dot.lisp

(defun make-dvec (input-dimension initial-element)
  (make-array input-dimension :element-type 'double-float :initial-element initial-element))

(defmacro dovec (vec var &body body)
  `(loop for ,var fixnum from 0 to (1- (length ,vec)) do ,@body))

(defun dot (x y)
  (declare (type (simple-array double-float) x y)
           (optimize (speed 3) (safety 0)))
  (let ((result 0.0d0))
    (declare (type double-float result))
    (dovec x i (incf result (* (aref x i) (aref y i))))
    result))

(defun dot! (x y result)
  (declare (type (simple-array double-float) x y)
           (type (simple-array double-float 1) result)
           (optimize (speed 3) (safety 0)))
  (setf (aref result 0) 0d0)
  (dovec x i (incf (aref result 0) (* (aref x i) (aref y i)))))

(defparameter dv1 (make-dvec 10000 2d0))   ; 100 -> 10000
(defparameter dv2 (make-dvec 10000 10d0))  ; 100 -> 10000
(defparameter result (make-dvec 1 0d0))

(time (loop repeat 100000 do (dot dv1 dv2))) ; 10,000,000 ->  100,000
;; Evaluation took:
;;   18.397 seconds of real time
;;   17.781488 seconds of total run time (17.004876 user, 0.776612 system)
;;   [ Run times consist of 1.090 seconds GC time, and 16.692 seconds non-GC time. ]
;;   96.65% CPU
;;   41,492,780,804 processor cycles
;;   16,001,580,288 bytes consed

(time (loop repeat 100000 do (dot! dv1 dv2 result))) ; 10,000,000 ->  100,000
;; Evaluation took:
;;   4.168 seconds of real time
;;   4.125039 seconds of total run time (4.105985 user, 0.019054 system)
;;   98.97% CPU
;;   9,400,476,442 processor cycles
;;   34,304 bytes consed

gistfile1.lisp

(defun foo (x out)
  (declare (optimize (speed 3) (safety 0)))
  (declare (type double-float x))
  (declare (type (simple-array double-float *) out))
  (setf (aref out 0) (+ x x))
  (values))

(disassemble #'foo)