;;; fast: with optimization declarations and THE

CL-USER> (defun test ()
	   (declare (optimize speed (safety 0)))
	   (let ((foo (make-array (* 1024 1024 10) :element-type '(unsigned-byte 8))))
	     (with-open-file (s "/dev/zero" :element-type '(unsigned-byte 8))
	       (time (read-sequence foo s)))
	     (time (the (SIMPLE-ARRAY (UNSIGNED-BYTE 8) (*)) (copy-seq (the (SIMPLE-ARRAY (UNSIGNED-BYTE 8) (*)) foo))))
	     nil))
STYLE-WARNING: redefining TEST in DEFUN
TEST
CL-USER> (test)
Evaluation took:
  0.014 seconds of real time
  0.008001 seconds of user run time
  0.008 seconds of system run time
  0 calls to %EVAL
  0 page faults and
  40,960 bytes consed.
Evaluation took:
  0.014 seconds of real time
  0.016001 seconds of user run time
  0.0 seconds of system run time
  0 calls to %EVAL
  0 page faults and
  10,485,776 bytes consed.
NIL

;;; slow: with optimization declarations, but without THE


CL-USER> (defun test ()
	   (declare (optimize speed (safety 0)))
	   (let ((foo (make-array (* 1024 1024 10) :element-type '(unsigned-byte 8))))
	     (with-open-file (s "/dev/zero" :element-type '(unsigned-byte 8))
	       (time (read-sequence foo s)))
	     (time (copy-seq foo))
	     nil))
; in: LAMBDA NIL
;     (COPY-SEQ FOO)
; 
; note: unable to
;   optimize
; due to type uncertainty:
;   The result is a (VALUES (OR (SIMPLE-ARRAY * (*)) (AND SEQUENCE (NOT VECTOR)))
;                           &OPTIONAL), not a (VALUES
;                                              (SIMPLE-ARRAY (UNSIGNED-BYTE 8)
;                                               (*))
;                                              &REST T).
; 
; compilation unit finished
;   printed 1 note
STYLE-WARNING: redefining TEST in DEFUN
TEST
CL-USER> (test)
Evaluation took:
  0.022 seconds of real time
  0.012001 seconds of user run time
  0.008 seconds of system run time
  0 calls to %EVAL
  0 page faults and
  45,056 bytes consed.
Evaluation took:
  0.989 seconds of real time
  0.976061 seconds of user run time
  0.012001 seconds of system run time
  [Run times include 0.02 seconds GC run time.]
  0 calls to %EVAL
  0 page faults and
  10,497,440 bytes consed.
NIL
CL-USER>