diff --git a/SRC/cgttrs.f b/SRC/cgttrs.f
index 9ff93a4cf..7fac67bb1 100644
--- a/SRC/cgttrs.f
+++ b/SRC/cgttrs.f
@@ -157,7 +157,8 @@ SUBROUTINE CGTTRS( TRANS, N, NRHS, DL, D, DU, DU2, IPIV, B,
 *     ..
 *     .. External Functions ..
       INTEGER            ILAENV
-      EXTERNAL           ILAENV
+      LOGICAL            LSAME
+      EXTERNAL           ILAENV, LSAME
 *     ..
 *     .. External Subroutines ..
       EXTERNAL           CGTTS2, XERBLA
@@ -168,9 +169,9 @@ SUBROUTINE CGTTRS( TRANS, N, NRHS, DL, D, DU, DU2, IPIV, B,
 *     .. Executable Statements ..
 *
       INFO = 0
-      NOTRAN = ( TRANS.EQ.'N' .OR. TRANS.EQ.'n' )
-      IF( .NOT.NOTRAN .AND. .NOT.( TRANS.EQ.'T' .OR. TRANS.EQ.
-     $    't' ) .AND. .NOT.( TRANS.EQ.'C' .OR. TRANS.EQ.'c' ) ) THEN
+      NOTRAN = LSAME( TRANS, 'N' )
+      IF( .NOT.NOTRAN .AND. .NOT.LSAME( TRANS, 'T' ) .AND.
+     $    .NOT.LSAME( TRANS, 'C' ) ) THEN
          INFO = -1
       ELSE IF( N.LT.0 ) THEN
          INFO = -2
@@ -193,7 +194,7 @@ SUBROUTINE CGTTRS( TRANS, N, NRHS, DL, D, DU, DU2, IPIV, B,
 *
       IF( NOTRAN ) THEN
          ITRANS = 0
-      ELSE IF( TRANS.EQ.'T' .OR. TRANS.EQ.'t' ) THEN
+      ELSE IF( LSAME( TRANS, 'T' ) ) THEN
          ITRANS = 1
       ELSE
          ITRANS = 2
diff --git a/SRC/dgttrs.f b/SRC/dgttrs.f
index 1f3d84469..500f71ab2 100644
--- a/SRC/dgttrs.f
+++ b/SRC/dgttrs.f
@@ -157,7 +157,8 @@ SUBROUTINE DGTTRS( TRANS, N, NRHS, DL, D, DU, DU2, IPIV, B,
 *     ..
 *     .. External Functions ..
       INTEGER            ILAENV
-      EXTERNAL           ILAENV
+      LOGICAL            LSAME
+      EXTERNAL           ILAENV, LSAME
 *     ..
 *     .. External Subroutines ..
       EXTERNAL           DGTTS2, XERBLA
@@ -168,9 +169,9 @@ SUBROUTINE DGTTRS( TRANS, N, NRHS, DL, D, DU, DU2, IPIV, B,
 *     .. Executable Statements ..
 *
       INFO = 0
-      NOTRAN = ( TRANS.EQ.'N' .OR. TRANS.EQ.'n' )
-      IF( .NOT.NOTRAN .AND. .NOT.( TRANS.EQ.'T' .OR. TRANS.EQ.
-     $    't' ) .AND. .NOT.( TRANS.EQ.'C' .OR. TRANS.EQ.'c' ) ) THEN
+      NOTRAN = LSAME( TRANS, 'N' )
+      IF( .NOT.NOTRAN .AND. .NOT.LSAME( TRANS, 'T' ) .AND.
+     $    .NOT.LSAME( TRANS, 'C' ) ) THEN
          INFO = -1
       ELSE IF( N.LT.0 ) THEN
          INFO = -2
diff --git a/SRC/sgttrs.f b/SRC/sgttrs.f
index 306c8f1bc..68921b6b8 100644
--- a/SRC/sgttrs.f
+++ b/SRC/sgttrs.f
@@ -157,7 +157,8 @@ SUBROUTINE SGTTRS( TRANS, N, NRHS, DL, D, DU, DU2, IPIV, B,
 *     ..
 *     .. External Functions ..
       INTEGER            ILAENV
-      EXTERNAL           ILAENV
+      LOGICAL            LSAME
+      EXTERNAL           ILAENV, LSAME
 *     ..
 *     .. External Subroutines ..
       EXTERNAL           SGTTS2, XERBLA
@@ -168,9 +169,9 @@ SUBROUTINE SGTTRS( TRANS, N, NRHS, DL, D, DU, DU2, IPIV, B,
 *     .. Executable Statements ..
 *
       INFO = 0
-      NOTRAN = ( TRANS.EQ.'N' .OR. TRANS.EQ.'n' )
-      IF( .NOT.NOTRAN .AND. .NOT.( TRANS.EQ.'T' .OR. TRANS.EQ.
-     $    't' ) .AND. .NOT.( TRANS.EQ.'C' .OR. TRANS.EQ.'c' ) ) THEN
+      NOTRAN = LSAME( TRANS, 'N' )
+      IF( .NOT.NOTRAN .AND. .NOT.LSAME( TRANS, 'T' ) .AND.
+     $    .NOT.LSAME( TRANS, 'C' ) ) THEN
          INFO = -1
       ELSE IF( N.LT.0 ) THEN
          INFO = -2
diff --git a/SRC/zgttrs.f b/SRC/zgttrs.f
index 180acb6dc..2238b8d63 100644
--- a/SRC/zgttrs.f
+++ b/SRC/zgttrs.f
@@ -157,7 +157,8 @@ SUBROUTINE ZGTTRS( TRANS, N, NRHS, DL, D, DU, DU2, IPIV, B,
 *     ..
 *     .. External Functions ..
       INTEGER            ILAENV
-      EXTERNAL           ILAENV
+      LOGICAL            LSAME
+      EXTERNAL           ILAENV, LSAME
 *     ..
 *     .. External Subroutines ..
       EXTERNAL           XERBLA, ZGTTS2
@@ -168,9 +169,9 @@ SUBROUTINE ZGTTRS( TRANS, N, NRHS, DL, D, DU, DU2, IPIV, B,
 *     .. Executable Statements ..
 *
       INFO = 0
-      NOTRAN = ( TRANS.EQ.'N' .OR. TRANS.EQ.'n' )
-      IF( .NOT.NOTRAN .AND. .NOT.( TRANS.EQ.'T' .OR. TRANS.EQ.
-     $    't' ) .AND. .NOT.( TRANS.EQ.'C' .OR. TRANS.EQ.'c' ) ) THEN
+      NOTRAN = LSAME( TRANS, 'N' )
+      IF( .NOT.NOTRAN .AND. .NOT.LSAME( TRANS, 'T' ) .AND.
+     $    .NOT.LSAME( TRANS, 'C' ) ) THEN
          INFO = -1
       ELSE IF( N.LT.0 ) THEN
          INFO = -2
@@ -193,7 +194,7 @@ SUBROUTINE ZGTTRS( TRANS, N, NRHS, DL, D, DU, DU2, IPIV, B,
 *
       IF( NOTRAN ) THEN
          ITRANS = 0
-      ELSE IF( TRANS.EQ.'T' .OR. TRANS.EQ.'t' ) THEN
+      ELSE IF( LSAME( TRANS, 'T' ) ) THEN
          ITRANS = 1
       ELSE
          ITRANS = 2