/* blas/source_her2k.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(HER2K,Order,Uplo,Trans,N,K,alpha,A,lda,B,ldb,beta,C,ldc);

  {

    const BASE alpha_real = CONST_REAL0(alpha);

    BASE alpha_imag = CONST_IMAG0(alpha);

    if (beta == 1.0 && ((alpha_real == 0.0 && alpha_imag == 0.0) || K == 0))

      return;

    if (Order == CblasRowMajor) {

      uplo = Uplo;

      trans = Trans;

    } else {

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

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

      alpha_imag *= -1;           /* conjugate alpha */

    }

    /* form  C := beta*C */

    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) = 0.0;

          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) = 0.0;

        }

      }

    } else {

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

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

      }

    }

    if (alpha_real == 0.0 && alpha_imag == 0.0)

      return;

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

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

        /* Cii += alpha Aik conj(Bik) + conj(alpha) Bik conj(Aik) */

        {

          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);

            /* temp1 = alpha * Aik */

            const BASE temp1_real = alpha_real * Aik_real - alpha_imag * Aik_imag;

            const BASE temp1_imag = alpha_real * Aik_imag + alpha_imag * Aik_real;

            const BASE Bik_real = CONST_REAL(B, i * ldb + k);

            const BASE Bik_imag = CONST_IMAG(B, i * ldb + k);

            temp_real += temp1_real * Bik_real + temp1_imag * Bik_imag;

          }

          REAL(C, i * ldc + i) += 2 * temp_real;

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

        }

        /* Cij += alpha Aik conj(Bjk) + conj(alpha) Bik conj(Ajk) */

        for (j = i + 1; 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);

            /* temp1 = alpha * Aik */

            const BASE temp1_real = alpha_real * Aik_real - alpha_imag * Aik_imag;

            const BASE temp1_imag = alpha_real * Aik_imag + alpha_imag * Aik_real;

            const BASE Bik_real = CONST_REAL(B, i * ldb + k);

            const BASE Bik_imag = CONST_IMAG(B, i * ldb + k);

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

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

            /* temp2 = alpha * Ajk */

            const BASE temp2_real = alpha_real * Ajk_real - alpha_imag * Ajk_imag;

            const BASE temp2_imag = alpha_real * Ajk_imag + alpha_imag * Ajk_real;

            const BASE Bjk_real = CONST_REAL(B, j * ldb + k);

            const BASE Bjk_imag = CONST_IMAG(B, j * ldb + k);

            /* Cij += alpha * Aik * conj(Bjk) + conj(alpha) * Bik * conj(Ajk) */

            temp_real += ((temp1_real * Bjk_real + temp1_imag * Bjk_imag)

                          + (Bik_real * temp2_real + Bik_imag * temp2_imag));

            temp_imag += ((temp1_real * (-Bjk_imag) + temp1_imag * Bjk_real)

                          + (Bik_real * (-temp2_imag) + Bik_imag * temp2_real));

          }

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

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

        }

      }

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

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

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

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

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

          BASE Bki_real = CONST_REAL(B, k * ldb + i);

          BASE Bki_imag = CONST_IMAG(B, k * ldb + i);

          /* temp1 = alpha * conj(Aki) */

          BASE temp1_real = alpha_real * Aki_real - alpha_imag * (-Aki_imag);

          BASE temp1_imag = alpha_real * (-Aki_imag) + alpha_imag * Aki_real;

          /* temp2 = conj(alpha) * conj(Bki) */

          BASE temp2_real = alpha_real * Bki_real - alpha_imag * Bki_imag;

          BASE temp2_imag = -(alpha_real * Bki_imag + alpha_imag * Bki_real);

          /* Cii += alpha * conj(Aki) * Bki + conj(alpha) * conj(Bki) * Aki */

          {

            REAL(C, i * lda + i) += 2 * (temp1_real * Bki_real - temp1_imag * Bki_imag);

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

          }

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

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

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

            BASE Bkj_real = CONST_REAL(B, k * ldb + j);

            BASE Bkj_imag = CONST_IMAG(B, k * ldb + j);

            /* Cij += alpha * conj(Aki) * Bkj + conj(alpha) * conj(Bki) * Akj */

            REAL(C, i * lda + j) += (temp1_real * Bkj_real - temp1_imag * Bkj_imag)

