#include "blaswrap.h"
/*  -- translated by f2c (version 19990503).
   You must link the resulting object file with the libraries:
	-lf2c -lm   (in that order)
*/

#include "f2c.h"

/* Table of constant values */

static real c_b15 = 1.f;
static integer c__1 = 1;

/* Subroutine */ int slavsy_(char *uplo, char *trans, char *diag, integer *n, 
	integer *nrhs, real *a, integer *lda, integer *ipiv, real *b, integer 
	*ldb, integer *info)
{
    /* System generated locals */
    integer a_dim1, a_offset, b_dim1, b_offset, i__1;

    /* Local variables */
    extern /* Subroutine */ int sger_(integer *, integer *, real *, real *, 
	    integer *, real *, integer *, real *, integer *);
    static integer j, k;
    extern logical lsame_(char *, char *);
    extern /* Subroutine */ int sscal_(integer *, real *, real *, integer *), 
	    sgemv_(char *, integer *, integer *, real *, real *, integer *, 
	    real *, integer *, real *, real *, integer *), sswap_(
	    integer *, real *, integer *, real *, integer *);
    static real t1, t2, d11, d12, d21, d22;
    static integer kp;
    extern /* Subroutine */ int xerbla_(char *, integer *);
    static logical nounit;


#define a_ref(a_1,a_2) a[(a_2)*a_dim1 + a_1]
#define b_ref(a_1,a_2) b[(a_2)*b_dim1 + a_1]


/*  -- LAPACK auxiliary routine (version 3.0) --   
       Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd.,   
       Courant Institute, Argonne National Lab, and Rice University   
       February 29, 1992   


    Purpose   
    =======   

    SLAVSY  performs one of the matrix-vector operations   
       x := A*x  or  x := A'*x,   
    where x is an N element vector and A is one of the factors   
    from the block U*D*U' or L*D*L' factorization computed by SSYTRF.   

    If TRANS = 'N', multiplies by U  or U * D  (or L  or L * D)   
    If TRANS = 'T', multiplies by U' or D * U' (or L' or D * L')   
    If TRANS = 'C', multiplies by U' or D * U' (or L' or D * L')   

    Arguments   
    =========   

    UPLO    (input) CHARACTER*1   
            Specifies whether the factor stored in A is upper or lower   
            triangular.   
            = 'U':  Upper triangular   
            = 'L':  Lower triangular   

    TRANS   (input) CHARACTER*1   
            Specifies the operation to be performed:   
            = 'N':  x := A*x   
            = 'T':  x := A'*x   
            = 'C':  x := A'*x   

    DIAG    (input) CHARACTER*1   
            Specifies whether or not the diagonal blocks are unit   
            matrices.  If the diagonal blocks are assumed to be unit,   
            then A = U or A = L, otherwise A = U*D or A = L*D.   
            = 'U':  Diagonal blocks are assumed to be unit matrices.   
            = 'N':  Diagonal blocks are assumed to be non-unit matrices.   

    N       (input) INTEGER   
            The number of rows and columns of the matrix A.  N >= 0.   

    NRHS    (input) INTEGER   
            The number of right hand sides, i.e., the number of vectors   
            x to be multiplied by A.  NRHS >= 0.   

    A       (input) REAL array, dimension (LDA,N)   
            The block diagonal matrix D and the multipliers used to   
            obtain the factor U or L as computed by SSYTRF.   

    LDA     (input) INTEGER   
            The leading dimension of the array A.  LDA >= max(1,N).   

    IPIV    (input) INTEGER array, dimension (N)   
            The pivot indices from SSYTRF.   

    B       (input/output) REAL array, dimension (LDB,NRHS)   
            On entry, B contains NRHS vectors of length N.   
            On exit, B is overwritten with the product A * B.   

    LDB     (input) INTEGER   
            The leading dimension of the array B.  LDB >= max(1,N).   

    INFO    (output) INTEGER   
            = 0: successful exit   
            < 0: if INFO = -k, the k-th argument had an illegal value   

    =====================================================================   


       Test the input parameters.   

