Handle corner cases of LWORK (Reference-LAPACK PR 942)

lapack-netlib/SRC/sgebrd.f

@@ -122,7 +122,8 @@
 *> \param[in] LWORK
 *> \verbatim
 *>          LWORK is INTEGER
-*>          The length of the array WORK.  LWORK >= max(1,M,N).
+*>          The length of the array WORK.
+*>          LWORK >= 1, if MIN(M,N) = 0, and LWORK >= MAX(M,N), otherwise.
 *>          For optimum performance LWORK >= (M+N)*NB, where NB
 *>          is the optimal blocksize.
 *>
@@ -223,8 +224,8 @@
 *     ..
 *     .. Local Scalars ..
       LOGICAL            LQUERY
-      INTEGER            I, IINFO, J, LDWRKX, LDWRKY, LWKOPT, MINMN, NB,
+      INTEGER            I, IINFO, J, LDWRKX, LDWRKY, LWKMIN, LWKOPT,
-     $                   NBMIN, NX, WS
+     $                   MINMN, NB, NBMIN, NX, WS
 *     ..
 *     .. External Subroutines ..
       EXTERNAL           SGEBD2, SGEMM, SLABRD, XERBLA
@@ -242,9 +243,16 @@
 *     Test the input parameters
 *
       INFO = 0
-      NB = MAX( 1, ILAENV( 1, 'SGEBRD', ' ', M, N, -1, -1 ) )
+      MINMN = MIN( M, N )
-      LWKOPT = ( M+N )*NB
+      IF( MINMN.EQ.0 ) THEN
-      WORK( 1 ) = SROUNDUP_LWORK(LWKOPT)
+         LWKMIN = 1
+         LWKOPT = 1
+      ELSE
+         LWKMIN = MAX( M, N )
+         NB = MAX( 1, ILAENV( 1, 'SGEBRD', ' ', M, N, -1, -1 ) )
+         LWKOPT = ( M+N )*NB
+      ENDIF
+      WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
       LQUERY = ( LWORK.EQ.-1 )
       IF( M.LT.0 ) THEN
          INFO = -1
@@ -252,7 +260,7 @@
          INFO = -2
       ELSE IF( LDA.LT.MAX( 1, M ) ) THEN
          INFO = -4
-      ELSE IF( LWORK.LT.MAX( 1, M, N ) .AND. .NOT.LQUERY ) THEN
+      ELSE IF( LWORK.LT.LWKMIN .AND. .NOT.LQUERY ) THEN
          INFO = -10
       END IF
       IF( INFO.LT.0 ) THEN
@@ -264,7 +272,6 @@
 *
 *     Quick return if possible
 *
-      MINMN = MIN( M, N )
       IF( MINMN.EQ.0 ) THEN
          WORK( 1 ) = 1
          RETURN
@@ -283,7 +290,7 @@
 *        Determine when to switch from blocked to unblocked code.
 *
          IF( NX.LT.MINMN ) THEN
-            WS = ( M+N )*NB
+            WS = LWKOPT
             IF( LWORK.LT.WS ) THEN
 *
 *              Not enough work space for the optimal NB, consider using
@@ -342,7 +349,8 @@
 *
       CALL SGEBD2( M-I+1, N-I+1, A( I, I ), LDA, D( I ), E( I ),
      $             TAUQ( I ), TAUP( I ), WORK, IINFO )
-      WORK( 1 ) = SROUNDUP_LWORK(WS)
+*
+      WORK( 1 ) = SROUNDUP_LWORK( WS )
       RETURN
 *
 *     End of SGEBRD

lapack-netlib/SRC/sgehrd.f

@@ -89,7 +89,7 @@
 *>
 *> \param[out] WORK
 *> \verbatim
-*>          WORK is REAL array, dimension (LWORK)
+*>          WORK is REAL array, dimension (MAX(1,LWORK))
 *>          On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
 *> \endverbatim
 *>
@@ -173,7 +173,7 @@
       INTEGER            IHI, ILO, INFO, LDA, LWORK, N
 *     ..
 *     .. Array Arguments ..
-      REAL              A( LDA, * ), TAU( * ), WORK( * )
+      REAL               A( LDA, * ), TAU( * ), WORK( * )
 *     ..
 *
 *  =====================================================================
@@ -182,7 +182,7 @@
       INTEGER            NBMAX, LDT, TSIZE
       PARAMETER          ( NBMAX = 64, LDT = NBMAX+1,
      $                     TSIZE = LDT*NBMAX )
-      REAL              ZERO, ONE
+      REAL               ZERO, ONE
       PARAMETER          ( ZERO = 0.0E+0,
      $                     ONE = 1.0E+0 )
 *     ..
@@ -190,7 +190,7 @@
       LOGICAL            LQUERY
       INTEGER            I, IB, IINFO, IWT, J, LDWORK, LWKOPT, NB,
      $                   NBMIN, NH, NX
-      REAL              EI
+      REAL               EI
 *     ..
 *     .. External Subroutines ..
       EXTERNAL           SAXPY, SGEHD2, SGEMM, SLAHR2, SLARFB, STRMM,
@@ -222,13 +222,19 @@
          INFO = -8
       END IF
 *
+      NH = IHI - ILO + 1
       IF( INFO.EQ.0 ) THEN
 *
 *       Compute the workspace requirements
 *
-         NB = MIN( NBMAX, ILAENV( 1, 'SGEHRD', ' ', N, ILO, IHI, -1 ) )
+         IF( NH.LE.1 ) THEN
-         LWKOPT = N*NB + TSIZE
+            LWKOPT = 1
-         WORK( 1 ) = SROUNDUP_LWORK(LWKOPT)
+         ELSE
+            NB = MIN( NBMAX, ILAENV( 1, 'SGEHRD', ' ', N, ILO, IHI,
+     $                              -1 ) )
+            LWKOPT = N*NB + TSIZE
+         ENDIF
+         WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
       END IF
 *
       IF( INFO.NE.0 ) THEN
@@ -249,7 +255,6 @@
 *
 *     Quick return if possible
 *
-      NH = IHI - ILO + 1
       IF( NH.LE.1 ) THEN
          WORK( 1 ) = 1
          RETURN
@@ -269,7 +274,7 @@
 *
 *           Determine if workspace is large enough for blocked code
 *
-            IF( LWORK.LT.N*NB+TSIZE ) THEN
+            IF( LWORK.LT.LWKOPT ) THEN
 *
 *              Not enough workspace to use optimal NB:  determine the
 *              minimum value of NB, and reduce NB or force use of
@@ -345,7 +350,8 @@
 *     Use unblocked code to reduce the rest of the matrix
 *
       CALL SGEHD2( N, I, IHI, A, LDA, TAU, WORK, IINFO )
-      WORK( 1 ) = SROUNDUP_LWORK(LWKOPT)
+*
+      WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
 *
       RETURN
 *

lapack-netlib/SRC/sgelq.f

@@ -98,7 +98,7 @@
 *> \param[in] LWORK
 *> \verbatim
 *>          LWORK is INTEGER
-*>          The dimension of the array WORK.
+*>          The dimension of the array WORK. LWORK >= 1.
 *>          If LWORK = -1 or -2, then a workspace query is assumed. The routine
 *>          only calculates the sizes of the T and WORK arrays, returns these
 *>          values as the first entries of the T and WORK arrays, and no error
@@ -295,9 +295,9 @@
         T( 2 ) = MB
         T( 3 ) = NB
         IF( MINW ) THEN
-          WORK( 1 ) = SROUNDUP_LWORK(LWMIN)
+          WORK( 1 ) = SROUNDUP_LWORK( LWMIN )
         ELSE
-          WORK( 1 ) = SROUNDUP_LWORK(LWREQ)
+          WORK( 1 ) = SROUNDUP_LWORK( LWREQ )
         END IF
       END IF
       IF( INFO.NE.0 ) THEN
@@ -322,7 +322,7 @@
      $                LWORK, INFO )
       END IF
 *
-      WORK( 1 ) = SROUNDUP_LWORK(LWREQ)
+      WORK( 1 ) = SROUNDUP_LWORK( LWREQ )
       RETURN
 *
 *     End of SGELQ

lapack-netlib/SRC/sgelqf.f

@@ -93,7 +93,8 @@
 *> \param[in] LWORK
 *> \verbatim
 *>          LWORK is INTEGER
-*>          The dimension of the array WORK.  LWORK >= max(1,M).
+*>          The dimension of the array WORK.
+*>          LWORK >= 1, if MIN(M,N) = 0, and LWORK >= M, otherwise.
 *>          For optimum performance LWORK >= M*NB, where NB is the
 *>          optimal blocksize.
 *>
@@ -175,9 +176,8 @@
 *     Test the input arguments
 *
       INFO = 0
+      K = MIN( M, N )
       NB = ILAENV( 1, 'SGELQF', ' ', M, N, -1, -1 )
-      LWKOPT = M*NB
-      WORK( 1 ) = SROUNDUP_LWORK(LWKOPT)
       LQUERY = ( LWORK.EQ.-1 )
       IF( M.LT.0 ) THEN
          INFO = -1
@@ -185,19 +185,25 @@
          INFO = -2
       ELSE IF( LDA.LT.MAX( 1, M ) ) THEN
          INFO = -4
-      ELSE IF( LWORK.LT.MAX( 1, M ) .AND. .NOT.LQUERY ) THEN
+      ELSE IF( .NOT.LQUERY ) THEN
-         INFO = -7
+         IF( LWORK.LE.0 .OR. ( N.GT.0 .AND. LWORK.LT.MAX( 1, M ) ) )
+     $      INFO = -7
       END IF
       IF( INFO.NE.0 ) THEN
          CALL XERBLA( 'SGELQF', -INFO )
          RETURN
       ELSE IF( LQUERY ) THEN
+         IF( K.EQ.0 ) THEN
+            LWKOPT = 1
+         ELSE
+            LWKOPT = M*NB
+         END IF
+         WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
          RETURN
       END IF
 *
 *     Quick return if possible
 *
-      K = MIN( M, N )
       IF( K.EQ.0 ) THEN
          WORK( 1 ) = 1
          RETURN
@@ -267,7 +273,7 @@
      $   CALL SGELQ2( M-I+1, N-I+1, A( I, I ), LDA, TAU( I ), WORK,
      $                IINFO )
 *
-      WORK( 1 ) = SROUNDUP_LWORK(IWS)
+      WORK( 1 ) = SROUNDUP_LWORK( IWS )
       RETURN
 *
 *     End of SGELQF

lapack-netlib/SRC/sgemlq.f

@@ -110,13 +110,14 @@
 *>
 *> \param[out] WORK
 *> \verbatim
-*>         (workspace) REAL array, dimension (MAX(1,LWORK))
+*>          (workspace) DOUBLE PRECISION array, dimension (MAX(1,LWORK))
+*>          On exit, if INFO = 0, WORK(1) returns the minimal LWORK.
 *> \endverbatim
 *>
 *> \param[in] LWORK
 *> \verbatim
 *>          LWORK is INTEGER
-*>          The dimension of the array WORK.
+*>          The dimension of the array WORK. LWORK >= 1.
 *>          If LWORK = -1, then a workspace query is assumed. The routine
 *>          only calculates the size of the WORK array, returns this
 *>          value as WORK(1), and no error message related to WORK
@@ -187,7 +188,7 @@
 *     ..
 *     .. Local Scalars ..
       LOGICAL            LEFT, RIGHT, TRAN, NOTRAN, LQUERY
-      INTEGER            MB, NB, LW, NBLCKS, MN
+      INTEGER            MB, NB, LW, NBLCKS, MN, MINMNK, LWMIN
 *     ..
 *     .. External Functions ..
       LOGICAL            LSAME
@@ -207,7 +208,7 @@
 *
 *     Test the input arguments
 *
-      LQUERY  = LWORK.EQ.-1
+      LQUERY  = ( LWORK.EQ.-1 )
       NOTRAN  = LSAME( TRANS, 'N' )
       TRAN    = LSAME( TRANS, 'T' )
       LEFT    = LSAME( SIDE, 'L' )
@@ -222,6 +223,13 @@
         LW = M * MB
         MN = N
       END IF
+*
+      MINMNK = MIN( M, N, K )
+      IF( MINMNK.EQ.0 ) THEN
+         LWMIN = 1
+      ELSE
+         LWMIN = MAX( 1, LW )
+      END IF
 *
       IF( ( NB.GT.K ) .AND. ( MN.GT.K ) ) THEN
         IF( MOD( MN - K, NB - K ) .EQ. 0 ) THEN
@@ -250,12 +258,12 @@
         INFO = -9
       ELSE IF( LDC.LT.MAX( 1, M ) ) THEN
         INFO = -11
-      ELSE IF( ( LWORK.LT.MAX( 1, LW ) ) .AND. ( .NOT.LQUERY ) ) THEN
+      ELSE IF( LWORK.LT.LWMIN .AND. .NOT.LQUERY ) THEN
         INFO = -13
       END IF
 *
       IF( INFO.EQ.0 ) THEN
-        WORK( 1 ) = SROUNDUP_LWORK( LW )
+        WORK( 1 ) = SROUNDUP_LWORK( LWMIN )
       END IF
 *
       IF( INFO.NE.0 ) THEN
@@ -267,7 +275,7 @@
 *
 *     Quick return if possible
 *
-      IF( MIN( M, N, K ).EQ.0 ) THEN
+      IF( MINMNK.EQ.0 ) THEN
         RETURN
       END IF
 *
@@ -280,7 +288,7 @@
      $                 MB, C, LDC, WORK, LWORK, INFO )
       END IF
 *
-      WORK( 1 ) = SROUNDUP_LWORK( LW )
+      WORK( 1 ) = SROUNDUP_LWORK( LWMIN )
 *
       RETURN
 *

lapack-netlib/SRC/sgemqr.f

@@ -189,12 +189,13 @@
 *     ..
 *     .. Local Scalars ..
       LOGICAL            LEFT, RIGHT, TRAN, NOTRAN, LQUERY
-      INTEGER            MB, NB, LW, NBLCKS, MN
+      INTEGER            MB, NB, LW, NBLCKS, MN, MINMNK, LWMIN
 *     ..
 *     .. External Functions ..
       LOGICAL            LSAME
+      EXTERNAL           LSAME
       REAL               SROUNDUP_LWORK
-      EXTERNAL           LSAME, SROUNDUP_LWORK
+      EXTERNAL           SROUNDUP_LWORK
 *     ..
 *     .. External Subroutines ..
       EXTERNAL           SGEMQRT, SLAMTSQR, XERBLA
@@ -206,7 +207,7 @@
 *
 *     Test the input arguments
 *
-      LQUERY  = LWORK.EQ.-1
+      LQUERY  = ( LWORK.EQ.-1 )
       NOTRAN  = LSAME( TRANS, 'N' )
       TRAN    = LSAME( TRANS, 'T' )
       LEFT    = LSAME( SIDE, 'L' )
@@ -221,6 +222,13 @@
         LW = MB * NB
         MN = N
       END IF
+*
+      MINMNK = MIN( M, N, K )
+      IF( MINMNK.EQ.0 ) THEN
+         LWMIN = 1
+      ELSE
+         LWMIN = MAX( 1, LW )
+      END IF
 *
       IF( ( MB.GT.K ) .AND. ( MN.GT.K ) ) THEN
         IF( MOD( MN - K, MB - K ).EQ.0 ) THEN
@@ -249,12 +257,12 @@
         INFO = -9
       ELSE IF( LDC.LT.MAX( 1, M ) ) THEN
         INFO = -11
-      ELSE IF( ( LWORK.LT.MAX( 1, LW ) ) .AND. ( .NOT.LQUERY ) ) THEN
+      ELSE IF( LWORK.LT.LWMIN .AND. .NOT.LQUERY ) THEN
         INFO = -13
       END IF
 *
       IF( INFO.EQ.0 ) THEN
-        WORK( 1 ) = SROUNDUP_LWORK(LW)
+        WORK( 1 ) = SROUNDUP_LWORK( LWMIN )
       END IF
 *
       IF( INFO.NE.0 ) THEN
@@ -266,7 +274,7 @@
 *
 *     Quick return if possible
 *
-      IF( MIN( M, N, K ).EQ.0 ) THEN
+      IF( MINMNK.EQ.0 ) THEN
         RETURN
       END IF
 *
@@ -279,7 +287,7 @@
      $                 NB, C, LDC, WORK, LWORK, INFO )
       END IF
 *
-      WORK( 1 ) = SROUNDUP_LWORK(LW)
+      WORK( 1 ) = SROUNDUP_LWORK( LWMIN )
 *
       RETURN
 *

