Set SCALE early for robust triangular solvers

1) The docs define SCALE as an output argument. Set SCALE *before*
the quick return case to have SCALE defined in all cases. This is
how the similar routine TRSYL handles the case already.

2) Remove invocations of LABAD in complex routines and be consistent
with their real counterparts, which do not call LABAD.

SRC/clatbs.f

@@ -278,7 +278,7 @@ SUBROUTINE CLATBS( UPLO, TRANS, DIAG, NORMIN, N, KD, AB, LDAB, X,
      $                   CDOTU, CLADIV
 *     ..
 *     .. External Subroutines ..
-      EXTERNAL           CAXPY, CSSCAL, CTBSV, SLABAD, SSCAL, XERBLA
+      EXTERNAL           CAXPY, CSSCAL, CTBSV, SSCAL, XERBLA
 *     ..
 *     .. Intrinsic Functions ..
       INTRINSIC          ABS, AIMAG, CMPLX, CONJG, MAX, MIN, REAL
@@ -324,17 +324,14 @@ SUBROUTINE CLATBS( UPLO, TRANS, DIAG, NORMIN, N, KD, AB, LDAB, X,
 *
 *     Quick return if possible
 *
+      SCALE = ONE
       IF( N.EQ.0 )
      $   RETURN
 *
 *     Determine machine dependent parameters to control overflow.
 *
-      SMLNUM = SLAMCH( 'Safe minimum' )
-      BIGNUM = ONE / SMLNUM
-      CALL SLABAD( SMLNUM, BIGNUM )
-      SMLNUM = SMLNUM / SLAMCH( 'Precision' )
+      SMLNUM = SLAMCH( 'Safe minimum' ) / SLAMCH( 'Precision' )
       BIGNUM = ONE / SMLNUM
-      SCALE = ONE
 *
       IF( LSAME( NORMIN, 'N' ) ) THEN
 *

SRC/clatrs.f

@@ -274,7 +274,7 @@ SUBROUTINE CLATRS( UPLO, TRANS, DIAG, NORMIN, N, A, LDA, X, SCALE,
      $                   CDOTU, CLADIV
 *     ..
 *     .. External Subroutines ..
-      EXTERNAL           CAXPY, CSSCAL, CTRSV, SLABAD, SSCAL, XERBLA
+      EXTERNAL           CAXPY, CSSCAL, CTRSV, SSCAL, XERBLA
 *     ..
 *     .. Intrinsic Functions ..
       INTRINSIC          ABS, AIMAG, CMPLX, CONJG, MAX, MIN, REAL
@@ -318,17 +318,14 @@ SUBROUTINE CLATRS( UPLO, TRANS, DIAG, NORMIN, N, A, LDA, X, SCALE,
 *
 *     Quick return if possible
 *
+      SCALE = ONE
       IF( N.EQ.0 )
      $   RETURN
 *
 *     Determine machine dependent parameters to control overflow.
 *
-      SMLNUM = SLAMCH( 'Safe minimum' )
-      BIGNUM = ONE / SMLNUM
-      CALL SLABAD( SMLNUM, BIGNUM )
-      SMLNUM = SMLNUM / SLAMCH( 'Precision' )
+      SMLNUM = SLAMCH( 'Safe minimum' ) / SLAMCH( 'Precision' )
       BIGNUM = ONE / SMLNUM
-      SCALE = ONE
 *
       IF( LSAME( NORMIN, 'N' ) ) THEN
 *

SRC/dlatbs.f

@@ -310,14 +310,14 @@ SUBROUTINE DLATBS( UPLO, TRANS, DIAG, NORMIN, N, KD, AB, LDAB, X,
 *
 *     Quick return if possible
 *
+      SCALE = ONE
       IF( N.EQ.0 )
      $   RETURN
 *
 *     Determine machine dependent parameters to control overflow.
 *
       SMLNUM = DLAMCH( 'Safe minimum' ) / DLAMCH( 'Precision' )
       BIGNUM = ONE / SMLNUM
-      SCALE = ONE
 *
       IF( LSAME( NORMIN, 'N' ) ) THEN
 *

SRC/dlatrs.f

@@ -304,14 +304,14 @@ SUBROUTINE DLATRS( UPLO, TRANS, DIAG, NORMIN, N, A, LDA, X, SCALE,
 *
 *     Quick return if possible
 *
+      SCALE = ONE
       IF( N.EQ.0 )
      $   RETURN
 *
 *     Determine machine dependent parameters to control overflow.
 *
       SMLNUM = DLAMCH( 'Safe minimum' ) / DLAMCH( 'Precision' )
       BIGNUM = ONE / SMLNUM
-      SCALE = ONE
 *
       IF( LSAME( NORMIN, 'N' ) ) THEN
 *

