src/parsec/disk-image/parsec/parsec-benchmark/pkgs/libs/gsl/src/fft/c_pass_6.c - public/gem5-resources - Git at Google

 /* fft/c_pass_6.c
  *
  * Copyright (C) 1996, 1997, 1998, 1999, 2000 Brian Gough
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or (at
  * your option) any later version.
  *
  * This program is distributed in the hope that it will be useful, but
  * WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  */

 static int
 FUNCTION(fft_complex,pass_6) (const BASE in[],
                               const size_t istride,
                               BASE out[],
                               const size_t ostride,
                               const gsl_fft_direction sign,
                               const size_t product,
                               const size_t n,
                               const TYPE(gsl_complex) twiddle1[],
                               const TYPE(gsl_complex) twiddle2[],
                               const TYPE(gsl_complex) twiddle3[],
                               const TYPE(gsl_complex) twiddle4[],
                               const TYPE(gsl_complex) twiddle5[])
 {

   size_t i = 0, j = 0;
   size_t k, k1;

   const size_t factor = 6;
   const size_t m = n / factor;
   const size_t q = n / product;
   const size_t p_1 = product / factor;
   const size_t jump = (factor - 1) * p_1;

   const ATOMIC tau = sqrt (3.0) / 2.0;

   for (k = 0; k < q; k++)
     {
       ATOMIC w1_real, w1_imag, w2_real, w2_imag, w3_real, w3_imag, w4_real,
         w4_imag, w5_real, w5_imag;

       if (k == 0)
         {
           w1_real = 1.0;
           w1_imag = 0.0;
           w2_real = 1.0;
           w2_imag = 0.0;
           w3_real = 1.0;
           w3_imag = 0.0;
           w4_real = 1.0;
           w4_imag = 0.0;
           w5_real = 1.0;
           w5_imag = 0.0;
         }
       else
         {
           if (sign == gsl_fft_forward)
             {
               /* forward tranform */
               w1_real = GSL_REAL(twiddle1[k - 1]);
               w1_imag = GSL_IMAG(twiddle1[k - 1]);
               w2_real = GSL_REAL(twiddle2[k - 1]);
               w2_imag = GSL_IMAG(twiddle2[k - 1]);
               w3_real = GSL_REAL(twiddle3[k - 1]);
               w3_imag = GSL_IMAG(twiddle3[k - 1]);
               w4_real = GSL_REAL(twiddle4[k - 1]);
               w4_imag = GSL_IMAG(twiddle4[k - 1]);
               w5_real = GSL_REAL(twiddle5[k - 1]);
               w5_imag = GSL_IMAG(twiddle5[k - 1]);
             }
           else
             {
               /* backward tranform: w -> conjugate(w) */
               w1_real = GSL_REAL(twiddle1[k - 1]);
               w1_imag = -GSL_IMAG(twiddle1[k - 1]);
               w2_real = GSL_REAL(twiddle2[k - 1]);
               w2_imag = -GSL_IMAG(twiddle2[k - 1]);
               w3_real = GSL_REAL(twiddle3[k - 1]);
               w3_imag = -GSL_IMAG(twiddle3[k - 1]);
               w4_real = GSL_REAL(twiddle4[k - 1]);
               w4_imag = -GSL_IMAG(twiddle4[k - 1]);
               w5_real = GSL_REAL(twiddle5[k - 1]);
               w5_imag = -GSL_IMAG(twiddle5[k - 1]);
             }
         }

       for (k1 = 0; k1 < p_1; k1++)
         {
           const ATOMIC z0_real = REAL(in,istride,i);
           const ATOMIC z0_imag = IMAG(in,istride,i);
           const ATOMIC z1_real = REAL(in,istride,i+m);
           const ATOMIC z1_imag = IMAG(in,istride,i+m);
           const ATOMIC z2_real = REAL(in,istride,i+2*m);
           const ATOMIC z2_imag = IMAG(in,istride,i+2*m);
           const ATOMIC z3_real = REAL(in,istride,i+3*m);
           const ATOMIC z3_imag = IMAG(in,istride,i+3*m);
           const ATOMIC z4_real = REAL(in,istride,i+4*m);
           const ATOMIC z4_imag = IMAG(in,istride,i+4*m);
           const ATOMIC z5_real = REAL(in,istride,i+5*m);
           const ATOMIC z5_imag = IMAG(in,istride,i+5*m);

           /* compute x = W(6) z */

           /* W(6) is a combination of sums and differences of W(3) acting
              on the even and odd elements of z */

           /* ta1 = z2 + z4 */
           const ATOMIC ta1_real = z2_real + z4_real;
           const ATOMIC ta1_imag = z2_imag + z4_imag;

