# dlib C++ Library - cblas_zgbmv.c

    /*
     * cblas_zgbmv.c
     * The program is a C interface of zgbmv
     *
     * Keita Teranishi  5/20/98
     *
     */
    #include <stdio.h>
    #include <stdlib.h>
    #include "cblas.h"
    #include "cblas_f77.h"
    void cblas_zgbmv(const enum CBLAS_ORDER order,
                     const enum CBLAS_TRANSPOSE TransA, const CBLAS_INT_TYPE M, const CBLAS_INT_TYPE N,
                     const CBLAS_INT_TYPE KL, const CBLAS_INT_TYPE KU,
                     const void *alpha, const void  *A, const CBLAS_INT_TYPE lda,
                     const void  *X, const CBLAS_INT_TYPE incX, const void *beta,
                     void  *Y, const CBLAS_INT_TYPE incY)
    {
       char TA;
    #ifdef F77_CHAR
       F77_CHAR F77_TA;
    #else
       #define F77_TA &TA
    #endif
    #ifdef F77_INT
       F77_INT F77_M=M, F77_N=N, F77_lda=lda, F77_incX=incX, F77_incY=incY;
       F77_INT F77_KL=KL,F77_KU=KU;
    #else
       #define F77_M M
       #define F77_N N
       #define F77_lda lda
       #define F77_KL KL
       #define F77_KU KU
       #define F77_incX incx
       #define F77_incY incY
    #endif
       CBLAS_INT_TYPE n, i=0, incx=incX;
       const double *xx= (double *)X, *alp= (double *)alpha, *bet = (double *)beta;
       double ALPHA[2],BETA[2];
       CBLAS_INT_TYPE tincY, tincx;
       double *x=(double *)X, *y=(double *)Y, *st=0, *tx;

       if (order == CblasColMajor)
       {
          if (TransA == CblasNoTrans) TA = 'N';
          else if (TransA == CblasTrans) TA = 'T';
          else if (TransA == CblasConjTrans) TA = 'C';
          else
          {
             cblas_xerbla(2, "cblas_zgbmv","Illegal TransA setting, %d\n", TransA);
             return;
          }
          #ifdef F77_CHAR
             F77_TA = C2F_CHAR(&TA);
          #endif
          F77_zgbmv(F77_TA, &F77_M, &F77_N, &F77_KL, &F77_KU, alpha,
                         A, &F77_lda, X, &F77_incX, beta, Y, &F77_incY);
       }
       else if (order == CblasRowMajor)
       {
          if (TransA == CblasNoTrans) TA = 'T';
          else if (TransA == CblasTrans) TA = 'N';
          else if (TransA == CblasConjTrans)
          {
             ALPHA[0]= *alp;
             ALPHA[1]= -alp[1];
             BETA[0]= *bet;
             BETA[1]= -bet[1];
             TA = 'N';
             if (M > 0)
             {
                n = M << 1;
                x = malloc(n*sizeof(double));
                tx = x;

                if( incX > 0 ) {
                   i = incX << 1 ;
                   tincx = 2;
                   st= x+n;
                } else {
                   i = incX *(-2);
                   tincx = -2;
                   st = x-2;
                   x +=(n-2);
                }
                do
                {
                   *x = *xx;
                   x[1] = -xx[1];
                   x += tincx ;
                   xx += i;
                }
                while (x != st);
                x=tx;

                #ifdef F77_INT
                   F77_incX = 1;
                #else
                   incx = 1;
                #endif

                if( incY > 0 )
                  tincY = incY;
                else
                  tincY = -incY;

                y++;

                if (N > 0)
                {
                   i = tincY << 1;
                   n = i * N ;
                   st = y + n;
                   do {
                      *y = -(*y);
                      y += i;
                   } while(y != st);
                   y -= n;
                }
             }
             else x = (double *) X;

          }
          else
          {
             cblas_xerbla(2, "cblas_zgbmv","Illegal TransA setting, %d\n", TransA);
             return;
          }
          #ifdef F77_CHAR
             F77_TA = C2F_CHAR(&TA);
          #endif
          if (TransA == CblasConjTrans)
             F77_zgbmv(F77_TA, &F77_N, &F77_M, &F77_KU, &F77_KL, ALPHA,
                            A ,&F77_lda, x,&F77_incX, BETA, Y, &F77_incY);
          else
             F77_zgbmv(F77_TA, &F77_N, &F77_M, &F77_KU, &F77_KL, alpha,
                            A ,&F77_lda, x,&F77_incX, beta, Y, &F77_incY);
          if (TransA == CblasConjTrans)
          {
             if (x != X) free(x);
             if (N > 0)
             {
                do
                {
                   *y = -(*y);
                   y += i;
                }
                while (y != st);
             }
          }
       }
       else cblas_xerbla(1, "cblas_zgbmv", "Illegal Order setting, %d\n", order);
       return;
    }