109 SUBROUTINE sgetrf( M, N, A, LDA, IPIV, INFO )
117 INTEGER INFO, LDA, M, N
128 parameter( one = 1.0e+0 )
131 INTEGER I, IINFO, J, JB, NB
150 ELSE IF( n.LT.0 )
THEN
152 ELSE IF( lda.LT.max( 1, m ) )
THEN
156 CALL xerbla(
'SGETRF', -info )
162 IF( m.EQ.0 .OR. n.EQ.0 )
167 nb = ilaenv( 1,
'SGETRF',
' ', m, n, -1, -1 )
168 IF( nb.LE.1 .OR. nb.GE.min( m, n ) )
THEN
172 CALL sgetf2( m, n, a, lda, ipiv, info )
177 DO 20 j = 1, min( m, n ), nb
178 jb = min( min( m, n )-j+1, nb )
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 )
201 CALL slaswp( n-j-jb+1, a( 1, j+jb ), lda, j, j+jb-1,
206 CALL strsm(
'Left',
'Lower',
'No transpose',
'Unit', jb,
207 $ n-j-jb+1, one, a( j, j ), lda, a( j, j+jb ),
213 CALL sgemm(
'No transpose',
'No transpose', m-j-jb+1,
214 $ n-j-jb+1, jb, -one, a( j+jb, j ), lda,
215 $ a( j, j+jb ), lda, one, a( j+jb, j+jb ),
subroutine sgetrf(M, N, A, LDA, IPIV, INFO)
SGETRF
subroutine xerbla(SRNAME, INFO)
XERBLA
subroutine sgemm(TRANSA, TRANSB, M, N, K, ALPHA, A, LDA, B, LDB, BETA, C, LDC)
SGEMM
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 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.