Correct some comments referring to the (now) nonexistent *truncate-x*

;;; Carnegie Mellon University, and has been placed in the public domain.

;;;

(ext:file-comment

  "$Header: /Volumes/share2/src/cmucl/cvs2git/cvsroot/src/code/bignum.lisp,v 1.44 2008/10/21 03:03:13 rtoy Exp $")

  "$Header: /Volumes/share2/src/cmucl/cvs2git/cvsroot/src/code/bignum.lisp,v 1.45 2008/10/21 17:35:17 rtoy Exp $")

;;;

;;; **********************************************************************

;;;

;;; TRY-BIGNUM-TRUNCATE-GUESS -- Internal.

;;;

;;; This takes a digit guess, multiplies it by *truncate-y* for a result one

;;; greater in length than len-y, and subtracts this result from *truncate-x*.

;;; This takes a digit guess, multiplies it by truncate-y for a result one

;;; greater in length than len-y, and subtracts this result from truncate-x.

;;; Low-x-digit is the first digit of x to start the subtraction, and we know x

;;; is long enough to subtract a len-y plus one length bignum from it.  Next we

;;; check the result of the subtraction, and if the high digit in x became

;;; DO-TRUNCATE -- Internal.

;;;

;;; This divides *truncate-x* by *truncate-y*, and len-x and len-y tell us how

;;; This divides truncate-x by truncate-y, and len-x and len-y tell us how

;;; much of the buffers we care about.  TRY-BIGNUM-TRUNCATE-GUESS modifies

;;; *truncate-x* on each interation, and this buffer becomes our remainder.

;;; truncate-x on each interation, and this buffer becomes our remainder.

;;;

;;; *truncate-x* definitely has at least three digits, and it has one more than

;;; *truncate-y*.  This keeps i, i-1, i-2, and low-x-digit happy.  Thanks to

;;; truncate-x definitely has at least three digits, and it has one more than

;;; truncate-y.  This keeps i, i-1, i-2, and low-x-digit happy.  Thanks to

;;; SHIFT-AND-STORE-TRUNCATE-BUFFERS.

;;;

(defun do-truncate (len-x len-y truncate-x truncate-y)

;;;

;;; Stores two bignums into the truncation bignum buffers, shifting them on the

;;; way in.  This assumes x and y are positive and at least two in length, and

;;; it assumes *truncate-x* and *truncate-y* are one digit longer than x and y.

;;; it assumes truncate-x and truncate-y are one digit longer than x and y.

;;;

(defun shift-and-store-truncate-buffers (x len-x y len-y shift truncate-x truncate-y)

  (declare (type bignum-index len-x len-y)

;;; %FLOOR for machines with a 32x32 divider.

;;;

#+32x16-divide

(declaim (inline 32x16-subtract-with-borrow 32x16-add-with-carry

		 32x16-divide 32x16-multiply 32x16-multiply-split))