lapack-netlib/SRC/sgeqlf.f

@@ -88,7 +88,8 @@
 *> \param[in] LWORK
 *> \verbatim
 *>          LWORK is INTEGER
-*>          The dimension of the array WORK.  LWORK >= max(1,N).
+*>          The dimension of the array WORK.
+*>          LWORK >= 1, if MIN(M,N) = 0, and LWORK >= N, otherwise.
 *>          For optimum performance LWORK >= N*NB, where NB is the
 *>          optimal blocksize.
 *>
@@ -189,8 +190,9 @@
          END IF
          WORK( 1 ) = SROUNDUP_LWORK(LWKOPT)
 *
-         IF( LWORK.LT.MAX( 1, N ) .AND. .NOT.LQUERY ) THEN
+         IF( .NOT.LQUERY ) THEN
-            INFO = -7
+            IF( LWORK.LE.0 .OR. ( M.GT.0 .AND. LWORK.LT.MAX( 1, N ) ) )
+     $         INFO = -7
          END IF
       END IF
 *

lapack-netlib/SRC/sgeqp3rk.f

@@ -427,7 +427,8 @@
 *> \verbatim
 *>          LWORK is INTEGER
 *>          The dimension of the array WORK.
-*.          LWORK >= (3*N + NRHS - 1)
+*>          LWORK >= 1, if MIN(M,N) = 0, and
+*>          LWORK >= (3*N+NRHS-1), otherwise.
 *>          For optimal performance LWORK >= (2*N + NB*( N+NRHS+1 )),
 *>          where NB is the optimal block size for SGEQP3RK returned
 *>          by ILAENV. Minimal block size MINNB=2.
@@ -618,8 +619,9 @@
 *     .. External Functions ..
       LOGICAL            SISNAN
       INTEGER            ISAMAX, ILAENV
-      REAL               SLAMCH, SNRM2
+      REAL               SLAMCH, SNRM2, SROUNDUP_LWORK
-      EXTERNAL           SISNAN, SLAMCH, SNRM2, ISAMAX, ILAENV
+      EXTERNAL           SISNAN, SLAMCH, SNRM2, ISAMAX, ILAENV,
+     $                   SROUNDUP_LWORK
 *     ..
 *     .. Intrinsic Functions ..
       INTRINSIC          REAL, MAX, MIN
@@ -696,7 +698,7 @@
 *
             LWKOPT = 2*N + NB*( N+NRHS+1 )
          END IF
-         WORK( 1 ) = REAL( LWKOPT )
+         WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
 *
          IF( ( LWORK.LT.IWS ) .AND. .NOT.LQUERY ) THEN
             INFO = -15
@@ -719,7 +721,7 @@
          K = 0
          MAXC2NRMK = ZERO
          RELMAXC2NRMK = ZERO
-         WORK( 1 ) = REAL( LWKOPT )
+         WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
          RETURN
       END IF
 *
@@ -772,7 +774,7 @@
 *
 *        Array TAU is not set and contains undefined elements.
 *
-         WORK( 1 ) = REAL( LWKOPT )
+         WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
          RETURN
       END IF
 *
@@ -791,7 +793,7 @@
             TAU( J ) = ZERO
          END DO
 *
-         WORK( 1 ) = REAL( LWKOPT )
+         WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
          RETURN
 *
       END IF
@@ -822,7 +824,7 @@
          DO J = 1, MINMN
             TAU( J ) = ZERO
          END DO
-         WORK( 1 ) = REAL( LWKOPT )
+         WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
          RETURN
       END IF
 *
@@ -867,7 +869,7 @@
             TAU( J ) = ZERO
          END DO
 *
-         WORK( 1 ) = REAL( LWKOPT )
+         WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
          RETURN
       END IF
 *
@@ -985,7 +987,7 @@
 *
 *              Return from the routine.
 *
-               WORK( 1 ) = REAL( LWKOPT )
+               WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
 *
                RETURN
 *
@@ -1072,7 +1074,7 @@
 *
       END IF
 *
-      WORK( 1 ) = REAL( LWKOPT )
+      WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
 *
       RETURN
 *

lapack-netlib/SRC/sgeqr.f

@@ -99,7 +99,7 @@
 *> \param[in] LWORK
 *> \verbatim
 *>          LWORK is INTEGER
-*>          The dimension of the array WORK.
+*>          The dimension of the array WORK. LWORK >= 1.
 *>          If LWORK = -1 or -2, then a workspace query is assumed. The routine
 *>          only calculates the sizes of the T and WORK arrays, returns these
 *>          values as the first entries of the T and WORK arrays, and no error
@@ -168,6 +168,8 @@
 *>
 *> \endverbatim
 *>
+*> \ingroup geqr
+*>
 *  =====================================================================
       SUBROUTINE SGEQR( M, N, A, LDA, T, TSIZE, WORK, LWORK,
      $                  INFO )
@@ -188,11 +190,13 @@
 *     ..
 *     .. Local Scalars ..
       LOGICAL            LQUERY, LMINWS, MINT, MINW
-      INTEGER            MB, NB, MINTSZ, NBLCKS
+      INTEGER            MB, NB, MINTSZ, NBLCKS, LWMIN, LWREQ
 *     ..
 *     .. External Functions ..
       LOGICAL            LSAME
       EXTERNAL           LSAME
+      REAL               SROUNDUP_LWORK
+      EXTERNAL           SROUNDUP_LWORK
 *     ..
 *     .. External Subroutines ..
       EXTERNAL           SLATSQR, SGEQRT, XERBLA
@@ -244,8 +248,10 @@
 *
 *     Determine if the workspace size satisfies minimal size
 *
+      LWMIN = MAX( 1, N )
+      LWREQ = MAX( 1, N*NB )
       LMINWS = .FALSE.
-      IF( ( TSIZE.LT.MAX( 1, NB*N*NBLCKS + 5 ) .OR. LWORK.LT.NB*N )
+      IF( ( TSIZE.LT.MAX( 1, NB*N*NBLCKS + 5 ) .OR. LWORK.LT.LWREQ )
      $    .AND. ( LWORK.GE.N ) .AND. ( TSIZE.GE.MINTSZ )
      $    .AND. ( .NOT.LQUERY ) ) THEN
         IF( TSIZE.LT.MAX( 1, NB*N*NBLCKS + 5 ) ) THEN
@@ -253,7 +259,7 @@
           NB = 1
           MB = M
         END IF
-        IF( LWORK.LT.NB*N ) THEN
+        IF( LWORK.LT.LWREQ ) THEN
           LMINWS = .TRUE.
           NB = 1
         END IF
@@ -268,7 +274,7 @@
       ELSE IF( TSIZE.LT.MAX( 1, NB*N*NBLCKS + 5 )
      $   .AND. ( .NOT.LQUERY ) .AND. ( .NOT.LMINWS ) ) THEN
         INFO = -6
-      ELSE IF( ( LWORK.LT.MAX( 1, N*NB ) ) .AND. ( .NOT.LQUERY )
+      ELSE IF( ( LWORK.LT.LWREQ ) .AND. ( .NOT.LQUERY )
      $   .AND. ( .NOT.LMINWS ) ) THEN
         INFO = -8
       END IF
@@ -282,9 +288,9 @@
         T( 2 ) = MB
         T( 3 ) = NB
         IF( MINW ) THEN
-          WORK( 1 ) = MAX( 1, N )
+          WORK( 1 ) = SROUNDUP_LWORK( LWMIN )
         ELSE
-          WORK( 1 ) = MAX( 1, NB*N )
+          WORK( 1 ) = SROUNDUP_LWORK( LWREQ )
         END IF
       END IF
       IF( INFO.NE.0 ) THEN
@@ -309,7 +315,7 @@
      $                LWORK, INFO )
       END IF
 *
-      WORK( 1 ) = MAX( 1, NB*N )
+      WORK( 1 ) = SROUNDUP_LWORK( LWREQ )
 *
       RETURN
 *

lapack-netlib/SRC/sgeqrfp.f

@@ -97,7 +97,8 @@
 *> \param[in] LWORK
 *> \verbatim
 *>          LWORK is INTEGER
-*>          The dimension of the array WORK.  LWORK >= max(1,N).
+*>          The dimension of the array WORK.
+*>          LWORK >= 1, if MIN(M,N) = 0, and LWORK >= N, otherwise.
 *>          For optimum performance LWORK >= N*NB, where NB is
 *>          the optimal blocksize.
 *>
@@ -162,8 +163,8 @@
 *
 *     .. Local Scalars ..
       LOGICAL            LQUERY
-      INTEGER            I, IB, IINFO, IWS, K, LDWORK, LWKOPT, NB,
+      INTEGER            I, IB, IINFO, IWS, K, LDWORK, LWKMIN, LWKOPT,
-     $                   NBMIN, NX
+     $                   NB, NBMIN, NX
 *     ..
 *     .. External Subroutines ..
       EXTERNAL           SGEQR2P, SLARFB, SLARFT, XERBLA
@@ -173,8 +174,9 @@
 *     ..
 *     .. External Functions ..
       INTEGER            ILAENV
+      EXTERNAL           ILAENV
       REAL               SROUNDUP_LWORK
-      EXTERNAL           ILAENV, SROUNDUP_LWORK
+      EXTERNAL           SROUNDUP_LWORK
 *     ..
 *     .. Executable Statements ..
 *
@@ -182,8 +184,16 @@
 *
       INFO = 0
       NB = ILAENV( 1, 'SGEQRF', ' ', M, N, -1, -1 )
-      LWKOPT = N*NB
+      K = MIN( M, N )
-      WORK( 1 ) = SROUNDUP_LWORK(LWKOPT)
+      IF( K.EQ.0 ) THEN
+         LWKMIN = 1
+         LWKOPT = 1
+      ELSE
+         LWKMIN = N
+         LWKOPT = N*NB
+      END IF
+      WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
+*
       LQUERY = ( LWORK.EQ.-1 )
       IF( M.LT.0 ) THEN
          INFO = -1
@@ -191,7 +201,7 @@
          INFO = -2
       ELSE IF( LDA.LT.MAX( 1, M ) ) THEN
          INFO = -4
-      ELSE IF( LWORK.LT.MAX( 1, N ) .AND. .NOT.LQUERY ) THEN
+      ELSE IF( LWORK.LT.LWKMIN .AND. .NOT.LQUERY ) THEN
          INFO = -7
       END IF
       IF( INFO.NE.0 ) THEN
@@ -211,7 +221,7 @@
 *
       NBMIN = 2
       NX = 0
-      IWS = N
+      IWS = LWKMIN
       IF( NB.GT.1 .AND. NB.LT.K ) THEN
 *
 *        Determine when to cross over from blocked to unblocked code.
@@ -273,7 +283,7 @@
      $   CALL SGEQR2P( M-I+1, N-I+1, A( I, I ), LDA, TAU( I ), WORK,
      $                IINFO )
 *
-      WORK( 1 ) = SROUNDUP_LWORK(IWS)
+      WORK( 1 ) = SROUNDUP_LWORK( IWS )
       RETURN
 *
 *     End of SGEQRFP

lapack-netlib/SRC/sgesvj.f

@@ -208,7 +208,7 @@
 *>
 *> \param[in,out] WORK
 *> \verbatim
-*>          WORK is REAL array, dimension (LWORK)
+*>          WORK is REAL array, dimension (MAX(1,LWORK))
 *>          On entry,
 *>          If JOBU = 'C' :
 *>          WORK(1) = CTOL, where CTOL defines the threshold for convergence.
@@ -239,7 +239,12 @@
 *> \param[in] LWORK
 *> \verbatim
 *>          LWORK is INTEGER
-*>         length of WORK, WORK >= MAX(6,M+N)
+*>          Length of WORK.
+*>          LWORK >= 1, if MIN(M,N) = 0, and LWORK >= MAX(6,M+N), otherwise.
+*>
+*>          If on entry LWORK = -1, then a workspace query is assumed and
+*>          no computation is done; WORK(1) is set to the minial (and optimal)
+*>          length of WORK.
 *> \endverbatim
 *>
 *> \param[out] INFO
@@ -260,7 +265,7 @@
 *> \author Univ. of Colorado Denver
 *> \author NAG Ltd.
 *
-*> \ingroup realGEcomputational
+*> \ingroup gesvj
 *
 *> \par Further Details:
 *  =====================
@@ -351,9 +356,9 @@
       INTEGER            BLSKIP, EMPTSW, i, ibr, IERR, igl, IJBLSK, ir1,
      $                   ISWROT, jbc, jgl, KBL, LKAHEAD, MVL, N2, N34,
      $                   N4, NBL, NOTROT, p, PSKIPPED, q, ROWSKIP,
-     $                   SWBAND
+     $                   SWBAND, MINMN, LWMIN
-      LOGICAL            APPLV, GOSCALE, LOWER, LSVEC, NOSCALE, ROTOK,
+      LOGICAL            APPLV, GOSCALE, LOWER, LQUERY, LSVEC, NOSCALE,
-     $                   RSVEC, UCTOL, UPPER
+     $                   ROTOK, RSVEC, UCTOL, UPPER
 *     ..
 *     .. Local Arrays ..
       REAL               FASTR( 5 )
@@ -369,8 +374,8 @@
       INTEGER            ISAMAX
       EXTERNAL           ISAMAX
 *     from LAPACK
-      REAL               SLAMCH
+      REAL               SLAMCH, SROUNDUP_LWORK
-      EXTERNAL           SLAMCH
+      EXTERNAL           SLAMCH, SROUNDUP_LWORK
       LOGICAL            LSAME
       EXTERNAL           LSAME
 *     ..
@@ -394,6 +399,14 @@
       UPPER = LSAME( JOBA, 'U' )
       LOWER = LSAME( JOBA, 'L' )
 *
+      MINMN = MIN( M, N )
+      IF( MINMN.EQ.0 ) THEN
+         LWMIN = 1
+      ELSE
+         LWMIN = MAX( 6, M+N )
+      END IF
+*
+      LQUERY = ( LWORK.EQ.-1 )
       IF( .NOT.( UPPER .OR. LOWER .OR. LSAME( JOBA, 'G' ) ) ) THEN
          INFO = -1
       ELSE IF( .NOT.( LSVEC .OR. UCTOL .OR. LSAME( JOBU, 'N' ) ) ) THEN
@@ -413,7 +426,7 @@
          INFO = -11
       ELSE IF( UCTOL .AND. ( WORK( 1 ).LE.ONE ) ) THEN
          INFO = -12
-      ELSE IF( LWORK.LT.MAX( M+N, 6 ) ) THEN
+      ELSE IF( LWORK.LT.LWMIN .AND. ( .NOT.LQUERY ) ) THEN
          INFO = -13
       ELSE
          INFO = 0
@@ -423,11 +436,14 @@
       IF( INFO.NE.0 ) THEN
          CALL XERBLA( 'SGESVJ', -INFO )
          RETURN
+      ELSE IF( LQUERY ) THEN
+         WORK( 1 ) = SROUNDUP_LWORK( LWMIN )
+         RETURN
       END IF
 *
 * #:) Quick return for void matrix
 *
-      IF( ( M.EQ.0 ) .OR. ( N.EQ.0 ) )RETURN
+      IF( MINMN.EQ.0 ) RETURN
 *
 *     Set numerical parameters
 *     The stopping criterion for Jacobi rotations is

lapack-netlib/SRC/sgetri.f

@@ -137,8 +137,9 @@
 *     ..
 *     .. External Functions ..
       INTEGER            ILAENV
+      EXTERNAL           ILAENV
       REAL               SROUNDUP_LWORK
-      EXTERNAL           ILAENV, SROUNDUP_LWORK
+      EXTERNAL           SROUNDUP_LWORK
 *     ..
 *     .. External Subroutines ..
       EXTERNAL           SGEMM, SGEMV, SSWAP, STRSM, STRTRI, XERBLA
@@ -152,8 +153,9 @@
 *
       INFO = 0
       NB = ILAENV( 1, 'SGETRI', ' ', N, -1, -1, -1 )
-      LWKOPT = N*NB
+      LWKOPT = MAX( 1, N*NB )
-      WORK( 1 ) = SROUNDUP_LWORK(LWKOPT)
+      WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
+*
       LQUERY = ( LWORK.EQ.-1 )
       IF( N.LT.0 ) THEN
          INFO = -1
@@ -251,7 +253,7 @@
      $      CALL SSWAP( N, A( 1, J ), 1, A( 1, JP ), 1 )
    60 CONTINUE
 *
-      WORK( 1 ) = SROUNDUP_LWORK(IWS)
+      WORK( 1 ) = SROUNDUP_LWORK( IWS )
       RETURN
 *
 *     End of SGETRI

