float cblas_sdsdot(const int N, const float alpha, const float *X,
const int incX, const float *Y, const int incY)
{
if (N > 0)
{
if (incX < 0)
{
if (incY < 0) return(ATL_sdsdot(N, alpha, X, -incX, Y, -incY));
else return(ATL_sdsdot(N, alpha, X+(1-N)*incX, incX, Y, incY));
}
else if (incY < 0)
return(ATL_sdsdot(N, alpha, X+(N-1)*incX, -incX, Y, -incY));
else return(ATL_sdsdot(N, alpha, X, incX, Y, incY));
}
else return(0.0f);
}
void ATL_F77wrap_sdsdot
(
F77_INTEGER * N,
float * B,
float * X,
F77_INTEGER * INCX,
float * Y,
F77_INTEGER * INCY,
float * DOT
)
{
/*
* Purpose
* =======
*
* ATL_F77wrap_sdsdot computes the dot product b + x^T * y of two n vec-
* tors x and y. The result is internally computed using double preci-
* sion arithmetic and casted to a single precision scalar just before
* being returned.
*
* Notes
* =====
*
* This routine is an internal wrapper function written in C called by
* the corresponding Fortran 77 user callable subroutine. It calls the
* appropriate ATLAS routine performing the actual computation.
*
* This wrapper layer resolves the following portability issues:
*
* - the routines' name sheme translation imposed by the Fortran / C
* compilers of your target computer,
* - the translation of Fortran characters into the ATLAS correspon-
* ding C enumerated type (in cooperation with the Fortan user cal-
* lable subroutine),
* - the translation of Fortran integers into the proper C correspon-
* ding native type;
*
* and the following ease-of-programming issue:
*
* - a pointer to the the first entry of vector operands (when appli-
* cable) is passed to the ATLAS computational routine even if the
* corresponding input increment value is negative. This allows for
* a more natural expression in C of the computation performed by
* these ATLAS functions.
*
* ---------------------------------------------------------------------
*/
/* ..
* .. Executable Statements ..
*
*/
if( (*INCX) < 0 )
{
if( (*INCY) < 0 )
{
*DOT = ATL_sdsdot( *N, *B, X, -(*INCX), Y, -(*INCY) );
}
else
{
*DOT = ATL_sdsdot( *N, *B, V1N( N, X, INCX ), *INCX, Y, *INCY );
}
}
else if( (*INCY) < 0 )
{
*DOT = ATL_sdsdot( *N, *B, VN1( N, X, INCX ), -(*INCX), Y, -(*INCY) );
}
else
{
*DOT = ATL_sdsdot( *N, *B, X, *INCX, Y, *INCY );
}
/*
* End of ATL_F77wrap_sdsdot
*/
}