83 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			83 lines
		
	
	
		
			2.3 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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| /* routines shared by the various buffered solvers */
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| 
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| #include "kernel/ifftw.h"
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| 
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| #define DEFAULT_MAXNBUF ((INT)256)
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| 
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| /* approx. 512KB of buffers for complex data */
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| #define MAXBUFSZ (256 * 1024 / (INT)(sizeof(R)))
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| 
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| INT X(nbuf)(INT n, INT vl, INT maxnbuf)
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| {
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|      INT i, nbuf, lb; 
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| 
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|      if (!maxnbuf) 
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| 	  maxnbuf = DEFAULT_MAXNBUF;
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| 
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|      nbuf = X(imin)(maxnbuf,
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| 		    X(imin)(vl, X(imax)((INT)1, MAXBUFSZ / n)));
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| 
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|      /*
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|       * Look for a buffer number (not too small) that divides the
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|       * vector length, in order that we only need one child plan:
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|       */
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|      lb = X(imax)(1, nbuf / 4);
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|      for (i = nbuf; i >= lb; --i)
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|           if (vl % i == 0)
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|                return i;
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| 
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|      /* whatever... */
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|      return nbuf;
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| }
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| 
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| #define SKEW 6 /* need to be even for SIMD */
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| #define SKEWMOD 8 
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| 
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| INT X(bufdist)(INT n, INT vl)
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| {
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|      if (vl == 1)
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| 	  return n;
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|      else 
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| 	  /* return smallest X such that X >= N and X == SKEW (mod SKEWMOD) */
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| 	  return n + X(modulo)(SKEW - n, SKEWMOD);
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| }
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| 
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| int X(toobig)(INT n)
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| {
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|      return n > MAXBUFSZ;
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| }
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| 
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| /* TRUE if there exists i < which such that maxnbuf[i] and
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|    maxnbuf[which] yield the same value, in which case we canonicalize
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|    on the minimum value */
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| int X(nbuf_redundant)(INT n, INT vl, size_t which, 
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| 		      const INT *maxnbuf, size_t nmaxnbuf)
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| {
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|      size_t i;
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|      (void)nmaxnbuf; /* UNUSED */
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|      for (i = 0; i < which; ++i)
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| 	  if (X(nbuf)(n, vl, maxnbuf[i]) == X(nbuf)(n, vl, maxnbuf[which]))
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| 	       return 1;
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|      return 0;
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| }
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