           /* ta2 = z0 - ta1/2 */
           const ATOMIC ta2_real = z0_real - ta1_real / 2;
           const ATOMIC ta2_imag = z0_imag - ta1_imag / 2;

           /* ta3 = (+/-) sin(pi/3)*(z2 - z4) */
           const ATOMIC ta3_real = ((int) sign) * tau * (z2_real - z4_real);
           const ATOMIC ta3_imag = ((int) sign) * tau * (z2_imag - z4_imag);

           /* a0 = z0 + ta1 */
           const ATOMIC a0_real = z0_real + ta1_real;
           const ATOMIC a0_imag = z0_imag + ta1_imag;

           /* a1 = ta2 + i ta3 */
           const ATOMIC a1_real = ta2_real - ta3_imag;
           const ATOMIC a1_imag = ta2_imag + ta3_real;

           /* a2 = ta2 - i ta3 */
           const ATOMIC a2_real = ta2_real + ta3_imag;
           const ATOMIC a2_imag = ta2_imag - ta3_real;

           /* tb1 = z5 + z1 */
           const ATOMIC tb1_real = z5_real + z1_real;
           const ATOMIC tb1_imag = z5_imag + z1_imag;

           /* tb2 = z3 - tb1/2 */
           const ATOMIC tb2_real = z3_real - tb1_real / 2;
           const ATOMIC tb2_imag = z3_imag - tb1_imag / 2;

           /* tb3 = (+/-) sin(pi/3)*(z5 - z1) */
           const ATOMIC tb3_real = ((int) sign) * tau * (z5_real - z1_real);
           const ATOMIC tb3_imag = ((int) sign) * tau * (z5_imag - z1_imag);

           /* b0 = z3 + tb1 */
           const ATOMIC b0_real = z3_real + tb1_real;
           const ATOMIC b0_imag = z3_imag + tb1_imag;

           /* b1 = tb2 + i tb3 */
           const ATOMIC b1_real = tb2_real - tb3_imag;
           const ATOMIC b1_imag = tb2_imag + tb3_real;

           /* b2 = tb2 - i tb3 */
           const ATOMIC b2_real = tb2_real + tb3_imag;
           const ATOMIC b2_imag = tb2_imag - tb3_real;

           /* x0 = a0 + b0 */
           const ATOMIC x0_real = a0_real + b0_real;
           const ATOMIC x0_imag = a0_imag + b0_imag;

           /* x4 = a1 + b1 */
           const ATOMIC x4_real = a1_real + b1_real;
           const ATOMIC x4_imag = a1_imag + b1_imag;

           /* x2 = a2 + b2 */
           const ATOMIC x2_real = a2_real + b2_real;
           const ATOMIC x2_imag = a2_imag + b2_imag;

           /* x3 = a0 - b0 */
           const ATOMIC x3_real = a0_real - b0_real;
           const ATOMIC x3_imag = a0_imag - b0_imag;

           /* x1 = a1 - b1 */
           const ATOMIC x1_real = a1_real - b1_real;
           const ATOMIC x1_imag = a1_imag - b1_imag;

           /* x5 = a2 - b2 */
           const ATOMIC x5_real = a2_real - b2_real;
           const ATOMIC x5_imag = a2_imag - b2_imag;

           /* apply twiddle factors */

           /* to0 = 1 * x0 */
           REAL(out,ostride,j) = x0_real;
           IMAG(out,ostride,j) = x0_imag;

           /* to1 = w1 * x1 */
           REAL(out,ostride,j+p_1) = w1_real * x1_real - w1_imag * x1_imag;
           IMAG(out,ostride,j+p_1) = w1_real * x1_imag + w1_imag * x1_real;

           /* to2 = w2 * x2 */
           REAL(out,ostride,j+2*p_1) = w2_real * x2_real - w2_imag * x2_imag;
           IMAG(out,ostride,j+2*p_1) = w2_real * x2_imag + w2_imag * x2_real;

           /* to3 = w3 * x3 */
           REAL(out,ostride,j+3*p_1) = w3_real * x3_real - w3_imag * x3_imag;
           IMAG(out,ostride,j+3*p_1) = w3_real * x3_imag + w3_imag * x3_real;

           /* to4 = w4 * x4 */
           REAL(out,ostride,j+4*p_1) = w4_real * x4_real - w4_imag * x4_imag;
           IMAG(out,ostride,j+4*p_1) = w4_real * x4_imag + w4_imag * x4_real;

