[BACK]Return to mul.c CVS log [TXT][DIR] Up to [local] / OpenXM_contrib / gmp / mpfr

Diff for /OpenXM_contrib/gmp/mpfr/Attic/mul.c between version 1.1 and 1.1.1.2

version 1.1, 2000/09/09 14:12:19 version 1.1.1.2, 2003/08/25 16:06:07
Line 1 
Line 1 
 /* mpfr_mul -- multiply two floating-point numbers  /* mpfr_mul -- multiply two floating-point numbers
   
 Copyright (C) 1999 PolKA project, Inria Lorraine and Loria  Copyright 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
   
 This file is part of the MPFR Library.  This file is part of the MPFR Library.
   
 The MPFR Library is free software; you can redistribute it and/or modify  The MPFR Library is free software; you can redistribute it and/or modify
 it under the terms of the GNU Library General Public License as published by  it under the terms of the GNU Lesser General Public License as published by
 the Free Software Foundation; either version 2 of the License, or (at your  the Free Software Foundation; either version 2.1 of the License, or (at your
 option) any later version.  option) any later version.
   
 The MPFR Library is distributed in the hope that it will be useful, but  The MPFR Library is distributed in the hope that it will be useful, but
 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
 License for more details.  License for more details.
   
 You should have received a copy of the GNU Library General Public License  You should have received a copy of the GNU Lesser General Public License
 along with the MPFR Library; see the file COPYING.LIB.  If not, write to  along with the MPFR Library; see the file COPYING.LIB.  If not, write to
 the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,  the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 MA 02111-1307, USA. */  MA 02111-1307, USA. */
   
 #include <stdio.h>  
 #include "gmp.h"  #include "gmp.h"
 #include "gmp-impl.h"  #include "gmp-impl.h"
 #include "mpfr.h"  #include "mpfr.h"
   #include "mpfr-impl.h"
   
 /* Remains to do:  int
 - do not use all bits of b and c when PREC(b)>PREC(a) or PREC(c)>PREC(a)  mpfr_mul (mpfr_ptr a, mpfr_srcptr b, mpfr_srcptr c, mp_rnd_t rnd_mode)
   [current complexity is O(PREC(b)*PREC(c))]  
 */  
   
 void  
 #if __STDC__  
 mpfr_mul(mpfr_ptr a, mpfr_srcptr b, mpfr_srcptr c, unsigned char rnd_mode)  
 #else  
 mpfr_mul(a, b, c, rnd_mode)  
      mpfr_ptr a;  
      mpfr_srcptr b;  
      mpfr_srcptr c;  
      unsigned char rnd_mode;  
 #endif  
 {  {
   unsigned int bn, cn, an, tn, k; int cc;    int sign_product, cc, inexact, ec, em = 0;
   mp_limb_t *ap=MANT(a), *bp=MANT(b), *cp=MANT(c), *tmp, b1;    mp_exp_t bx, cx;
   long int sign_product;    mp_limb_t *ap, *bp, *cp, *tmp;
   TMP_DECL(marker);    mp_limb_t b1;
     mp_prec_t aq, bq, cq;
     mp_size_t an, bn, cn, tn, k;
     TMP_DECL(marker);
   
   /* deal with NaN and zero */    /* deal with NaN and zero */
   if (FLAG_NAN(b) || FLAG_NAN(c)) { SET_NAN(a); return; }    if (MPFR_IS_NAN(b) || MPFR_IS_NAN(c))
   if (!NOTZERO(b) || !NOTZERO(c)) { SET_ZERO(a); return; }      {
         MPFR_SET_NAN(a);
         MPFR_RET_NAN;
       }
   
