MATHLIB_cos.cpp

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#define ELEMENT_COUNT(x) c7x::element_count_of<x>::value
 
/******************************************************************************/
/*                                                                            */
/* Includes                                                                   */
/*                                                                            */
/******************************************************************************/
 
#include "MATHLIB_types.h"
#include "MATHLIB_utility.h"
 
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/*                                                                            */
/* MATHLIB_cos                                                                 */
/*                                                                            */
/******************************************************************************/
 
// this method performs cosine coputation of input vector
template <typename T> MATHLIB_STATUS MATHLIB_cos(size_t length, T *pSrc, T *pDst)
{
 
   // variables
   MATHLIB_STATUS status       = MATHLIB_SUCCESS; // return function status
   size_t         numBlocks    = 0;               // compute loop's iteration count
   size_t         remNumBlocks = 0;               // when numBlocks is not a multiple of SIMD width
 
   // derive c7x vector type from template typename
   typedef typename c7x::make_full_vector<T>::type vec;
 
   // Compile-time decision: float_vec => int_vec and double_vec=> long_vec
   typedef
       typename std::conditional<ELEMENT_COUNT(c7x::float_vec) == ELEMENT_COUNT(vec), c7x::int_vec, c7x::long_vec>::type
           vec_type;
 
   __SE_TEMPLATE_v1 se0Params = __gen_SE_TEMPLATE_v1();
   __SA_TEMPLATE_v1 sa0Params = __gen_SA_TEMPLATE_v1();
 
   // check for null pointers and non-zero length
   status = MATHLIB_checkParams(length, pSrc, pDst);
 
   if (status == MATHLIB_SUCCESS) {
 
      MATHLIB_SE0SA01DSequentialInit(&se0Params, &sa0Params, length, pSrc, pDst);
 
      // calculate compute loop's iteration counter
      numBlocks    = length / c7x::element_count_of<vec>::value;
      remNumBlocks = length % c7x::element_count_of<vec>::value;
      if (remNumBlocks) {
         numBlocks++;
      }
 
      // open SE0, SE1, and SA0 for reading and writing operands
      MATHLIB_SE0SA0Open(&se0Params, &sa0Params, pSrc);
 
      /**********************************************************************/
      /* Create and assign values for constants employed on cos computation */
      /**********************************************************************/
 
      vec InvPI, HalfPI, One, MAX, Zero, s1, s2, s3, s4, C1, C2;
 
      InvPI  = (vec) 0.318309886183791;
      HalfPI = (vec) 1.5707963268;
      One    = (vec) 1.0;
      MAX    = (vec) 1048576.0;
 
      Zero = (vec) 0.0;
      s1   = (vec) -1.666665668e-1;
      s2   = (vec) 8.333025139e-3;
      s3   = (vec) -1.980741872e-4;
      s4   = (vec) 2.601903036e-6;
      C1   = (vec) 3.140625;
      C2   = (vec) 9.67653589793e-4;
 
      // compute loop to perform vector cos
      for (size_t i = 0; i < numBlocks; i++) {
         vec inVec = c7x::strm_eng<0, vec>::get_adv();
 
         /**********************************************************************/
         /* Create and assign values for variables employed on cos computation */
         /**********************************************************************/
 
         vec Sign, X, Y, Z, F, G, R;
 
         vec_type int_one = (vec_type) 1;
         vec_type N;
 
         vec negativeOne = (vec) -1;
         vec negativeR;
         Sign = One;
 
         //      if (Y > MAX) {
         //        Y = HalfPI;
         //      }
         Y              = __abs(inVec) + HalfPI;
         __vpred cmp_gt = __cmp_lt_pred((vec) MAX, Y);
         Y              = __select(cmp_gt, HalfPI, Y);
 
         // X = Y * (1/PI)
         X = Y * InvPI;
 
         N = __float_to_int(X);
         Z = c7x::convert<vec>(N);
 
         /**********************************************************************/
         /* Sign checking for quadrant 3 or 4                                  */
         /**********************************************************************/
 
         //      if ((N % 2) != 0) {
         //         Sign = -Sign;
         //      }
         vec_type andN    = N & int_one;
         vec convert_andN = c7x::convert<vec>(andN);
         __vpred  cmp_mod = __cmp_le_pred(convert_andN, Zero);
         vec      Sign_T  = __select(cmp_mod, Sign, negativeOne);
 
         F = (Y - (Z * C1)) - (Z * C2);
         R = F;
 
         //      if (F < Zero) {
         //        R = -R;
         //      }
         negativeR     = -R;
         __vpred cmp_F = __cmp_lt_pred(F, Zero);
         R             = __select(cmp_F, R, negativeR);
 
         G = F * F;
 
         __vpred cmp_RMin = __cmp_lt_pred(R, Zero);
 
         vec outputRMin = R * Sign_T;
         R              = ((((((s4 * G) + s3) * G) + s2) * G) + s1) * G;
         vec outVec     = ((F + (F * R)) * Sign_T);
 
         outVec = __select(cmp_RMin, outVec, outputRMin);
 
         // outVec.print();
 
         __vpred tmp  = c7x::strm_agen<0, vec>::get_vpred();
         vec    *addr = c7x::strm_agen<0, vec>::get_adv(pDst);
         __vstore_pred(tmp, addr, outVec);
      }
 
      MATHLIB_SE0SA0Close();
   }
 
   return status;
}
 
/******************************************************************************/
/*                                                                            */
/* Explicit templatization for datatypes supported by MATHLIB_cos              */
/*                                                                            */
/******************************************************************************/
 
// single precision
template MATHLIB_STATUS MATHLIB_cos<float>(size_t length, float *pSrc, float *pDst);
 
/******************************************************************************/
/*                                                                            */
/* C-interface wrapper functions                                              */
/*                                                                            */
/******************************************************************************/
 
extern "C" {
 
// single-precision wrapper
MATHLIB_STATUS MATHLIB_cos_sp(size_t length, float *pSrc, float *pDst)
{
   MATHLIB_STATUS status = MATHLIB_cos(length, pSrc, pDst);
   return status;
}
 
} // extern "C"