       Parameter adjustments */
    a_dim1 = *lda;
    a_offset = 1 + a_dim1 * 1;
    a -= a_offset;
    --ipiv;
    b_dim1 = *ldb;
    b_offset = 1 + b_dim1 * 1;
    b -= b_offset;

    /* Function Body */
    *info = 0;
    if (! lsame_(uplo, "U") && ! lsame_(uplo, "L")) {
	*info = -1;
    } else if (! lsame_(trans, "N") && ! lsame_(trans, 
	    "T") && ! lsame_(trans, "C")) {
	*info = -2;
    } else if (! lsame_(diag, "U") && ! lsame_(diag, 
	    "N")) {
	*info = -3;
    } else if (*n < 0) {
	*info = -4;
    } else if (*lda < max(1,*n)) {
	*info = -6;
    } else if (*ldb < max(1,*n)) {
	*info = -9;
    }
    if (*info != 0) {
	i__1 = -(*info);
	xerbla_("SLAVSY ", &i__1);
	return 0;
    }

/*     Quick return if possible. */

    if (*n == 0) {
	return 0;
    }

    nounit = lsame_(diag, "N");
/* ------------------------------------------   

       Compute  B := A * B  (No transpose)   

   ------------------------------------------ */
    if (lsame_(trans, "N")) {

/*        Compute  B := U*B   
          where U = P(m)*inv(U(m))* ... *P(1)*inv(U(1)) */

	if (lsame_(uplo, "U")) {

/*        Loop forward applying the transformations. */

	    k = 1;
L10:
	    if (k > *n) {
		goto L30;
	    }
	    if (ipiv[k] > 0) {

/*              1 x 1 pivot block   

                Multiply by the diagonal element if forming U * D. */

		if (nounit) {
		    sscal_(nrhs, &a_ref(k, k), &b_ref(k, 1), ldb);
		}

/*              Multiply by  P(K) * inv(U(K))  if K > 1. */

		if (k > 1) {

/*                 Apply the transformation. */

		    i__1 = k - 1;
		    sger_(&i__1, nrhs, &c_b15, &a_ref(1, k), &c__1, &b_ref(k, 
			    1), ldb, &b_ref(1, 1), ldb);

/*                 Interchange if P(K) .ne. I. */

		    kp = ipiv[k];
		    if (kp != k) {
			sswap_(nrhs, &b_ref(k, 1), ldb, &b_ref(kp, 1), ldb);
		    }
		}
		++k;
	    } else {

/*              2 x 2 pivot block   

                Multiply by the diagonal block if forming U * D. */

		if (nounit) {
		    d11 = a_ref(k, k);
		    d22 = a_ref(k + 1, k + 1);
		    d12 = a_ref(k, k + 1);
		    d21 = d12;
		    i__1 = *nrhs;
		    for (j = 1; j <= i__1; ++j) {
			t1 = b_ref(k, j);
			t2 = b_ref(k + 1, j);
			b_ref(k, j) = d11 * t1 + d12 * t2;
			b_ref(k + 1, j) = d21 * t1 + d22 * t2;
/* L20: */
		    }
		}

/*              Multiply by  P(K) * inv(U(K))  if K > 1. */

		if (k > 1) {

/*                 Apply the transformations. */

		    i__1 = k - 1;
		    sger_(&i__1, nrhs, &c_b15, &a_ref(1, k), &c__1, &b_ref(k, 
			    1), ldb, &b_ref(1, 1), ldb);
		    i__1 = k - 1;
		    sger_(&i__1, nrhs, &c_b15, &a_ref(1, k + 1), &c__1, &
			    b_ref(k + 1, 1), ldb, &b_ref(1, 1), ldb);

/*                 Interchange if P(K) .ne. I. */

		    kp = (i__1 = ipiv[k], abs(i__1));
		    if (kp != k) {
			sswap_(nrhs, &b_ref(k, 1), ldb, &b_ref(kp, 1), ldb);
		    }
		}
		k += 2;
	    }
	    goto L10;
L30:

/*        Compute  B := L*B   
          where L = P(1)*inv(L(1))* ... *P(m)*inv(L(m)) . */

	    ;
	} else {

/*           Loop backward applying the transformations to B. */

	    k = *n;
L40:
	    if (k < 1) {
		goto L60;
	    }

/*           Test the pivot index.  If greater than zero, a 1 x 1   
             pivot was used, otherwise a 2 x 2 pivot was used. */

	    if (ipiv[k] > 0) {

/*              1 x 1 pivot block:   

