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Diff for /OpenXM_contrib/gmp/mpf/Attic/set_prc.c between version 1.1.1.2 and 1.1.1.3

version 1.1.1.2, 2000/09/09 14:13:14 version 1.1.1.3, 2003/08/25 16:06:35
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 /* mpf_set_prec(x) -- Change the precision of x.  /* mpf_set_prec(x) -- Change the precision of x.
   
 Copyright (C) 1993, 1994, 1995, 2000 Free Software Foundation, Inc.  Copyright 1993, 1994, 1995, 2000, 2001 Free Software Foundation, Inc.
   
 This file is part of the GNU MP Library.  This file is part of the GNU MP Library.
   
Line 22  MA 02111-1307, USA. */
Line 22  MA 02111-1307, USA. */
 #include "gmp.h"  #include "gmp.h"
 #include "gmp-impl.h"  #include "gmp-impl.h"
   
   
   /* A full new_prec+1 limbs are always retained, even though just new_prec
      would satisfy the requested precision.  If size==new_prec+1 then
      certainly new_prec+1 should be kept since no copying is needed in that
      case.  If just new_prec was kept for size>new_prec+1 it'd be a bit
      inconsistent.  */
   
 void  void
 #if __STDC__  mpf_set_prec (mpf_ptr x, unsigned long int new_prec_in_bits)
 mpf_set_prec (mpf_ptr x, unsigned long int prec_in_bits)  
 #else  
 mpf_set_prec (x, prec_in_bits)  
      mpf_ptr x;  
      unsigned long int prec_in_bits;  
 #endif  
 {  {
   mp_size_t prec;    mp_size_t  old_prec, new_prec, new_prec_plus1;
   mp_size_t size = ABS (x->_mp_size);    mp_size_t  size, sign;
     mp_ptr     xp;
   
   prec = (MAX (53, prec_in_bits) + 2 * BITS_PER_MP_LIMB - 1)/BITS_PER_MP_LIMB;    new_prec = __GMPF_BITS_TO_PREC (new_prec_in_bits);
     old_prec = PREC(x);
   
   /* We want the most significant limbs, so move the limbs down if we are    /* do nothing if already the right precision */
      about to truncate the value.  */    if (new_prec == old_prec)
   if (size > prec + 1)      return;
     {  
       mp_size_t offset = size - (prec + 1);  
       mp_ptr xp = x->_mp_d;  
   
       MPN_COPY_INCR (xp, xp + offset, prec + 1);    PREC(x) = new_prec;
     new_prec_plus1 = new_prec + 1;
   
     /* retain most significant limbs */
     sign = SIZ(x);
     size = ABS (sign);
     xp = PTR(x);
     if (size > new_prec_plus1)
       {
         SIZ(x) = (sign >= 0 ? new_prec_plus1 : -new_prec_plus1);
         MPN_COPY_INCR (xp, xp + size - new_prec_plus1, new_prec_plus1);
     }      }
   
   x->_mp_d = (mp_ptr) (*_mp_reallocate_func)    PTR(x) = __GMP_REALLOCATE_FUNC_LIMBS (xp, old_prec+1, new_prec_plus1);
     (x->_mp_d,  
      (x->_mp_prec + 1) * BYTES_PER_MP_LIMB, (prec + 1) * BYTES_PER_MP_LIMB);  
   x->_mp_prec = prec;  
   
   /* If the precision decreased, truncate the number.  */  
   if (size > prec + 1)  
     x->_mp_size = x->_mp_size >= 0 ? (prec + 1) : -(prec + 1);  
 }  }
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  Added in v.1.1.1.3
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