updated comments in (c,z)lahef.f for column interchange

diff --git a/SRC/clahef.f b/SRC/clahef.f
index 27c24c4735c16f45821bd27d10382abe52c0b491..004ce603e95c4923cf5bbec8636c090bb6374e9b 100644 (file)
--- a/SRC/clahef.f
+++ b/SRC/clahef.f
@@ -341,7 +341,10 @@
 *
             IF( KP.NE.KK ) THEN
 *
-*              Copy non-updated column KK to column KP
+*              Copy non-updated column KK to column KP of submatrix A
+*              at step K. No need to copy element into column K
+*              (or K and K-1) of A, since these columns will be later
+*              overwritten.
 *
                A( KP, KP ) = REAL( A( KK, KK ) )
                CALL CCOPY( KK-1-KP, A( KP+1, KK ), 1, A( KP, KP+1 ),
@@ -595,7 +598,10 @@
 *
             IF( KP.NE.KK ) THEN
 *
-*              Copy non-updated column KK to column KP
+*              Copy non-updated column KK to column KP of submatrix A
+*              at step K. No need to copy element into column K
+*              (or K and K+1) of A, since these columns will be later
+*              overwritten.
 *
                A( KP, KP ) = REAL( A( KK, KK ) )
                CALL CCOPY( KP-KK-1, A( KK+1, KK ), 1, A( KP, KK+1 ),

diff --git a/SRC/zlahef.f b/SRC/zlahef.f
index f83b655f102954fa9bfc7b5bb0b5c29533eec848..2566c7d380676eb995a02d2b23c0e05c9c9de4ff 100644 (file)
--- a/SRC/zlahef.f
+++ b/SRC/zlahef.f
@@ -341,7 +341,10 @@
 *
             IF( KP.NE.KK ) THEN
 *
-*              Copy non-updated column KK to column KP
+*              Copy non-updated column KK to column KP of submatrix A
+*              at step K. No need to copy element into column K
+*              (or K and K-1) of A, since these columns will be later
+*              overwritten.
 *
                A( KP, KP ) = DBLE( A( KK, KK ) )
                CALL ZCOPY( KK-1-KP, A( KP+1, KK ), 1, A( KP, KP+1 ),
@@ -595,7 +598,10 @@
 *
             IF( KP.NE.KK ) THEN
 *
-*              Copy non-updated column KK to column KP
+*              Copy non-updated column KK to column KP of submatrix A
+*              at step K. No need to copy element into column K
+*              (or K and K+1) of A, since these columns will be later
+*              overwritten.
 *
                A( KP, KP ) = DBLE( A( KK, KK ) )
                CALL ZCOPY( KP-KK-1, A( KK+1, KK ), 1, A( KP, KK+1 ),