                Multiply by the diagonal element if forming L * D. */

		if (nounit) {
		    sscal_(nrhs, &a_ref(k, k), &b_ref(k, 1), ldb);
		}

/*              Multiply by  P(K) * inv(L(K))  if K < N. */

		if (k != *n) {
		    kp = ipiv[k];

/*                 Apply the transformation. */

		    i__1 = *n - k;
		    sger_(&i__1, nrhs, &c_b15, &a_ref(k + 1, k), &c__1, &
			    b_ref(k, 1), ldb, &b_ref(k + 1, 1), ldb);

/*                 Interchange if a permutation was applied at the   
                   K-th step of the factorization. */

		    if (kp != k) {
			sswap_(nrhs, &b_ref(k, 1), ldb, &b_ref(kp, 1), ldb);
		    }
		}
		--k;

	    } else {

/*              2 x 2 pivot block:   

                Multiply by the diagonal block if forming L * D. */

		if (nounit) {
		    d11 = a_ref(k - 1, k - 1);
		    d22 = a_ref(k, k);
		    d21 = a_ref(k, k - 1);
		    d12 = d21;
		    i__1 = *nrhs;
		    for (j = 1; j <= i__1; ++j) {
			t1 = b_ref(k - 1, j);
			t2 = b_ref(k, j);
			b_ref(k - 1, j) = d11 * t1 + d12 * t2;
			b_ref(k, j) = d21 * t1 + d22 * t2;
/* L50: */
		    }
		}

/*              Multiply by  P(K) * inv(L(K))  if K < N. */

		if (k != *n) {

/*                 Apply the transformation. */

		    i__1 = *n - k;
		    sger_(&i__1, nrhs, &c_b15, &a_ref(k + 1, k), &c__1, &
			    b_ref(k, 1), ldb, &b_ref(k + 1, 1), ldb);
		    i__1 = *n - k;
		    sger_(&i__1, nrhs, &c_b15, &a_ref(k + 1, k - 1), &c__1, &
			    b_ref(k - 1, 1), ldb, &b_ref(k + 1, 1), ldb);

/*                 Interchange if a permutation was applied at the   
                   K-th step of the factorization. */

		    kp = (i__1 = ipiv[k], abs(i__1));
		    if (kp != k) {
			sswap_(nrhs, &b_ref(k, 1), ldb, &b_ref(kp, 1), ldb);
		    }
		}
		k += -2;
	    }
	    goto L40;
L60:
	    ;
	}
/* ----------------------------------------   

       Compute  B := A' * B  (transpose)   

   ---------------------------------------- */
    } else {

/*        Form  B := U'*B   
          where U  = P(m)*inv(U(m))* ... *P(1)*inv(U(1))   
          and   U' = inv(U'(1))*P(1)* ... *inv(U'(m))*P(m) */

	if (lsame_(uplo, "U")) {

/*           Loop backward applying the transformations. */

	    k = *n;
L70:
	    if (k < 1) {
		goto L90;
	    }

/*           1 x 1 pivot block. */

	    if (ipiv[k] > 0) {
		if (k > 1) {

/*                 Interchange if P(K) .ne. I. */

		    kp = ipiv[k];
		    if (kp != k) {
			sswap_(nrhs, &b_ref(k, 1), ldb, &b_ref(kp, 1), ldb);
		    }

/*                 Apply the transformation */

		    i__1 = k - 1;
		    sgemv_("Transpose", &i__1, nrhs, &c_b15, &b[b_offset], 
			    ldb, &a_ref(1, k), &c__1, &c_b15, &b_ref(k, 1), 
			    ldb);
		}
		if (nounit) {
		    sscal_(nrhs, &a_ref(k, k), &b_ref(k, 1), ldb);
		}
		--k;

/*           2 x 2 pivot block. */

	    } else {
		if (k > 2) {

/*                 Interchange if P(K) .ne. I. */

		    kp = (i__1 = ipiv[k], abs(i__1));
		    if (kp != k - 1) {
			sswap_(nrhs, &b_ref(k - 1, 1), ldb, &b_ref(kp, 1), 
				ldb);
		    }

