From 42fe66c8488b5d7a9117e9ca72d0a563f765cd08 Mon Sep 17 00:00:00 2001
From: Julien Langou <julien.langou@ucdenver.edu>
Date: Thu, 23 Mar 2017 15:40:14 -0400
Subject: Fix #135

Thanks Cezary Dendek!
---
 SRC/dbdsqr.f | 29 +++++++++++++++++++++++------
 SRC/sbdsqr.f | 28 ++++++++++++++++++++++------
 2 files changed, 45 insertions(+), 12 deletions(-)

diff --git a/SRC/dbdsqr.f b/SRC/dbdsqr.f
index b9894d89..0e46e71c 100644
--- a/SRC/dbdsqr.f
+++ b/SRC/dbdsqr.f
@@ -212,6 +212,17 @@
 *>          algorithm through its inner loop. The algorithms stops
 *>          (and so fails to converge) if the number of passes
 *>          through the inner loop exceeds MAXITR*N**2.
+*>
+*> \endverbatim
+*
+*> \par Note:
+*  ===========
+*>
+*> \verbatim
+*>  Bug report from Cezary Dendek.
+*>  On March 23rd 2017, the INTEGER variable MAXIT = MAXITR*N**2 is
+*>  removed since it can overflow pretty easily (for N larger or equal
+*>  than 18,919). We instead use MAXITDIVN = MAXITR*N.
 *> \endverbatim
 *
 *  Authors:
@@ -266,8 +277,8 @@
 *     ..
 *     .. Local Scalars ..
       LOGICAL            LOWER, ROTATE
-      INTEGER            I, IDIR, ISUB, ITER, J, LL, LLL, M, MAXIT, NM1,
-     $                   NM12, NM13, OLDLL, OLDM
+      INTEGER            I, IDIR, ISUB, ITER, ITERDIVN, J, LL, LLL, M,
+     $                   MAXITDIVN, NM1, NM12, NM13, OLDLL, OLDM
       DOUBLE PRECISION   ABSE, ABSS, COSL, COSR, CS, EPS, F, G, H, MU,
      $                   OLDCS, OLDSN, R, SHIFT, SIGMN, SIGMX, SINL,
      $                   SINR, SLL, SMAX, SMIN, SMINL, SMINOA,
@@ -412,8 +423,9 @@
 *     (MAXIT is the maximum number of passes through the inner
 *     loop permitted before nonconvergence signalled.)
 *
-      MAXIT = MAXITR*N*N
-      ITER = 0
+      MAXITDIVN = MAXITR*N
+      ITERDIVN = 0
+      ITER = -1
       OLDLL = -1
       OLDM = -1
 *
@@ -429,8 +441,13 @@
 *
       IF( M.LE.1 )
      $   GO TO 160
-      IF( ITER.GT.MAXIT )
-     $   GO TO 200
+*
+      IF( ITER.GE.N ) THEN
+         ITER = ITER - N
+         ITERDIVN = ITERDIVN + 1
+         IF( ITERDIVN.GE.MAXITDIVN )
+     $      GO TO 200
+      END IF
 *
 *     Find diagonal block of matrix to work on
 *
diff --git a/SRC/sbdsqr.f b/SRC/sbdsqr.f
index 7dc3dd7c..14560108 100644
--- a/SRC/sbdsqr.f
+++ b/SRC/sbdsqr.f
@@ -214,6 +214,16 @@
 *>          through the inner loop exceeds MAXITR*N**2.
 *> \endverbatim
 *
+*> \par Note:
+*  ===========
+*>
+*> \verbatim
+*>  Bug report from Cezary Dendek.
+*>  On March 23rd 2017, the INTEGER variable MAXIT = MAXITR*N**2 is
+*>  removed since it can overflow pretty easily (for N larger or equal
+*>  than 18,919). We instead use MAXITDIVN = MAXITR*N.
+*> \endverbatim
+*
 *  Authors:
 *  ========
 *
@@ -266,8 +276,8 @@
 *     ..
 *     .. Local Scalars ..
       LOGICAL            LOWER, ROTATE
-      INTEGER            I, IDIR, ISUB, ITER, J, LL, LLL, M, MAXIT, NM1,
-     $                   NM12, NM13, OLDLL, OLDM
+      INTEGER            I, IDIR, ISUB, ITER, ITERDIVN, J, LL, LLL, M,
+     $                   MAXITDIVN, NM1, NM12, NM13, OLDLL, OLDM
       REAL               ABSE, ABSS, COSL, COSR, CS, EPS, F, G, H, MU,
      $                   OLDCS, OLDSN, R, SHIFT, SIGMN, SIGMX, SINL,
      $                   SINR, SLL, SMAX, SMIN, SMINL,  SMINOA,
@@ -412,8 +422,9 @@
 *     (MAXIT is the maximum number of passes through the inner
 *     loop permitted before nonconvergence signalled.)
 *
-      MAXIT = MAXITR*N*N
-      ITER = 0
+      MAXITDIVN = MAXITR*N
+      ITERDIVN = 0
+      ITER = -1
       OLDLL = -1
       OLDM = -1
 *
@@ -429,8 +440,13 @@
 *
       IF( M.LE.1 )
      $   GO TO 160
-      IF( ITER.GT.MAXIT )
-     $   GO TO 200
+*
+      IF( ITER.GE.N ) THEN
+         ITER = ITER - N
+         ITERDIVN = ITERDIVN + 1
+         IF( ITERDIVN.GE.MAXITDIVN )
+     $      GO TO 200
+      END IF
 *
 *     Find diagonal block of matrix to work on
 *
-- 
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