```      SUBROUTINE STRMM(SIDE,UPLO,TRANSA,DIAG,M,N,ALPHA,A,LDA,B,LDB)
*     .. Scalar Arguments ..
REAL ALPHA
INTEGER LDA,LDB,M,N
CHARACTER DIAG,SIDE,TRANSA,UPLO
*     ..
*     .. Array Arguments ..
REAL A(LDA,*),B(LDB,*)
*     ..
*
*  Purpose
*  =======
*
*  STRMM  performs one of the matrix-matrix operations
*
*     B := alpha*op( A )*B,   or   B := alpha*B*op( A ),
*
*  where  alpha  is a scalar,  B  is an m by n matrix,  A  is a unit, or
*  non-unit,  upper or lower triangular matrix  and  op( A )  is one  of
*
*     op( A ) = A   or   op( A ) = A'.
*
*  Arguments
*  ==========
*
*  SIDE   - CHARACTER*1.
*           On entry,  SIDE specifies whether  op( A ) multiplies B from
*           the left or right as follows:
*
*              SIDE = 'L' or 'l'   B := alpha*op( A )*B.
*
*              SIDE = 'R' or 'r'   B := alpha*B*op( A ).
*
*           Unchanged on exit.
*
*  UPLO   - CHARACTER*1.
*           On entry, UPLO specifies whether the matrix A is an upper or
*           lower triangular matrix as follows:
*
*              UPLO = 'U' or 'u'   A is an upper triangular matrix.
*
*              UPLO = 'L' or 'l'   A is a lower triangular matrix.
*
*           Unchanged on exit.
*
*  TRANSA - CHARACTER*1.
*           On entry, TRANSA specifies the form of op( A ) to be used in
*           the matrix multiplication as follows:
*
*              TRANSA = 'N' or 'n'   op( A ) = A.
*
*              TRANSA = 'T' or 't'   op( A ) = A'.
*
*              TRANSA = 'C' or 'c'   op( A ) = A'.
*
*           Unchanged on exit.
*
*  DIAG   - CHARACTER*1.
*           On entry, DIAG specifies whether or not A is unit triangular
*           as follows:
*
*              DIAG = 'U' or 'u'   A is assumed to be unit triangular.
*
*              DIAG = 'N' or 'n'   A is not assumed to be unit
*                                  triangular.
*
*           Unchanged on exit.
*
*  M      - INTEGER.
*           On entry, M specifies the number of rows of B. M must be at
*           least zero.
*           Unchanged on exit.
*
*  N      - INTEGER.
*           On entry, N specifies the number of columns of B.  N must be
*           at least zero.
*           Unchanged on exit.
*
*  ALPHA  - REAL            .
*           On entry,  ALPHA specifies the scalar  alpha. When  alpha is
*           zero then  A is not referenced and  B need not be set before
*           entry.
*           Unchanged on exit.
*
*  A      - REAL             array of DIMENSION ( LDA, k ), where k is m
*           when  SIDE = 'L' or 'l'  and is  n  when  SIDE = 'R' or 'r'.
*           Before entry  with  UPLO = 'U' or 'u',  the  leading  k by k
*           upper triangular part of the array  A must contain the upper
*           triangular matrix  and the strictly lower triangular part of
*           A is not referenced.
*           Before entry  with  UPLO = 'L' or 'l',  the  leading  k by k
*           lower triangular part of the array  A must contain the lower
*           triangular matrix  and the strictly upper triangular part of
*           A is not referenced.
*           Note that when  DIAG = 'U' or 'u',  the diagonal elements of
*           A  are not referenced either,  but are assumed to be  unity.
*           Unchanged on exit.
*
*  LDA    - INTEGER.
*           On entry, LDA specifies the first dimension of A as declared
*           in the calling (sub) program.  When  SIDE = 'L' or 'l'  then
*           LDA  must be at least  max( 1, m ),  when  SIDE = 'R' or 'r'
*           then LDA must be at least max( 1, n ).
*           Unchanged on exit.
*
*  B      - REAL             array of DIMENSION ( LDB, n ).
*           Before entry,  the leading  m by n part of the array  B must
*           contain the matrix  B,  and  on exit  is overwritten  by the
*           transformed matrix.
*
*  LDB    - INTEGER.
*           On entry, LDB specifies the first dimension of B as declared
*           in  the  calling  (sub)  program.   LDB  must  be  at  least
*           max( 1, m ).
*           Unchanged on exit.
*
*
*  Level 3 Blas routine.
*
*  -- Written on 8-February-1989.
*     Jack Dongarra, Argonne National Laboratory.
*     Iain Duff, AERE Harwell.
*     Jeremy Du Croz, Numerical Algorithms Group Ltd.
*     Sven Hammarling, Numerical Algorithms Group Ltd.
*
*
*     .. External Functions ..
LOGICAL LSAME
EXTERNAL LSAME
*     ..
*     .. External Subroutines ..
EXTERNAL XERBLA
*     ..
*     .. Intrinsic Functions ..
INTRINSIC MAX
*     ..
*     .. Local Scalars ..
REAL TEMP
INTEGER I,INFO,J,K,NROWA
LOGICAL LSIDE,NOUNIT,UPPER
*     ..
*     .. Parameters ..
