bug#69249: bug in native-compile?

[Robert Boyer]

Look out, here it comes, as Tracy Schwarz says.

The following DISASSEMBLE might tell you what you need to do for native-compile. 

Speaking with the utmost sincerity, I know less about the following than I do about what Proust called the greatest painting in the world, the View of Delft by Vermmer.  Check it out.

https://www.mauritshuis.nl/en/our-collection/artworks/92-view-of-delft/

Again, this is in SBCL on my $100 Lenovo Chromebook.

* (disassemble 'foo-with-declare)
; disassembly for FOO-WITH-DECLARE
; Size: 60 bytes. Origin: #x52A4AF19                          ; FOO-WITH-DECLARE
; 19:       4883EC10         SUB RSP, 16
; 1D:       BA14000000       MOV EDX, 20
; 22:       B904000000       MOV ECX, 4
; 27:       48892C24         MOV [RSP], RBP
; 2B:       488BEC           MOV RBP, RSP
; 2E:       B842BD3550       MOV EAX, #x5035BD42              ; #<FDEFN EXPT>
; 33:       FFD0             CALL RAX
; 35:       31C0             XOR EAX, EAX
; 37:       31C9             XOR ECX, ECX
; 39:       EB0C             JMP L1
; 3B:       0F1F440000       NOP
; 40: L0:   4801C1           ADD RCX, RAX
; 43:       4883C002         ADD RAX, 2
; 47: L1:   4839D0           CMP RAX, RDX
; 4A:       7EF4             JLE L0
; 4C:       488BD1           MOV RDX, RCX
; 4F:       488BE5           MOV RSP, RBP
; 52:       F8               CLC
; 53:       5D               POP RBP
; 54:       C3               RET
NIL
* 

Bob

On Sun, Feb 18, 2024 at 4:25 PM Robert Boyer <robertstephenboyer@gmail.com> wrote:

And you should know what DECLARE and THE do for AREF.  All the difference in the world, and I will give you a simple demo if you wish.

Bob

On Sun, Feb 18, 2024 at 4:19 PM Robert Boyer <robertstephenboyer@gmail.com> wrote:

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!

https://www.youtube.com/watch?v=w6r4E514nJg

Bob

Bob

On Sun, Feb 18, 2024 at 3:28 PM Andreas Schwab <schwab@linux-m68k.org> wrote:

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.

--

Anything I seem to state should be taken as a question.  I am at least 77 and feeble.

--

Anything I seem to state should be taken as a question.  I am at least 77 and feeble.