This message is about how important DECLARE and THE are. If you do not
handle DECLARE and THE right, people will laugh at native-compile.
Here is an SBCL transcript. I am running on a $100 Lenovo Chromebook.
I got SBCL with the command sudo apt-get install sbcl.
* (declaim (optimize (safety 0) (speed 3) (debug 0)))
NIL
* (defun foo-with-declare (n)
(let ((i 0)
(sum 0)
(max (expt 10 n)))
(declare (fixnum i sum max))
(loop (cond ((<= i max)
(setq sum (the fixnum (+ sum i))))
(t (return sum)))
(incf i))))
FOO-WITH-DECLARE
* (time (foo-with-declare 8))
Evaluation took:
0.125 seconds of real time
0.123203 seconds of total run time (0.123193 user, 0.000010 system)
98.40% CPU
135,905,516 processor cycles
0 bytes consed
5000000050000000
* (defun foo-without-declare (n)
(let ((i 0)
(sum 0)
(max (expt 10 n)))
(loop (cond ((<= i max)
(setq sum (+ sum i)))
(t (return sum)))
(incf i))))
WARNING: redefining COMMON-LISP-USER::FOO-WITHOUT-DECLARE in DEFUN
FOO-WITHOUT-DECLARE
* (time (foo-without-declare 8))
Evaluation took:
1.080 seconds of real time
1.072932 seconds of total run time (1.072932 user, 0.000000 system)
99.35% CPU
1,181,369,303 processor cycles
0 bytes consed
5000000050000000
People go wow about 8X. How does native-compile do?
There is a great song by Alabama 'If you gonna play in Texas, you gotta have a fiddle in the band'. Check it out!
Bob
Bob
On Feb 18 2024, Robert Boyer wrote:
> Furthermore, such declare forms are necessary for life as we know it
> in the free world, so that fixnum arithmetic can be used where
> appropriate!
If you are programming in Emacs Lisp, you need to follow the rules of
Emacs Lisp.
--
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510 2552 DF73 E780 A9DA AEC1
"And now for something completely different."
--
Anything I seem to state should be taken as a question. I am at least 77 and feeble.