lapack-netlib/SRC/sgetsls.f

@@ -127,7 +127,7 @@
 *> \param[in] LWORK
 *> \verbatim
 *>          LWORK is INTEGER
-*>          The dimension of the array WORK.
+*>          The dimension of the array WORK. LWORK >= 1.
 *>          If LWORK = -1 or -2, then a workspace query is assumed.
 *>          If LWORK = -1, the routine calculates optimal size of WORK for the
 *>          optimal performance and returns this value in WORK(1).
@@ -226,7 +226,10 @@
 *
 *     Determine the optimum and minimum LWORK
 *
-       IF( M.GE.N ) THEN
+       IF( MIN( M, N, NRHS ).EQ.0 ) THEN
+         WSIZEO = 1
+         WSIZEM = 1
+       ELSE IF( M.GE.N ) THEN
          CALL SGEQR( M, N, A, LDA, TQ, -1, WORKQ, -1, INFO2 )
          TSZO = INT( TQ( 1 ) )
          LWO  = INT( WORKQ( 1 ) )

lapack-netlib/SRC/sgetsqrhrt.f

@@ -130,14 +130,17 @@
 *>
 *> \param[in] LWORK
 *> \verbatim
+*>          LWORK is INTEGER
 *>          The dimension of the array WORK.
-*>          LWORK >= MAX( LWT + LW1, MAX( LWT+N*N+LW2, LWT+N*N+N ) ),
+*>          If MIN(M,N) = 0, LWORK >= 1, else
+*>          LWORK >= MAX( 1, LWT + LW1, MAX( LWT+N*N+LW2, LWT+N*N+N ) ),
 *>          where
 *>             NUM_ALL_ROW_BLOCKS = CEIL((M-N)/(MB1-N)),
 *>             NB1LOCAL = MIN(NB1,N).
 *>             LWT = NUM_ALL_ROW_BLOCKS * N * NB1LOCAL,
 *>             LW1 = NB1LOCAL * N,
-*>             LW2 = NB1LOCAL * MAX( NB1LOCAL, ( N - NB1LOCAL ) ),
+*>             LW2 = NB1LOCAL * MAX( NB1LOCAL, ( N - NB1LOCAL ) ).
+*>
 *>          If LWORK = -1, then a workspace query is assumed.
 *>          The routine only calculates the optimal size of the WORK
 *>          array, returns this value as the first entry of the WORK
@@ -216,7 +219,7 @@
 *     Test the input arguments
 *
       INFO = 0
-      LQUERY  = LWORK.EQ.-1
+      LQUERY = ( LWORK.EQ.-1 )
       IF( M.LT.0 ) THEN
          INFO = -1
       ELSE IF( N.LT.0 .OR. M.LT.N ) THEN
@@ -229,7 +232,7 @@
          INFO = -5
       ELSE IF( LDA.LT.MAX( 1, M ) ) THEN
          INFO = -7
-      ELSE IF( LDT.LT.MAX( 1,  MIN( NB2, N ) ) ) THEN
+      ELSE IF( LDT.LT.MAX( 1, MIN( NB2, N ) ) ) THEN
          INFO = -9
       ELSE
 *
@@ -267,8 +270,9 @@
             LW2 = NB1LOCAL * MAX( NB1LOCAL, ( N - NB1LOCAL ) )
 *
             LWORKOPT = MAX( LWT + LW1, MAX( LWT+N*N+LW2, LWT+N*N+N ) )
+            LWORKOPT = MAX( 1, LWORKOPT )
 *
-            IF( ( LWORK.LT.MAX( 1, LWORKOPT ) ).AND.(.NOT.LQUERY) ) THEN
+            IF( LWORK.LT.LWORKOPT .AND. .NOT.LQUERY ) THEN
                INFO = -11
             END IF
 *
@@ -350,4 +354,4 @@
 *
 *     End of SGETSQRHRT
 *
-      END
+      END

lapack-netlib/SRC/sgges3.f

@@ -234,6 +234,8 @@
 *> \verbatim
 *>          LWORK is INTEGER
 *>          The dimension of the array WORK.
+*>          If N = 0, LWORK >= 1, else LWORK >= 6*N+16.
+*>          For good performance, LWORK must generally be larger.
 *>
 *>          If LWORK = -1, then a workspace query is assumed; the routine
 *>          only calculates the optimal size of the WORK array, returns
@@ -309,7 +311,8 @@
       LOGICAL            CURSL, ILASCL, ILBSCL, ILVSL, ILVSR, LASTSL,
      $                   LQUERY, LST2SL, WANTST
       INTEGER            I, ICOLS, IERR, IHI, IJOBVL, IJOBVR, ILEFT,
-     $                   ILO, IP, IRIGHT, IROWS, ITAU, IWRK, LWKOPT
+     $                   ILO, IP, IRIGHT, IROWS, ITAU, IWRK, LWKOPT,
+     $                   LWKMIN
       REAL               ANRM, ANRMTO, BIGNUM, BNRM, BNRMTO, EPS, PVSL,
      $                   PVSR, SAFMAX, SAFMIN, SMLNUM
 *     ..
@@ -361,6 +364,12 @@
 *
       INFO = 0
       LQUERY = ( LWORK.EQ.-1 )
+      IF( N.EQ.0 ) THEN
+         LWKMIN = 1
+      ELSE
+         LWKMIN = 6*N+16
+      END IF
+*
       IF( IJOBVL.LE.0 ) THEN
          INFO = -1
       ELSE IF( IJOBVR.LE.0 ) THEN
@@ -377,7 +386,7 @@
          INFO = -15
       ELSE IF( LDVSR.LT.1 .OR. ( ILVSR .AND. LDVSR.LT.N ) ) THEN
          INFO = -17
-      ELSE IF( LWORK.LT.6*N+16 .AND. .NOT.LQUERY ) THEN
+      ELSE IF( LWORK.LT.LWKMIN .AND. .NOT.LQUERY ) THEN
          INFO = -19
       END IF
 *
@@ -385,7 +394,7 @@
 *
       IF( INFO.EQ.0 ) THEN
          CALL SGEQRF( N, N, B, LDB, WORK, WORK, -1, IERR )
-         LWKOPT = MAX( 6*N+16, 3*N+INT( WORK( 1 ) ) )
+         LWKOPT = MAX( LWKMIN, 3*N+INT( WORK( 1 ) ) )
          CALL SORMQR( 'L', 'T', N, N, N, B, LDB, WORK, A, LDA, WORK,
      $                -1, IERR )
          LWKOPT = MAX( LWKOPT, 3*N+INT( WORK( 1 ) ) )
@@ -407,7 +416,11 @@
      $                   IERR )
             LWKOPT = MAX( LWKOPT, 2*N+INT( WORK( 1 ) ) )
          END IF
-         WORK( 1 ) = SROUNDUP_LWORK(LWKOPT)
+         IF( N.EQ.0 ) THEN
+            WORK( 1 ) = 1
+         ELSE
+            WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
+         END IF
       END IF
 *
       IF( INFO.NE.0 ) THEN
@@ -421,6 +434,7 @@
 *
       IF( N.EQ.0 ) THEN
          SDIM = 0
+         WORK( 1 ) = 1
          RETURN
       END IF
 *
@@ -657,7 +671,7 @@
 *
    40 CONTINUE
 *
-      WORK( 1 ) = SROUNDUP_LWORK(LWKOPT)
+      WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
 *
       RETURN
 *

lapack-netlib/SRC/sggev3.f

@@ -189,6 +189,8 @@
 *> \param[in] LWORK
 *> \verbatim
 *>          LWORK is INTEGER
+*>          The dimension of the array WORK. LWORK >= MAX(1,8*N).
+*>          For good performance, LWORK should generally be larger.
 *>
 *>          If LWORK = -1, then a workspace query is assumed; the routine
 *>          only calculates the optimal size of the WORK array, returns
@@ -248,7 +250,8 @@
       LOGICAL            ILASCL, ILBSCL, ILV, ILVL, ILVR, LQUERY
       CHARACTER          CHTEMP
       INTEGER            ICOLS, IERR, IHI, IJOBVL, IJOBVR, ILEFT, ILO,
-     $                   IN, IRIGHT, IROWS, ITAU, IWRK, JC, JR, LWKOPT
+     $                   IN, IRIGHT, IROWS, ITAU, IWRK, JC, JR, LWKOPT,
+     $                   LWKMIN
       REAL               ANRM, ANRMTO, BIGNUM, BNRM, BNRMTO, EPS,
      $                   SMLNUM, TEMP
 *     ..
@@ -298,6 +301,7 @@
 *
       INFO = 0
       LQUERY = ( LWORK.EQ.-1 )
+      LWKMIN = MAX( 1, 8*N )
       IF( IJOBVL.LE.0 ) THEN
          INFO = -1
       ELSE IF( IJOBVR.LE.0 ) THEN
@@ -312,7 +316,7 @@
          INFO = -12
       ELSE IF( LDVR.LT.1 .OR. ( ILVR .AND. LDVR.LT.N ) ) THEN
          INFO = -14
-      ELSE IF( LWORK.LT.MAX( 1, 8*N ) .AND. .NOT.LQUERY ) THEN
+      ELSE IF( LWORK.LT.LWKMIN .AND. .NOT.LQUERY ) THEN
          INFO = -16
       END IF
 *
@@ -320,28 +324,31 @@
 *
       IF( INFO.EQ.0 ) THEN
          CALL SGEQRF( N, N, B, LDB, WORK, WORK, -1, IERR )
-         LWKOPT = MAX( 1, 8*N, 3*N+INT ( WORK( 1 ) ) )
+         LWKOPT = MAX( LWKMIN, 3*N+INT( WORK( 1 ) ) )
          CALL SORMQR( 'L', 'T', N, N, N, B, LDB, WORK, A, LDA, WORK,
      $                -1, IERR )
-         LWKOPT = MAX( LWKOPT, 3*N+INT ( WORK( 1 ) ) )
+         LWKOPT = MAX( LWKOPT, 3*N+INT( WORK( 1 ) ) )
          CALL SGGHD3( JOBVL, JOBVR, N, 1, N, A, LDA, B, LDB, VL, LDVL,
      $                VR, LDVR, WORK, -1, IERR )
-         LWKOPT = MAX( LWKOPT, 3*N+INT ( WORK( 1 ) ) )
+         LWKOPT = MAX( LWKOPT, 3*N+INT( WORK( 1 ) ) )
          IF( ILVL ) THEN
             CALL SORGQR( N, N, N, VL, LDVL, WORK, WORK, -1, IERR )
-            LWKOPT = MAX( LWKOPT, 3*N+INT ( WORK( 1 ) ) )
+            LWKOPT = MAX( LWKOPT, 3*N+INT( WORK( 1 ) ) )
             CALL SLAQZ0( 'S', JOBVL, JOBVR, N, 1, N, A, LDA, B, LDB,
      $                   ALPHAR, ALPHAI, BETA, VL, LDVL, VR, LDVR,
      $                   WORK, -1, 0, IERR )
-            LWKOPT = MAX( LWKOPT, 2*N+INT ( WORK( 1 ) ) )
+            LWKOPT = MAX( LWKOPT, 2*N+INT( WORK( 1 ) ) )
          ELSE
             CALL SLAQZ0( 'E', JOBVL, JOBVR, N, 1, N, A, LDA, B, LDB,
      $                   ALPHAR, ALPHAI, BETA, VL, LDVL, VR, LDVR,
      $                   WORK, -1, 0, IERR )
-            LWKOPT = MAX( LWKOPT, 2*N+INT ( WORK( 1 ) ) )
+            LWKOPT = MAX( LWKOPT, 2*N+INT( WORK( 1 ) ) )
+         END IF
+         IF( N.EQ.0 ) THEN
+            WORK( 1 ) = 1
+         ELSE
+            WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
          END IF
-         WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
-*
       END IF
 *
       IF( INFO.NE.0 ) THEN

lapack-netlib/SRC/sgghd3.f

@@ -179,14 +179,14 @@
 *>
 *> \param[out] WORK
 *> \verbatim
-*>          WORK is REAL array, dimension (LWORK)
+*>          WORK is REAL array, dimension (MAX(1,LWORK))
 *>          On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
 *> \endverbatim
 *>
-*> \param[in]  LWORK
+*> \param[in] LWORK
 *> \verbatim
 *>          LWORK is INTEGER
-*>          The length of the array WORK.  LWORK >= 1.
+*>          The length of the array WORK. LWORK >= 1.
 *>          For optimum performance LWORK >= 6*N*NB, where NB is the
 *>          optimal blocksize.
 *>
@@ -276,7 +276,12 @@
 *
       INFO = 0
       NB = ILAENV( 1, 'SGGHD3', ' ', N, ILO, IHI, -1 )
-      LWKOPT = MAX( 6*N*NB, 1 )
+      NH = IHI - ILO + 1
+      IF( NH.LE.1 ) THEN
+         LWKOPT = 1
+      ELSE
+         LWKOPT = 6*N*NB
+      END IF
       WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
       INITQ = LSAME( COMPQ, 'I' )
       WANTQ = INITQ .OR. LSAME( COMPQ, 'V' )
@@ -326,7 +331,6 @@
 *
 *     Quick return if possible
 *
-      NH = IHI - ILO + 1
       IF( NH.LE.1 ) THEN
          WORK( 1 ) = ONE
          RETURN
@@ -886,6 +890,7 @@
       IF ( JCOL.LT.IHI )
      $   CALL SGGHRD( COMPQ2, COMPZ2, N, JCOL, IHI, A, LDA, B, LDB, Q,
      $                LDQ, Z, LDZ, IERR )
+*
       WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
 *
       RETURN

lapack-netlib/SRC/sggqrf.f

@@ -236,8 +236,9 @@
 *     ..
 *     .. External Functions ..
       INTEGER            ILAENV
+      EXTERNAL           ILAENV
       REAL               SROUNDUP_LWORK
-      EXTERNAL           ILAENV, SROUNDUP_LWORK
+      EXTERNAL           SROUNDUP_LWORK
 *     ..
 *     .. Intrinsic Functions ..
       INTRINSIC          INT, MAX, MIN
@@ -251,8 +252,9 @@
       NB2 = ILAENV( 1, 'SGERQF', ' ', N, P, -1, -1 )
       NB3 = ILAENV( 1, 'SORMQR', ' ', N, M, P, -1 )
       NB = MAX( NB1, NB2, NB3 )
-      LWKOPT = MAX( N, M, P )*NB
+      LWKOPT = MAX( 1, MAX( N, M, P )*NB )
-      WORK( 1 ) = SROUNDUP_LWORK(LWKOPT)
+      WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
+*
       LQUERY = ( LWORK.EQ.-1 )
       IF( N.LT.0 ) THEN
          INFO = -1
@@ -289,6 +291,7 @@
 *
       CALL SGERQF( N, P, B, LDB, TAUB, WORK, LWORK, INFO )
       LWKOPT = MAX( LOPT, INT( WORK( 1 ) ) )
+*
       WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
 *
       RETURN

lapack-netlib/SRC/sggrqf.f

@@ -250,7 +250,7 @@
       NB2 = ILAENV( 1, 'SGEQRF', ' ', P, N, -1, -1 )
       NB3 = ILAENV( 1, 'SORMRQ', ' ', M, N, P, -1 )
       NB = MAX( NB1, NB2, NB3 )
-      LWKOPT = MAX( N, M, P)*NB
+      LWKOPT = MAX( 1, MAX( N, M, P )*NB )
       WORK( 1 ) = SROUNDUP_LWORK(LWKOPT)
       LQUERY = ( LWORK.EQ.-1 )
       IF( M.LT.0 ) THEN

lapack-netlib/SRC/sggsvd3.f

@@ -278,7 +278,7 @@
 *> \param[in] LWORK
 *> \verbatim
 *>          LWORK is INTEGER
-*>          The dimension of the array WORK.
+*>          The dimension of the array WORK. LWORK >= 1.
 *>
 *>          If LWORK = -1, then a workspace query is assumed; the routine
 *>          only calculates the optimal size of the WORK array, returns

