===================================================================
RCS file: /home/cvs/OpenXM_contrib/gmp/mpfr/Attic/add.c,v
retrieving revision 1.1
retrieving revision 1.1.1.2
diff -u -p -r1.1 -r1.1.1.2
--- OpenXM_contrib/gmp/mpfr/Attic/add.c	2000/09/09 14:12:19	1.1
+++ OpenXM_contrib/gmp/mpfr/Attic/add.c	2003/08/25 16:06:06	1.1.1.2
@@ -1,404 +1,105 @@
 /* mpfr_add -- add two floating-point numbers
 
-Copyright (C) 1999 PolKA project, Inria Lorraine and Loria
+Copyright 1999, 2000, 2001 Free Software Foundation.
+Contributed by the Spaces project, INRIA Lorraine.
 
 This file is part of the MPFR Library.
 
 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
-the Free Software Foundation; either version 2 of the License, or (at your
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or (at your
 option) any later version.
 
 The MPFR Library 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 Library General Public
+or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
 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
 the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 MA 02111-1307, USA. */
 
-#include <stdio.h>
 #include "gmp.h"
 #include "gmp-impl.h"
 #include "mpfr.h"
+#include "mpfr-impl.h"
 
-extern void mpfr_sub1 _PROTO((mpfr_ptr, mpfr_srcptr, mpfr_srcptr, 
-			      unsigned char, int));
-
-#define ONE ((mp_limb_t) 1)
-
-/* signs of b and c are supposed equal,
-   diff_exp is the difference between the exponents of b and c,
-   which is supposed >= 0 */
-
-void 
-#if __STDC__
-mpfr_add1(mpfr_ptr a, mpfr_srcptr b, mpfr_srcptr c, 
-	  unsigned char rnd_mode, int diff_exp) 
-#else
-mpfr_add1(a, b, c, rnd_mode, diff_exp) 
-     mpfr_ptr a; 
-     mpfr_srcptr b; 
-     mpfr_srcptr c; 
-     unsigned char rnd_mode; 
-     int diff_exp;
-#endif
+int
+mpfr_add (mpfr_ptr a, mpfr_srcptr b, mpfr_srcptr c, mp_rnd_t rnd_mode)
 {
-  mp_limb_t *ap, *bp, *cp, cc, c2, c3=0; unsigned int an,bn,cn; int sh,dif,k;
-  TMP_DECL(marker); 
-
-  TMP_MARK(marker); 
-  ap = MANT(a);
-  bp = MANT(b);
-  cp = MANT(c); 
-  if (ap == bp) {
-    bp = (mp_ptr) TMP_ALLOC(ABSSIZE(b) * BYTES_PER_MP_LIMB); 
-    MPN_COPY (bp, ap, ABSSIZE(b));
-    if (ap == cp) { cp = bp; }
-  }
-  else if (ap == cp)
+  if (MPFR_IS_NAN(b) || MPFR_IS_NAN(c))
     {
-      cp = (mp_ptr) TMP_ALLOC (ABSSIZE(c) * BYTES_PER_MP_LIMB);
-      MPN_COPY(cp, ap, ABSSIZE(c)); 
+      MPFR_SET_NAN(a);
+      MPFR_RET_NAN;
     }
 
-  an = (PREC(a)-1)/mp_bits_per_limb+1; /* number of significant limbs of a */
+  MPFR_CLEAR_NAN(a);
 
