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 )