Hi Eliot,

On Sat, 20 Sep 2014, Eliot Miranda wrote:

> Hi Levente,
> 
> On Sat, Sep 20, 2014 at 8:24 AM, Levente Uzonyi <leves at elte.hu> wrote:
>       Cool. I think the spaceship operator for strings should use #compare:with:collated: to save a comparison in the most common case.
>
>       The performance of symbols would be close to dyadic blocks, if it were cheap and easy to create a block on the fly.
> 
> 
> I don't know what cheap enough in this case is but Spur is over 5 times faster at creating blocks than the existing Cog V3 VM:

I meant compiling a sortblock, which can be passed to #sort: or #sorted:. 
It seems to be too expensive to be used by default:

[ Compiler evaluate: ('[ :a :b | a {1} {2} b {1} ]' format: { #abs. #< }) ] bench. '3,560 per second.'

| c d |
c := (1 to: 20) collect: [:i | 1000000 atRandom-500000].
d := c copy.
{
[ d copyFrom: c ] bench.
[ d copyFrom: c; sort: [:a :b | a abs < b abs] ] bench.
[ d copyFrom: c; sort: (Compiler evaluate: ('[ :a :b | a {1} {2} b {1} ]' format: { #abs. #< })) ] bench.
}.
#('9,720,000 per second.' '125,000 per second.' '7,310 per second.')

But there could be a special message which compiles an optimized block. 
Something like

#(-1 0 1 2) sort: #abs ascending compiled

where #compiled returns the block [ :a :b | a abs < b abs ].
It could be useful when the collection is large enough:

| c d |
c := (1 to: 200000) collect: [:i | 1000000 atRandom-500000].
d := c copy.
{
[ d copyFrom: c ] bench.
[ d copyFrom: c; sort: [:a :b | a abs < b abs] ] bench.
[ d copyFrom: c; sort: (Compiler evaluate: ('[ :a :b | a {1} {2} b {1} ]' format: { #abs. #< })) ] bench.
}.
#('1,390 per second.' '3.38 per second.' '3.58 per second.')


Levente

P.S.: The numbers below are impressive. :)

> 
> 
> [1 to: 1,000,000,000 do: [:i| [nil class]]] timeToRun
> 
> Spur: 5,950ms
> Cog: 31,951ms
> 
> 31951 / 5950.0                 5.37
> 5950 - 31951 / 319.51    -81.4%
> 
> So ignoring the loop overhead, Spur creates a block in less than 6 nanoseconds on a 2.2GHz MBP Core i7.
> 
> 
> A slightly more realistic example which creates a new home context for every block created is
> 
> 
> [1 to: 10,000,000 do: [:i| [[nil class]] value. [[nil class]] value. [[nil class]] value. [[nil class]] value. [[nil class]] value. [[nil class]] value. [[nil class]] value. [[nil class]] value. [[nil class]]
> value. [[nil class]] value.]] timeToRun 
> 
> Spur: 2,568ms
> Cog: 11,601ms
> 
> 11601 / 2568.0 4.51752336448598
> 2568 - 11601 / 116.01 -77.8639772433411
> 
> So here Spur creates two closures and a context in 2.568 / 100,000,000 = 26 nsecs, compared to 160 for Cog V3.
>
>       Levente
>
>       On Fri, 19 Sep 2014, commits at source.squeak.org wrote:
>
>             Nicolas Cellier uploaded a new version of Collections to project The Trunk:
>             http://source.squeak.org/trunk/Collections-nice.582.mcz
>
>             ==================== Summary ====================
>
>             Name: Collections-nice.582
>             Author: nice
>             Time: 19 September 2014, 10:22:13.338 pm
>             UUID: 52a598f1-224e-4649-a95f-4e78547b5ed5
>             Ancestors: Collections-nice.581
>
>             Port TAG-SortFunctions of Travis Griggs from Cincom public store - version (11,tgriggs)
>
>             Note that no collation policy were used for String.
>             The spaceship operator <=> is also required in Kernel-Numbers.
>
>             See also the blog http://objology.blogspot.fr/2010/11/tag-sortfunctions.html
>             and http://objology.blogspot.fr/2010/11/tag-sortfunctions-redux.html
>
>             Note about the cost of these sort functions:
>             as shown by this mini-bench on cog, using a Symbol costs a bit more (perform:) than a block activation, and monadic block a bit more than dyadic one because activated twice more, but
>             it seems acceptable to me with regard to the great simplification and expressiveness of code :
>
>             | collec1 collec2 collec3 |
>             collec1 := (1 to: 200000) collect: [:i | 1000000 atRandom-500000].
>             collec2 := collec1 copy.
>             collec3 := collec1 copy.
>             {
>             [collec1 sort: [:a :b | a abs < b abs]] timeToRun.
>             [collec2 sort: [:e | e abs] ascending] timeToRun.
>             [collec3 sort: #abs ascending] timeToRun.
>             }
>             #(345 532 912)
> 
> 
> 
> 
> 
> --
> best,Eliot
> 
>