              + (temp2_real * Akj_real - temp2_imag * Akj_imag);

            IMAG(C, i * lda + j) += (temp1_real * Bkj_imag + temp1_imag * Bkj_real)

              + (temp2_real * Akj_imag + temp2_imag * Akj_real);

          }

        }

      }

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

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

        /* Cij += alpha Aik conj(Bjk) + conj(alpha) Bik conj(Ajk) */

        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);

            /* temp1 = alpha * Aik */

            const BASE temp1_real = alpha_real * Aik_real - alpha_imag * Aik_imag;

            const BASE temp1_imag = alpha_real * Aik_imag + alpha_imag * Aik_real;

            const BASE Bik_real = CONST_REAL(B, i * ldb + k);

            const BASE Bik_imag = CONST_IMAG(B, i * ldb + k);

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

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

            /* temp2 = alpha * Ajk */

            const BASE temp2_real = alpha_real * Ajk_real - alpha_imag * Ajk_imag;

            const BASE temp2_imag = alpha_real * Ajk_imag + alpha_imag * Ajk_real;

            const BASE Bjk_real = CONST_REAL(B, j * ldb + k);

            const BASE Bjk_imag = CONST_IMAG(B, j * ldb + k);

            /* Cij += alpha * Aik * conj(Bjk) + conj(alpha) * Bik * conj(Ajk) */

            temp_real += ((temp1_real * Bjk_real + temp1_imag * Bjk_imag)

                          + (Bik_real * temp2_real + Bik_imag * temp2_imag));

            temp_imag += ((temp1_real * (-Bjk_imag) + temp1_imag * Bjk_real)

                          + (Bik_real * (-temp2_imag) + Bik_imag * temp2_real));

          }

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

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

        }

        /* Cii += alpha Aik conj(Bik) + conj(alpha) Bik conj(Aik) */

        {

          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);

            /* temp1 = alpha * Aik */

            const BASE temp1_real = alpha_real * Aik_real - alpha_imag * Aik_imag;

            const BASE temp1_imag = alpha_real * Aik_imag + alpha_imag * Aik_real;

            const BASE Bik_real = CONST_REAL(B, i * ldb + k);

            const BASE Bik_imag = CONST_IMAG(B, i * ldb + k);

            temp_real += temp1_real * Bik_real + temp1_imag * Bik_imag;

          }

          REAL(C, i * ldc + i) += 2 * temp_real;

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

        }

      }

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

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

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

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

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

          BASE Bki_real = CONST_REAL(B, k * ldb + i);

          BASE Bki_imag = CONST_IMAG(B, k * ldb + i);

          /* temp1 = alpha * conj(Aki) */

          BASE temp1_real = alpha_real * Aki_real - alpha_imag * (-Aki_imag);

          BASE temp1_imag = alpha_real * (-Aki_imag) + alpha_imag * Aki_real;

          /* temp2 = conj(alpha) * conj(Bki) */

          BASE temp2_real = alpha_real * Bki_real - alpha_imag * Bki_imag;

          BASE temp2_imag = -(alpha_real * Bki_imag + alpha_imag * Bki_real);

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

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

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

            BASE Bkj_real = CONST_REAL(B, k * ldb + j);

            BASE Bkj_imag = CONST_IMAG(B, k * ldb + j);

            /* Cij += alpha * conj(Aki) * Bkj + conj(alpha) * conj(Bki) * Akj */

            REAL(C, i * lda + j) += (temp1_real * Bkj_real - temp1_imag * Bkj_imag)

              + (temp2_real * Akj_real - temp2_imag * Akj_imag);

            IMAG(C, i * lda + j) += (temp1_real * Bkj_imag + temp1_imag * Bkj_real)

              + (temp2_real * Akj_imag + temp2_imag * Akj_real);

          }

          /* Cii += alpha * conj(Aki) * Bki + conj(alpha) * conj(Bki) * Aki */

          {

            REAL(C, i * lda + i) += 2 * (temp1_real * Bki_real - temp1_imag * Bki_imag);

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

          }

        }

      }

    } else {

      BLAS_ERROR("unrecognized operation");

    }

  }

}