169 SUBROUTINE zunmqr( SIDE, TRANS, M, N, K, A, LDA, TAU, C, LDC,
170 $ work, lwork, info )
178 CHARACTER SIDE, TRANS
179 INTEGER INFO, K, LDA, LDC, LWORK, M, N
182 COMPLEX*16 A( lda, * ), C( ldc, * ), TAU( * ), WORK( * )
189 parameter( nbmax = 64, ldt = nbmax+1 )
192 LOGICAL LEFT, LQUERY, NOTRAN
193 INTEGER I, I1, I2, I3, IB, IC, IINFO, IWS, JC, LDWORK,
194 $ lwkopt, mi, nb, nbmin, ni, nq, nw
197 COMPLEX*16 T( ldt, nbmax )
202 EXTERNAL lsame, ilaenv
215 left = lsame( side,
'L' )
216 notran = lsame( trans,
'N' )
217 lquery = ( lwork.EQ.-1 )
228 IF( .NOT.left .AND. .NOT.lsame( side,
'R' ) )
THEN
230 ELSE IF( .NOT.notran .AND. .NOT.lsame( trans,
'C' ) )
THEN
232 ELSE IF( m.LT.0 )
THEN
234 ELSE IF( n.LT.0 )
THEN
236 ELSE IF( k.LT.0 .OR. k.GT.nq )
THEN
238 ELSE IF( lda.LT.max( 1, nq ) )
THEN
240 ELSE IF( ldc.LT.max( 1, m ) )
THEN
242 ELSE IF( lwork.LT.max( 1, nw ) .AND. .NOT.lquery )
THEN
251 nb = min( nbmax, ilaenv( 1,
'ZUNMQR', side // trans, m, n, k,
253 lwkopt = max( 1, nw )*nb
258 CALL xerbla(
'ZUNMQR', -info )
260 ELSE IF( lquery )
THEN
266 IF( m.EQ.0 .OR. n.EQ.0 .OR. k.EQ.0 )
THEN
273 IF( nb.GT.1 .AND. nb.LT.k )
THEN
275 IF( lwork.LT.iws )
THEN
277 nbmin = max( 2, ilaenv( 2,
'ZUNMQR', side // trans, m, n, k,
284 IF( nb.LT.nbmin .OR. nb.GE.k )
THEN
288 CALL zunm2r( side, trans, m, n, k, a, lda, tau, c, ldc, work,
294 IF( ( left .AND. .NOT.notran ) .OR.
295 $ ( .NOT.left .AND. notran ) )
THEN
300 i1 = ( ( k-1 ) / nb )*nb + 1
314 ib = min( nb, k-i+1 )
319 CALL zlarft(
'Forward',
'Columnwise', nq-i+1, ib, a( i, i ),
320 $ lda, tau( i ), t, ldt )
337 CALL zlarfb( side, trans,
'Forward',
'Columnwise', mi, ni,
338 $ ib, a( i, i ), lda, t, ldt, c( ic, jc ), ldc,
subroutine zlarfb(SIDE, TRANS, DIRECT, STOREV, M, N, K, V, LDV, T, LDT, C, LDC, WORK, LDWORK)
ZLARFB applies a block reflector or its conjugate-transpose to a general rectangular matrix...
subroutine zunm2r(SIDE, TRANS, M, N, K, A, LDA, TAU, C, LDC, WORK, INFO)
ZUNM2R multiplies a general matrix by the unitary matrix from a QR factorization determined by cgeqrf...
subroutine xerbla(SRNAME, INFO)
XERBLA
subroutine zlarft(DIRECT, STOREV, N, K, V, LDV, TAU, T, LDT)
ZLARFT forms the triangular factor T of a block reflector H = I - vtvH
subroutine zunmqr(SIDE, TRANS, M, N, K, A, LDA, TAU, C, LDC, WORK, LWORK, INFO)
ZUNMQR