lapack-netlib/SRC/sggsvp3.f

@@ -227,7 +227,7 @@
 *> \param[in] LWORK
 *> \verbatim
 *>          LWORK is INTEGER
-*>          The dimension of the array WORK.
+*>          The dimension of the array WORK. LWORK >= 1.
 *>
 *>          If LWORK = -1, then a workspace query is assumed; the routine
 *>          only calculates the optimal size of the WORK array, returns
@@ -300,8 +300,9 @@
 *     ..
 *     .. External Functions ..
       LOGICAL            LSAME
+      EXTERNAL           LSAME
       REAL               SROUNDUP_LWORK
-      EXTERNAL           LSAME, SROUNDUP_LWORK
+      EXTERNAL           SROUNDUP_LWORK
 *     ..
 *     .. External Subroutines ..
       EXTERNAL           SGEQP3, SGEQR2, SGERQ2, SLACPY, SLAPMT,

lapack-netlib/SRC/slamswlq.f

@@ -127,17 +127,20 @@
 *>
 *> \param[out] WORK
 *> \verbatim
-*>         (workspace) REAL array, dimension (MAX(1,LWORK))
+*>          (workspace) REAL array, dimension (MAX(1,LWORK))
+*>          On exit, if INFO = 0, WORK(1) returns the minimal LWORK.
 *> \endverbatim
 *>
 *> \param[in] LWORK
 *> \verbatim
 *>          LWORK is INTEGER
 *>          The dimension of the array WORK.
-*>          If SIDE = 'L', LWORK >= max(1,NB) * MB;
+*>
-*>          if SIDE = 'R', LWORK >= max(1,M) * MB.
+*>          If MIN(M,N,K) = 0, LWORK >= 1.
+*>          If SIDE = 'L', LWORK >= max(1,NB*MB).
+*>          If SIDE = 'R', LWORK >= max(1,M*MB).
 *>          If LWORK = -1, then a workspace query is assumed; the routine
-*>          only calculates the optimal size of the WORK array, returns
+*>          only calculates the minimal size of the WORK array, returns
 *>          this value as the first entry of the WORK array, and no error
 *>          message related to LWORK is issued by XERBLA.
 *> \endverbatim
@@ -189,33 +192,38 @@
 *>     SIAM J. Sci. Comput, vol. 34, no. 1, 2012
 *> \endverbatim
 *>
+*> \ingroup lamswlq
+*>
 *  =====================================================================
       SUBROUTINE SLAMSWLQ( SIDE, TRANS, M, N, K, MB, NB, A, LDA, T,
-     $    LDT, C, LDC, WORK, LWORK, INFO )
+     $                     LDT, C, LDC, WORK, LWORK, INFO )
 *
 *  -- LAPACK computational routine --
 *  -- LAPACK is a software package provided by Univ. of Tennessee,    --
 *  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
 *
 *     .. Scalar Arguments ..
-      CHARACTER         SIDE, TRANS
+      CHARACTER          SIDE, TRANS
-      INTEGER           INFO, LDA, M, N, K, MB, NB, LDT, LWORK, LDC
+      INTEGER            INFO, LDA, M, N, K, MB, NB, LDT, LWORK, LDC
 *     ..
 *     .. Array Arguments ..
-      REAL              A( LDA, * ), WORK( * ), C(LDC, * ),
+      REAL               A( LDA, * ), WORK( * ), C( LDC, * ),
-     $      T( LDT, * )
+     $                   T( LDT, * )
 *     ..
 *
 * =====================================================================
 *
 *     ..
 *     .. Local Scalars ..
-      LOGICAL    LEFT, RIGHT, TRAN, NOTRAN, LQUERY
+      LOGICAL            LEFT, RIGHT, TRAN, NOTRAN, LQUERY
-      INTEGER    I, II, KK, LW, CTR
+      INTEGER            I, II, KK, LW, CTR, MINMNK, LWMIN
 *     ..
 *     .. External Functions ..
       LOGICAL            LSAME
       EXTERNAL           LSAME
+      REAL               SROUNDUP_LWORK
+      EXTERNAL           SROUNDUP_LWORK
+*     ..
 *     .. External Subroutines ..
       EXTERNAL           STPMLQT, SGEMLQT, XERBLA
 *     ..
@@ -223,52 +231,60 @@
 *
 *     Test the input arguments
 *
-      LQUERY  = LWORK.LT.0
+      LQUERY  = ( LWORK.EQ.-1 )
       NOTRAN  = LSAME( TRANS, 'N' )
       TRAN    = LSAME( TRANS, 'T' )
       LEFT    = LSAME( SIDE, 'L' )
       RIGHT   = LSAME( SIDE, 'R' )
-      IF (LEFT) THEN
+      IF( LEFT ) THEN
         LW = N * MB
       ELSE
         LW = M * MB
       END IF
+*
+      MINMNK = MIN( M, N, K )
+      IF( MINMNK.EQ.0 ) THEN
+        LWMIN = 1
+      ELSE
+        LWMIN = MAX( 1, LW )
+      END IF
 *
       INFO = 0
       IF( .NOT.LEFT .AND. .NOT.RIGHT ) THEN
-         INFO = -1
+        INFO = -1
       ELSE IF( .NOT.TRAN .AND. .NOT.NOTRAN ) THEN
-         INFO = -2
+        INFO = -2
       ELSE IF( K.LT.0 ) THEN
         INFO = -5
       ELSE IF( M.LT.K ) THEN
         INFO = -3
       ELSE IF( N.LT.0 ) THEN
         INFO = -4
-      ELSE IF( K.LT.MB .OR. MB.LT.1) THEN
+      ELSE IF( K.LT.MB .OR. MB.LT.1 ) THEN
         INFO = -6
       ELSE IF( LDA.LT.MAX( 1, K ) ) THEN
         INFO = -9
-      ELSE IF( LDT.LT.MAX( 1, MB) ) THEN
+      ELSE IF( LDT.LT.MAX( 1, MB ) ) THEN
         INFO = -11
       ELSE IF( LDC.LT.MAX( 1, M ) ) THEN
-         INFO = -13
+        INFO = -13
-      ELSE IF(( LWORK.LT.MAX(1,LW)).AND.(.NOT.LQUERY)) THEN
+      ELSE IF( LWORK.LT.LWMIN .AND. (.NOT.LQUERY) ) THEN
         INFO = -15
       END IF
 *
+      IF( INFO.EQ.0 ) THEN
+        WORK( 1 ) = SROUNDUP_LWORK( LWMIN )
+      END IF
       IF( INFO.NE.0 ) THEN
         CALL XERBLA( 'SLAMSWLQ', -INFO )
-        WORK(1) = LW
         RETURN
-      ELSE IF (LQUERY) THEN
+      ELSE IF( LQUERY ) THEN
-        WORK(1) = LW
         RETURN
       END IF
 *
 *     Quick return if possible
 *
-      IF( MIN(M,N,K).EQ.0 ) THEN
+      IF( MINMNK.EQ.0 ) THEN
         RETURN
       END IF
 *
@@ -402,7 +418,7 @@
 *
       END IF
 *
-      WORK(1) = LW
+      WORK( 1 ) = SROUNDUP_LWORK( LWMIN )
       RETURN
 *
 *     End of SLAMSWLQ

lapack-netlib/SRC/slamtsqr.f

@@ -128,22 +128,24 @@
 *>
 *> \param[out] WORK
 *> \verbatim
-*>         (workspace) REAL array, dimension (MAX(1,LWORK))
+*>          (workspace) REAL array, dimension (MAX(1,LWORK))
-*>
+*>          On exit, if INFO = 0, WORK(1) returns the minimal LWORK.
 *> \endverbatim
+*>
 *> \param[in] LWORK
 *> \verbatim
 *>          LWORK is INTEGER
 *>          The dimension of the array WORK.
+*>          If MIN(M,N,K) = 0, LWORK >= 1.
+*>          If SIDE = 'L', LWORK >= max(1,N*NB).
+*>          If SIDE = 'R', LWORK >= max(1,MB*NB).
 *>
-*>          If SIDE = 'L', LWORK >= max(1,N)*NB;
-*>          if SIDE = 'R', LWORK >= max(1,MB)*NB.
 *>          If LWORK = -1, then a workspace query is assumed; the routine
-*>          only calculates the optimal size of the WORK array, returns
+*>          only calculates the minimal size of the WORK array, returns
 *>          this value as the first entry of the WORK array, and no error
 *>          message related to LWORK is issued by XERBLA.
-*>
 *> \endverbatim
+*>
 *> \param[out] INFO
 *> \verbatim
 *>          INFO is INTEGER
@@ -191,33 +193,38 @@
 *>     SIAM J. Sci. Comput, vol. 34, no. 1, 2012
 *> \endverbatim
 *>
+*> \ingroup lamtsqr
+*>
 *  =====================================================================
       SUBROUTINE SLAMTSQR( SIDE, TRANS, M, N, K, MB, NB, A, LDA, T,
-     $        LDT, C, LDC, WORK, LWORK, INFO )
+     $                     LDT, C, LDC, WORK, LWORK, INFO )
 *
 *  -- LAPACK computational routine --
 *  -- LAPACK is a software package provided by Univ. of Tennessee,    --
 *  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
 *
 *     .. Scalar Arguments ..
-      CHARACTER         SIDE, TRANS
+      CHARACTER          SIDE, TRANS
-      INTEGER           INFO, LDA, M, N, K, MB, NB, LDT, LWORK, LDC
+      INTEGER            INFO, LDA, M, N, K, MB, NB, LDT, LWORK, LDC
 *     ..
 *     .. Array Arguments ..
-      REAL              A( LDA, * ), WORK( * ), C(LDC, * ),
+      REAL               A( LDA, * ), WORK( * ), C( LDC, * ),
-     $                T( LDT, * )
+     $                   T( LDT, * )
 *     ..
 *
 * =====================================================================
 *
 *     ..
 *     .. Local Scalars ..
-      LOGICAL    LEFT, RIGHT, TRAN, NOTRAN, LQUERY
+      LOGICAL            LEFT, RIGHT, TRAN, NOTRAN, LQUERY
-      INTEGER    I, II, KK, LW, CTR, Q
+      INTEGER            I, II, KK, LW, CTR, Q, MINMNK, LWMIN
 *     ..
 *     .. External Functions ..
       LOGICAL            LSAME
       EXTERNAL           LSAME
+      REAL               SROUNDUP_LWORK
+      EXTERNAL           SROUNDUP_LWORK
+*     ..
 *     .. External Subroutines ..
       EXTERNAL           SGEMQRT, STPMQRT, XERBLA
 *     ..
@@ -225,12 +232,13 @@
 *
 *     Test the input arguments
 *
-      LQUERY  = LWORK.LT.0
+      INFO = 0
+      LQUERY  = ( LWORK.EQ.-1 )
       NOTRAN  = LSAME( TRANS, 'N' )
       TRAN    = LSAME( TRANS, 'T' )
       LEFT    = LSAME( SIDE, 'L' )
       RIGHT   = LSAME( SIDE, 'R' )
-      IF (LEFT) THEN
+      IF( LEFT ) THEN
         LW = N * NB
         Q = M
       ELSE
@@ -238,11 +246,17 @@
         Q = N
       END IF
 *
-      INFO = 0
+      MINMNK = MIN( M, N, K )
+      IF( MINMNK.EQ.0 ) THEN
+        LWMIN = 1
+      ELSE
+        LWMIN = MAX( 1, LW )
+      END IF
+*
       IF( .NOT.LEFT .AND. .NOT.RIGHT ) THEN
-         INFO = -1
+        INFO = -1
       ELSE IF( .NOT.TRAN .AND. .NOT.NOTRAN ) THEN
-         INFO = -2
+        INFO = -2
       ELSE IF( M.LT.K ) THEN
         INFO = -3
       ELSE IF( N.LT.0 ) THEN
@@ -253,38 +267,38 @@
         INFO = -7
       ELSE IF( LDA.LT.MAX( 1, Q ) ) THEN
         INFO = -9
-      ELSE IF( LDT.LT.MAX( 1, NB) ) THEN
+      ELSE IF( LDT.LT.MAX( 1, NB ) ) THEN
         INFO = -11
       ELSE IF( LDC.LT.MAX( 1, M ) ) THEN
-         INFO = -13
+        INFO = -13
-      ELSE IF(( LWORK.LT.MAX(1,LW)).AND.(.NOT.LQUERY)) THEN
+      ELSE IF( LWORK.LT.LWMIN. AND. (.NOT.LQUERY) ) THEN
         INFO = -15
       END IF
 *
-*     Determine the block size if it is tall skinny or short and wide
+      IF( INFO.EQ.0 ) THEN
-*
+        WORK( 1 ) = SROUNDUP_LWORK( LWMIN )
-      IF( INFO.EQ.0)  THEN
-          WORK(1) = LW
       END IF
 *
       IF( INFO.NE.0 ) THEN
         CALL XERBLA( 'SLAMTSQR', -INFO )
         RETURN
-      ELSE IF (LQUERY) THEN
+      ELSE IF( LQUERY ) THEN
-       RETURN
+        RETURN
       END IF
 *
 *     Quick return if possible
 *
-      IF( MIN(M,N,K).EQ.0 ) THEN
+      IF( MINMNK.EQ.0 ) THEN
         RETURN
       END IF
+*
+*     Determine the block size if it is tall skinny or short and wide
 *
       IF((MB.LE.K).OR.(MB.GE.MAX(M,N,K))) THEN
         CALL SGEMQRT( SIDE, TRANS, M, N, K, NB, A, LDA,
-     $        T, LDT, C, LDC, WORK, INFO)
+     $        T, LDT, C, LDC, WORK, INFO )
         RETURN
-       END IF
+      END IF
 *
       IF(LEFT.AND.NOTRAN) THEN
 *
@@ -410,7 +424,7 @@
 *
       END IF
 *
-      WORK(1) = LW
+      WORK( 1 ) = SROUNDUP_LWORK( LWMIN )
       RETURN
 *
 *     End of SLAMTSQR