           /* to5 = w5 * x5 */
           REAL(out,ostride,j+5*p_1) = w5_real * x5_real - w5_imag * x5_imag;
           IMAG(out,ostride,j+5*p_1) = w5_real * x5_imag + w5_imag * x5_real;

           i++;
           j++;
         }
       j += jump;
     }
   return 0;
 }
	/* fft/c_pass_6.c
	*
	* Copyright (C) 1996, 1997, 1998, 1999, 2000 Brian Gough
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or (at
	* your option) any later version.
	*
	* This program is distributed in the hope that it will be useful, but
	* WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
	*/

	static int
	FUNCTION(fft_complex,pass_6) (const BASE in[],
	const size_t istride,
	BASE out[],
	const size_t ostride,
	const gsl_fft_direction sign,
	const size_t product,
	const size_t n,
	const TYPE(gsl_complex) twiddle1[],
	const TYPE(gsl_complex) twiddle2[],
	const TYPE(gsl_complex) twiddle3[],
	const TYPE(gsl_complex) twiddle4[],
	const TYPE(gsl_complex) twiddle5[])
	{

	size_t i = 0, j = 0;
	size_t k, k1;

	const size_t factor = 6;
	const size_t m = n / factor;
	const size_t q = n / product;
	const size_t p_1 = product / factor;
	const size_t jump = (factor - 1) * p_1;

	const ATOMIC tau = sqrt (3.0) / 2.0;

	for (k = 0; k < q; k++)
	{
	ATOMIC w1_real, w1_imag, w2_real, w2_imag, w3_real, w3_imag, w4_real,
	w4_imag, w5_real, w5_imag;

	if (k == 0)
	{
	w1_real = 1.0;
	w1_imag = 0.0;
	w2_real = 1.0;
	w2_imag = 0.0;
	w3_real = 1.0;
	w3_imag = 0.0;
	w4_real = 1.0;
	w4_imag = 0.0;
	w5_real = 1.0;
	w5_imag = 0.0;
	}
	else
	{
	if (sign == gsl_fft_forward)
	{
	/* forward tranform */
	w1_real = GSL_REAL(twiddle1[k - 1]);
	w1_imag = GSL_IMAG(twiddle1[k - 1]);
	w2_real = GSL_REAL(twiddle2[k - 1]);
	w2_imag = GSL_IMAG(twiddle2[k - 1]);
	w3_real = GSL_REAL(twiddle3[k - 1]);
	w3_imag = GSL_IMAG(twiddle3[k - 1]);
	w4_real = GSL_REAL(twiddle4[k - 1]);
	w4_imag = GSL_IMAG(twiddle4[k - 1]);
	w5_real = GSL_REAL(twiddle5[k - 1]);
	w5_imag = GSL_IMAG(twiddle5[k - 1]);
	}
	else
	{
	/* backward tranform: w -> conjugate(w) */
	w1_real = GSL_REAL(twiddle1[k - 1]);
	w1_imag = -GSL_IMAG(twiddle1[k - 1]);
	w2_real = GSL_REAL(twiddle2[k - 1]);
	w2_imag = -GSL_IMAG(twiddle2[k - 1]);
	w3_real = GSL_REAL(twiddle3[k - 1]);
	w3_imag = -GSL_IMAG(twiddle3[k - 1]);
	w4_real = GSL_REAL(twiddle4[k - 1]);
	w4_imag = -GSL_IMAG(twiddle4[k - 1]);
	w5_real = GSL_REAL(twiddle5[k - 1]);
	w5_imag = -GSL_IMAG(twiddle5[k - 1]);
	}
	}

	for (k1 = 0; k1 < p_1; k1++)
	{
	const ATOMIC z0_real = REAL(in,istride,i);
	const ATOMIC z0_imag = IMAG(in,istride,i);
	const ATOMIC z1_real = REAL(in,istride,i+m);
	const ATOMIC z1_imag = IMAG(in,istride,i+m);
	const ATOMIC z2_real = REAL(in,istride,i+2*m);
	const ATOMIC z2_imag = IMAG(in,istride,i+2*m);
	const ATOMIC z3_real = REAL(in,istride,i+3*m);
	const ATOMIC z3_imag = IMAG(in,istride,i+3*m);
	const ATOMIC z4_real = REAL(in,istride,i+4*m);
	const ATOMIC z4_imag = IMAG(in,istride,i+4*m);
	const ATOMIC z5_real = REAL(in,istride,i+5*m);
	const ATOMIC z5_imag = IMAG(in,istride,i+5*m);

	/* compute x = W(6) z */

	/* W(6) is a combination of sums and differences of W(3) acting
	on the even and odd elements of z */

	/* ta1 = z2 + z4 */
	const ATOMIC ta1_real = z2_real + z4_real;
	const ATOMIC ta1_imag = z2_imag + z4_imag;

