# dlib C++ Library - cblas_chpr2.c

    /*
     * cblas_chpr2.c
     * The program is a C interface to chpr2.
     *
     * Keita Teranishi  5/20/98
     *
     */
    #include <stdio.h>
    #include <stdlib.h>
    #include "cblas.h"
    #include "cblas_f77.h"
    void cblas_chpr2(const enum CBLAS_ORDER order, const enum CBLAS_UPLO Uplo,
                          const CBLAS_INT_TYPE N,const void *alpha, const void *X,
                          const CBLAS_INT_TYPE incX,const void *Y, const CBLAS_INT_TYPE incY, void *Ap)

    {
       char UL;
    #ifdef F77_CHAR
       F77_CHAR F77_UL;
    #else
       #define F77_UL &UL
    #endif

    #ifdef F77_INT
       F77_INT F77_N=N,  F77_incX=incX, F77_incY=incY;
    #else
       #define F77_N N
       #define F77_incX incx
       #define F77_incY incy
    #endif
       CBLAS_INT_TYPE n, i, j, tincx, tincy, incx=incX, incy=incY;
       float *x=(float *)X, *xx=(float *)X, *y=(float *)Y,
             *yy=(float *)Y, *tx, *ty, *stx, *sty;

       if (order == CblasColMajor)
       {
          if (Uplo == CblasLower) UL = 'L';
          else if (Uplo == CblasUpper) UL = 'U';
          else
          {
             cblas_xerbla(2, "cblas_chpr2","Illegal Uplo setting, %d\n",Uplo );
             return;
          }
          #ifdef F77_CHAR
             F77_UL = C2F_CHAR(&UL);
          #endif

          F77_chpr2(F77_UL, &F77_N, alpha, X, &F77_incX, Y, &F77_incY, Ap);

       }  else if (order == CblasRowMajor)
       {
          if (Uplo == CblasUpper) UL = 'L';
          else if (Uplo == CblasLower) UL = 'U';
          else
          {
             cblas_xerbla(2, "cblas_chpr2","Illegal Uplo setting, %d\n", Uplo);
             return;
          }
          #ifdef F77_CHAR
             F77_UL = C2F_CHAR(&UL);
          #endif
          if (N > 0)
          {
             n = N << 1;
             x = malloc(n*sizeof(float));
             y = malloc(n*sizeof(float));
             tx = x;
             ty = y;
             if( incX > 0 ) {
                i = incX << 1 ;
                tincx = 2;
                stx= x+n;
             } else {
                i = incX *(-2);
                tincx = -2;
                stx = x-2;
                x +=(n-2);
             }

             if( incY > 0 ) {
                j = incY << 1;
                tincy = 2;
                sty= y+n;
             } else {
                j = incY *(-2);
                tincy = -2;
                sty = y-2;
                y +=(n-2);
             }

             do
             {
                *x = *xx;
                x[1] = -xx[1];
                x += tincx ;
                xx += i;
             }
             while (x != stx);
             do
             {
                *y = *yy;
                y[1] = -yy[1];
                y += tincy ;
                yy += j;
             }
             while (y != sty);

             x=tx;
             y=ty;

             #ifdef F77_INT
                F77_incX = 1;
                F77_incY = 1;
             #else
                incx = 1;
                incy = 1;
             #endif

          }  else
          {
             x = (float *) X;
             y = (void  *) Y;
          }
          F77_chpr2(F77_UL, &F77_N, alpha, y, &F77_incY, x, &F77_incX, Ap);
       } else
       {
          cblas_xerbla(1, "cblas_chpr2","Illegal Order setting, %d\n", order);
          return;
       }
       if(X!=x)
          free(x);
       if(Y!=y)
          free(y);
       return;
    }