From 44948e7c8e4cff62a9a944030e22ef7a93903c37 Mon Sep 17 00:00:00 2001
From: julie <julielangou@users.noreply.github.com>
Date: Fri, 21 Sep 2012 02:21:29 +0000
Subject:

---
 SRC/ztprfb.f | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

(limited to 'SRC/ztprfb.f')

diff --git a/SRC/ztprfb.f b/SRC/ztprfb.f
index 9110f494..d3d84505 100644
--- a/SRC/ztprfb.f
+++ b/SRC/ztprfb.f
@@ -184,6 +184,11 @@
 *>          The leading dimension of the array WORK.
 *>          If SIDE = 'L', LDWORK >= K; 
 *>          if SIDE = 'R', LDWORK >= M.
+*>
+*>          If LDWORK = -1, then a workspace query is assumed; the routine
+*>          only calculates the optimal size of 2nd dimension of the WORK array,
+*>          returns this value as the first entry of the WORK array, and no 
+*>          error message related to LDWORK is issued by XERBLA.
 *> \endverbatim
 *
 *  Authors:
@@ -273,7 +278,7 @@
 *     ..
 *     .. Local Scalars ..
       INTEGER   I, J, MP, NP, KP
-      LOGICAL   LEFT, FORWARD, COLUMN, RIGHT, BACKWARD, ROW
+      LOGICAL   LEFT, LQUERY, FORWARD, COLUMN, RIGHT, BACKWARD, ROW
 *     ..
 *     .. External Functions ..
       LOGICAL   LSAME
@@ -287,6 +292,7 @@
 *     ..
 *     .. Executable Statements ..
 *
+      LQUERY = ( LDWORK.EQ.-1 )
 *     Quick return if possible
 *
       IF( M.LE.0 .OR. N.LE.0 .OR. K.LE.0 .OR. L.LT.0 ) RETURN
@@ -323,6 +329,19 @@
          FORWARD = .FALSE.
          BACKWARD = .FALSE.
       END IF
+* ---------------------------------------------------------------------------
+*      
+*     Workspace Query
+*
+      IF( LQUERY .AND. LEFT  ) THEN
+         LDWORK=MAX(1,K)
+      ELSE IF ( LQUERY .AND. RIGHT  ) THEN
+         LDWORK=MAX(1,M)
+      END IF
+          
+      IF( LQUERY ) THEN
+         RETURN
+      END IF
 *
 * ---------------------------------------------------------------------------
 *      
-- 
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