[src/add1sp.c] fixed issues found with --enable-assert=full

git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@10688 280ebfd0-de03-0410-8827-d642c229c3f4

1 files changed, 22 insertions, 18 deletions

diff --git a/src/add1sp.c b/src/add1sp.c
index 55affc356..176fe403a 100644
--- a/src/add1sp.c
+++ b/src/add1sp.c
@@ -88,7 +88,7 @@ int mpfr_add1sp (mpfr_ptr a, mpfr_srcptr b, mpfr_srcptr c, mpfr_rnd_t rnd_mode)
   mpfr_clears (tmpa, tmpb, tmpc, (mpfr_ptr) 0);
   return inexact;
 }
-# define mpfr_add1sp mpfr_add1sp2
+# define mpfr_add1sp mpfr_add1sp_ref
 #endif  /* MPFR_WANT_ASSERT >= 2 */
 
 /* Debugging support */
@@ -230,13 +230,13 @@ mpfr_add1sp2 (mpfr_ptr a, mpfr_srcptr b, mpfr_srcptr c, mpfr_rnd_t rnd_mode,
   mp_limb_t mask;
   mpfr_uexp_t d;
 
-  MPFR_ASSERTD(p < GMP_NUMB_BITS);
+  MPFR_ASSERTD(GMP_NUMB_BITS < p && p < 2 * GMP_NUMB_BITS);
 
   if (bx == cx)
     {
       /* since bp[1], cp[1] >= MPFR_LIMB_HIGHBIT, a carry always occurs */
       a0 = bp[0] + cp[0];
-      a1 = bp[1] + cp[1] + (sb < bp[0]);
+      a1 = bp[1] + cp[1] + (a0 < bp[0]);
       ap[0] = (a0 >> 1) | (a1 << (GMP_NUMB_BITS - 1));
       ap[1] = MPFR_LIMB_HIGHBIT | (a1 >> 1);
       bx ++;
@@ -246,7 +246,7 @@ mpfr_add1sp2 (mpfr_ptr a, mpfr_srcptr b, mpfr_srcptr c, mpfr_rnd_t rnd_mode,
     }
   else if (bx > cx)
     {
-    BGreater1:
+    BGreater2:
       d = (mpfr_uexp_t) bx - cx;
       mask = MPFR_LIMB_MASK(sh);
       if (d < GMP_NUMB_BITS) /* 0 < d < GMP_NUMB_BITS */
@@ -254,30 +254,34 @@ mpfr_add1sp2 (mpfr_ptr a, mpfr_srcptr b, mpfr_srcptr c, mpfr_rnd_t rnd_mode,
           a0 = bp[0];
           a1 = bp[1];
           sb = cp[0] << (GMP_NUMB_BITS - d); /* bits from cp[-1] after shift */
-          ap[0] = a0 + ((cp[1] << (GMP_NUMB_BITS - d)) | (cp[0] >> d));
+          a0 += (cp[1] << (GMP_NUMB_BITS - d)) | (cp[0] >> d);
           ap[1] = a1 + (cp[1] >> d);
-          if (ap[0] < a0) /* carry in low word */
+          if (a0 < bp[0]) /* carry in low word */
             ap[1] ++;
           if (ap[1] < a1) /* carry in high word */
             {
-              sb |= ap[0] & 1;
+            exponent_shift:
+              sb |= a0 & 1;
               /* shift a by 1 */
-              ap[0] = (ap[1] << (GMP_NUMB_BITS - 1)) | (ap[0] >> 1);
+              a0 = (ap[1] << (GMP_NUMB_BITS - 1)) | (a0 >> 1);
               ap[1] = MPFR_LIMB_HIGHBIT | (ap[1] >> 1);
               bx ++;
             }
-          rb = ap[0] & (MPFR_LIMB_ONE << (sh - 1));
-          sb |= (ap[0] & mask) ^ rb;
-          ap[0] = ap[0] & ~mask;
+          rb = a0 & (MPFR_LIMB_ONE << (sh - 1));
+          sb |= (a0 & mask) ^ rb;
+          ap[0] = a0 & ~mask;
         }
       else if (d < 2*GMP_NUMB_BITS) /* GMP_NUMB_BITS <= d < 2*GMP_NUMB_BITS */
         {
-          sb = cp[0] | (cp[1] << (2*GMP_NUMB_BITS-d));
-          ap[1] = bp[1];
-          ap[0] = bp[0] + (cp[1] >> (d - GMP_NUMB_BITS));
-          rb = ap[0] & (MPFR_LIMB_ONE << (sh - 1));
-          sb |= (ap[0] & mask) ^ rb;
-          ap[0] = ap[0] & ~mask;
+          sb = (d == GMP_NUMB_BITS) ? cp[0]
+            : cp[0] | (cp[1] << (2*GMP_NUMB_BITS-d));
+          a0 = bp[0] + (cp[1] >> (d - GMP_NUMB_BITS));
+          ap[1] = bp[1] + (a0 < bp[0]);
+          if (ap[1] == 0)
+            goto exponent_shift;
+          rb = a0 & (MPFR_LIMB_ONE << (sh - 1));
+          sb |= (a0 & mask) ^ rb;
+          ap[0] = a0 & ~mask;
         }
       else /* d >= 2*GMP_NUMB_BITS */
         {
@@ -293,7 +297,7 @@ mpfr_add1sp2 (mpfr_ptr a, mpfr_srcptr b, mpfr_srcptr c, mpfr_rnd_t rnd_mode,
       mp_limb_t *tp;
       tx = bx; bx = cx; cx = tx;
       tp = bp; bp = cp; cp = tp;
-      goto BGreater1;
+      goto BGreater2;
     }
 
   /* now perform rounding */