text: /* ssyr2k.f -- translated by f2c (version 20061008).
     You must link the resulting object file with libf2c:
  	on Microsoft Windows system, link with libf2c.lib;
  	on Linux or Unix systems, link with .../path/to/libf2c.a -lm
  	or, if you install libf2c.a in a standard place, with -lf2c -lm
  	-- in that order, at the end of the command line, as in
  		cc *.o -lf2c -lm
  	Source for libf2c is in /netlib/f2c/libf2c.zip, e.g.,
  
  		http://www.netlib.org/f2c/libf2c.zip
  */
  
  #include "f2c.h"
  ////#include "blaswrap.h"
  
  /* Subroutine */ int ssyr2k_(char *uplo, char *trans, integer *n, integer *k, 
  	real *alpha, real *a, integer *lda, real *b, integer *ldb, real *beta, 
  	 real *c__, integer *ldc)
  {
      /* System generated locals */
      integer a_dim1, a_offset, b_dim1, b_offset, c_dim1, c_offset, i__1, i__2, 
  	    i__3;
  
      /* Local variables */
      integer i__, j, l, info;
      real temp1, temp2;
      extern logical lsame_(char *, char *);
      integer nrowa;
      logical upper;
      extern /* Subroutine */ int xerbla_(char *, integer *);
  
  /*     .. Scalar Arguments .. */
  /*     .. */
  /*     .. Array Arguments .. */
  /*     .. */
  
  /*  Purpose */
  /*  ======= */
  
  /*  SSYR2K  performs one of the symmetric rank 2k operations */
  
  /*     C := alpha*A*B' + alpha*B*A' + beta*C, */
  
  /*  or */
  
  /*     C := alpha*A'*B + alpha*B'*A + beta*C, */
  
  /*  where  alpha and beta  are scalars, C is an  n by n  symmetric matrix */
  /*  and  A and B  are  n by k  matrices  in the  first  case  and  k by n */
  /*  matrices in the second case. */
  
  /*  Arguments */
  /*  ========== */
  
  /*  UPLO   - CHARACTER*1. */
  /*           On  entry,   UPLO  specifies  whether  the  upper  or  lower */
  /*           triangular  part  of the  array  C  is to be  referenced  as */
  /*           follows: */
  
  /*              UPLO = 'U' or 'u'   Only the  upper triangular part of  C */
  /*                                  is to be referenced. */
  
  /*              UPLO = 'L' or 'l'   Only the  lower triangular part of  C */
  /*                                  is to be referenced. */
  
  /*           Unchanged on exit. */
  
  /*  TRANS  - CHARACTER*1. */
  /*           On entry,  TRANS  specifies the operation to be performed as */
  /*           follows: */
  
  /*              TRANS = 'N' or 'n'   C := alpha*A*B' + alpha*B*A' + */
  /*                                        beta*C. */
  
  /*              TRANS = 'T' or 't'   C := alpha*A'*B + alpha*B'*A + */
  /*                                        beta*C. */
  
  /*              TRANS = 'C' or 'c'   C := alpha*A'*B + alpha*B'*A + */
  /*                                        beta*C. */
  
  /*           Unchanged on exit. */
  
  /*  N      - INTEGER. */
  /*           On entry,  N specifies the order of the matrix C.  N must be */
  /*           at least zero. */
  /*           Unchanged on exit. */
  
  /*  K      - INTEGER. */
  /*           On entry with  TRANS = 'N' or 'n',  K  specifies  the number */
  /*           of  columns  of the  matrices  A and B,  and on  entry  with */
  /*           TRANS = 'T' or 't' or 'C' or 'c',  K  specifies  the  number */
  /*           of rows of the matrices  A and B.  K must be at least  zero. */
  /*           Unchanged on exit. */
  
  /*  ALPHA  - REAL            . */
  /*           On entry, ALPHA specifies the scalar alpha. */
  /*           Unchanged on exit. */
  
  /*  A      - REAL             array of DIMENSION ( LDA, ka ), where ka is */
  /*           k  when  TRANS = 'N' or 'n',  and is  n  otherwise. */
  /*           Before entry with  TRANS = 'N' or 'n',  the  leading  n by k */
  /*           part of the array  A  must contain the matrix  A,  otherwise */
  /*           the leading  k by n  part of the array  A  must contain  the */
  /*           matrix A. */
  /*           Unchanged on exit. */
  
  /*  LDA    - INTEGER. */
  /*           On entry, LDA specifies the first dimension of A as declared */
  /*           in  the  calling  (sub)  program.   When  TRANS = 'N' or 'n' */
  /*           then  LDA must be at least  max( 1, n ), otherwise  LDA must */
  /*           be at least  max( 1, k ). */
  /*           Unchanged on exit. */
  
  /*  B      - REAL             array of DIMENSION ( LDB, kb ), where kb is */
  /*           k  when  TRANS = 'N' or 'n',  and is  n  otherwise. */
  /*           Before entry with  TRANS = 'N' or 'n',  the  leading  n by k */
  /*           part of the array  B  must contain the matrix  B,  otherwise */
  /*           the leading  k by n  part of the array  B  must contain  the */
  /*           matrix B. */
  /*           Unchanged on exit. */
  
