SUBROUTINE CTRSM (SIDE, UPLO, TRANSA, DIAG, M, N, ALPHA, A, LDA,
     $   B, LDB)
C     .. Scalar Arguments ..
      CHARACTER*1        SIDE, UPLO, TRANSA, DIAG
      INTEGER            M, N, LDA, LDB
      COMPLEX            ALPHA
C     .. Array Arguments ..
      COMPLEX            A( LDA, * ), B( LDB, * )
C     .. External Functions ..
      LOGICAL            LSAME
      EXTERNAL           LSAME
C     .. External Subroutines ..
      EXTERNAL           XERBLA
C     .. Intrinsic Functions ..
      INTRINSIC          CONJG, MAX
C     .. Local Scalars ..
      LOGICAL            LSIDE, NOCONJ, NOUNIT, UPPER
      INTEGER            I, INFO, J, K, NROWA
      COMPLEX            TEMP
C     .. Parameters ..
      COMPLEX            ONE
      PARAMETER        ( ONE  = ( 1.0E+0, 0.0E+0 ) )
      COMPLEX            ZERO
      PARAMETER        ( ZERO = ( 0.0E+0, 0.0E+0 ) )
C***FIRST EXECUTABLE STATEMENT  CTRSM
C
C     Test the input parameters.
C
      LSIDE  = LSAME( SIDE  , 'L' )
      IF( LSIDE )THEN
         NROWA = M
      ELSE
         NROWA = N
      END IF
      NOCONJ = LSAME( TRANSA, 'T' )
      NOUNIT = LSAME( DIAG  , 'N' )
      UPPER  = LSAME( UPLO  , 'U' )
C
      INFO   = 0
      IF(      ( .NOT.LSIDE                ).AND.
     $         ( .NOT.LSAME( SIDE  , 'R' ) )      )THEN
         INFO = 1
      ELSE IF( ( .NOT.UPPER                ).AND.
     $         ( .NOT.LSAME( UPLO  , 'L' ) )      )THEN
         INFO = 2
      ELSE IF( ( .NOT.LSAME( TRANSA, 'N' ) ).AND.
     $         ( .NOT.LSAME( TRANSA, 'T' ) ).AND.
     $         ( .NOT.LSAME( TRANSA, 'C' ) )      )THEN
         INFO = 3
      ELSE IF( ( .NOT.LSAME( DIAG  , 'U' ) ).AND.
     $         ( .NOT.LSAME( DIAG  , 'N' ) )      )THEN
         INFO = 4
      ELSE IF( M  .LT.0               )THEN
         INFO = 5
      ELSE IF( N  .LT.0               )THEN
         INFO = 6
      ELSE IF( LDA.LT.MAX( 1, NROWA ) )THEN
         INFO = 9
      ELSE IF( LDB.LT.MAX( 1, M     ) )THEN
         INFO = 11
      END IF
      IF( INFO.NE.0 )THEN
         CALL XERBLA( 'CTRSM ', INFO )
         RETURN
      END IF
C
C     Quick return if possible.
C
      IF( N.EQ.0 )
     $   RETURN
C
C     And when  alpha.eq.zero.
C
      IF( ALPHA.EQ.ZERO )THEN
         DO 20, J = 1, N
            DO 10, I = 1, M
               B( I, J ) = ZERO
   10       CONTINUE
   20    CONTINUE
         RETURN
      END IF
C
C     Start the operations.
C
      IF( LSIDE )THEN
         IF( LSAME( TRANSA, 'N' ) )THEN
C
C           Form  B := alpha*inv( A )*B.
C
            IF( UPPER )THEN
               DO 60, J = 1, N
                  IF( ALPHA.NE.ONE )THEN
                     DO 30, I = 1, M
                        B( I, J ) = ALPHA*B( I, J )
   30                CONTINUE
                  END IF
                  DO 50, K = M, 1, -1
                     IF( B( K, J ).NE.ZERO )THEN
                        IF( NOUNIT )
     $                     B( K, J ) = B( K, J )/A( K, K )
                        DO 40, I = 1, K - 1
                           B( I, J ) = B( I, J ) - B( K, J )*A( I, K )
   40                   CONTINUE
                     END IF
   50             CONTINUE
   60          CONTINUE
            ELSE
               DO 100, J = 1, N
                  IF( ALPHA.NE.ONE )THEN
                     DO 70, I = 1, M
                        B( I, J ) = ALPHA*B( I, J )
   70                CONTINUE
                  END IF
                  DO 90 K = 1, M
                     IF( B( K, J ).NE.ZERO )THEN
                        IF( NOUNIT )
     $                     B( K, J ) = B( K, J )/A( K, K )
                        DO 80, I = K + 1, M
                           B( I, J ) = B( I, J ) - B( K, J )*A( I, K )
   80                   CONTINUE
                     END IF
   90             CONTINUE
  100          CONTINUE
            END IF
         ELSE
C
C           Form  B := alpha*inv( A' )*B
C           or    B := alpha*inv( conjg( A' ) )*B.