-  sh = an*mp_bits_per_limb-PREC(a); /* non-significant bits in low limb */
-  bn = (PREC(b)-1)/mp_bits_per_limb+1; /* number of significant limbs of b */
-  EXP(a) = EXP(b);
-
-  if (SIGN(a)!=SIGN(b)) CHANGE_SIGN(a);
-
-  /* case 1: diff_exp>=prec(a), i.e. c only affects the last bit
-     through rounding */
-  dif = PREC(a)-diff_exp;
-
-  if (dif<=0) { 
-    
-    /* diff_exp>=PREC(a): c does not overlap with a */
-    /* either PREC(b)<=PREC(a), and we can copy the mantissa of b directly 
-       into that of a, or PREC(b)>PREC(a) and we have to round b+c */
-
-    if (PREC(b)<=PREC(a)) {
-
-      MPN_COPY(ap+(an-bn), bp, bn);
-      /* fill low significant limbs with zero */
-
-      for (bp=ap;bn<an;bn++) *bp++=0;
-
-      /* now take c into account */
-      if (rnd_mode==GMP_RNDN) { 
-	
-	/* to nearest */
-	/* if diff_exp > PREC(a), no change */
-
-	if (diff_exp==PREC(a)) {
-
-	  /* if c is not zero, then as it is normalized, we have to add
-	     one to the lsb of a if c>1/2, or c=1/2 and lsb(a)=1 (round to
-	     even) */
-	  
-	  if (NOTZERO(c)) { 
-
-	    /* c is not zero */
-	    /* check whether mant(c)=1/2 or not */
-
-	    cc = *cp - (ONE<<(mp_bits_per_limb-1));
-	    if (cc==0) {
-	      bp = cp+(PREC(c)-1)/mp_bits_per_limb;
-	      while (cp<bp && cc==0) cc = *++cp;
-	    }
-
-	    if (cc || (ap[an-1] & (ONE<<sh))) goto add_one_ulp;
-	    /* mant(c) != 1/2 or mant(c) = 1/2: add 1 iff lsb(a)=1 */
-	  }
-	}
-      }
-      else if ((ISNONNEG(b) && rnd_mode==GMP_RNDU) || 
-	       (ISNEG(b) && rnd_mode==GMP_RNDD)) {
-	
-	/* round up */
-	if (NOTZERO(c)) goto add_one_ulp;
-      }
-      /* in the other cases (round to zero, or up/down with sign -/+),
-         nothing to do */
+  if (MPFR_IS_INF(b))
+    {
+      if (!MPFR_IS_INF(c) || MPFR_SIGN(b) == MPFR_SIGN(c))
+        {
+          MPFR_SET_INF(a);
+          MPFR_SET_SAME_SIGN(a, b);
+          MPFR_RET(0); /* exact */
+        }
+      else
+        {
+          MPFR_SET_NAN(a);
+          MPFR_RET_NAN;
+        }
     }
-    else { 
-
-      /* PREC(b)>PREC(a) : we have to round b+c */      
-      k=bn-an;
-
-      /* first copy the 'an' most significant limbs of b to a */
-      MPN_COPY(ap, bp+k, an);
-      if (rnd_mode==GMP_RNDN) { 
-	
-	/* to nearest */
-	/* first check whether the truncated bits from b are 1/2*lsb(a) */
-	
-	if (sh) {
-	  cc = *ap & ((ONE<<sh)-1);
-	  *ap &= ~cc; /* truncate last bits */
-	  cc -= ONE<<(sh-1);
-	}
-	else /* no bit to truncate */
-	  cc = bp[--k] - (ONE<<(mp_bits_per_limb-1));
-
-	if ((long)cc>0) goto add_one_ulp; /* trunc(b)>1/2*lsb(a) -> round up */
-	else if (cc==0) {
-
-	  while (k>1 && cc==0) cc=bp[--k];
-
-	  /* now if the truncated part of b = 1/2*lsb(a), check whether c=0 */
-	  if (NOTZERO(c) || (*ap & (ONE<<sh))) goto add_one_ulp;
-	  /* if trunc(b)+c is exactly 1/2*lsb(a) : round to even lsb */
-	}
-
-	/* if cc<0 : trunc(b) < 1/2*lsb(a) -> round down, i.e. do nothing */
+  else
+    if (MPFR_IS_INF(c))
+      {
+        MPFR_SET_INF(a);
+        MPFR_SET_SAME_SIGN(a, c);
+        MPFR_RET(0); /* exact */
       }
-      else if ((ISNONNEG(b) && rnd_mode==GMP_RNDU) || 
-	       (ISNEG(b) && rnd_mode==GMP_RNDD)) {
 