  /*  LDB    - INTEGER. */
  /*           On entry, LDB specifies the first dimension of B as declared */
  /*           in  the  calling  (sub)  program.   When  TRANS = 'N' or 'n' */
  /*           then  LDB must be at least  max( 1, n ), otherwise  LDB must */
  /*           be at least  max( 1, k ). */
  /*           Unchanged on exit. */
  
  /*  BETA   - REAL            . */
  /*           On entry, BETA specifies the scalar beta. */
  /*           Unchanged on exit. */
  
  /*  C      - REAL             array of DIMENSION ( LDC, n ). */
  /*           Before entry  with  UPLO = 'U' or 'u',  the leading  n by n */
  /*           upper triangular part of the array C must contain the upper */
  /*           triangular part  of the  symmetric matrix  and the strictly */
  /*           lower triangular part of C is not referenced.  On exit, the */
  /*           upper triangular part of the array  C is overwritten by the */
  /*           upper triangular part of the updated matrix. */
  /*           Before entry  with  UPLO = 'L' or 'l',  the leading  n by n */
  /*           lower triangular part of the array C must contain the lower */
  /*           triangular part  of the  symmetric matrix  and the strictly */
  /*           upper triangular part of C is not referenced.  On exit, the */
  /*           lower triangular part of the array  C is overwritten by the */
  /*           lower triangular part of the updated matrix. */
  
  /*  LDC    - INTEGER. */
  /*           On entry, LDC specifies the first dimension of C as declared */
  /*           in  the  calling  (sub)  program.   LDC  must  be  at  least */
  /*           max( 1, n ). */
  /*           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 .. */
  /*     .. */
  /*     .. External Subroutines .. */
  /*     .. */
  /*     .. Intrinsic Functions .. */
  /*     .. */
  /*     .. Local Scalars .. */
  /*     .. */
  /*     .. Parameters .. */
  /*     .. */
  
  /*     Test the input parameters. */
  
      /* Parameter adjustments */
      a_dim1 = *lda;
      a_offset = 1 + a_dim1;
      a -= a_offset;
      b_dim1 = *ldb;
      b_offset = 1 + b_dim1;
      b -= b_offset;
      c_dim1 = *ldc;
      c_offset = 1 + c_dim1;
      c__ -= c_offset;
  
      /* Function Body */
      if (lsame_(trans, "N")) {
  	nrowa = *n;
      } else {
  	nrowa = *k;
      }
      upper = lsame_(uplo, "U");
  
      info = 0;
      if (! upper && ! lsame_(uplo, "L")) {
  	info = 1;
      } else if (! lsame_(trans, "N") && ! lsame_(trans, 
  	    "T") && ! lsame_(trans, "C")) {
  	info = 2;
      } else if (*n < 0) {
  	info = 3;
      } else if (*k < 0) {
  	info = 4;
      } else if (*lda < max(1,nrowa)) {
  	info = 7;
      } else if (*ldb < max(1,nrowa)) {
  	info = 9;
      } else if (*ldc < max(1,*n)) {
  	info = 12;
      }
      if (info != 0) {
  	xerbla_("SSYR2K", &info);
  	return 0;
      }
  
  /*     Quick return if possible. */
  
      if (*n == 0 || (*alpha == 0.f || *k == 0) && *beta == 1.f) {
  	return 0;
      }
  
  /*     And when  alpha.eq.zero. */
  
      if (*alpha == 0.f) {
  	if (upper) {
  	    if (*beta == 0.f) {
  		i__1 = *n;
  		for (j = 1; j <= i__1; ++j) {
  		    i__2 = j;
  		    for (i__ = 1; i__ <= i__2; ++i__) {
  			c__[i__ + j * c_dim1] = 0.f;
  /* L10: */
  		    }
  /* L20: */
  		}
  	    } else {
  		i__1 = *n;
  		for (j = 1; j <= i__1; ++j) {
  		    i__2 = j;
  		    for (i__ = 1; i__ <= i__2; ++i__) {
  			c__[i__ + j * c_dim1] = *beta * c__[i__ + j * c_dim1];
  /* L30: */
  		    }
  /* L40: */
  		}
  	    }
  	} else {
  	    if (*beta == 0.f) {
  		i__1 = *n;
  		for (j = 1; j <= i__1; ++j) {
  		    i__2 = *n;
  		    for (i__ = j; i__ <= i__2; ++i__) {
  			c__[i__ + j * c_dim1] = 0.f;
  /* L50: */
  		    }
  /* L60: */
  		}
  	    } else {
  		i__1 = *n;
  		for (j = 1; j <= i__1; ++j) {
  		    i__2 = *n;
  		    for (i__ = j; i__ <= i__2; ++i__) {
  			c__[i__ + j * c_dim1] = *beta * c__[i__ + j * c_dim1];
  /* L70: */
  		    }
  /* L80: */
  		}
  	    }
  	}
  	return 0;
      }
  