	/* ta2 = z0 - ta1/2 */
	const ATOMIC ta2_real = z0_real - ta1_real / 2;
	const ATOMIC ta2_imag = z0_imag - ta1_imag / 2;

	/* ta3 = (+/-) sin(pi/3)(z2 - z4) /
	const ATOMIC ta3_real = ((int) sign) * tau * (z2_real - z4_real);
	const ATOMIC ta3_imag = ((int) sign) * tau * (z2_imag - z4_imag);

	/* a0 = z0 + ta1 */
	const ATOMIC a0_real = z0_real + ta1_real;
	const ATOMIC a0_imag = z0_imag + ta1_imag;

	/* a1 = ta2 + i ta3 */
	const ATOMIC a1_real = ta2_real - ta3_imag;
	const ATOMIC a1_imag = ta2_imag + ta3_real;

	/* a2 = ta2 - i ta3 */
	const ATOMIC a2_real = ta2_real + ta3_imag;
	const ATOMIC a2_imag = ta2_imag - ta3_real;

	/* tb1 = z5 + z1 */
	const ATOMIC tb1_real = z5_real + z1_real;
	const ATOMIC tb1_imag = z5_imag + z1_imag;

	/* tb2 = z3 - tb1/2 */
	const ATOMIC tb2_real = z3_real - tb1_real / 2;
	const ATOMIC tb2_imag = z3_imag - tb1_imag / 2;

	/* tb3 = (+/-) sin(pi/3)(z5 - z1) /
	const ATOMIC tb3_real = ((int) sign) * tau * (z5_real - z1_real);
	const ATOMIC tb3_imag = ((int) sign) * tau * (z5_imag - z1_imag);

	/* b0 = z3 + tb1 */
	const ATOMIC b0_real = z3_real + tb1_real;
	const ATOMIC b0_imag = z3_imag + tb1_imag;

	/* b1 = tb2 + i tb3 */
	const ATOMIC b1_real = tb2_real - tb3_imag;
	const ATOMIC b1_imag = tb2_imag + tb3_real;

	/* b2 = tb2 - i tb3 */
	const ATOMIC b2_real = tb2_real + tb3_imag;
	const ATOMIC b2_imag = tb2_imag - tb3_real;

	/* x0 = a0 + b0 */
	const ATOMIC x0_real = a0_real + b0_real;
	const ATOMIC x0_imag = a0_imag + b0_imag;

	/* x4 = a1 + b1 */
	const ATOMIC x4_real = a1_real + b1_real;
	const ATOMIC x4_imag = a1_imag + b1_imag;

	/* x2 = a2 + b2 */
	const ATOMIC x2_real = a2_real + b2_real;
	const ATOMIC x2_imag = a2_imag + b2_imag;

	/* x3 = a0 - b0 */
	const ATOMIC x3_real = a0_real - b0_real;
	const ATOMIC x3_imag = a0_imag - b0_imag;

	/* x1 = a1 - b1 */
	const ATOMIC x1_real = a1_real - b1_real;
	const ATOMIC x1_imag = a1_imag - b1_imag;

	/* x5 = a2 - b2 */
	const ATOMIC x5_real = a2_real - b2_real;
	const ATOMIC x5_imag = a2_imag - b2_imag;

	/* apply twiddle factors */

	/* to0 = 1 * x0 */
	REAL(out,ostride,j) = x0_real;
	IMAG(out,ostride,j) = x0_imag;

	/* to1 = w1 * x1 */
	REAL(out,ostride,j+p_1) = w1_real * x1_real - w1_imag * x1_imag;
	IMAG(out,ostride,j+p_1) = w1_real * x1_imag + w1_imag * x1_real;

	/* to2 = w2 * x2 */
	REAL(out,ostride,j+2p_1) = w2_real x2_real - w2_imag * x2_imag;
	IMAG(out,ostride,j+2p_1) = w2_real x2_imag + w2_imag * x2_real;

	/* to3 = w3 * x3 */
	REAL(out,ostride,j+3p_1) = w3_real x3_real - w3_imag * x3_imag;
	IMAG(out,ostride,j+3p_1) = w3_real x3_imag + w3_imag * x3_real;

	/* to4 = w4 * x4 */
	REAL(out,ostride,j+4p_1) = w4_real x4_real - w4_imag * x4_imag;
	IMAG(out,ostride,j+4p_1) = w4_real x4_imag + w4_imag * x4_real;

	/* to5 = w5 * x5 */
	REAL(out,ostride,j+5p_1) = w5_real x5_real - w5_imag * x5_imag;
	IMAG(out,ostride,j+5p_1) = w5_real x5_imag + w5_imag * x5_real;

	i++;
	j++;
	}
	j += jump;
	}
	return 0;
	}