SRC/slatbs.f

@@ -310,14 +310,14 @@ SUBROUTINE SLATBS( UPLO, TRANS, DIAG, NORMIN, N, KD, AB, LDAB, X,
 *
 *     Quick return if possible
 *
+      SCALE = ONE
       IF( N.EQ.0 )
      $   RETURN
 *
 *     Determine machine dependent parameters to control overflow.
 *
       SMLNUM = SLAMCH( 'Safe minimum' ) / SLAMCH( 'Precision' )
       BIGNUM = ONE / SMLNUM
-      SCALE = ONE
 *
       IF( LSAME( NORMIN, 'N' ) ) THEN
 *

SRC/slatrs.f

@@ -304,14 +304,14 @@ SUBROUTINE SLATRS( UPLO, TRANS, DIAG, NORMIN, N, A, LDA, X, SCALE,
 *
 *     Quick return if possible
 *
+      SCALE = ONE
       IF( N.EQ.0 )
      $   RETURN
 *
 *     Determine machine dependent parameters to control overflow.
 *
       SMLNUM = SLAMCH( 'Safe minimum' ) / SLAMCH( 'Precision' )
       BIGNUM = ONE / SMLNUM
-      SCALE = ONE
 *
       IF( LSAME( NORMIN, 'N' ) ) THEN
 *

SRC/zlatbs.f

@@ -278,7 +278,7 @@ SUBROUTINE ZLATBS( UPLO, TRANS, DIAG, NORMIN, N, KD, AB, LDAB, X,
      $                   ZDOTU, ZLADIV
 *     ..
 *     .. External Subroutines ..
-      EXTERNAL           DSCAL, XERBLA, ZAXPY, ZDSCAL, ZTBSV, DLABAD
+      EXTERNAL           DSCAL, XERBLA, ZAXPY, ZDSCAL, ZTBSV
 *     ..
 *     .. Intrinsic Functions ..
       INTRINSIC          ABS, DBLE, DCMPLX, DCONJG, DIMAG, MAX, MIN
@@ -324,17 +324,14 @@ SUBROUTINE ZLATBS( UPLO, TRANS, DIAG, NORMIN, N, KD, AB, LDAB, X,
 *
 *     Quick return if possible
 *
+      SCALE = ONE
       IF( N.EQ.0 )
      $   RETURN
 *
 *     Determine machine dependent parameters to control overflow.
 *
-      SMLNUM = DLAMCH( 'Safe minimum' )
-      BIGNUM = ONE / SMLNUM
-      CALL DLABAD( SMLNUM, BIGNUM )
-      SMLNUM = SMLNUM / DLAMCH( 'Precision' )
+      SMLNUM = DLAMCH( 'Safe minimum' ) / DLAMCH( 'Precision' )
       BIGNUM = ONE / SMLNUM
-      SCALE = ONE
 *
       IF( LSAME( NORMIN, 'N' ) ) THEN
 *

SRC/zlatrs.f

@@ -274,7 +274,7 @@ SUBROUTINE ZLATRS( UPLO, TRANS, DIAG, NORMIN, N, A, LDA, X, SCALE,
      $                   ZDOTU, ZLADIV
 *     ..
 *     .. External Subroutines ..
-      EXTERNAL           DSCAL, XERBLA, ZAXPY, ZDSCAL, ZTRSV, DLABAD
+      EXTERNAL           DSCAL, XERBLA, ZAXPY, ZDSCAL, ZTRSV
 *     ..
 *     .. Intrinsic Functions ..
       INTRINSIC          ABS, DBLE, DCMPLX, DCONJG, DIMAG, MAX, MIN
@@ -318,17 +318,14 @@ SUBROUTINE ZLATRS( UPLO, TRANS, DIAG, NORMIN, N, A, LDA, X, SCALE,
 *
 *     Quick return if possible
 *
+      SCALE = ONE
       IF( N.EQ.0 )
      $   RETURN
 *
 *     Determine machine dependent parameters to control overflow.
 *
-      SMLNUM = DLAMCH( 'Safe minimum' )
-      BIGNUM = ONE / SMLNUM
-      CALL DLABAD( SMLNUM, BIGNUM )
-      SMLNUM = SMLNUM / DLAMCH( 'Precision' )
+      SMLNUM = DLAMCH( 'Safe minimum' ) / DLAMCH( 'Precision' )
       BIGNUM = ONE / SMLNUM
-      SCALE = ONE
 *
       IF( LSAME( NORMIN, 'N' ) ) THEN
 *