--- gforth/prim	1999/05/09 21:21:55	1.30
+++ gforth/prim	1999/05/16 17:13:22	1.33
@@ -129,6 +129,7 @@ EXEC(*(Xt *)a_addr);
 :
  @ execute ;
 
+\fhas? skipbranchprims 0= [IF]
 \+glocals
 
 branch-lp+!#	--	gforth	branch_lp_plus_store_number
@@ -208,6 +209,8 @@ else
   INC_IP(1);
 
 \+
+\f[THEN]
+\fhas? skiploopprims 0= [IF]
 
 condbranch((next),--		cmFORTH	paren_next,
 if ((*rp)--) {
@@ -437,30 +440,33 @@ n = rp[4];
   r> r> r> r> r> r> dup itmp ! >r >r >r >r >r >r itmp @ ;
 [IFUNDEF] itmp variable itmp [THEN]
 
+\f[THEN]
+
 \ digit is high-level: 0/0%
 
 move	c_from c_to ucount --		core
-"" If @i{ucount}>0, copy the contents of @i{ucount} address units
-at @i{c-from} to @i{c-to}. @code{move} chooses its copy direction
-to avoid problems when @i{c-from}, @i{c-to} overlap.""
+""Copy the contents of @i{ucount} address units at @i{c-from} to
+@i{c-to}. @code{move} works correctly even if the two areas overlap.""
 memmove(c_to,c_from,ucount);
 /* make an Ifdef for bsd and others? */
 :
  >r 2dup u< IF r> cmove> ELSE r> cmove THEN ;
 
 cmove	c_from c_to u --	string
-"" If @i{u}>0, copy the contents of @i{ucount} characters from
-data space at @i{c-from} to @i{c-to}. The copy proceeds @code{char}-by-@code{char}
-from low address to high address.""
+""Copy the contents of @i{ucount} characters from data space at
+@i{c-from} to @i{c-to}. The copy proceeds @code{char}-by-@code{char}
+from low address to high address; i.e., for overlapping areas it is
+safe if @i{c-to}=<@i{c-from}.""
 while (u-- > 0)
   *c_to++ = *c_from++;
 :
  bounds ?DO  dup c@ I c! 1+  LOOP  drop ;
 
 cmove>	c_from c_to u --	string	c_move_up
-"" If @i{u}>0, copy the contents of @i{ucount} characters from
-data space at @i{c-from} to @i{c-to}. The copy proceeds @code{char}-by-@code{char}
-from high address to low address.""
+""Copy the contents of @i{ucount} characters from data space at
+@i{c-from} to @i{c-to}. The copy proceeds @code{char}-by-@code{char}
+from high address to low address; i.e., for overlapping areas it is
+safe if @i{c-to}>=@i{c-from}.""
 while (u-- > 0)
   c_to[u] = c_from[u];
 :
@@ -713,6 +719,7 @@ ud = (UDCell)u1 * (UDCell)u2;
    and >r >r 2dup d+ swap r> + swap r> ;
 
 um/mod	ud u1 -- u2 u3		core	u_m_slash_mod
+""ud=u3*u1+u2, u1>u2>=0""
 #ifdef BUGGY_LONG_LONG
 UDCell r = umdiv(ud,u1);
 u2=r.hi;
@@ -928,6 +935,13 @@ dcomparisons(du, ud1 ud2, d_u_, ud1, ud2
 \+
 
 within	u1 u2 u3 -- f		core-ext
+""u2=<u1<u3 or: u3=<u2 and u1 is not in [u3,u2).  This works for
+unsigned and signed numbers (but not a mixture).  Another way to think
+about this word is to consider the numbers as a circle (wrapping
+around from @code{max-u} to 0 for unsigned, and from @code{max-n} to
+min-n for signed numbers); now consider the range from u2 towards
+increasing numbers up to and excluding u3 (giving an empty range if
+u2=u3; if u1 is in this range, @code{within} returns true.""
 f = FLAG(u1-u2 < u3-u2);
 :
  over - >r - r> u< ;