-	/* first check whether trunc(b)+c is zero or not */
-	if (sh) {
-	  cc = *ap & ((ONE<<sh)-1); *ap &= ~cc; /* truncate last bits */
-	}
-	else cc = bp[--k] - (ONE<<(mp_bits_per_limb-1));
-	while (cc==0 && k>1) cc=bp[--k];
-	if (cc || NOTZERO(c)) goto add_one_ulp;
-      }
+  MPFR_ASSERTN(MPFR_IS_FP(b) && MPFR_IS_FP(c));
 
-      /* in the other cases (round to zero, or up/down with sign -/+),
-         nothing to do, since b and c don't overlap, there can't be any
-	 carry */
-
+  if (MPFR_IS_ZERO(b))
+    {
+      if (MPFR_IS_ZERO(c))
+        {
+          if (MPFR_SIGN(a) !=
+              (rnd_mode != GMP_RNDD ?
+               ((MPFR_SIGN(b) < 0 && MPFR_SIGN(c) < 0) ? -1 : 1) :
+               ((MPFR_SIGN(b) > 0 && MPFR_SIGN(c) > 0) ? 1 : -1)))
+            {
+              MPFR_CHANGE_SIGN(a);
+            }
+          MPFR_CLEAR_INF(a);
+          MPFR_SET_ZERO(a);
+          MPFR_RET(0); /* 0 + 0 is exact */
+        }
+      return mpfr_set(a, c, rnd_mode);
     }
-  }
-  else { 
-    /* diff_exp < PREC(a) : c overlaps with a by dif bits */
-    /* first copy upper part of c into a (after shift) */
-    unsigned char overlap;
-    
-    k = (dif-1)/mp_bits_per_limb + 1; /* only the highest k limbs from c
-					 have to be considered */
-    cn = (PREC(c)-1)/mp_bits_per_limb + 1;
-    MPN_ZERO(ap+k, an-k); /* do it now otherwise ap[k] may be destroyed
-			     in case dif<0 */
 
-    if (dif<=PREC(c)) { 
-      /* c has to be truncated */
-      dif = dif % mp_bits_per_limb;
-      dif = (dif) ? mp_bits_per_limb-dif-sh : -sh;
-
-      /* we have to shift by dif bits to the right */
-
-      if (dif>0) mpn_rshift(ap, cp+(cn-k), k, dif);
-      else if (dif<0) {
-	ap[k] = mpn_lshift(ap, cp+(cn-k), k, -dif);
-
-	/* put the non-significant bits in low limb for further rounding */
-
-	if (cn >= k+1)
-	  ap[0] += cp[cn-k-1]>>(mp_bits_per_limb+dif);
-      }
-      else MPN_COPY(ap, cp+(cn-k), k);
-      overlap=1;
+  if (MPFR_IS_ZERO(c))
+    {
+      return mpfr_set(a, b, rnd_mode);
     }
-    else { 
 
-      /* c is not truncated, but we have to fill low limbs with 0 */
+  MPFR_CLEAR_INF(a); /* clear Inf flag */
 