C
            IF( UPPER )THEN
               DO 140, J = 1, N
                  DO 130, I = 1, M
                     TEMP = ALPHA*B( I, J )
                     IF( NOCONJ )THEN
                        DO 110, K = 1, I - 1
                           TEMP = TEMP - A( K, I )*B( K, J )
  110                   CONTINUE
                        IF( NOUNIT )
     $                     TEMP = TEMP/A( I, I )
                     ELSE
                        DO 120, K = 1, I - 1
                           TEMP = TEMP - CONJG( A( K, I ) )*B( K, J )
  120                   CONTINUE
                        IF( NOUNIT )
     $                     TEMP = TEMP/CONJG( A( I, I ) )
                     END IF
                     B( I, J ) = TEMP
  130             CONTINUE
  140          CONTINUE
            ELSE
               DO 180, J = 1, N
                  DO 170, I = M, 1, -1
                     TEMP = ALPHA*B( I, J )
                     IF( NOCONJ )THEN
                        DO 150, K = I + 1, M
                           TEMP = TEMP - A( K, I )*B( K, J )
  150                   CONTINUE
                        IF( NOUNIT )
     $                     TEMP = TEMP/A( I, I )
                     ELSE
                        DO 160, K = I + 1, M
                           TEMP = TEMP - CONJG( A( K, I ) )*B( K, J )
  160                   CONTINUE
                        IF( NOUNIT )
     $                     TEMP = TEMP/CONJG( A( I, I ) )
                     END IF
                     B( I, J ) = TEMP
  170             CONTINUE
  180          CONTINUE
            END IF
         END IF
      ELSE
         IF( LSAME( TRANSA, 'N' ) )THEN
C
C           Form  B := alpha*B*inv( A ).
C
            IF( UPPER )THEN
               DO 230, J = 1, N
                  IF( ALPHA.NE.ONE )THEN
                     DO 190, I = 1, M
                        B( I, J ) = ALPHA*B( I, J )
  190                CONTINUE
                  END IF
                  DO 210, K = 1, J - 1
                     IF( A( K, J ).NE.ZERO )THEN
                        DO 200, I = 1, M
                           B( I, J ) = B( I, J ) - A( K, J )*B( I, K )
  200                   CONTINUE
                     END IF
  210             CONTINUE
                  IF( NOUNIT )THEN
                     TEMP = ONE/A( J, J )
                     DO 220, I = 1, M
                        B( I, J ) = TEMP*B( I, J )
  220                CONTINUE
                  END IF
  230          CONTINUE
            ELSE
               DO 280, J = N, 1, -1
                  IF( ALPHA.NE.ONE )THEN
                     DO 240, I = 1, M
                        B( I, J ) = ALPHA*B( I, J )
  240                CONTINUE
                  END IF
                  DO 260, K = J + 1, N
                     IF( A( K, J ).NE.ZERO )THEN
                        DO 250, I = 1, M
                           B( I, J ) = B( I, J ) - A( K, J )*B( I, K )
  250                   CONTINUE
                     END IF
  260             CONTINUE
                  IF( NOUNIT )THEN
                     TEMP = ONE/A( J, J )
                     DO 270, I = 1, M
                       B( I, J ) = TEMP*B( I, J )
  270                CONTINUE
                  END IF
  280          CONTINUE
            END IF
         ELSE
C
C           Form  B := alpha*B*inv( A' )
C           or    B := alpha*B*inv( conjg( A' ) ).
C
            IF( UPPER )THEN
               DO 330, K = N, 1, -1
                  IF( NOUNIT )THEN
                     IF( NOCONJ )THEN
                        TEMP = ONE/A( K, K )
                     ELSE
                        TEMP = ONE/CONJG( A( K, K ) )
                     END IF
                     DO 290, I = 1, M
                        B( I, K ) = TEMP*B( I, K )
  290                CONTINUE
                  END IF
                  DO 310, J = 1, K - 1
                     IF( A( J, K ).NE.ZERO )THEN
                        IF( NOCONJ )THEN
                           TEMP = A( J, K )
                        ELSE
                           TEMP = CONJG( A( J, K ) )
                        END IF
                        DO 300, I = 1, M
                           B( I, J ) = B( I, J ) - TEMP*B( I, K )
  300                   CONTINUE
                     END IF
  310             CONTINUE
                  IF( ALPHA.NE.ONE )THEN
                     DO 320, I = 1, M
                        B( I, K ) = ALPHA*B( I, K )
  320                CONTINUE
                  END IF
  330          CONTINUE
            ELSE
               DO 380, K = 1, N
                  IF( NOUNIT )THEN
                     IF( NOCONJ )THEN
                        TEMP = ONE/A( K, K )
                     ELSE
                        TEMP = ONE/CONJG( A( K, K ) )
                     END IF
                     DO 340, I = 1, M
                        B( I, K ) = TEMP*B( I, K )
  340                CONTINUE
                  END IF
                  DO 360, J = K + 1, N
                     IF( A( J, K ).NE.ZERO )THEN
                        IF( NOCONJ )THEN
                           TEMP = A( J, K )
                        ELSE
                           TEMP = CONJG( A( J, K ) )
                        END IF
                        DO 350, I = 1, M
                           B( I, J ) = B( I, J ) - TEMP*B( I, K )
  350                   CONTINUE
                     END IF
  360             CONTINUE
                  IF( ALPHA.NE.ONE )THEN
                     DO 370, I = 1, M
                        B( I, K ) = ALPHA*B( I, K )
  370                CONTINUE
                  END IF
  380          CONTINUE
            END IF
         END IF
      END IF
C
      RETURN
C
C     End of CTRSM .
C
      END