Levente Uzonyi uploaded a new version of Kernel to project The Trunk: http://source.squeak.org/trunk/Kernel-ul.1192.mcz
==================== Summary ====================
Name: Kernel-ul.1192 Author: ul Time: 24 October 2018, 10:50:43.875546 pm UUID: 72dfb776-3d77-4b84-9d69-d000e9a67ae1 Ancestors: Kernel-eem.1191
- improved Integer >> #isPrime's performance - slightly faster Categorizer >> #numberOfCategoryOfElement:
=============== Diff against Kernel-eem.1191 ===============
Item was changed: ----- Method: Categorizer>>numberOfCategoryOfElement: (in category 'accessing') ----- numberOfCategoryOfElement: element "Answer the index of the category with which the argument, element, is associated."
+ | categoryIndex elementIndex elementArraySize | - | categoryIndex elementIndex | categoryIndex := 1. elementIndex := 0. + elementArraySize := elementArray size. + [(elementIndex := elementIndex + 1) <= elementArraySize] - [(elementIndex := elementIndex + 1) <= elementArray size] whileTrue: ["point to correct category" [elementIndex > (categoryStops at: categoryIndex)] whileTrue: [categoryIndex := categoryIndex + 1]. "see if this is element" element = (elementArray at: elementIndex) ifTrue: [^categoryIndex]]. ^0!
Item was changed: ----- Method: Integer>>isPrime (in category 'testing') ----- isPrime "Answer true if the receiver is a prime number. See isProbablyPrime for a probabilistic implementation that is much faster for large integers, and that is correct to an extremely high statistical level of confidence (effectively deterministic)." + | probe step limit | + self <= 3 ifTrue: [ ^self >= 2 ]. + self \ 2 = 0 ifTrue: [ ^false ]. + self \ 3 = 0 ifTrue: [ ^false ]. + self <= 1073741823 ifFalse: [ "1 << 30 - 1. For numbers larger than this (on 64-bit platforms) #isProbablyPrime is usually quicker." - self <= 1 ifTrue: [ ^false ]. - self even ifTrue: [ ^self = 2]. - self <= 1073741823 ifFalse: [ "1 << 30 - 1. For numbers larger than this, the calculation takes longer than #isProbablyPrime when the receiver is a prime. The absolue turning point is about at 1 << 35 - 1." ^self isProbablyPrime ]. + probe := 5. + step := 2. "Step will oscillate between 2 and 4 because at this point self \ 6 is either 1 or 5." + limit := self sqrtFloor. "On 64-bit platforms this could be written as self asFloat sqrt truncated (+ 1), which is faster because it creates no intermediate objects. Knowing that self has at most 30 bits because of the check above, this value will never be larger than 32767." + [ probe <= limit ] whileTrue: [ + self \ probe = 0 ifTrue: [ ^false ]. + probe := probe + step. + step := 6 - step ]. - 3 to: self sqrtFloor by: 2 do: [ :each | - self \ each = 0 ifTrue: [ ^false ] ]. ^true!
Item was added: + ----- Method: LargeNegativeInteger>>isPrime (in category 'testing') ----- + isPrime + + ^false!