lapack-netlib/SRC/slaswlq.f

@@ -96,22 +96,24 @@
 *>          The leading dimension of the array T.  LDT >= MB.
 *> \endverbatim
 *>
-*>
 *> \param[out] WORK
 *> \verbatim
-*>         (workspace) REAL array, dimension (MAX(1,LWORK))
+*>          (workspace) REAL array, dimension (MAX(1,LWORK))
-*>
+*>          On exit, if INFO = 0, WORK(1) returns the minimal LWORK.
 *> \endverbatim
+*>
 *> \param[in] LWORK
 *> \verbatim
 *>          LWORK is INTEGER
-*>          The dimension of the array WORK.  LWORK >= MB * M.
+*>          The dimension of the array WORK.
+*>          LWORK >= 1, if MIN(M,N) = 0, and LWORK >= MB*M, otherwise.
+*>
 *>          If LWORK = -1, then a workspace query is assumed; the routine
-*>          only calculates the optimal size of the WORK array, returns
+*>          only calculates the minimal size of the WORK array, returns
 *>          this value as the first entry of the WORK array, and no error
 *>          message related to LWORK is issued by XERBLA.
-*>
 *> \endverbatim
+
 *> \param[out] INFO
 *> \verbatim
 *>          INFO is INTEGER
@@ -163,32 +165,35 @@
 *>
 *  =====================================================================
       SUBROUTINE SLASWLQ( M, N, MB, NB, A, LDA, T, LDT, WORK, LWORK,
-     $                  INFO)
+     $                    INFO )
 *
 *  -- LAPACK computational routine --
 *  -- LAPACK is a software package provided by Univ. of Tennessee,    --
 *  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd. --
 *
 *     .. Scalar Arguments ..
-      INTEGER           INFO, LDA, M, N, MB, NB, LWORK, LDT
+      INTEGER            INFO, LDA, M, N, MB, NB, LWORK, LDT
 *     ..
 *     .. Array Arguments ..
-      REAL              A( LDA, * ), WORK( * ), T( LDT, *)
+      REAL               A( LDA, * ), WORK( * ), T( LDT, * )
 *     ..
 *
 *  =====================================================================
 *
 *     ..
 *     .. Local Scalars ..
-      LOGICAL    LQUERY
+      LOGICAL            LQUERY
-      INTEGER    I, II, KK, CTR
+      INTEGER            I, II, KK, CTR, MINMN, LWMIN
 *     ..
 *     .. EXTERNAL FUNCTIONS ..
       LOGICAL            LSAME
+      EXTERNAL           LSAME
       REAL               SROUNDUP_LWORK
-      EXTERNAL           LSAME, SROUNDUP_LWORK
+      EXTERNAL           SROUNDUP_LWORK
+*     ..
 *     .. EXTERNAL SUBROUTINES ..
       EXTERNAL           SGELQT, SGEQRT, STPLQT, STPQRT, XERBLA
+*     ..
 *     .. INTRINSIC FUNCTIONS ..
       INTRINSIC          MAX, MIN, MOD
 *     ..
@@ -199,12 +204,19 @@
       INFO = 0
 *
       LQUERY = ( LWORK.EQ.-1 )
+*
+      MINMN = MIN( M, N )
+      IF( MINMN.EQ.0 ) THEN
+        LWMIN = 1
+      ELSE
+        LWMIN = M*MB
+      END IF
 *
       IF( M.LT.0 ) THEN
         INFO = -1
       ELSE IF( N.LT.0 .OR. N.LT.M ) THEN
         INFO = -2
-      ELSE IF( MB.LT.1 .OR. ( MB.GT.M .AND. M.GT.0 )) THEN
+      ELSE IF( MB.LT.1 .OR. ( MB.GT.M .AND. M.GT.0 ) ) THEN
         INFO = -3
       ELSE IF( NB.LE.0 ) THEN
         INFO = -4
@@ -212,60 +224,60 @@
         INFO = -6
       ELSE IF( LDT.LT.MB ) THEN
         INFO = -8
-      ELSE IF( ( LWORK.LT.M*MB) .AND. (.NOT.LQUERY) ) THEN
+      ELSE IF( LWORK.LT.LWMIN .AND. (.NOT.LQUERY) ) THEN
         INFO = -10
       END IF
-      IF( INFO.EQ.0)  THEN
+      IF( INFO.EQ.0 ) THEN
-      WORK(1) = MB*M
+        WORK( 1 ) = SROUNDUP_LWORK( LWMIN )
       END IF
 *
       IF( INFO.NE.0 ) THEN
         CALL XERBLA( 'SLASWLQ', -INFO )
         RETURN
-      ELSE IF (LQUERY) THEN
+      ELSE IF( LQUERY ) THEN
-       RETURN
+        RETURN
       END IF
 *
 *     Quick return if possible
 *
-      IF( MIN(M,N).EQ.0 ) THEN
+      IF( MINMN.EQ.0 ) THEN
-          RETURN
+        RETURN
       END IF
 *
 *     The LQ Decomposition
 *
-       IF((M.GE.N).OR.(NB.LE.M).OR.(NB.GE.N)) THEN
+      IF( (M.GE.N) .OR. (NB.LE.M) .OR. (NB.GE.N) ) THEN
-        CALL SGELQT( M, N, MB, A, LDA, T, LDT, WORK, INFO)
+        CALL SGELQT( M, N, MB, A, LDA, T, LDT, WORK, INFO )
         RETURN
-       END IF
+      END IF
 *
-       KK = MOD((N-M),(NB-M))
+      KK = MOD((N-M),(NB-M))
-       II=N-KK+1
+      II = N-KK+1
 *
-*      Compute the LQ factorization of the first block A(1:M,1:NB)
+*     Compute the LQ factorization of the first block A(1:M,1:NB)
 *
-       CALL SGELQT( M, NB, MB, A(1,1), LDA, T, LDT, WORK, INFO)
+      CALL SGELQT( M, NB, MB, A(1,1), LDA, T, LDT, WORK, INFO )
-       CTR = 1
+      CTR = 1
 *
-       DO I = NB+1, II-NB+M , (NB-M)
+      DO I = NB+1, II-NB+M, (NB-M)
 *
-*      Compute the QR factorization of the current block A(1:M,I:I+NB-M)
+*       Compute the QR factorization of the current block A(1:M,I:I+NB-M)
 *
-         CALL STPLQT( M, NB-M, 0, MB, A(1,1), LDA, A( 1, I ),
+        CALL STPLQT( M, NB-M, 0, MB, A(1,1), LDA, A( 1, I ),
-     $                  LDA, T(1, CTR * M + 1),
+     $                 LDA, T(1, CTR * M + 1),
-     $                  LDT, WORK, INFO )
+     $                 LDT, WORK, INFO )
-         CTR = CTR + 1
+        CTR = CTR + 1
-       END DO
+      END DO
 *
 *     Compute the QR factorization of the last block A(1:M,II:N)
 *
-       IF (II.LE.N) THEN
+      IF( II.LE.N ) THEN
         CALL STPLQT( M, KK, 0, MB, A(1,1), LDA, A( 1, II ),
-     $                  LDA, T(1, CTR * M + 1), LDT,
+     $                 LDA, T(1, CTR * M + 1), LDT,
-     $                  WORK, INFO )
+     $                 WORK, INFO )
-       END IF
+      END IF
 *
-      WORK( 1 ) = SROUNDUP_LWORK(M * MB)
+      WORK( 1 ) = SROUNDUP_LWORK( LWMIN )
       RETURN
 *
 *     End of SLASWLQ

lapack-netlib/SRC/slatrs3.f

@@ -151,13 +151,16 @@
 *>
 *> \param[out] WORK
 *> \verbatim
-*>          WORK is REAL array, dimension (LWORK).
+*>          WORK is REAL array, dimension (MAX(1,LWORK))
-*>          On exit, if INFO = 0, WORK(1) returns the optimal size of
+*>          On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
-*>          WORK.
 *> \endverbatim
 *>
 *> \param[in] LWORK
+*> \verbatim
 *>          LWORK is INTEGER
+*>          The dimension of the array WORK.
+*>
+*>          If MIN(N,NRHS) = 0, LWORK >= 1, else
 *>          LWORK >= MAX(1, 2*NBA * MAX(NBA, MIN(NRHS, 32)), where
 *>          NBA = (N + NB - 1)/NB and NB is the optimal block size.
 *>
@@ -165,6 +168,7 @@
 *>          only calculates the optimal dimensions of the WORK array, returns
 *>          this value as the first entry of the WORK array, and no error
 *>          message related to LWORK is issued by XERBLA.
+*> \endverbatim
 *>
 *> \param[out] INFO
 *> \verbatim
@@ -181,7 +185,7 @@
 *> \author Univ. of Colorado Denver
 *> \author NAG Ltd.
 *
-*> \ingroup doubleOTHERauxiliary
+*> \ingroup latrs3
 *> \par Further Details:
 *  =====================
 *  \verbatim
@@ -253,7 +257,7 @@
       LOGICAL            LQUERY, NOTRAN, NOUNIT, UPPER
       INTEGER            AWRK, I, IFIRST, IINC, ILAST, II, I1, I2, J,
      $                   JFIRST, JINC, JLAST, J1, J2, K, KK, K1, K2,
-     $                   LANRM, LDS, LSCALE, NB, NBA, NBX, RHS
+     $                   LANRM, LDS, LSCALE, NB, NBA, NBX, RHS, LWMIN
       REAL               ANRM, BIGNUM, BNRM, RSCAL, SCAL, SCALOC,
      $                   SCAMIN, SMLNUM, TMAX
 *     ..
@@ -264,7 +268,8 @@
       EXTERNAL           ILAENV, LSAME, SLAMCH, SLANGE, SLARMM
 *     ..
 *     .. External Subroutines ..
-      EXTERNAL           SLATRS, SSCAL, XERBLA
+      REAL               SROUNDUP_LWORK
+      EXTERNAL           SLATRS, SSCAL, SROUNDUP_LWORK, XERBLA
 *     ..
 *     .. Intrinsic Functions ..
       INTRINSIC          ABS, MAX, MIN
@@ -292,15 +297,24 @@
 *     row. WORK( I + KK * LDS ) is the scale factor of the vector
 *     segment associated with the I-th block row and the KK-th vector
 *     in the block column.
+*
       LSCALE = NBA * MAX( NBA, MIN( NRHS, NBRHS ) )
       LDS = NBA
+*
 *     The second part stores upper bounds of the triangular A. There are
 *     a total of NBA x NBA blocks, of which only the upper triangular
 *     part or the lower triangular part is referenced. The upper bound of
 *     the block A( I, J ) is stored as WORK( AWRK + I + J * NBA ).
+*
       LANRM = NBA * NBA
       AWRK = LSCALE
-      WORK( 1 ) = LSCALE + LANRM
+*
+      IF( MIN( N, NRHS ).EQ.0 ) THEN
+         LWMIN = 1
+      ELSE
+         LWMIN = LSCALE + LANRM
+      END IF
+      WORK( 1 ) = SROUNDUP_LWORK( LWMIN )
 *
 *     Test the input parameters.
 *
@@ -322,7 +336,7 @@
          INFO = -8
       ELSE IF( LDX.LT.MAX( 1, N ) ) THEN
          INFO = -10
-      ELSE IF( .NOT.LQUERY .AND. LWORK.LT.WORK( 1 ) ) THEN
+      ELSE IF( .NOT.LQUERY .AND. LWORK.LT.LWMIN ) THEN
          INFO = -14
       END IF
       IF( INFO.NE.0 ) THEN
@@ -650,6 +664,8 @@
          END DO
       END DO
       RETURN
+*
+      WORK( 1 ) = SROUNDUP_LWORK( LWMIN )
 *
 *     End of SLATRS3
 *

lapack-netlib/SRC/slatsqr.f

@@ -101,15 +101,18 @@
 *>
 *> \param[out] WORK
 *> \verbatim
-*>         (workspace) REAL array, dimension (MAX(1,LWORK))
+*>          (workspace) REAL array, dimension (MAX(1,LWORK))
+*>          On exit, if INFO = 0, WORK(1) returns the minimal LWORK.
 *> \endverbatim
 *>
 *> \param[in] LWORK
 *> \verbatim
 *>          LWORK is INTEGER
-*>          The dimension of the array WORK.  LWORK >= NB*N.
+*>          The dimension of the array WORK.
+*>          LWORK >= 1, if MIN(M,N) = 0, and LWORK >= NB*N, otherwise.
+*>
 *>          If LWORK = -1, then a workspace query is assumed; the routine
-*>          only calculates the optimal size of the WORK array, returns
+*>          only calculates the minimal size of the WORK array, returns
 *>          this value as the first entry of the WORK array, and no error
 *>          message related to LWORK is issued by XERBLA.
 *> \endverbatim
@@ -161,33 +164,39 @@
 *>     SIAM J. Sci. Comput, vol. 34, no. 1, 2012
 *> \endverbatim
 *>
+*> \ingroup latsqr
+*>
 *  =====================================================================
       SUBROUTINE SLATSQR( M, N, MB, NB, A, LDA, T, LDT, WORK,
-     $                    LWORK, INFO)
+     $                    LWORK, INFO )
 *
 *  -- LAPACK computational routine --
 *  -- LAPACK is a software package provided by Univ. of Tennessee,    --
 *  -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd. --
 *
 *     .. Scalar Arguments ..
-      INTEGER           INFO, LDA, M, N, MB, NB, LDT, LWORK
+      INTEGER            INFO, LDA, M, N, MB, NB, LDT, LWORK
 *     ..
 *     .. Array Arguments ..
-      REAL  A( LDA, * ), WORK( * ), T(LDT, *)
+      REAL               A( LDA, * ), WORK( * ), T( LDT, * )
 *     ..
 *
 *  =====================================================================
 *
 *     ..
 *     .. Local Scalars ..
-      LOGICAL    LQUERY
+      LOGICAL            LQUERY
-      INTEGER    I, II, KK, CTR
+      INTEGER            I, II, KK, CTR, MINMN, LWMIN
 *     ..
 *     .. EXTERNAL FUNCTIONS ..
       LOGICAL            LSAME
       EXTERNAL           LSAME
+      REAL               SROUNDUP_LWORK
+      EXTERNAL           SROUNDUP_LWORK
+*     ..
 *     .. EXTERNAL SUBROUTINES ..
       EXTERNAL           SGEQRT, STPQRT, XERBLA
+*     ..
 *     .. INTRINSIC FUNCTIONS ..
       INTRINSIC          MAX, MIN, MOD
 *     ..
@@ -198,6 +207,13 @@
       INFO = 0
 *
       LQUERY = ( LWORK.EQ.-1 )
+*
+      MINMN = MIN( M, N )
+      IF( MINMN.EQ.0 ) THEN
+        LWMIN = 1
+      ELSE
+        LWMIN = N*NB
+      END IF
 *
       IF( M.LT.0 ) THEN
         INFO = -1
@@ -205,64 +221,65 @@
         INFO = -2
       ELSE IF( MB.LT.1 ) THEN
         INFO = -3
-      ELSE IF( NB.LT.1 .OR. ( NB.GT.N .AND. N.GT.0 )) THEN
+      ELSE IF( NB.LT.1 .OR. ( NB.GT.N .AND. N.GT.0 ) ) THEN
         INFO = -4
       ELSE IF( LDA.LT.MAX( 1, M ) ) THEN
         INFO = -6
       ELSE IF( LDT.LT.NB ) THEN
         INFO = -8
-      ELSE IF( LWORK.LT.(N*NB) .AND. (.NOT.LQUERY) ) THEN
+      ELSE IF( LWORK.LT.LWMIN .AND. (.NOT.LQUERY) ) THEN
         INFO = -10
       END IF
-      IF( INFO.EQ.0)  THEN
+*
-        WORK(1) = NB*N
+      IF( INFO.EQ.0 )  THEN
+        WORK( 1 ) = SROUNDUP_LWORK( LWMIN )
       END IF
       IF( INFO.NE.0 ) THEN
         CALL XERBLA( 'SLATSQR', -INFO )
         RETURN
-      ELSE IF (LQUERY) THEN
+      ELSE IF( LQUERY ) THEN
-       RETURN
+        RETURN
       END IF
 *
 *     Quick return if possible
 *
-      IF( MIN(M,N).EQ.0 ) THEN
+      IF( MINMN.EQ.0 ) THEN
-          RETURN
+        RETURN
       END IF
 *
 *     The QR Decomposition
 *
-       IF ((MB.LE.N).OR.(MB.GE.M)) THEN
+      IF( (MB.LE.N) .OR. (MB.GE.M) ) THEN
-         CALL SGEQRT( M, N, NB, A, LDA, T, LDT, WORK, INFO)
+        CALL SGEQRT( M, N, NB, A, LDA, T, LDT, WORK, INFO )
-         RETURN
+        RETURN
-       END IF
+      END IF
-       KK = MOD((M-N),(MB-N))
+      KK = MOD((M-N),(MB-N))
-       II=M-KK+1
+      II = M-KK+1
 *
-*      Compute the QR factorization of the first block A(1:MB,1:N)
+*     Compute the QR factorization of the first block A(1:MB,1:N)
 *
-       CALL SGEQRT( MB, N, NB, A(1,1), LDA, T, LDT, WORK, INFO )
+      CALL SGEQRT( MB, N, NB, A(1,1), LDA, T, LDT, WORK, INFO )
 *
-       CTR = 1
+      CTR = 1
-       DO I = MB+1, II-MB+N ,  (MB-N)
+      DO I = MB+1, II-MB+N, (MB-N)
 *
-*      Compute the QR factorization of the current block A(I:I+MB-N,1:N)
+*       Compute the QR factorization of the current block A(I:I+MB-N,1:N)
 *
-         CALL STPQRT( MB-N, N, 0, NB, A(1,1), LDA, A( I, 1 ), LDA,
+        CALL STPQRT( MB-N, N, 0, NB, A(1,1), LDA, A( I, 1 ), LDA,
-     $                 T(1, CTR * N + 1),
+     $                T(1, CTR * N + 1),
-     $                  LDT, WORK, INFO )
+     $                LDT, WORK, INFO )
-         CTR = CTR + 1
+        CTR = CTR + 1
-       END DO
+      END DO
 *
-*      Compute the QR factorization of the last block A(II:M,1:N)
+*     Compute the QR factorization of the last block A(II:M,1:N)
 *
-       IF (II.LE.M) THEN
+      IF( II.LE.M ) THEN
-         CALL STPQRT( KK, N, 0, NB, A(1,1), LDA, A( II, 1 ), LDA,
+        CALL STPQRT( KK, N, 0, NB, A(1,1), LDA, A( II, 1 ), LDA,
-     $                 T(1, CTR * N + 1), LDT,
+     $                T(1, CTR * N + 1), LDT,
-     $                  WORK, INFO )
+     $                WORK, INFO )
-       END IF
+      END IF
 *
-      work( 1 ) = N*NB
+      WORK( 1 ) = SROUNDUP_LWORK( LWMIN )
       RETURN
 *
 *     End of SLATSQR