REAL ONE,ZERO
PARAMETER (ONE=1.0E+0,ZERO=0.0E+0)
*     ..
*
*     Test the input parameters.
*
LSIDE = LSAME(SIDE,'L')
IF (LSIDE) THEN
NROWA = M
ELSE
NROWA = N
END IF
NOUNIT = LSAME(DIAG,'N')
UPPER = LSAME(UPLO,'U')
*
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('STRMM ',INFO)
RETURN
END IF
*
*     Quick return if possible.
*
IF (N.EQ.0) RETURN
*
*     And when  alpha.eq.zero.
*
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
*
*     Start the operations.
*
IF (LSIDE) THEN
IF (LSAME(TRANSA,'N')) THEN
*
*           Form  B := alpha*A*B.
*
IF (UPPER) THEN
DO 50 J = 1,N
DO 40 K = 1,M
IF (B(K,J).NE.ZERO) THEN
TEMP = ALPHA*B(K,J)
DO 30 I = 1,K - 1
B(I,J) = B(I,J) + TEMP*A(I,K)
30                         CONTINUE
IF (NOUNIT) TEMP = TEMP*A(K,K)
B(K,J) = TEMP
END IF
40                 CONTINUE
50             CONTINUE
ELSE
DO 80 J = 1,N
DO 70 K = M,1,-1
IF (B(K,J).NE.ZERO) THEN
TEMP = ALPHA*B(K,J)
B(K,J) = TEMP
IF (NOUNIT) B(K,J) = B(K,J)*A(K,K)
DO 60 I = K + 1,M
B(I,J) = B(I,J) + TEMP*A(I,K)
60                         CONTINUE
END IF
70                 CONTINUE
80             CONTINUE
END IF
ELSE
*
*           Form  B := alpha*A'*B.
*
IF (UPPER) THEN
DO 110 J = 1,N
DO 100 I = M,1,-1
TEMP = B(I,J)
IF (NOUNIT) TEMP = TEMP*A(I,I)
DO 90 K = 1,I - 1
TEMP = TEMP + A(K,I)*B(K,J)
90                     CONTINUE
B(I,J) = ALPHA*TEMP
100                 CONTINUE
110             CONTINUE
ELSE
DO 140 J = 1,N
DO 130 I = 1,M
TEMP = B(I,J)
IF (NOUNIT) TEMP = TEMP*A(I,I)
DO 120 K = I + 1,M
TEMP = TEMP + A(K,I)*B(K,J)
120                     CONTINUE
B(I,J) = ALPHA*TEMP
130                 CONTINUE
140             CONTINUE
END IF
END IF
ELSE
IF (LSAME(TRANSA,'N')) THEN
*
*           Form  B := alpha*B*A.
*
IF (UPPER) THEN
DO 180 J = N,1,-1
TEMP = ALPHA
IF (NOUNIT) TEMP = TEMP*A(J,J)
DO 150 I = 1,M
B(I,J) = TEMP*B(I,J)
150                 CONTINUE
DO 170 K = 1,J - 1
IF (A(K,J).NE.ZERO) THEN
TEMP = ALPHA*A(K,J)
DO 160 I = 1,M
B(I,J) = B(I,J) + TEMP*B(I,K)
160                         CONTINUE
END IF
170                 CONTINUE
180             CONTINUE
ELSE
DO 220 J = 1,N
TEMP = ALPHA
IF (NOUNIT) TEMP = TEMP*A(J,J)
DO 190 I = 1,M
B(I,J) = TEMP*B(I,J)
190                 CONTINUE
DO 210 K = J + 1,N
IF (A(K,J).NE.ZERO) THEN
TEMP = ALPHA*A(K,J)
DO 200 I = 1,M
B(I,J) = B(I,J) + TEMP*B(I,K)
200                         CONTINUE
END IF
210                 CONTINUE
220             CONTINUE
END IF
ELSE
*
*           Form  B := alpha*B*A'.
*
IF (UPPER) THEN
DO 260 K = 1,N
DO 240 J = 1,K - 1
IF (A(J,K).NE.ZERO) THEN
TEMP = ALPHA*A(J,K)
DO 230 I = 1,M
B(I,J) = B(I,J) + TEMP*B(I,K)
230                         CONTINUE
END IF
240                 CONTINUE
TEMP = ALPHA
IF (NOUNIT) TEMP = TEMP*A(K,K)
IF (TEMP.NE.ONE) THEN
DO 250 I = 1,M
B(I,K) = TEMP*B(I,K)
250                     CONTINUE
END IF
260             CONTINUE
ELSE
DO 300 K = N,1,-1
DO 280 J = K + 1,N
IF (A(J,K).NE.ZERO) THEN
TEMP = ALPHA*A(J,K)
DO 270 I = 1,M
B(I,J) = B(I,J) + TEMP*B(I,K)
270                         CONTINUE
END IF
280                 CONTINUE
TEMP = ALPHA
IF (NOUNIT) TEMP = TEMP*A(K,K)
IF (TEMP.NE.ONE) THEN
DO 290 I = 1,M
B(I,K) = TEMP*B(I,K)
290                     CONTINUE
END IF
300             CONTINUE
END IF
END IF
END IF
*
RETURN
*
*     End of STRMM .
*
END

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