/*                 Apply the transformations */

		    i__1 = k - 2;
		    sgemv_("Transpose", &i__1, nrhs, &c_b15, &b[b_offset], 
			    ldb, &a_ref(1, k), &c__1, &c_b15, &b_ref(k, 1), 
			    ldb);
		    i__1 = k - 2;
		    sgemv_("Transpose", &i__1, nrhs, &c_b15, &b[b_offset], 
			    ldb, &a_ref(1, k - 1), &c__1, &c_b15, &b_ref(k - 
			    1, 1), ldb);
		}

/*              Multiply by the diagonal block if non-unit. */

		if (nounit) {
		    d11 = a_ref(k - 1, k - 1);
		    d22 = a_ref(k, k);
		    d12 = a_ref(k - 1, k);
		    d21 = d12;
		    i__1 = *nrhs;
		    for (j = 1; j <= i__1; ++j) {
			t1 = b_ref(k - 1, j);
			t2 = b_ref(k, j);
			b_ref(k - 1, j) = d11 * t1 + d12 * t2;
			b_ref(k, j) = d21 * t1 + d22 * t2;
/* L80: */
		    }
		}
		k += -2;
	    }
	    goto L70;
L90:

/*        Form  B := L'*B   
          where L  = P(1)*inv(L(1))* ... *P(m)*inv(L(m))   
          and   L' = inv(L'(m))*P(m)* ... *inv(L'(1))*P(1) */

	    ;
	} else {

/*           Loop forward applying the L-transformations. */

	    k = 1;
L100:
	    if (k > *n) {
		goto L120;
	    }

/*           1 x 1 pivot block */

	    if (ipiv[k] > 0) {
		if (k < *n) {

/*                 Interchange if P(K) .ne. I. */

		    kp = ipiv[k];
		    if (kp != k) {
			sswap_(nrhs, &b_ref(k, 1), ldb, &b_ref(kp, 1), ldb);
		    }

/*                 Apply the transformation */

		    i__1 = *n - k;
		    sgemv_("Transpose", &i__1, nrhs, &c_b15, &b_ref(k + 1, 1),
			     ldb, &a_ref(k + 1, k), &c__1, &c_b15, &b_ref(k, 
			    1), ldb);
		}
		if (nounit) {
		    sscal_(nrhs, &a_ref(k, k), &b_ref(k, 1), ldb);
		}
		++k;

/*           2 x 2 pivot block. */

	    } else {
		if (k < *n - 1) {

/*              Interchange if P(K) .ne. I. */

		    kp = (i__1 = ipiv[k], abs(i__1));
		    if (kp != k + 1) {
			sswap_(nrhs, &b_ref(k + 1, 1), ldb, &b_ref(kp, 1), 
				ldb);
		    }

/*                 Apply the transformation */

		    i__1 = *n - k - 1;
		    sgemv_("Transpose", &i__1, nrhs, &c_b15, &b_ref(k + 2, 1),
			     ldb, &a_ref(k + 2, k + 1), &c__1, &c_b15, &b_ref(
			    k + 1, 1), ldb);
		    i__1 = *n - k - 1;
		    sgemv_("Transpose", &i__1, nrhs, &c_b15, &b_ref(k + 2, 1),
			     ldb, &a_ref(k + 2, k), &c__1, &c_b15, &b_ref(k, 
			    1), ldb);
		}

/*              Multiply by the diagonal block if non-unit. */

		if (nounit) {
		    d11 = a_ref(k, k);
		    d22 = a_ref(k + 1, k + 1);
		    d21 = a_ref(k + 1, k);
		    d12 = d21;
		    i__1 = *nrhs;
		    for (j = 1; j <= i__1; ++j) {
			t1 = b_ref(k, j);
			t2 = b_ref(k + 1, j);
			b_ref(k, j) = d11 * t1 + d12 * t2;
			b_ref(k + 1, j) = d21 * t1 + d22 * t2;
/* L110: */
		    }
		}
		k += 2;
	    }
	    goto L100;
L120:
	    ;
	}

    }
    return 0;

/*     End of SLAVSY */

} /* slavsy_ */

#undef b_ref
#undef a_ref



.