-      k = diff_exp/mp_bits_per_limb;
-      overlap = diff_exp%mp_bits_per_limb;
-
-      /* warning: a shift of zero bit is not allowed */
-      MPN_ZERO(ap, an-k-cn); 
-      if (overlap) { 
-	cc=mpn_rshift(ap+(an-k-cn), cp, cn, overlap); 
-	if (an-k-cn>0) ap[an-k-cn-1]=cc;
-      }
-      else MPN_COPY(ap+(an-k-cn), cp, cn);
-      overlap=0;
+  if (MPFR_SIGN(b) != MPFR_SIGN(c))
+    { /* signs differ, it's a subtraction */
+      return mpfr_sub1(a, b, c, rnd_mode, 0);
     }
-
-    /* here overlap=1 iff ulp(c)<ulp(a) */
-    /* then put high limbs to zero */
-    /* now add 'an' upper limbs of b in place */
-
-    if (PREC(b)<=PREC(a)) {
-      overlap += 2;
-      cc = mpn_add_n(ap+(an-bn), ap+(an-bn), bp, bn);
+  else
+    { /* signs are equal, it's an addition */
+      if (MPFR_EXP(b) < MPFR_EXP(c))
+        {
+          return mpfr_add1(a, c, b, rnd_mode,
+                           (mp_exp_unsigned_t) MPFR_EXP(c) - MPFR_EXP(b));
+        }
+      else
+        {
+          return mpfr_add1(a, b, c, rnd_mode,
+                           (mp_exp_unsigned_t) MPFR_EXP(b) - MPFR_EXP(c));
+        }
     }
-    else
-      /* PREC(b) > PREC(a): we have to truncate b */
-      cc = mpn_add_n(ap, ap, bp+(bn-an), an); 
-
-    if (cc) { 
-
-      /* shift one bit to the right */
-
-      c3 = (ap[0]&1) && (PREC(a)%mp_bits_per_limb==0);
-      mpn_rshift(ap, ap, an, 1);
-      ap[an-1] += ONE<<(mp_bits_per_limb-1);
-      EXP(a)++;
-    }
-    
-    /* remains to do the rounding */
-
-    if (rnd_mode==GMP_RNDN) { 
-
-      /* to nearest */
-
-      int kc;
-      
-      /* four cases: overlap =
-         (0) PREC(b) > PREC(a) and diff_exp+PREC(c) <= PREC(a)
-         (1) PREC(b) > PREC(a) and diff_exp+PREC(c) > PREC(a)
-         (2) PREC(b) <= PREC(a) and diff_exp+PREC(c) <= PREC(a)
-         (3)  PREC(b) <= PREC(a) and diff_exp+PREC(c) > PREC(a) */
-      
-      switch (overlap)
-	{
-        case 1: /* both b and c to round */
-	  kc = cn-k; /* remains kc limbs from c */
-	  k = bn-an; /* remains k limbs from b */
-	
-	  /* truncate last bits and store the difference with 1/2*ulp in cc */
-
-	  cc = *ap & ((ONE<<sh)-1);
-	  *ap &= ~cc; /* truncate last bits */
-	  cc -= ONE<<(sh-1);
-	  while ((cc==0 || cc==-1) && k!=0 && kc!=0) {
-	    kc--;
-	    cc += mpn_add_1(&c2, bp+(--k), 1,(cp[kc+1]<<(mp_bits_per_limb-dif))
-			    +(cp[kc]>>dif));
-	    if (cc==0 || cc==-1) cc=c2;
-	  }
-	  if ((long)cc>0) goto add_one_ulp;
-	  else if ((long)cc<-1) 
-	    { TMP_FREE(marker); return; /* the carry can be at most 1 */ }
-	  else if (kc==0) goto round_b;
-
-	  /* else round c: go through */
-
-	case 3: /* only c to round */
-	  bp=cp; k=cn-k; goto to_nearest;
-
-	case 0: /* only b to round */
-        round_b:
-	  k=bn-an; dif=0; goto to_nearest;
-        
-	  /* otherwise the result is exact: nothing to do */
-	}
-    }
-    else if ((ISNONNEG(b) && rnd_mode==GMP_RNDU) || 
-	     (ISNEG(b) && rnd_mode==GMP_RNDD)) {
-      cc = *ap & ((ONE<<sh)-1);
-      *ap &= ~cc; /* truncate last bits */
-      if (cc || c3) goto add_one_ulp; /* will happen most of the time */
-      else { 
-	