lapack-netlib/SRC/ssyevd.f

@@ -96,8 +96,7 @@
 *>
 *> \param[out] WORK
 *> \verbatim
-*>          WORK is REAL array,
+*>          WORK is REAL array, dimension (MAX(1,LWORK))
-*>                                         dimension (LWORK)
 *>          On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
 *> \endverbatim
 *>
@@ -251,7 +250,7 @@
      $                  N*ILAENV( 1, 'SSYTRD', UPLO, N, -1, -1, -1 ) )
             LIOPT = LIWMIN
          END IF
-         WORK( 1 ) = SROUNDUP_LWORK(LOPT)
+         WORK( 1 ) = SROUNDUP_LWORK( LOPT )
          IWORK( 1 ) = LIOPT
 *
          IF( LWORK.LT.LWMIN .AND. .NOT.LQUERY ) THEN
@@ -335,7 +334,7 @@
       IF( ISCALE.EQ.1 )
      $   CALL SSCAL( N, ONE / SIGMA, W, 1 )
 *
-      WORK( 1 ) = SROUNDUP_LWORK(LOPT)
+      WORK( 1 ) = SROUNDUP_LWORK( LOPT )
       IWORK( 1 ) = LIOPT
 *
       RETURN

lapack-netlib/SRC/ssyevr.f

@@ -271,7 +271,8 @@
 *> \param[in] LWORK
 *> \verbatim
 *>          LWORK is INTEGER
-*>          The dimension of the array WORK.  LWORK >= max(1,26*N).
+*>          The dimension of the array WORK.
+*>          If N <= 1, LWORK >= 1, else LWORK >= 26*N.
 *>          For optimal efficiency, LWORK >= (NB+6)*N,
 *>          where NB is the max of the blocksize for SSYTRD and SORMTR
 *>          returned by ILAENV.
@@ -292,7 +293,8 @@
 *> \param[in] LIWORK
 *> \verbatim
 *>          LIWORK is INTEGER
-*>          The dimension of the array IWORK.  LIWORK >= max(1,10*N).
+*>          The dimension of the array IWORK.
+*>          If N <= 1, LIWORK >= 1, else LIWORK >= 10*N.
 *>
 *>          If LIWORK = -1, then a workspace query is assumed; the
 *>          routine only calculates the optimal sizes of the WORK and
@@ -392,8 +394,13 @@
 *
       LQUERY = ( ( LWORK.EQ.-1 ) .OR. ( LIWORK.EQ.-1 ) )
 *
-      LWMIN = MAX( 1, 26*N )
+      IF( N.LE.1 ) THEN
-      LIWMIN = MAX( 1, 10*N )
+         LWMIN  = 1
+         LIWMIN = 1
+      ELSE
+         LWMIN  = 26*N
+         LIWMIN = 10*N
+      END IF
 *
       INFO = 0
       IF( .NOT.( WANTZ .OR. LSAME( JOBZ, 'N' ) ) ) THEN
@@ -428,7 +435,7 @@
          NB = ILAENV( 1, 'SSYTRD', UPLO, N, -1, -1, -1 )
          NB = MAX( NB, ILAENV( 1, 'SORMTR', UPLO, N, -1, -1, -1 ) )
          LWKOPT = MAX( ( NB+1 )*N, LWMIN )
-         WORK( 1 ) = SROUNDUP_LWORK(LWKOPT)
+         WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
          IWORK( 1 ) = LIWMIN
 *
          IF( LWORK.LT.LWMIN .AND. .NOT.LQUERY ) THEN
@@ -677,7 +684,7 @@
 *
 *     Set WORK(1) to optimal workspace size.
 *
-      WORK( 1 ) = SROUNDUP_LWORK(LWKOPT)
+      WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
       IWORK( 1 ) = LIWMIN
 *
       RETURN

lapack-netlib/SRC/ssyevr_2stage.f

@@ -278,6 +278,7 @@
 *> \verbatim
 *>          LWORK is INTEGER
 *>          The dimension of the array WORK.
+*>          If N <= 1,               LWORK must be at least 1.
 *>          If JOBZ = 'N' and N > 1, LWORK must be queried.
 *>                                   LWORK = MAX(1, 26*N, dimension) where
 *>                                   dimension = max(stage1,stage2) + (KD+1)*N + 5*N
@@ -300,13 +301,14 @@
 *> \param[out] IWORK
 *> \verbatim
 *>          IWORK is INTEGER array, dimension (MAX(1,LIWORK))
-*>          On exit, if INFO = 0, IWORK(1) returns the optimal LWORK.
+*>          On exit, if INFO = 0, IWORK(1) returns the optimal LIWORK.
 *> \endverbatim
 *>
 *> \param[in] LIWORK
 *> \verbatim
 *>          LIWORK is INTEGER
-*>          The dimension of the array IWORK.  LIWORK >= max(1,10*N).
+*>          The dimension of the array IWORK.
+*>          If N <= 1, LIWORK >= 1, else LIWORK >= 10*N.
 *>
 *>          If LIWORK = -1, then a workspace query is assumed; the
 *>          routine only calculates the optimal size of the IWORK array,
@@ -445,8 +447,14 @@
       IB     = ILAENV2STAGE( 2, 'SSYTRD_2STAGE', JOBZ, N, KD, -1, -1 )
       LHTRD  = ILAENV2STAGE( 3, 'SSYTRD_2STAGE', JOBZ, N, KD, IB, -1 )
       LWTRD  = ILAENV2STAGE( 4, 'SSYTRD_2STAGE', JOBZ, N, KD, IB, -1 )
-      LWMIN  = MAX( 26*N, 5*N + LHTRD + LWTRD )
+*
-      LIWMIN = MAX( 1, 10*N )
+      IF( N.LE.1 ) THEN
+         LWMIN  = 1
+         LIWMIN = 1
+      ELSE
+         LWMIN  = MAX( 26*N, 5*N + LHTRD + LWTRD )
+         LIWMIN = 10*N
+      END IF
 *
       INFO = 0
       IF( .NOT.( LSAME( JOBZ, 'N' ) ) ) THEN
@@ -485,7 +493,7 @@
 *         NB = ILAENV( 1, 'SSYTRD', UPLO, N, -1, -1, -1 )
 *         NB = MAX( NB, ILAENV( 1, 'SORMTR', UPLO, N, -1, -1, -1 ) )
 *         LWKOPT = MAX( ( NB+1 )*N, LWMIN )
-         WORK( 1 ) = SROUNDUP_LWORK(LWMIN)
+         WORK( 1 )  = SROUNDUP_LWORK( LWMIN )
          IWORK( 1 ) = LIWMIN
       END IF
 *
@@ -505,7 +513,7 @@
       END IF
 *
       IF( N.EQ.1 ) THEN
-         WORK( 1 ) = 26
+         WORK( 1 ) = 1
          IF( ALLEIG .OR. INDEIG ) THEN
             M = 1
             W( 1 ) = A( 1, 1 )
@@ -733,7 +741,7 @@
 *
 *     Set WORK(1) to optimal workspace size.
 *
-      WORK( 1 ) = SROUNDUP_LWORK(LWMIN)
+      WORK( 1 )  = SROUNDUP_LWORK( LWMIN )
       IWORK( 1 ) = LIWMIN
 *
       RETURN

lapack-netlib/SRC/ssyevx.f

@@ -338,14 +338,14 @@
       IF( INFO.EQ.0 ) THEN
          IF( N.LE.1 ) THEN
             LWKMIN = 1
-            WORK( 1 ) = SROUNDUP_LWORK(LWKMIN)
+            LWKOPT = 1
          ELSE
             LWKMIN = 8*N
             NB = ILAENV( 1, 'SSYTRD', UPLO, N, -1, -1, -1 )
             NB = MAX( NB, ILAENV( 1, 'SORMTR', UPLO, N, -1, -1, -1 ) )
             LWKOPT = MAX( LWKMIN, ( NB + 3 )*N )
-            WORK( 1 ) = SROUNDUP_LWORK(LWKOPT)
          END IF
+         WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
 *
          IF( LWORK.LT.LWKMIN .AND. .NOT.LQUERY )
      $      INFO = -17
@@ -542,7 +542,7 @@
 *
 *     Set WORK(1) to optimal workspace size.
 *
-      WORK( 1 ) = SROUNDUP_LWORK(LWKOPT)
+      WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
 *
       RETURN
 *

lapack-netlib/SRC/ssysv_aa.f

@@ -177,12 +177,13 @@
 *
 *     .. Local Scalars ..
       LOGICAL            LQUERY
-      INTEGER            LWKOPT, LWKOPT_SYTRF, LWKOPT_SYTRS
+      INTEGER            LWKMIN, LWKOPT, LWKOPT_SYTRF, LWKOPT_SYTRS
 *     ..
 *     .. External Functions ..
       LOGICAL            LSAME
+      EXTERNAL           LSAME
       REAL               SROUNDUP_LWORK
-      EXTERNAL           LSAME, SROUNDUP_LWORK
+      EXTERNAL           SROUNDUP_LWORK
 *     ..
 *     .. External Subroutines ..
       EXTERNAL           XERBLA, SSYTRS_AA, SSYTRF_AA
@@ -196,6 +197,7 @@
 *
       INFO = 0
       LQUERY = ( LWORK.EQ.-1 )
+      LWKMIN = MAX( 1, 2*N, 3*N-2 )
       IF( .NOT.LSAME( UPLO, 'U' ) .AND. .NOT.LSAME( UPLO, 'L' ) ) THEN
          INFO = -1
       ELSE IF( N.LT.0 ) THEN
@@ -206,18 +208,18 @@
          INFO = -5
       ELSE IF( LDB.LT.MAX( 1, N ) ) THEN
          INFO = -8
-      ELSE IF( LWORK.LT.MAX(2*N, 3*N-2) .AND. .NOT.LQUERY ) THEN
+      ELSE IF( LWORK.LT.LWKMIN .AND. .NOT.LQUERY ) THEN
          INFO = -10
       END IF
 *
       IF( INFO.EQ.0 ) THEN
          CALL SSYTRF_AA( UPLO, N, A, LDA, IPIV, WORK, -1, INFO )
-         LWKOPT_SYTRF = INT( WORK(1) )
+         LWKOPT_SYTRF = INT( WORK( 1 ) )
          CALL SSYTRS_AA( UPLO, N, NRHS, A, LDA, IPIV, B, LDB, WORK,
      $                   -1, INFO )
-         LWKOPT_SYTRS = INT( WORK(1) )
+         LWKOPT_SYTRS = INT( WORK( 1 ) )
-         LWKOPT = MAX( LWKOPT_SYTRF, LWKOPT_SYTRS )
+         LWKOPT = MAX( LWKMIN, LWKOPT_SYTRF, LWKOPT_SYTRS )
-         WORK( 1 ) = SROUNDUP_LWORK(LWKOPT)
+         WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
       END IF
 *
       IF( INFO.NE.0 ) THEN
@@ -239,7 +241,7 @@
 *
       END IF
 *
-      WORK( 1 ) = SROUNDUP_LWORK(LWKOPT)
+      WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
 *
       RETURN
 *

lapack-netlib/SRC/ssysv_aa_2stage.f

@@ -100,14 +100,14 @@
 *>
 *> \param[out] TB
 *> \verbatim
-*>          TB is REAL array, dimension (LTB)
+*>          TB is REAL array, dimension (MAX(1,LTB))
 *>          On exit, details of the LU factorization of the band matrix.
 *> \endverbatim
 *>
 *> \param[in] LTB
 *> \verbatim
 *>          LTB is INTEGER
-*>          The size of the array TB. LTB >= 4*N, internally
+*>          The size of the array TB. LTB >= MAX(1,4*N), internally
 *>          used to select NB such that LTB >= (3*NB+1)*N.
 *>
 *>          If LTB = -1, then a workspace query is assumed; the
@@ -147,14 +147,15 @@
 *>
 *> \param[out] WORK
 *> \verbatim
-*>          WORK is REAL workspace of size LWORK
+*>          WORK is REAL workspace of size (MAX(1,LWORK))
+*>          On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
 *> \endverbatim
 *>
 *> \param[in] LWORK
 *> \verbatim
 *>          LWORK is INTEGER
-*>          The size of WORK. LWORK >= N, internally used to select NB
+*>          The size of WORK. LWORK >= MAX(1,N), internally used to
-*>          such that LWORK >= N*NB.
+*>          select NB such that LWORK >= N*NB.
 *>
 *>          If LWORK = -1, then a workspace query is assumed; the
 *>          routine only calculates the optimal size of the WORK array,
@@ -204,12 +205,13 @@
 *     ..
 *     .. Local Scalars ..
       LOGICAL            UPPER, TQUERY, WQUERY
-      INTEGER            LWKOPT
+      INTEGER            LWKMIN, LWKOPT
 *     ..
 *     .. External Functions ..
       LOGICAL            LSAME
+      EXTERNAL           LSAME
       REAL               SROUNDUP_LWORK
-      EXTERNAL           LSAME, SROUNDUP_LWORK
+      EXTERNAL           SROUNDUP_LWORK
 *     ..
 *     .. External Subroutines ..
       EXTERNAL           SSYTRF_AA_2STAGE, SSYTRS_AA_2STAGE,
@@ -226,6 +228,7 @@
       UPPER = LSAME( UPLO, 'U' )
       WQUERY = ( LWORK.EQ.-1 )
       TQUERY = ( LTB.EQ.-1 )
+      LWKMIN = MAX( 1, N )
       IF( .NOT.UPPER .AND. .NOT.LSAME( UPLO, 'L' ) ) THEN
          INFO = -1
       ELSE IF( N.LT.0 ) THEN
@@ -234,18 +237,19 @@
          INFO = -3
       ELSE IF( LDA.LT.MAX( 1, N ) ) THEN
          INFO = -5
-      ELSE IF( LTB.LT.( 4*N ) .AND. .NOT.TQUERY ) THEN
+      ELSE IF( LTB.LT.MAX( 1, 4*N ) .AND. .NOT.TQUERY ) THEN
          INFO = -7
       ELSE IF( LDB.LT.MAX( 1, N ) ) THEN
          INFO = -11
-      ELSE IF( LWORK.LT.N .AND. .NOT.WQUERY ) THEN
+      ELSE IF( LWORK.LT.LWKMIN .AND. .NOT.WQUERY ) THEN
          INFO = -13
       END IF
 *
       IF( INFO.EQ.0 ) THEN
          CALL SSYTRF_AA_2STAGE( UPLO, N, A, LDA, TB, -1, IPIV,
      $                          IPIV2, WORK, -1, INFO )
-         LWKOPT = INT( WORK(1) )
+         LWKOPT = MAX( LWKMIN, INT( WORK( 1 ) ) )
+         WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
       END IF
 *
       IF( INFO.NE.0 ) THEN
@@ -255,7 +259,6 @@
          RETURN
       END IF
 *
-*
 *     Compute the factorization A = U**T*T*U or A = L*T*L**T.
 *
       CALL SSYTRF_AA_2STAGE( UPLO, N, A, LDA, TB, LTB, IPIV, IPIV2,
@@ -269,7 +272,7 @@
 *
       END IF
 *
-      WORK( 1 ) = SROUNDUP_LWORK(LWKOPT)
+      WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
 *
       RETURN
 *

