/* ======================================================================== */
/* TEXAS INSTRUMENTS, INC. */
/* */
/* NAME */
/* DSPF_sp_bitrev_cplx -- Bit reversal for Single Precision Complex */
/* numbers */
/* */
/* */
/* USAGE */
/* */
/* This routine is C Callable and can be called as: */
/* */
/* void DSPF_sp_bitrev_cplx(double *x, short *index, int nx); */
/* */
/* x : Complex input array to be bit-reversed. */
/* Contains 2*nx floats */
/* index : Array of size ~sqrt(nx) created by the routine */
/* bitrev_index to allow the fast implementation of the */
/* bit-reversal. */
/* nx : Number of elements in array x[]. Must be power of 2. */
/* */
/* DESCRIPTION */
/* This routine performs the bit-reversal of the input array x[], */
/* where x[] is a float array of length 2*nx containing single */
/* precision floating point complex pairs of data. This routine */
/* requires the index array provided by the program below. */
/* This index should be generated at compile time not by the DSP. */
/* */
/* TI retains all rights, title and interest in this code and only */
/* authorizes the use of the bit-reversal code and related table */
/* generation code with TMS320-family DSPs manufactured by TI. */
/* */
/* // ----------------------------------------------------------- // */
/* // This routine calculates the index for bit reversal of // */
/* // an array of length nx. The length of the index table is // */
/* // 2^(2*ceil(k/2)) where nx = 2^k. // */
/* // // */
/* // In other words, the length of the index table is: // */
/* // - for even power of radix: sqrt(nx) // */
/* // - for odd power of radix: sqrt(2*nx) // */
/* // ----------------------------------------------------------- // */
/* void bitrev_index(short *index, int nx) */
/* { */
/* int i, j, k, radix = 2; */
/* short nbits, nbot, ntop, ndiff, n2, raddiv2; */
/* */
/* nbits = 0; */
/* i = nx; */
/* while (i > 1) */
/* { */
/* i = i >> 1; */
/* nbits++; */
/* } */
/* */
/* raddiv2 = radix >> 1; */
/* nbot = nbits >> raddiv2; */
/* nbot = nbot << raddiv2 - 1; */
/* ndiff = nbits & raddiv2; */
/* ntop = nbot + ndiff; */
/* n2 = 1 << ntop; */
/* */
/* index[0] = 0; */
/* for ( i = 1, j = n2/radix + 1; i < n2 - 1; i++) */
/* { */
/* index[i] = j - 1; */
/* */
/* for (k = n2/radix; k*(radix-1) < j; k /= radix) */
/* j -= k*(radix-1); */
/* */
/* j += k; */
/* } */
/* index[n2 - 1] = n2 - 1; */
/* } */
/* */
/* ------------------------------------------------------------------------ */
/* Copyright (c) 2003 Texas Instruments, Incorporated. */
/* All Rights Reserved. */
/* ======================================================================== */
#ifndef DSPF_SP_BITREV_CPLX_
#define DSPF_SP_BITREV_CPLX_ 1
void DSPF_sp_bitrev_cplx(double * x, short * index, int n);
#endif
/* ========================================================================*/
/* End of file: dspf_sp_bitrev_cplx.h */
/* ------------------------------------------------------------------------*/
/* Copyright (C) 2003 Texas Instruments, Incorporated. */
/* All Rights Reserved. */
/* ========================================================================*/