-	/* same four cases too */
-	
-	int kc = cn-k; /* remains kc limbs from c */
-	switch (overlap)
-	{
-        case 1: /* both b and c to round */
-	  k = bn-an; /* remains k limbs from b */
-	  while (cc==0 && k!=0 && kc!=0) {
-	    kc--;
-	    cc = mpn_add_1(&c2, bp+(--k), 1,(cp[kc+1]<<(mp_bits_per_limb-dif))
-			   + (cp[kc]>>dif));
-	  }
-	  if (cc) goto add_one_ulp;
-	  else if (kc==0) goto round_b2;
-	  /* else round c: go through */
-	case 3: /* only c to round */
-	  while (kc) if (cp[--kc]) goto add_one_ulp;
-	  /* if dif>0 : remains to check last dif bits from c */
-	  if (dif>0 && (cp[0]<<(mp_bits_per_limb-dif))) goto add_one_ulp;
-	  break;
-	case 0: /* only b to round */
-        round_b2:
-	  k=bn-an;
-	  while (k) if (bp[--k]) goto add_one_ulp;
-        /* otherwise the result is exact: nothing to do */
-	}
-      }
-    }
-    /* else nothing to do: round towards zero, i.e. truncate last sh bits */
-    else 
-      *ap &= ~((ONE<<sh)-1);
-  }
-  goto end_of_add;
-    
-  to_nearest: /* 0 <= sh < mp_bits_per_limb : number of bits of a to truncate
-                 bp[k] : last significant limb from b */
-        if (sh) {
-	  cc = *ap & ((ONE<<sh)-1);
-	  *ap &= ~cc; /* truncate last bits */
-	  c2 = ONE<<(sh-1);
-	}
-	else /* no bit to truncate */
-	  { if (k) cc = bp[--k]; else cc = 0; c2 = ONE<<(mp_bits_per_limb-1); }
-	if (cc>c2) goto add_one_ulp; /* trunc(b)>1/2*lsb(a) -> round up */
-	else if (cc==c2) {
-	  cc=0; while (k && cc==0) cc=bp[--k];
-	  /* special case of rouding c shifted to the right */
-	  if (cc==0 && dif>0) cc=cp[0]<<(mp_bits_per_limb-dif);
-	  /* now if the truncated part of b = 1/2*lsb(a), check whether c=0 */
-	  if (cc || (*ap & (ONE<<sh))) goto add_one_ulp;
-	}
-        goto end_of_add;
-
-  add_one_ulp: /* add one unit in last place to a */
-    cc = mpn_add_1(ap, ap, an, ONE<<sh);
-    if (cc) { fprintf(stderr, "carry(3) in mpfr_add\n"); exit(1); }
-
- end_of_add:
-  TMP_FREE(marker); 
-  return;
 }
-
-void
-#if __STDC__
-mpfr_add(mpfr_ptr a, mpfr_srcptr b, mpfr_srcptr c, 
-	      unsigned char rnd_mode) 
-#else
-mpfr_add(a, b, c, rnd_mode)
-     mpfr_ptr a; 
-     mpfr_srcptr b; 
-     mpfr_srcptr c; 
-     unsigned char rnd_mode; 
-#endif
-{
-  int diff_exp;
-
-  if (FLAG_NAN(b) || FLAG_NAN(c)) {
-    SET_NAN(a); return;
-  }
-
-  if (!NOTZERO(b)) { mpfr_set(a, c, rnd_mode); return; }
-  if (!NOTZERO(c)) { mpfr_set(a, b, rnd_mode); return; }
-
-  diff_exp = EXP(b)-EXP(c);
-  if (SIGN(b) != SIGN(c)) { /* signs differ, it's a subtraction */
-    if (diff_exp<0) {
-      mpfr_sub1(a, c, b, rnd_mode, -diff_exp);
-    }
-    else if (diff_exp>0) mpfr_sub1(a, b, c, rnd_mode, diff_exp);
-    else { /* diff_exp=0 */
-      diff_exp = mpfr_cmp3(b,c,-1);
-      /* if b>0 and diff_exp>0 or b<0 and diff_exp<0: abs(b) > abs(c) */
-      if (diff_exp==0) SET_ZERO(a);
-      else if (diff_exp*SIGN(b)>0) mpfr_sub1(a, b, c, rnd_mode, 0);
-      else mpfr_sub1(a, c, b, rnd_mode, 0);
-    }
-  }
-  else /* signs are equal, it's an addition */
-    if (diff_exp<0) mpfr_add1(a, c, b, rnd_mode, -diff_exp);
-    else mpfr_add1(a, b, c, rnd_mode, diff_exp);
-}
-