83 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			83 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Copyright (c) 2003, 2007-14 Matteo Frigo
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|  * Copyright (c) 2003, 2007-14 Massachusetts Institute of Technology
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|  *
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|  * This program is free software; you can redistribute it and/or modify
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|  * it under the terms of the GNU General Public License as published by
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|  * the Free Software Foundation; either version 2 of the License, or
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|  * (at your option) any later version.
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|  *
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|  * This program is distributed in the hope that it will be useful,
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|  * but WITHOUT ANY WARRANTY; without even the implied warranty of
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|  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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|  * GNU General Public License for more details.
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|  *
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|  * You should have received a copy of the GNU General Public License
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|  * along with this program; if not, write to the Free Software
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|  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
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|  *
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|  */
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| 
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| #include "kernel/ifftw.h"
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| 
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| 
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| /* Given a solver which_dim, a vector sz, and whether or not the
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|    transform is out-of-place, return the actual dimension index that
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|    it corresponds to.  The basic idea here is that we return the
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|    which_dim'th valid dimension, starting from the end if
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|    which_dim < 0. */
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| static int really_pickdim(int which_dim, const tensor *sz, int oop, int *dp)
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| {
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|      int i;
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|      int count_ok = 0;
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|      if (which_dim > 0) {
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|           for (i = 0; i < sz->rnk; ++i) {
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|                if (oop || sz->dims[i].is == sz->dims[i].os)
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|                     if (++count_ok == which_dim) {
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|                          *dp = i;
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|                          return 1;
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|                     }
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|           }
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|      }
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|      else if (which_dim < 0) {
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|           for (i = sz->rnk - 1; i >= 0; --i) {
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|                if (oop || sz->dims[i].is == sz->dims[i].os)
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|                     if (++count_ok == -which_dim) {
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|                          *dp = i;
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|                          return 1;
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|                     }
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|           }
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|      }
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|      else { /* zero: pick the middle, if valid */
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| 	  i = (sz->rnk - 1) / 2;
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| 	  if (i >= 0 && (oop || sz->dims[i].is == sz->dims[i].os)) {
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| 	       *dp = i;
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| 	       return 1;
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| 	  }
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|      }
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|      return 0;
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| }
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| 
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| /* Like really_pickdim, but only returns 1 if no previous "buddy"
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|    which_dim in the buddies list would give the same dim. */
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| int X(pickdim)(int which_dim, const int *buddies, size_t nbuddies,
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| 	       const tensor *sz, int oop, int *dp)
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| {
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|      size_t i;
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|      int d1;
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| 
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|      if (!really_pickdim(which_dim, sz, oop, dp))
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|           return 0;
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| 
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|      /* check whether some buddy solver would produce the same dim.
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|         If so, consider this solver unapplicable and let the buddy
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|         take care of it.  The smallest-indexed buddy is applicable. */
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|      for (i = 0; i < nbuddies; ++i) {
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|           if (buddies[i] == which_dim)
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|                break;  /* found self */
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|           if (really_pickdim(buddies[i], sz, oop, &d1) && *dp == d1)
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|                return 0; /* found equivalent buddy */
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|      }
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|      return 1;
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| }
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