lapack-netlib/SRC/ssysvx.f

@@ -305,7 +305,7 @@
 *     ..
 *     .. Local Scalars ..
       LOGICAL            LQUERY, NOFACT
-      INTEGER            LWKOPT, NB
+      INTEGER            LWKMIN, LWKOPT, NB
       REAL               ANORM
 *     ..
 *     .. External Functions ..
@@ -327,6 +327,7 @@
       INFO = 0
       NOFACT = LSAME( FACT, 'N' )
       LQUERY = ( LWORK.EQ.-1 )
+      LWKMIN = MAX( 1, 3*N )
       IF( .NOT.NOFACT .AND. .NOT.LSAME( FACT, 'F' ) ) THEN
          INFO = -1
       ELSE IF( .NOT.LSAME( UPLO, 'U' ) .AND. .NOT.LSAME( UPLO, 'L' ) )
@@ -344,12 +345,12 @@
          INFO = -11
       ELSE IF( LDX.LT.MAX( 1, N ) ) THEN
          INFO = -13
-      ELSE IF( LWORK.LT.MAX( 1, 3*N ) .AND. .NOT.LQUERY ) THEN
+      ELSE IF( LWORK.LT.LWKMIN .AND. .NOT.LQUERY ) THEN
          INFO = -18
       END IF
 *
       IF( INFO.EQ.0 ) THEN
-         LWKOPT = MAX( 1, 3*N )
+         LWKOPT = LWKMIN
          IF( NOFACT ) THEN
             NB = ILAENV( 1, 'SSYTRF', UPLO, N, -1, -1, -1 )
             LWKOPT = MAX( LWKOPT, N*NB )

lapack-netlib/SRC/ssytrd_2stage.f

@@ -4,23 +4,23 @@
 *
 *  =========== DOCUMENTATION ===========
 *
-* Online html documentation available at 
+* Online html documentation available at
-*            http://www.netlib.org/lapack/explore-html/ 
+*            http://www.netlib.org/lapack/explore-html/
 *
 *> \htmlonly
-*> Download SSYTRD_2STAGE + dependencies 
+*> Download SSYTRD_2STAGE + dependencies
-*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/ssytrd_2stage.f"> 
+*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/ssytrd_2stage.f">
-*> [TGZ]</a> 
+*> [TGZ]</a>
-*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/ssytrd_2stage.f"> 
+*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/ssytrd_2stage.f">
-*> [ZIP]</a> 
+*> [ZIP]</a>
-*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/ssytrd_2stage.f"> 
+*> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/ssytrd_2stage.f">
 *> [TXT]</a>
-*> \endhtmlonly 
+*> \endhtmlonly
 *
 *  Definition:
 *  ===========
 *
-*       SUBROUTINE SSYTRD_2STAGE( VECT, UPLO, N, A, LDA, D, E, TAU, 
+*       SUBROUTINE SSYTRD_2STAGE( VECT, UPLO, N, A, LDA, D, E, TAU,
 *                                 HOUS2, LHOUS2, WORK, LWORK, INFO )
 *
 *       IMPLICIT NONE
@@ -34,7 +34,7 @@
 *       REAL               A( LDA, * ), TAU( * ),
 *                          HOUS2( * ), WORK( * )
 *       ..
-*  
+*
 *
 *> \par Purpose:
 *  =============
@@ -52,11 +52,11 @@
 *> \param[in] VECT
 *> \verbatim
 *>          VECT is CHARACTER*1
-*>          = 'N':  No need for the Housholder representation, 
+*>          = 'N':  No need for the Housholder representation,
 *>                  in particular for the second stage (Band to
 *>                  tridiagonal) and thus LHOUS2 is of size max(1, 4*N);
-*>          = 'V':  the Householder representation is needed to 
+*>          = 'V':  the Householder representation is needed to
-*>                  either generate Q1 Q2 or to apply Q1 Q2, 
+*>                  either generate Q1 Q2 or to apply Q1 Q2,
 *>                  then LHOUS2 is to be queried and computed.
 *>                  (NOT AVAILABLE IN THIS RELEASE).
 *> \endverbatim
@@ -86,7 +86,7 @@
 *>          triangular part of A is not referenced.
 *>          On exit, if UPLO = 'U', the band superdiagonal
 *>          of A are overwritten by the corresponding elements of the
-*>          internal band-diagonal matrix AB, and the elements above 
+*>          internal band-diagonal matrix AB, and the elements above
 *>          the KD superdiagonal, with the array TAU, represent the orthogonal
 *>          matrix Q1 as a product of elementary reflectors; if UPLO
 *>          = 'L', the diagonal and band subdiagonal of A are over-
@@ -117,13 +117,13 @@
 *> \param[out] TAU
 *> \verbatim
 *>          TAU is REAL array, dimension (N-KD)
-*>          The scalar factors of the elementary reflectors of 
+*>          The scalar factors of the elementary reflectors of
 *>          the first stage (see Further Details).
 *> \endverbatim
 *>
 *> \param[out] HOUS2
 *> \verbatim
-*>          HOUS2 is REAL array, dimension (LHOUS2)
+*>          HOUS2 is REAL array, dimension (MAX(1,LHOUS2))
 *>          Stores the Householder representation of the stage2
 *>          band to tridiagonal.
 *> \endverbatim
@@ -132,6 +132,8 @@
 *> \verbatim
 *>          LHOUS2 is INTEGER
 *>          The dimension of the array HOUS2.
+*>          LHOUS2 >= 1.
+*>
 *>          If LWORK = -1, or LHOUS2 = -1,
 *>          then a query is assumed; the routine
 *>          only calculates the optimal size of the HOUS2 array, returns
@@ -149,17 +151,19 @@
 *> \param[in] LWORK
 *> \verbatim
 *>          LWORK is INTEGER
-*>          The dimension of the array WORK. LWORK = MAX(1, dimension)
+*>          The dimension of the array WORK.
-*>          If LWORK = -1, or LHOUS2=-1,
+*>          If N = 0, LWORK >= 1, else LWORK = MAX(1, dimension).
+*>
+*>          If LWORK = -1, or LHOUS2 = -1,
 *>          then a workspace query is assumed; the routine
 *>          only calculates the optimal size of the WORK array, returns
 *>          this value as the first entry of the WORK array, and no error
 *>          message related to LWORK is issued by XERBLA.
 *>          LWORK = MAX(1, dimension) where
 *>          dimension   = max(stage1,stage2) + (KD+1)*N
-*>                      = N*KD + N*max(KD+1,FACTOPTNB) 
+*>                      = N*KD + N*max(KD+1,FACTOPTNB)
-*>                        + max(2*KD*KD, KD*NTHREADS) 
+*>                        + max(2*KD*KD, KD*NTHREADS)
-*>                        + (KD+1)*N 
+*>                        + (KD+1)*N
 *>          where KD is the blocking size of the reduction,
 *>          FACTOPTNB is the blocking used by the QR or LQ
 *>          algorithm, usually FACTOPTNB=128 is a good choice
@@ -177,12 +181,12 @@
 *  Authors:
 *  ========
 *
-*> \author Univ. of Tennessee 
+*> \author Univ. of Tennessee
-*> \author Univ. of California Berkeley 
+*> \author Univ. of California Berkeley
-*> \author Univ. of Colorado Denver 
+*> \author Univ. of Colorado Denver
-*> \author NAG Ltd. 
+*> \author NAG Ltd.
 *
-*> \ingroup realSYcomputational
+*> \ingroup hetrd_2stage
 *
 *> \par Further Details:
 *  =====================
@@ -202,7 +206,7 @@
 *>  http://doi.acm.org/10.1145/2063384.2063394
 *>
 *>  A. Haidar, J. Kurzak, P. Luszczek, 2013.
-*>  An improved parallel singular value algorithm and its implementation 
+*>  An improved parallel singular value algorithm and its implementation
 *>  for multicore hardware, In Proceedings of 2013 International Conference
 *>  for High Performance Computing, Networking, Storage and Analysis (SC '13).
 *>  Denver, Colorado, USA, 2013.
@@ -210,16 +214,16 @@
 *>  http://doi.acm.org/10.1145/2503210.2503292
 *>
 *>  A. Haidar, R. Solca, S. Tomov, T. Schulthess and J. Dongarra.
-*>  A novel hybrid CPU-GPU generalized eigensolver for electronic structure 
+*>  A novel hybrid CPU-GPU generalized eigensolver for electronic structure
 *>  calculations based on fine-grained memory aware tasks.
 *>  International Journal of High Performance Computing Applications.
 *>  Volume 28 Issue 2, Pages 196-209, May 2014.
-*>  http://hpc.sagepub.com/content/28/2/196 
+*>  http://hpc.sagepub.com/content/28/2/196
 *>
 *> \endverbatim
 *>
 *  =====================================================================
-      SUBROUTINE SSYTRD_2STAGE( VECT, UPLO, N, A, LDA, D, E, TAU, 
+      SUBROUTINE SSYTRD_2STAGE( VECT, UPLO, N, A, LDA, D, E, TAU,
      $                          HOUS2, LHOUS2, WORK, LWORK, INFO )
 *
       IMPLICIT NONE
@@ -265,10 +269,13 @@
 *
       KD     = ILAENV2STAGE( 1, 'SSYTRD_2STAGE', VECT, N, -1, -1, -1 )
       IB     = ILAENV2STAGE( 2, 'SSYTRD_2STAGE', VECT, N, KD, -1, -1 )
-      LHMIN  = ILAENV2STAGE( 3, 'SSYTRD_2STAGE', VECT, N, KD, IB, -1 )
+      IF( N.EQ.0 ) THEN
-      LWMIN  = ILAENV2STAGE( 4, 'SSYTRD_2STAGE', VECT, N, KD, IB, -1 )
+         LHMIN = 1
-*      WRITE(*,*),'SSYTRD_2STAGE N KD UPLO LHMIN LWMIN ',N, KD, UPLO,
+         LWMIN = 1
-*     $            LHMIN, LWMIN
+      ELSE
+         LHMIN = ILAENV2STAGE( 3, 'SSYTRD_2STAGE', VECT, N, KD, IB, -1 )
+         LWMIN = ILAENV2STAGE( 4, 'SSYTRD_2STAGE', VECT, N, KD, IB, -1 )
+      END IF
 *
       IF( .NOT.LSAME( VECT, 'N' ) ) THEN
          INFO = -1
@@ -309,14 +316,14 @@
       LWRK  = LWORK-LDAB*N
       ABPOS = 1
       WPOS  = ABPOS + LDAB*N
-      CALL SSYTRD_SY2SB( UPLO, N, KD, A, LDA, WORK( ABPOS ), LDAB, 
+      CALL SSYTRD_SY2SB( UPLO, N, KD, A, LDA, WORK( ABPOS ), LDAB,
      $                   TAU, WORK( WPOS ), LWRK, INFO )
       IF( INFO.NE.0 ) THEN
          CALL XERBLA( 'SSYTRD_SY2SB', -INFO )
          RETURN
       END IF
-      CALL SSYTRD_SB2ST( 'Y', VECT, UPLO, N, KD, 
+      CALL SSYTRD_SB2ST( 'Y', VECT, UPLO, N, KD,
-     $                   WORK( ABPOS ), LDAB, D, E, 
+     $                   WORK( ABPOS ), LDAB, D, E,
      $                   HOUS2, LHOUS2, WORK( WPOS ), LWRK, INFO )
       IF( INFO.NE.0 ) THEN
          CALL XERBLA( 'SSYTRD_SB2ST', -INFO )
@@ -324,8 +331,7 @@
       END IF
 *
 *
-      HOUS2( 1 ) = LHMIN
+      WORK( 1 ) = LWMIN
-      WORK( 1 )  = LWMIN
       RETURN
 *
 *     End of SSYTRD_2STAGE

lapack-netlib/SRC/ssytrd_sy2sb.f

@@ -124,7 +124,7 @@
 *> \param[out] WORK
 *> \verbatim
 *>          WORK is REAL array, dimension (LWORK)
-*>          On exit, if INFO = 0, or if LWORK=-1, 
+*>          On exit, if INFO = 0, or if LWORK = -1,
 *>          WORK(1) returns the size of LWORK.
 *> \endverbatim
 *>
@@ -132,7 +132,9 @@
 *> \verbatim
 *>          LWORK is INTEGER
 *>          The dimension of the array WORK which should be calculated
-*>          by a workspace query. LWORK = MAX(1, LWORK_QUERY)
+*>          by a workspace query.
+*>          If N <= KD+1, LWORK >= 1, else LWORK = MAX(1, LWORK_QUERY)
+*>
 *>          If LWORK = -1, then a workspace query is assumed; the routine
 *>          only calculates the optimal size of the WORK array, returns
 *>          this value as the first entry of the WORK array, and no error
@@ -294,8 +296,12 @@
       INFO   = 0
       UPPER  = LSAME( UPLO, 'U' )
       LQUERY = ( LWORK.EQ.-1 )
-      LWMIN  = ILAENV2STAGE( 4, 'SSYTRD_SY2SB', '', N, KD, -1, -1 )
+      IF( N.LE.KD+1 ) THEN
-      
+         LWMIN = 1
+      ELSE
+         LWMIN = ILAENV2STAGE( 4, 'SSYTRD_SY2SB', '', N, KD, -1, -1 )
+      END IF
+*
       IF( .NOT.UPPER .AND. .NOT.LSAME( UPLO, 'L' ) ) THEN
          INFO = -1
       ELSE IF( N.LT.0 ) THEN
@@ -314,7 +320,7 @@
          CALL XERBLA( 'SSYTRD_SY2SB', -INFO )
          RETURN
       ELSE IF( LQUERY ) THEN
-         WORK( 1 ) = SROUNDUP_LWORK(LWMIN)
+         WORK( 1 ) = SROUNDUP_LWORK( LWMIN )
          RETURN
       END IF
 *
@@ -507,7 +513,7 @@
 
       END IF
 *
-      WORK( 1 ) = SROUNDUP_LWORK(LWMIN)
+      WORK( 1 ) = SROUNDUP_LWORK( LWMIN )
       RETURN
 *
 *     End of SSYTRD_SY2SB

lapack-netlib/SRC/ssytrf.f

@@ -234,7 +234,7 @@
 *
          NB = ILAENV( 1, 'SSYTRF', UPLO, N, -1, -1, -1 )
          LWKOPT = MAX( 1, N*NB )
-         WORK( 1 ) = SROUNDUP_LWORK(LWKOPT)
+         WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
       END IF
 *
       IF( INFO.NE.0 ) THEN
@@ -353,7 +353,8 @@
       END IF
 *
    40 CONTINUE
-      WORK( 1 ) = SROUNDUP_LWORK(LWKOPT)
+*
+      WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
       RETURN
 *
 *     End of SSYTRF

lapack-netlib/SRC/ssytrf_aa.f

@@ -101,8 +101,10 @@
 *> \param[in] LWORK
 *> \verbatim
 *>          LWORK is INTEGER
-*>          The length of WORK.  LWORK >= MAX(1,2*N). For optimum performance
+*>          The length of WORK.
-*>          LWORK >= N*(1+NB), where NB is the optimal blocksize.
+*>          LWORK >= 1, if N <= 1, and LWORK >= 2*N, otherwise.
+*>          For optimum performance LWORK >= N*(1+NB), where NB is
+*>          the optimal blocksize, returned by ILAENV.
 *>
 *>          If LWORK = -1, then a workspace query is assumed; the routine
 *>          only calculates the optimal size of the WORK array, returns
@@ -128,7 +130,7 @@
 *> \ingroup hetrf_aa
 *
 *  =====================================================================
-      SUBROUTINE SSYTRF_AA( UPLO, N, A, LDA, IPIV, WORK, LWORK, INFO)
+      SUBROUTINE SSYTRF_AA( UPLO, N, A, LDA, IPIV, WORK, LWORK, INFO )
 *
 *  -- LAPACK computational routine --
 *  -- LAPACK is a software package provided by Univ. of Tennessee,    --
@@ -142,19 +144,19 @@
 *     ..
 *     .. Array Arguments ..
       INTEGER            IPIV( * )
-      REAL   A( LDA, * ), WORK( * )
+      REAL               A( LDA, * ), WORK( * )
 *     ..
 *
 *  =====================================================================
 *     .. Parameters ..
-      REAL   ZERO, ONE
+      REAL               ZERO, ONE
       PARAMETER          ( ZERO = 0.0E+0, ONE = 1.0E+0 )
 *
 *     .. Local Scalars ..
       LOGICAL            LQUERY, UPPER
-      INTEGER            J, LWKOPT
+      INTEGER            J, LWKMIN, LWKOPT
       INTEGER            NB, MJ, NJ, K1, K2, J1, J2, J3, JB
-      REAL   ALPHA
+      REAL               ALPHA
 *     ..
 *     .. External Functions ..
       LOGICAL            LSAME
@@ -180,19 +182,26 @@
       INFO = 0
       UPPER = LSAME( UPLO, 'U' )
       LQUERY = ( LWORK.EQ.-1 )
+      IF( N.LE.1 ) THEN
+         LWKMIN = 1
+         LWKOPT = 1
+      ELSE
+         LWKMIN = 2*N
+         LWKOPT = (NB+1)*N
+      END IF
+*
       IF( .NOT.UPPER .AND. .NOT.LSAME( UPLO, 'L' ) ) THEN
          INFO = -1
       ELSE IF( N.LT.0 ) THEN
          INFO = -2
       ELSE IF( LDA.LT.MAX( 1, N ) ) THEN
          INFO = -4
-      ELSE IF( LWORK.LT.MAX( 1, 2*N ) .AND. .NOT.LQUERY ) THEN
+      ELSE IF( LWORK.LT.LWKMIN .AND. .NOT.LQUERY ) THEN
          INFO = -7
       END IF
 *
       IF( INFO.EQ.0 ) THEN
-         LWKOPT = (NB+1)*N
+         WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
-         WORK( 1 ) = SROUNDUP_LWORK(LWKOPT)
       END IF
 *
       IF( INFO.NE.0 ) THEN
@@ -204,11 +213,11 @@
 *
 *     Quick return
 *
-      IF ( N.EQ.0 ) THEN
+      IF( N.EQ.0 ) THEN
           RETURN
       ENDIF
       IPIV( 1 ) = 1
-      IF ( N.EQ.1 ) THEN
+      IF( N.EQ.1 ) THEN
          RETURN
       END IF
 *
@@ -458,7 +467,8 @@
       END IF
 *
    20 CONTINUE
-      WORK( 1 ) = SROUNDUP_LWORK(LWKOPT)
+*
+      WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
       RETURN
 *
 *     End of SSYTRF_AA

