/* blas/source_herk.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_ARGS11(HERK,Order,Uplo,Trans,N,K,alpha,A,lda,beta,C,ldc);

  if (beta == 1.0 && (alpha == 0.0 || K == 0))

    return;

  if (Order == CblasRowMajor) {

    uplo = Uplo;

    trans = Trans;

  } else {

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

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

  }

  /* form  y := beta*y */

  if (beta == 0.0) {

    if (uplo == CblasUpper) {

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

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

          REAL(C, ldc * i + j) = 0.0;

          IMAG(C, ldc * i + j) = 0.0;

        }

      }

    } else {

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

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

          REAL(C, ldc * i + j) = 0.0;

          IMAG(C, ldc * i + j) = 0.0;

        }

      }

    }

  } else if (beta != 1.0) {

    if (uplo == CblasUpper) {

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

        REAL(C, ldc * i + i) *= beta;

        IMAG(C, ldc * i + i) = 0;

        for (j = i + 1; j < N; j++) {

          REAL(C, ldc * i + j) *= beta;

          IMAG(C, ldc * i + j) *= beta;

        }

      }

    } else {

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

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

          REAL(C, ldc * i + j) *= beta;

          IMAG(C, ldc * i + j) *= beta;

        }

        REAL(C, ldc * i + i) *= beta;

        IMAG(C, ldc * i + i) = 0;

      }

    }

  } else {

    /* set imaginary part of Aii to zero */

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

      IMAG(C, ldc * i + i) = 0.0;

    }

  }

  if (alpha == 0.0)

    return;

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

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

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

        BASE temp_real = 0.0;

        BASE temp_imag = 0.0;

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

          const BASE Aik_real = CONST_REAL(A, i * lda + k);

          const BASE Aik_imag = CONST_IMAG(A, i * lda + k);

          const BASE Ajk_real = CONST_REAL(A, j * lda + k);

          const BASE Ajk_imag = -CONST_IMAG(A, j * lda + k);

          temp_real += Aik_real * Ajk_real - Aik_imag * Ajk_imag;

          temp_imag += Aik_real * Ajk_imag + Aik_imag * Ajk_real;

        }

        REAL(C, i * ldc + j) += alpha * temp_real;

        IMAG(C, i * ldc + j) += alpha * temp_imag;

      }

    }

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

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

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

        BASE temp_real = 0.0;

        BASE temp_imag = 0.0;

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

          const BASE Aki_real = CONST_REAL(A, k * lda + i);

          const BASE Aki_imag = -CONST_IMAG(A, k * lda + i);

          const BASE Akj_real = CONST_REAL(A, k * lda + j);

          const BASE Akj_imag = CONST_IMAG(A, k * lda + j);

          temp_real += Aki_real * Akj_real - Aki_imag * Akj_imag;

          temp_imag += Aki_real * Akj_imag + Aki_imag * Akj_real;

        }

        REAL(C, i * ldc + j) += alpha * temp_real;

        IMAG(C, i * ldc + j) += alpha * temp_imag;

      }

    }

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

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

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

        BASE temp_real = 0.0;

        BASE temp_imag = 0.0;

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

          const BASE Aik_real = CONST_REAL(A, i * lda + k);

          const BASE Aik_imag = CONST_IMAG(A, i * lda + k);

          const BASE Ajk_real = CONST_REAL(A, j * lda + k);

          const BASE Ajk_imag = -CONST_IMAG(A, j * lda + k);

          temp_real += Aik_real * Ajk_real - Aik_imag * Ajk_imag;

          temp_imag += Aik_real * Ajk_imag + Aik_imag * Ajk_real;

        }

        REAL(C, i * ldc + j) += alpha * temp_real;

        IMAG(C, i * ldc + j) += alpha * temp_imag;

      }

    }

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

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

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

        BASE temp_real = 0.0;

        BASE temp_imag = 0.0;

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

          const BASE Aki_real = CONST_REAL(A, k * lda + i);

          const BASE Aki_imag = -CONST_IMAG(A, k * lda + i);

          const BASE Akj_real = CONST_REAL(A, k * lda + j);

          const BASE Akj_imag = CONST_IMAG(A, k * lda + j);

          temp_real += Aki_real * Akj_real - Aki_imag * Akj_imag;

          temp_imag += Aki_real * Akj_imag + Aki_imag * Akj_real;

        }

        REAL(C, i * ldc + j) += alpha * temp_real;

        IMAG(C, i * ldc + j) += alpha * temp_imag;

      }

    }

  } else {

    BLAS_ERROR("unrecognized operation");

  }

}