Eliot Miranda uploaded a new version of Collections to project The Trunk:
http://source.squeak.org/trunk/Collections-eem.717.mcz==================== Summary ====================
Name: Collections-eem.717
Author: eem
Time: 13 October 2016, 4:14:34.323953 pm
UUID: ff6f9273-5077-47f9-b660-0cdd4b184bb1
Ancestors: Collections-dtl.716
Revise upwards the cross-over in SequenceableCollection>>atAllPut: at which point to move from a simple loop using at:put: to connivance using replaceFrom:to:with:startingAt:. Add a comment that includes the code to actually test this, instead of simply claiming without support.
=============== Diff against Collections-dtl.716 ===============
Item was changed:
----- Method: SequenceableCollection>>atAllPut: (in category 'accessing') -----
atAllPut: anObject
"Put anObject at every one of the receiver's indices."
| size |
+ (size := self size) > 50 "first method faster for larger sizes; see below"
- (size := self size) > 26 "first method faster from 27 accesses and on"
ifTrue: [self from: 1 to: size put: anObject]
+ ifFalse: [1 to: size do: [:index | self at: index put: anObject]]
+
+ "Here's code to test what's a good cross over."
+ "(1 to: 3) collect:
+ [:j|
+ { Array. ByteArray. FloatArray. WordArray } collect:
+ [:class| | a e |
+ a := class new: 250.
+ e := a at: 1.
+ (1 to: a size) detect:
+ [:n| | t1 t2 |
+ t1 := [1 to: 1000 do: [:i| a from: 1 to: n put: e]] timeToRun.
+ t2 := [1 to: 1000 do: [:i| 1 to: n do: [:index | a at: index put: e]]] timeToRun.
+ t1 < t2]]]"
+ "32-bit Spur x86 #(#(69 54 9 63) #(64 52 10 55) #(63 53 9 61))"
+ "64-bit Spur x86-64 #(#(63 50 10 55) #(60 48 10 54) #(63 44 9 50))"!
- ifFalse: [1 to: size do: [:index | self at: index put: anObject]]!
Locked