   sign_product = SIGN(b) * SIGN(c);    MPFR_CLEAR_NAN(a);
   bn = (PREC(b)-1)/mp_bits_per_limb+1; /* number of significant limbs of b */  
   cn = (PREC(c)-1)/mp_bits_per_limb+1; /* number of significant limbs of c */    sign_product = MPFR_SIGN(b) * MPFR_SIGN(c);
   tn = (PREC(c)+PREC(b)-1)/mp_bits_per_limb+1;  
   k = bn+cn; /* effective nb of limbs used by b*c */    if (MPFR_IS_INF(b))
       {
         if (MPFR_IS_INF(c) || MPFR_NOTZERO(c))
           {
             if (MPFR_SIGN(a) != sign_product)
               MPFR_CHANGE_SIGN(a);
             MPFR_SET_INF(a);
             MPFR_RET(0); /* exact */
           }
         else
           {
             MPFR_SET_NAN(a);
             MPFR_RET_NAN;
           }
       }
     else if (MPFR_IS_INF(c))
       {
         if (MPFR_NOTZERO(b))
           {
             if (MPFR_SIGN(a) != sign_product)
               MPFR_CHANGE_SIGN(a);
             MPFR_SET_INF(a);
             MPFR_RET(0); /* exact */
           }
         else
           {
             MPFR_SET_NAN(a);
             MPFR_RET_NAN;
           }
       }
   
     MPFR_ASSERTN(MPFR_IS_FP(b) && MPFR_IS_FP(c));
     MPFR_CLEAR_INF(a); /* clear Inf flag */
   
     if (MPFR_IS_ZERO(b) || MPFR_IS_ZERO(c))
       {
         if (MPFR_SIGN(a) != sign_product)
           MPFR_CHANGE_SIGN(a);
         MPFR_SET_ZERO(a);
         MPFR_RET(0); /* 0 * 0 is exact */
       }
   
     bx = MPFR_EXP(b);
     cx = MPFR_EXP(c);
     /* Note: exponent of the result will be bx + cx + ec with ec in {-1,0,1} */
     if (bx >= 0 && cx > 0)
       { /* bx + cx > 0 */
         if (__mpfr_emax < 0 ||
             (mp_exp_unsigned_t) bx + cx > (mp_exp_unsigned_t) __mpfr_emax + 1)
           return mpfr_set_overflow(a, rnd_mode, sign_product);
   
         if ((mp_exp_unsigned_t) bx + cx == (mp_exp_unsigned_t) __mpfr_emax + 1)
           em = 1;
       }
     else if (bx <= 0 && cx < 0)
       { /* bx + cx < 0 */
         if (__mpfr_emin > 0 ||
             (mp_exp_unsigned_t) bx + cx < (mp_exp_unsigned_t) __mpfr_emin - 1)
           return mpfr_set_underflow(a, rnd_mode, sign_product);
   
         if ((mp_exp_unsigned_t) bx + cx == (mp_exp_unsigned_t) __mpfr_emin - 1)
           em = -1;
       }
     else
       { /* bx != 0 and cx doesn't have the same sign */
         if ((bx + cx) - 1 > __mpfr_emax)
           return mpfr_set_overflow(a, rnd_mode, sign_product);
   
         if ((bx + cx) - 1 == __mpfr_emax)
           em = 1;
   
         if ((bx + cx) + 1 < __mpfr_emin)
           return mpfr_set_underflow(a, rnd_mode, sign_product);
   
         if ((bx + cx) + 1 == __mpfr_emin)
           em = -1;
       }
   
     ap = MPFR_MANT(a);
     bp = MPFR_MANT(b);
     cp = MPFR_MANT(c);
   
     aq = MPFR_PREC(a);
     bq = MPFR_PREC(b);
     cq = MPFR_PREC(c);
   
     an = (aq-1)/BITS_PER_MP_LIMB + 1; /* number of significant limbs of a */
     bn = (bq-1)/BITS_PER_MP_LIMB + 1; /* number of significant limbs of b */
     cn = (cq-1)/BITS_PER_MP_LIMB + 1; /* number of significant limbs of c */
   