  /*     Start the operations. */
  
      if (lsame_(trans, "N")) {
  
  /*        Form  C := alpha*A*B' + alpha*B*A' + C. */
  
  	if (upper) {
  	    i__1 = *n;
  	    for (j = 1; j <= i__1; ++j) {
  		if (*beta == 0.f) {
  		    i__2 = j;
  		    for (i__ = 1; i__ <= i__2; ++i__) {
  			c__[i__ + j * c_dim1] = 0.f;
  /* L90: */
  		    }
  		} else if (*beta != 1.f) {
  		    i__2 = j;
  		    for (i__ = 1; i__ <= i__2; ++i__) {
  			c__[i__ + j * c_dim1] = *beta * c__[i__ + j * c_dim1];
  /* L100: */
  		    }
  		}
  		i__2 = *k;
  		for (l = 1; l <= i__2; ++l) {
  		    if (a[j + l * a_dim1] != 0.f || b[j + l * b_dim1] != 0.f) 
  			    {
  			temp1 = *alpha * b[j + l * b_dim1];
  			temp2 = *alpha * a[j + l * a_dim1];
  			i__3 = j;
  			for (i__ = 1; i__ <= i__3; ++i__) {
  			    c__[i__ + j * c_dim1] = c__[i__ + j * c_dim1] + a[
  				    i__ + l * a_dim1] * temp1 + b[i__ + l * 
  				    b_dim1] * temp2;
  /* L110: */
  			}
  		    }
  /* L120: */
  		}
  /* L130: */
  	    }
  	} else {
  	    i__1 = *n;
  	    for (j = 1; j <= i__1; ++j) {
  		if (*beta == 0.f) {
  		    i__2 = *n;
  		    for (i__ = j; i__ <= i__2; ++i__) {
  			c__[i__ + j * c_dim1] = 0.f;
  /* L140: */
  		    }
  		} else if (*beta != 1.f) {
  		    i__2 = *n;
  		    for (i__ = j; i__ <= i__2; ++i__) {
  			c__[i__ + j * c_dim1] = *beta * c__[i__ + j * c_dim1];
  /* L150: */
  		    }
  		}
  		i__2 = *k;
  		for (l = 1; l <= i__2; ++l) {
  		    if (a[j + l * a_dim1] != 0.f || b[j + l * b_dim1] != 0.f) 
  			    {
  			temp1 = *alpha * b[j + l * b_dim1];
  			temp2 = *alpha * a[j + l * a_dim1];
  			i__3 = *n;
  			for (i__ = j; i__ <= i__3; ++i__) {
  			    c__[i__ + j * c_dim1] = c__[i__ + j * c_dim1] + a[
  				    i__ + l * a_dim1] * temp1 + b[i__ + l * 
  				    b_dim1] * temp2;
  /* L160: */
  			}
  		    }
  /* L170: */
  		}
  /* L180: */
  	    }
  	}
      } else {
  
  /*        Form  C := alpha*A'*B + alpha*B'*A + C. */
  
  	if (upper) {
  	    i__1 = *n;
  	    for (j = 1; j <= i__1; ++j) {
  		i__2 = j;
  		for (i__ = 1; i__ <= i__2; ++i__) {
  		    temp1 = 0.f;
  		    temp2 = 0.f;
  		    i__3 = *k;
  		    for (l = 1; l <= i__3; ++l) {
  			temp1 += a[l + i__ * a_dim1] * b[l + j * b_dim1];
  			temp2 += b[l + i__ * b_dim1] * a[l + j * a_dim1];
  /* L190: */
  		    }
  		    if (*beta == 0.f) {
  			c__[i__ + j * c_dim1] = *alpha * temp1 + *alpha * 
  				temp2;
  		    } else {
  			c__[i__ + j * c_dim1] = *beta * c__[i__ + j * c_dim1] 
  				+ *alpha * temp1 + *alpha * temp2;
  		    }
  /* L200: */
  		}
  /* L210: */
  	    }
  	} else {
  	    i__1 = *n;
  	    for (j = 1; j <= i__1; ++j) {
  		i__2 = *n;
  		for (i__ = j; i__ <= i__2; ++i__) {
  		    temp1 = 0.f;
  		    temp2 = 0.f;
  		    i__3 = *k;
  		    for (l = 1; l <= i__3; ++l) {
  			temp1 += a[l + i__ * a_dim1] * b[l + j * b_dim1];
  			temp2 += b[l + i__ * b_dim1] * a[l + j * a_dim1];
  /* L220: */
  		    }
  		    if (*beta == 0.f) {
  			c__[i__ + j * c_dim1] = *alpha * temp1 + *alpha * 
  				temp2;
  		    } else {
  			c__[i__ + j * c_dim1] = *beta * c__[i__ + j * c_dim1] 
  				+ *alpha * temp1 + *alpha * temp2;
  		    }
  /* L230: */
  		}
  /* L240: */
  	    }
  	}
      }
  
      return 0;
  
  /*     End of SSYR2K. */
  
  } /* ssyr2k_ */
  