83 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
		
		
			
		
	
	
			83 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
|   | /*
 | ||
|  |  * Copyright (c) 2003, 2007-14 Matteo Frigo | ||
|  |  * Copyright (c) 2003, 2007-14 Massachusetts Institute of Technology | ||
|  |  * | ||
|  |  * 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 | ||
|  |  * | ||
|  |  */ | ||
|  | 
 | ||
|  | /* routines shared by the various buffered solvers */ | ||
|  | 
 | ||
|  | #include "kernel/ifftw.h"
 | ||
|  | 
 | ||
|  | #define DEFAULT_MAXNBUF ((INT)256)
 | ||
|  | 
 | ||
|  | /* approx. 512KB of buffers for complex data */ | ||
|  | #define MAXBUFSZ (256 * 1024 / (INT)(sizeof(R)))
 | ||
|  | 
 | ||
|  | INT X(nbuf)(INT n, INT vl, INT maxnbuf) | ||
|  | { | ||
|  |      INT i, nbuf, lb;  | ||
|  | 
 | ||
|  |      if (!maxnbuf)  | ||
|  | 	  maxnbuf = DEFAULT_MAXNBUF; | ||
|  | 
 | ||
|  |      nbuf = X(imin)(maxnbuf, | ||
|  | 		    X(imin)(vl, X(imax)((INT)1, MAXBUFSZ / n))); | ||
|  | 
 | ||
|  |      /*
 | ||
|  |       * Look for a buffer number (not too small) that divides the | ||
|  |       * vector length, in order that we only need one child plan: | ||
|  |       */ | ||
|  |      lb = X(imax)(1, nbuf / 4); | ||
|  |      for (i = nbuf; i >= lb; --i) | ||
|  |           if (vl % i == 0) | ||
|  |                return i; | ||
|  | 
 | ||
|  |      /* whatever... */ | ||
|  |      return nbuf; | ||
|  | } | ||
|  | 
 | ||
|  | #define SKEW 6 /* need to be even for SIMD */
 | ||
|  | #define SKEWMOD 8 
 | ||
|  | 
 | ||
|  | INT X(bufdist)(INT n, INT vl) | ||
|  | { | ||
|  |      if (vl == 1) | ||
|  | 	  return n; | ||
|  |      else  | ||
|  | 	  /* return smallest X such that X >= N and X == SKEW (mod SKEWMOD) */ | ||
|  | 	  return n + X(modulo)(SKEW - n, SKEWMOD); | ||
|  | } | ||
|  | 
 | ||
|  | int X(toobig)(INT n) | ||
|  | { | ||
|  |      return n > MAXBUFSZ; | ||
|  | } | ||
|  | 
 | ||
|  | /* TRUE if there exists i < which such that maxnbuf[i] and
 | ||
|  |    maxnbuf[which] yield the same value, in which case we canonicalize | ||
|  |    on the minimum value */ | ||
|  | int X(nbuf_redundant)(INT n, INT vl, size_t which,  | ||
|  | 		      const INT *maxnbuf, size_t nmaxnbuf) | ||
|  | { | ||
|  |      size_t i; | ||
|  |      (void)nmaxnbuf; /* UNUSED */ | ||
|  |      for (i = 0; i < which; ++i) | ||
|  | 	  if (X(nbuf)(n, vl, maxnbuf[i]) == X(nbuf)(n, vl, maxnbuf[which])) | ||
|  | 	       return 1; | ||
|  |      return 0; | ||
|  | } |