/* blas/source_trsm_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;

  INDEX n1, n2;

  const int nonunit = (Diag == CblasNonUnit);

  int side, uplo, trans;

  CHECK_ARGS12(TRSM,Order,Side,Uplo,TransA,Diag,M,N,alpha,A,lda,B,ldb);

  if (Order == CblasRowMajor) {

    n1 = M;

    n2 = N;

    side = Side;

    uplo = Uplo;

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

  } else {

    n1 = N;

    n2 = M;

    side = (Side == CblasLeft) ? CblasRight : CblasLeft;

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

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

  }

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

    /* form  B := alpha * inv(TriU(A)) *B */

    if (alpha != 1.0) {

      for (i = 0; i < n1; i++) {

        for (j = 0; j < n2; j++) {

          B[ldb * i + j] *= alpha;

        }

      }

    }

    for (i = n1; i > 0 && i--;) {

      if (nonunit) {

        BASE Aii = A[lda * i + i];

        for (j = 0; j < n2; j++) {

          B[ldb * i + j] /= Aii;

        }

      }

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

        const BASE Aki = A[k * lda + i];

        for (j = 0; j < n2; j++) {

          B[ldb * k + j] -= Aki * B[ldb * i + j];

        }

      }

    }

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

    /* form  B := alpha * inv(TriU(A))' *B */

    if (alpha != 1.0) {

      for (i = 0; i < n1; i++) {

        for (j = 0; j < n2; j++) {

          B[ldb * i + j] *= alpha;

        }

      }

    }

    for (i = 0; i < n1; i++) {

      if (nonunit) {

        BASE Aii = A[lda * i + i];

        for (j = 0; j < n2; j++) {

          B[ldb * i + j] /= Aii;

        }

      }

      for (k = i + 1; k < n1; k++) {

        const BASE Aik = A[i * lda + k];

        for (j = 0; j < n2; j++) {

          B[ldb * k + j] -= Aik * B[ldb * i + j];

        }

      }

    }

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

    /* form  B := alpha * inv(TriL(A))*B */

    if (alpha != 1.0) {

      for (i = 0; i < n1; i++) {

        for (j = 0; j < n2; j++) {

          B[ldb * i + j] *= alpha;

        }

      }

    }

    for (i = 0; i < n1; i++) {

      if (nonunit) {

        BASE Aii = A[lda * i + i];

        for (j = 0; j < n2; j++) {

          B[ldb * i + j] /= Aii;

        }

      }

      for (k = i + 1; k < n1; k++) {

        const BASE Aki = A[k * lda + i];

        for (j = 0; j < n2; j++) {

          B[ldb * k + j] -= Aki * B[ldb * i + j];

        }

      }

    }

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

    /* form  B := alpha * TriL(A)' *B */

    if (alpha != 1.0) {

      for (i = 0; i < n1; i++) {

        for (j = 0; j < n2; j++) {

          B[ldb * i + j] *= alpha;

        }

      }

    }

    for (i = n1; i > 0 && i--;) {

      if (nonunit) {

        BASE Aii = A[lda * i + i];

        for (j = 0; j < n2; j++) {

          B[ldb * i + j] /= Aii;

        }

      }

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

        const BASE Aik = A[i * lda + k];

        for (j = 0; j < n2; j++) {

          B[ldb * k + j] -= Aik * B[ldb * i + j];

        }

      }

    }

  } else if (side == CblasRight && uplo == CblasUpper && trans == CblasNoTrans) {

    /* form  B := alpha * B * inv(TriU(A)) */

    if (alpha != 1.0) {

      for (i = 0; i < n1; i++) {

        for (j = 0; j < n2; j++) {

          B[ldb * i + j] *= alpha;

        }

      }

    }

    for (i = 0; i < n1; i++) {

      for (j = 0; j < n2; j++) {

        if (nonunit) {

          BASE Ajj = A[lda * j + j];

          B[ldb * i + j] /= Ajj;

        }

        {

          BASE Bij = B[ldb * i + j];

          for (k = j + 1; k < n2; k++) {

            B[ldb * i + k] -= A[j * lda + k] * Bij;

          }

        }

      }

    }

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

    /* form  B := alpha * B * inv(TriU(A))' */

    if (alpha != 1.0) {

      for (i = 0; i < n1; i++) {

        for (j = 0; j < n2; j++) {

          B[ldb * i + j] *= alpha;

        }

      }

    }

    for (i = 0; i < n1; i++) {

      for (j = n2; j > 0 && j--;) {

        if (nonunit) {

          BASE Ajj = A[lda * j + j];

          B[ldb * i + j] /= Ajj;

        }

        {

          BASE Bij = B[ldb * i + j];

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

            B[ldb * i + k] -= A[k * lda + j] * Bij;

          }

        }

      }

    }

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

    /* form  B := alpha * B * inv(TriL(A)) */

    if (alpha != 1.0) {

      for (i = 0; i < n1; i++) {

        for (j = 0; j < n2; j++) {

          B[ldb * i + j] *= alpha;

        }

      }

    }

    for (i = 0; i < n1; i++) {

      for (j = n2; j > 0 && j--;) {

        if (nonunit) {

          BASE Ajj = A[lda * j + j];

          B[ldb * i + j] /= Ajj;

        }

        {

          BASE Bij = B[ldb * i + j];

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

            B[ldb * i + k] -= A[j * lda + k] * Bij;

          }

        }

      }

    }

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

    /* form  B := alpha * B * inv(TriL(A))' */

    if (alpha != 1.0) {

      for (i = 0; i < n1; i++) {

        for (j = 0; j < n2; j++) {

          B[ldb * i + j] *= alpha;

        }

      }

    }

    for (i = 0; i < n1; i++) {

      for (j = 0; j < n2; j++) {

        if (nonunit) {

          BASE Ajj = A[lda * j + j];

          B[ldb * i + j] /= Ajj;

        }

        {

          BASE Bij = B[ldb * i + j];

          for (k = j + 1; k < n2; k++) {

            B[ldb * i + k] -= A[k * lda + j] * Bij;

          }

        }

      }

    }

  } else {

    BLAS_ERROR("unrecognized operation");

  }

}