lapack-netlib/SRC/ssytrf_aa_2stage.f

@@ -94,7 +94,7 @@
 *> \param[in] LTB
 *> \verbatim
 *>          LTB is INTEGER
-*>          The size of the array TB. LTB >= 4*N, internally
+*>          The size of the array TB. LTB >= MAX(1,4*N), internally
 *>          used to select NB such that LTB >= (3*NB+1)*N.
 *>
 *>          If LTB = -1, then a workspace query is assumed; the
@@ -121,14 +121,14 @@
 *>
 *> \param[out] WORK
 *> \verbatim
-*>          WORK is REAL workspace of size LWORK
+*>          WORK is REAL workspace of size (MAX(1,LWORK))
 *> \endverbatim
 *>
 *> \param[in] LWORK
 *> \verbatim
 *>          LWORK is INTEGER
-*>          The size of WORK. LWORK >= N, internally used to select NB
+*>          The size of WORK. LWORK >= MAX(1,N), internally used to
-*>          such that LWORK >= N*NB.
+*>          select NB such that LWORK >= N*NB.
 *>
 *>          If LWORK = -1, then a workspace query is assumed; the
 *>          routine only calculates the optimal size of the WORK array,
@@ -212,9 +212,9 @@
          INFO = -2
       ELSE IF( LDA.LT.MAX( 1, N ) ) THEN
          INFO = -4
-      ELSE IF ( LTB .LT. 4*N .AND. .NOT.TQUERY ) THEN
+      ELSE IF( LTB.LT.MAX( 1, 4*N ) .AND. .NOT.TQUERY ) THEN
          INFO = -6
-      ELSE IF ( LWORK .LT. N .AND. .NOT.WQUERY ) THEN
+      ELSE IF( LWORK.LT.MAX( 1, N ) .AND. .NOT.WQUERY ) THEN
          INFO = -10
       END IF
 *
@@ -228,10 +228,10 @@
       NB = ILAENV( 1, 'SSYTRF_AA_2STAGE', UPLO, N, -1, -1, -1 )
       IF( INFO.EQ.0 ) THEN
          IF( TQUERY ) THEN
-            TB( 1 ) = (3*NB+1)*N
+            TB( 1 ) = SROUNDUP_LWORK( MAX( 1, (3*NB+1)*N ) )
          END IF
          IF( WQUERY ) THEN
-            WORK( 1 ) = SROUNDUP_LWORK(N*NB)
+            WORK( 1 ) = SROUNDUP_LWORK( MAX( 1, N*NB ) )
          END IF
       END IF
       IF( TQUERY .OR. WQUERY ) THEN
@@ -240,7 +240,7 @@
 *
 *     Quick return
 *
-      IF ( N.EQ.0 ) THEN
+      IF( N.EQ.0 ) THEN
          RETURN
       ENDIF
 *

lapack-netlib/SRC/ssytrf_rk.f

@@ -177,14 +177,14 @@
 *>
 *> \param[out] WORK
 *> \verbatim
-*>          WORK is REAL array, dimension ( MAX(1,LWORK) ).
+*>          WORK is REAL array, dimension (MAX(1,LWORK)).
 *>          On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
 *> \endverbatim
 *>
 *> \param[in] LWORK
 *> \verbatim
 *>          LWORK is INTEGER
-*>          The length of WORK.  LWORK >=1.  For best performance
+*>          The length of WORK.  LWORK >= 1.  For best performance
 *>          LWORK >= N*NB, where NB is the block size returned
 *>          by ILAENV.
 *>
@@ -312,7 +312,7 @@
 *
          NB = ILAENV( 1, 'SSYTRF_RK', UPLO, N, -1, -1, -1 )
          LWKOPT = MAX( 1, N*NB )
-         WORK( 1 ) = SROUNDUP_LWORK(LWKOPT)
+         WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
       END IF
 *
       IF( INFO.NE.0 ) THEN
@@ -488,7 +488,7 @@
 *
       END IF
 *
-      WORK( 1 ) = SROUNDUP_LWORK(LWKOPT)
+      WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
       RETURN
 *
 *     End of SSYTRF_RK

lapack-netlib/SRC/ssytrf_rook.f

@@ -118,7 +118,7 @@
 *> \param[in] LWORK
 *> \verbatim
 *>          LWORK is INTEGER
-*>          The length of WORK.  LWORK >=1.  For best performance
+*>          The length of WORK.  LWORK >= 1.  For best performance
 *>          LWORK >= N*NB, where NB is the block size returned by ILAENV.
 *>
 *>          If LWORK = -1, then a workspace query is assumed; the routine
@@ -260,7 +260,7 @@
 *
          NB = ILAENV( 1, 'SSYTRF_ROOK', UPLO, N, -1, -1, -1 )
          LWKOPT = MAX( 1, N*NB )
-         WORK( 1 ) = SROUNDUP_LWORK(LWKOPT)
+         WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
       END IF
 *
       IF( INFO.NE.0 ) THEN
@@ -383,7 +383,8 @@
       END IF
 *
    40 CONTINUE
-      WORK( 1 ) = SROUNDUP_LWORK(LWKOPT)
+*
+      WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
       RETURN
 *
 *     End of SSYTRF_ROOK

lapack-netlib/SRC/ssytri2.f

@@ -88,16 +88,16 @@
 *>
 *> \param[out] WORK
 *> \verbatim
-*>          WORK is REAL array, dimension (N+NB+1)*(NB+3)
+*>          WORK is REAL array, dimension (MAX(1,LWORK))
 *> \endverbatim
 *>
 *> \param[in] LWORK
 *> \verbatim
 *>          LWORK is INTEGER
 *>          The dimension of the array WORK.
-*>          WORK is size >= (N+NB+1)*(NB+3)
+*>          If N = 0, LWORK >= 1, else LWORK >= (N+NB+1)*(NB+3).
 *>          If LWORK = -1, then a workspace query is assumed; the routine
-*>           calculates:
+*>          calculates:
 *>              - the optimal size of the WORK array, returns
 *>          this value as the first entry of the WORK array,
 *>              - and no error message related to LWORK is issued by XERBLA.
@@ -120,7 +120,7 @@
 *> \author Univ. of Colorado Denver
 *> \author NAG Ltd.
 *
-*> \ingroup realSYcomputational
+*> \ingroup hetri2
 *
 *  =====================================================================
       SUBROUTINE SSYTRI2( UPLO, N, A, LDA, IPIV, WORK, LWORK, INFO )
@@ -147,7 +147,8 @@
 *     .. External Functions ..
       LOGICAL            LSAME
       INTEGER            ILAENV
-      EXTERNAL           LSAME, ILAENV
+      REAL               SROUNDUP_LWORK
+      EXTERNAL           LSAME, ILAENV, SROUNDUP_LWORK
 *     ..
 *     .. External Subroutines ..
       EXTERNAL           SSYTRI, SSYTRI2X, XERBLA
@@ -159,9 +160,13 @@
       INFO = 0
       UPPER = LSAME( UPLO, 'U' )
       LQUERY = ( LWORK.EQ.-1 )
+*
 *     Get blocksize
+*
       NBMAX = ILAENV( 1, 'SSYTRF', UPLO, N, -1, -1, -1 )
-      IF ( NBMAX .GE. N ) THEN
+      IF( N.EQ.0 ) THEN
+         MINSIZE = 1
+      ELSE IF( NBMAX.GE.N ) THEN
          MINSIZE = N
       ELSE
          MINSIZE = (N+NBMAX+1)*(NBMAX+3)
@@ -173,28 +178,29 @@
          INFO = -2
       ELSE IF( LDA.LT.MAX( 1, N ) ) THEN
          INFO = -4
-      ELSE IF (LWORK .LT. MINSIZE .AND. .NOT.LQUERY ) THEN
+      ELSE IF( LWORK.LT.MINSIZE .AND. .NOT.LQUERY ) THEN
          INFO = -7
       END IF
-*
-*     Quick return if possible
-*
 *
       IF( INFO.NE.0 ) THEN
          CALL XERBLA( 'SSYTRI2', -INFO )
          RETURN
       ELSE IF( LQUERY ) THEN
-         WORK(1)=MINSIZE
+         WORK( 1 ) = SROUNDUP_LWORK( MINSIZE )
          RETURN
       END IF
+*
+*     Quick return if possible
+*
       IF( N.EQ.0 )
      $   RETURN
-
+*
-      IF( NBMAX .GE. N ) THEN
+      IF( NBMAX.GE.N ) THEN
          CALL SSYTRI( UPLO, N, A, LDA, IPIV, WORK, INFO )
       ELSE
          CALL SSYTRI2X( UPLO, N, A, LDA, IPIV, WORK, NBMAX, INFO )
       END IF
+*
       RETURN
 *
 *     End of SSYTRI2

lapack-netlib/SRC/ssytri_3.f

@@ -119,16 +119,17 @@
 *>
 *> \param[out] WORK
 *> \verbatim
-*>          WORK is REAL array, dimension (N+NB+1)*(NB+3).
+*>          WORK is REAL array, dimension (MAX(1,LWORK)).
 *>          On exit, if INFO = 0, WORK(1) returns the optimal LWORK.
 *> \endverbatim
 *>
 *> \param[in] LWORK
 *> \verbatim
 *>          LWORK is INTEGER
-*>          The length of WORK. LWORK >= (N+NB+1)*(NB+3).
+*>          The length of WORK.
+*>          If N = 0, LWORK >= 1, else LWORK >= (N+NB+1)*(NB+3).
 *>
-*>          If LDWORK = -1, then a workspace query is assumed;
+*>          If LWORK = -1, then a workspace query is assumed;
 *>          the routine only calculates the optimal size of the optimal
 *>          size of the WORK array, returns this value as the first
 *>          entry of the WORK array, and no error message related to
@@ -209,8 +210,13 @@
 *
 *     Determine the block size
 *
-      NB = MAX( 1, ILAENV( 1, 'SSYTRI_3', UPLO, N, -1, -1, -1 ) )
+      IF( N.EQ.0 ) THEN
-      LWKOPT = ( N+NB+1 ) * ( NB+3 )
+         LWKOPT = 1
+      ELSE
+         NB = MAX( 1, ILAENV( 1, 'SSYTRI_3', UPLO, N, -1, -1, -1 ) )
+         LWKOPT = ( N+NB+1 ) * ( NB+3 )
+      END IF
+      WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
 *
       IF( .NOT.UPPER .AND. .NOT.LSAME( UPLO, 'L' ) ) THEN
          INFO = -1
@@ -218,7 +224,7 @@
          INFO = -2
       ELSE IF( LDA.LT.MAX( 1, N ) ) THEN
          INFO = -4
-      ELSE IF ( LWORK .LT. LWKOPT .AND. .NOT.LQUERY ) THEN
+      ELSE IF( LWORK.LT.LWKOPT .AND. .NOT.LQUERY ) THEN
          INFO = -8
       END IF
 *
@@ -226,7 +232,6 @@
          CALL XERBLA( 'SSYTRI_3', -INFO )
          RETURN
       ELSE IF( LQUERY ) THEN
-         WORK( 1 ) = SROUNDUP_LWORK(LWKOPT)
          RETURN
       END IF
 *
@@ -237,7 +242,7 @@
 *
       CALL SSYTRI_3X( UPLO, N, A, LDA, E, IPIV, WORK, NB, INFO )
 *
-      WORK( 1 ) = SROUNDUP_LWORK(LWKOPT)
+      WORK( 1 ) = SROUNDUP_LWORK( LWKOPT )
 *
       RETURN
 *

lapack-netlib/SRC/ssytrs_aa.f

@@ -105,7 +105,13 @@
 *> \param[in] LWORK
 *> \verbatim
 *>          LWORK is INTEGER
-*>          The dimension of the array WORK. LWORK >= max(1,3*N-2).
+*>          The dimension of the array WORK.
+*>          If MIN(N,NRHS) = 0, LWORK >= 1, else LWORK >= 3*N-2.
+*>
+*>          If LWORK = -1, then a workspace query is assumed; the routine
+*>          only calculates the minimal size of the WORK array, returns
+*>          this value as the first entry of the WORK array, and no error
+*>          message related to LWORK is issued by XERBLA.
 *> \endverbatim
 *>
 *> \param[out] INFO
@@ -141,7 +147,7 @@
 *     ..
 *     .. Array Arguments ..
       INTEGER            IPIV( * )
-      REAL   A( LDA, * ), B( LDB, * ), WORK( * )
+      REAL               A( LDA, * ), B( LDB, * ), WORK( * )
 *     ..
 *
 *  =====================================================================
@@ -151,24 +157,31 @@
 *     ..
 *     .. Local Scalars ..
       LOGICAL            LQUERY, UPPER
-      INTEGER            K, KP, LWKOPT
+      INTEGER            K, KP, LWKMIN
 *     ..
 *     .. External Functions ..
       LOGICAL            LSAME
+      EXTERNAL           LSAME
       REAL               SROUNDUP_LWORK
-      EXTERNAL           LSAME, SROUNDUP_LWORK
+      EXTERNAL           SROUNDUP_LWORK
 *     ..
 *     .. External Subroutines ..
       EXTERNAL           SGTSV, SSWAP, SLACPY, STRSM, XERBLA
 *     ..
 *     .. Intrinsic Functions ..
-      INTRINSIC          MAX
+      INTRINSIC          MIN, MAX
 *     ..
 *     .. Executable Statements ..
 *
       INFO = 0
       UPPER = LSAME( UPLO, 'U' )
       LQUERY = ( LWORK.EQ.-1 )
+      IF( MIN( N, NRHS ).EQ.0 ) THEN
+         LWKMIN = 1
+      ELSE
+         LWKMIN = 3*N-2
+      END IF
+*
       IF( .NOT.UPPER .AND. .NOT.LSAME( UPLO, 'L' ) ) THEN
          INFO = -1
       ELSE IF( N.LT.0 ) THEN
@@ -179,21 +192,20 @@
          INFO = -5
       ELSE IF( LDB.LT.MAX( 1, N ) ) THEN
          INFO = -8
-      ELSE IF( LWORK.LT.MAX( 1, 3*N-2 ) .AND. .NOT.LQUERY ) THEN
+      ELSE IF( LWORK.LT.LWKMIN .AND. .NOT.LQUERY ) THEN
          INFO = -10
       END IF
       IF( INFO.NE.0 ) THEN
          CALL XERBLA( 'SSYTRS_AA', -INFO )
          RETURN
       ELSE IF( LQUERY ) THEN
-         LWKOPT = (3*N-2)
+         WORK( 1 ) = SROUNDUP_LWORK( LWKMIN )
-         WORK( 1 ) = SROUNDUP_LWORK(LWKOPT)
          RETURN
       END IF
 *
 *     Quick return if possible
 *
-      IF( N.EQ.0 .OR. NRHS.EQ.0 )
+      IF( MIN( N, NRHS ).EQ.0 )
      $   RETURN
 *
       IF( UPPER ) THEN