nfunato

;;;
;;; Yet another porting of Dr. Norvig's Sudoku Solver, in Common Lisp
;;;
;;;                                                   @nfunato 2017-12-31

;;; Please see the original article (http://norvig.com/sudoku.html) for detail.

;;; Note
;;;
;;;  - I intentionally tried to keep the smell of the original code, except

nfunato

;;; anaphoras and the like

(defmacro aif (tst thn &optional els) `(let ((it ,tst)) (if it ,thn ,els)))
(defmacro awhen (tst &body body)      `(let ((it ,tst)) (when it ,@body)))
(defmacro aprog1 (f . fs)             `(let ((it ,f)) ,@fs it))

(defmacro acond (&rest cls)
  (if (null cls) nil
    (let ((cl1 (car cls)) (sym (gensym)))
      `(let ((,sym ,(car cl1)))

rygorous

Brief explanation what I did to get the speed-up, and the thought process behind it.

The original code went:

EnterLoop:
			movaps		xmm3, xmmword ptr [edx+ecx*2]		// Box1YZ
			cmpnltps	xmm3, xmm2
			movmskps	eax, xmm3

			cmp			eax, 0Ch