/* blas/source_syr2k_r.h

 *

 * Copyright (C) 2001, 2007 Brian Gough

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 3 of the License, or (at

 * your option) any later version.

 *

 * This program is distributed in the hope that it will be useful, but

 * WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

 */

{

  INDEX i, j, k;

  int uplo, trans;

  CHECK_ARGS13(SYR2K,Order,Uplo,Trans,N,K,alpha,A,lda,B,ldb,beta,C,ldc);

  if (alpha == 0.0 && beta == 1.0)

    return;

  if (Order == CblasRowMajor) {

    uplo = Uplo;

    trans = (Trans == CblasConjTrans) ? CblasTrans : Trans;

  } else {

    uplo = (Uplo == CblasUpper) ? CblasLower : CblasUpper;

    if (Trans == CblasTrans || Trans == CblasConjTrans) {

      trans = CblasNoTrans;

    } else {

      trans = CblasTrans;

    }

  }

  /* form  C := beta*C */

  if (beta == 0.0) {

    if (uplo == CblasUpper) {

      for (i = 0; i < N; i++) {

        for (j = i; j < N; j++) {

          C[ldc * i + j] = 0.0;

        }

      }

    } else {

      for (i = 0; i < N; i++) {

        for (j = 0; j <= i; j++) {

          C[ldc * i + j] = 0.0;

        }

      }

    }

  } else if (beta != 1.0) {

    if (uplo == CblasUpper) {

      for (i = 0; i < N; i++) {

        for (j = i; j < N; j++) {

          C[ldc * i + j] *= beta;

        }

      }

    } else {

      for (i = 0; i < N; i++) {

        for (j = 0; j <= i; j++) {

          C[ldc * i + j] *= beta;

        }

      }

    }

  }

  if (alpha == 0.0)

    return;

  if (uplo == CblasUpper && trans == CblasNoTrans) {

    for (i = 0; i < N; i++) {

      for (j = i; j < N; j++) {

        BASE temp = 0.0;

        for (k = 0; k < K; k++) {

          temp += (A[i * lda + k] * B[j * ldb + k]

                   + B[i * ldb + k] * A[j * lda + k]);

        }

        C[i * ldc + j] += alpha * temp;

      }

    }

  } else if (uplo == CblasUpper && trans == CblasTrans) {

    for (k = 0; k < K; k++) {

      for (i = 0; i < N; i++) {

        BASE temp1 = alpha * A[k * lda + i];

        BASE temp2 = alpha * B[k * ldb + i];

        for (j = i; j < N; j++) {

          C[i * lda + j] += temp1 * B[k * ldb + j] + temp2 * A[k * lda + j];

        }

      }

    }

  } else if (uplo == CblasLower && trans == CblasNoTrans) {

    for (i = 0; i < N; i++) {

      for (j = 0; j <= i; j++) {

        BASE temp = 0.0;

        for (k = 0; k < K; k++) {

          temp += (A[i * lda + k] * B[j * ldb + k]

                   + B[i * ldb + k] * A[j * lda + k]);

        }

        C[i * ldc + j] += alpha * temp;

      }

    }

  } else if (uplo == CblasLower && trans == CblasTrans) {

    for (k = 0; k < K; k++) {

      for (i = 0; i < N; i++) {

        BASE temp1 = alpha * A[k * lda + i];

        BASE temp2 = alpha * B[k * ldb + i];

        for (j = 0; j <= i; j++) {

          C[i * lda + j] += temp1 * B[k * ldb + j] + temp2 * A[k * lda + j];

        }

      }

    }

  } else {

    BLAS_ERROR("unrecognized operation");

  }

}