',
'No transpose',
'Unit',
212 $ jb, n-j-jb+1, one, a( j, j ), lda,
213 $ a( j, j+jb ), lda )
subroutine strsm(SIDE, UPLO, TRANSA, DIAG, M, N, ALPHA, A, LDA, B, LDB)
STRSM
subroutine slaswp(N, A, LDA, K1, K2, IPIV, INCX)
SLASWP performs a series of row interchanges on a general rectangular matrix.
subroutine sgetf2(M, N, A, LDA, IPIV, INFO)
SGETF2 computes the LU factorization of a general m-by-n matrix using partial pivoting with row inter...
subroutine sgemm(TRANSA, TRANSB, M, N, K, ALPHA, A, LDA, B, LDB, BETA, C, LDC)
SGEMM
subroutine sgetrf(M, N, A, LDA, IPIV, INFO)
SGETRF
subroutine xerbla(SRNAME, INFO)
XERBLA