Merge pull request #989 from angsch/bdsqr

Two small fixes of bdsqr

Author: langou

SRC/cbdsqr.f

@@ -166,7 +166,7 @@
 *>
 *> \param[out] RWORK
 *> \verbatim
-*>          RWORK is REAL array, dimension (4*N)
+*>          RWORK is REAL array, dimension (4*(N-1))
 *> \endverbatim
 *>
 *> \param[out] INFO
@@ -809,6 +809,12 @@ SUBROUTINE CBDSQR( UPLO, N, NCVT, NRU, NCC, D, E, VT, LDVT, U,
 *
   160 CONTINUE
       DO 170 I = 1, N
+         IF( D( I ).EQ.ZERO ) THEN
+*
+*           Avoid -ZERO
+*
+            D( I ) = ZERO
+         END IF
          IF( D( I ).LT.ZERO ) THEN
             D( I ) = -D( I )
 *

SRC/dbdsqr.f

@@ -817,6 +817,12 @@ SUBROUTINE DBDSQR( UPLO, N, NCVT, NRU, NCC, D, E, VT, LDVT, U,
 *
   160 CONTINUE
       DO 170 I = 1, N
+         IF( D( I ).EQ.ZERO ) THEN
+*
+*           Avoid -ZERO
+*
+            D( I ) = ZERO
+         END IF
          IF( D( I ).LT.ZERO ) THEN
             D( I ) = -D( I )
 *

SRC/sbdsqr.f

@@ -166,7 +166,7 @@
 *>
 *> \param[out] WORK
 *> \verbatim
-*>          WORK is REAL array, dimension (4*N)
+*>          WORK is REAL array, dimension (4*(N-1))
 *> \endverbatim
 *>
 *> \param[out] INFO
@@ -817,7 +817,14 @@ SUBROUTINE SBDSQR( UPLO, N, NCVT, NRU, NCC, D, E, VT, LDVT, U,
 *
   160 CONTINUE
       DO 170 I = 1, N
+         IF( D( I ).EQ.ZERO ) THEN
+*
+*           Avoid -ZERO
+*
+            D( I ) = ZERO
+         END IF
          IF( D( I ).LT.ZERO ) THEN
+
             D( I ) = -D( I )
 *
 *           Change sign of singular vectors, if desired

SRC/zbdsqr.f

@@ -166,7 +166,7 @@
 *>
 *> \param[out] RWORK
 *> \verbatim
-*>          RWORK is DOUBLE PRECISION array, dimension (4*N)
+*>          RWORK is DOUBLE PRECISION array, dimension (4*(N-1))
 *> \endverbatim
 *>
 *> \param[out] INFO
@@ -807,6 +807,12 @@ SUBROUTINE ZBDSQR( UPLO, N, NCVT, NRU, NCC, D, E, VT, LDVT, U,
 *
   160 CONTINUE
       DO 170 I = 1, N
+         IF( D( I ).EQ.ZERO ) THEN
+*
+*           Avoid -ZERO
+*
+            D( I ) = ZERO
+         END IF
          IF( D( I ).LT.ZERO ) THEN
             D( I ) = -D( I )
 *