mayerrobert

;;;; Mandelbrot with terminal I/O
;;;
;;; An attempt to write code that can be optimized by sbcl.
;;; Note that this is not a serious benchmark, most time is spent in I/O,
;;; it is mostly for looking at the resulting disassembly.
;;;
;;; from: https://demo.sourceprobe.com/github.com/sourceprobe/mandelbrot_lisp/mandel.lisp


(deftype window-dimension () `(integer 0 ,most-positive-fixnum))

mayerrobert

;;; It seems that this file shows two issues with sbcl:
;;;
;;; (1) sbcl sometimes doesn't find optimization opportunities,
;;;     it seems only SIMD code is affected.
;;; (2) Specifying ':fill-pointer nil' to 'make-array'
;;;     seems to make a difference, i.e. specifying ':fill-pointer nil'
;;;     (which doesn't make sense) considerably improves the generated code.
;;;
;;; Note how the hot loop starting at Windows:L10/ linux:L12 contains a lot of unneccessary
;;; "MOV [RBP-72], RCX" and "MOV RCX, [RBP-72]" instructions, or "MOV [RBP-48], RAX" twice in a row,

mayerrobert

;;;; Matrix multiplication optimization experiments
;;;
;;; This file contains functions to multiply two matrices written in Common Lisp.
;;;
;;; DISCLAIMER: while this code has some tests it might contains bugs,
;;;             I made it to experiment with SBCL's SIMD support.
;;;
;;; All functions use the naive nested loop algorithm which is O(n^3).
;;; This file contains 5 functions with various optimizations
;;; that should be portable Common Lisp and 5 functions that use sbcl's SB-SIMD.

mayerrobert

;;;; AOC 2022 day 10 in Common Lisp,
;;;; based on https://www.reddit.com/r/adventofcode/comments/zhjfo4/2022_day_10_solutions/izmspl7/

#| (mostly) original Python:

from itertools import accumulate

f = lambda x: int(x) if x[-1].isdigit() else 0
xs = [*map(f, open('day10.txt').read().split())]