     MPFR_ASSERTN((mp_size_unsigned_t) bn + cn <= MP_SIZE_T_MAX);
     k = bn + cn; /* effective nb of limbs used by b*c (= tn or tn+1) below */
   
     MPFR_ASSERTN(bq + cq >= bq); /* no integer overflow */
     tn = (bq + cq - 1) / BITS_PER_MP_LIMB + 1; /* <= k, thus no int overflow */
   
     MPFR_ASSERTN(k <= ((size_t) -1) / BYTES_PER_MP_LIMB);
   TMP_MARK(marker);    TMP_MARK(marker);
   tmp = (mp_limb_t*) TMP_ALLOC(k*BYTES_PER_MP_LIMB);    tmp = (mp_limb_t *) TMP_ALLOC((size_t) k * BYTES_PER_MP_LIMB);
   
   /* multiplies two mantissa in temporary allocated space */    /* multiplies two mantissa in temporary allocated space */
   b1 = (bn>=cn) ? mpn_mul(tmp, bp, bn, cp, cn) : mpn_mul(tmp, cp, cn, bp, bn);    b1 = (bn >= cn) ? mpn_mul (tmp, bp, bn, cp, cn)
       : mpn_mul (tmp, cp, cn, bp, bn);
   
   /* now tmp[0]..tmp[k-1] contains the product of both mantissa,    /* now tmp[0]..tmp[k-1] contains the product of both mantissa,
      with tmp[k-1]>=2^(mp_bits_per_limb-2) */       with tmp[k-1]>=2^(BITS_PER_MP_LIMB-2) */
   an = (PREC(a)-1)/mp_bits_per_limb+1; /* number of significant limbs of a */    b1 >>= BITS_PER_MP_LIMB - 1; /* msb from the product */
   b1 >>= mp_bits_per_limb-1; /* msb from the product */  
   
   if (b1==0) mpn_lshift(tmp, tmp, k, 1);    tmp += k - tn;
   cc = mpfr_round_raw(ap, tmp+bn+cn-tn,    if (b1 == 0)
                       PREC(b)+PREC(c), (sign_product<0), PREC(a), rnd_mode);      mpn_lshift (tmp, tmp, tn, 1);
   if (cc) { /* cc = 1 ==> result is a power of two */    cc = mpfr_round_raw (ap, tmp, bq + cq, sign_product < 0, aq,
     ap[an-1] = (mp_limb_t) 1 << (BITS_PER_MP_LIMB-1);                         rnd_mode, &inexact);
   }    if (cc) /* cc = 1 ==> result is a power of two */
   EXP(a) = EXP(b) + EXP(c) + b1 - 1 + cc;      ap[an-1] = GMP_LIMB_HIGHBIT;
   if (sign_product * SIGN(a)<0) CHANGE_SIGN(a);  
   TMP_FREE(marker);    TMP_FREE(marker);
   return;  
     ec = b1 - 1 + cc;
   
     if (em == 0)
       {
         mp_exp_t ax = bx + cx;
   
         if (ax == __mpfr_emax && ec > 0)
           return mpfr_set_overflow(a, rnd_mode, sign_product);
   
         if (ax == __mpfr_emin && ec < 0)
           return mpfr_set_underflow(a, rnd_mode, sign_product);
   
         MPFR_EXP(a) = ax + ec;
       }
     else if (em > 0)
       {
         if (ec >= 0)
           return mpfr_set_overflow(a, rnd_mode, sign_product);
   
         MPFR_EXP(a) = __mpfr_emax;
       }
     else
       {
         if (ec <= 0)
           return mpfr_set_underflow(a, rnd_mode, sign_product);
   
         MPFR_EXP(a) = __mpfr_emin;
       }
   
     if (MPFR_SIGN(a) != sign_product)
       MPFR_CHANGE_SIGN(a);
   
     return inexact;
 }  }
Legend:
Removed from v.1.1  
changed lines
  Added in v.1.1.1.2
FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>