The Trunk: Collections-ul.739.mcz

In case someone would like to defend the performance of #~~ and #notNil, here's a little benchmark I just wrote:

| base ifNilIfNotNil notIdentical notEqual notNil |
Smalltalk garbageCollect.
base := (1 to: 5) collect: [ :run |
        [ 1 to: 100000000 do: [ :i | ] ] timeToRun ].

ifNilIfNotNil := (1 to: 5) collect: [ :run |
        [ 1 to: 100000000 do: [ :i | i ifNil: [ false ] ifNotNil: [ true ] ] ] timeToRun ].

notIdentical := (1 to: 5) collect: [ :run |
        [ 1 to: 100000000 do: [ :i | i ~~ nil ] ] timeToRun ].

notEqual := (1 to: 5) collect: [ :run |
        [ 1 to: 100000000 do: [ :i | i ~= nil ] ] timeToRun ].


notNil := (1 to: 5) collect: [ :run |
        [ 1 to: 100000000 do: [ :i | i notNil ] ] timeToRun ].

{
        #ifNilIfNotNil -> ifNilIfNotNil.
        #notIdentical -> notIdentical.
        #notEqual -> notEqual.
        #notNil -> notNil
}
        replace: [ :each |
                each key -> (each value average - base average) asFloat ];
        sort: #value ascending

"{#ifNilIfNotNil->73.6 . #notNil->336.8 . #notIdentical->511.6 . #notEqual->3354.0}"

So it's 4.5x faster than #notNil and 7x faster than #~~ on 64-bit Spur on Linux. Once we have jitted #~~, I'll change the code again.

Levente

On Tue, 28 Feb 2017, [hidden email] wrote:

Levente Uzonyi uploaded a new version of Collections to project The Trunk:
http://source.squeak.org/trunk/Collections-ul.739.mcz

==================== Summary ====================

Name: Collections-ul.739
Author: ul
Time: 28 February 2017, 7:34:55.711173 pm
UUID: 66c6ecf2-71bf-4e7d-80e6-5ace72fa19ba
Ancestors: Collections-ul.738

- use micro optimization for #~~ and #notNil in common collection methods
- reuse one of the OrderedCollections in RunArray >> #scanFrom:
- two other minor tweaks in KeyedSet
- removed accidentally commited Set >> #includes2:

=============== Diff against Collections-ul.738 ===============

Item was changed:
 ----- Method: Dictionary>>includesKey: (in category 'testing') -----
 includesKey: key
        "Answer whether the receiver has a key equal to the argument, key."

+       (array at: (self scanFor: key)) ifNil: [ ^false ] ifNotNil: [ ^true ]!
-        ^(array at: (self scanFor: key)) notNil!

Item was changed:
 ----- Method: KeyedSet>>includesKey: (in category 'testing') -----
 includesKey: key

+       (array at: (self scanFor: key)) ifNil: [ ^false ] ifNotNil: [ ^true ]!
-       ^ (array at: (self scanFor: key)) notNil!

Item was changed:
 ----- Method: KeyedSet>>remove:ifAbsent: (in category 'removing') -----
 remove: oldObject ifAbsent: aBlock

        | index |
        index := self scanFor: (keyBlock value: oldObject).
+       (array at: index) ifNil: [ ^ aBlock value ].
-       (array at: index) == nil ifTrue: [ ^ aBlock value ].
        array at: index put: nil.
        tally := tally - 1.
        self fixCollisionsFrom: index.
        ^ oldObject!

Item was changed:
 ----- Method: KeyedSet>>removeKey:ifAbsent: (in category 'removing') -----
 removeKey: key ifAbsent: aBlock

        | index obj |
        index := self scanFor: key.
+       obj := (array at: index) ifNil: [ ^ aBlock value ].
-       (obj := array at: index) == nil ifTrue: [ ^ aBlock value ].
        array at: index put: nil.
        tally := tally - 1.
        self fixCollisionsFrom: index.
        ^ obj enclosedSetElement!

Item was changed:
 ----- Method: RunArray class>>scanFrom: (in category 'instance creation') -----
 scanFrom: strm
        "Read the style section of a fileOut or sources file.  nextChunk has already been done.  We need to return a RunArray of TextAttributes of various kinds.  These are written by the implementors of writeScanOn:"
        | runs values attrList char |
        (strm peekFor: $( ) ifFalse: [^ nil].
        runs := OrderedCollection new.
        [strm skipSeparators.
         strm peekFor: $)] whileFalse:
                [runs add: (Number readFrom: strm)].
        values := OrderedCollection new.        "Value array"
        attrList := OrderedCollection new.      "Attributes list"
        [(char := strm peek) == nil] whileFalse: [
                (char isSeparator or: [ char = $!! ])
                        ifTrue: [ "n.b. Skip $!! to meet expectations of RunArrayTest>>testScanFromTrailer.
                                        The example string used in that test does not seem to match the implemention
                                        of the fileOut serialization, but the test may be right and the implementation
                                        wrong. In any case, relax the parsing here to meet the test expectations, and to
                                        be more consistent with the original version of this method that assumed any
                                        unexpected charater to be a separator. -dtl Jan 2014"
                                strm next "space, cr do nothing"]
                        ifFalse: [char == $,
                                        ifTrue: [strm next.
                                                values add: attrList asArray.
+                                               attrList reset ]
-                                               attrList := OrderedCollection new]
                                        ifFalse: [attrList add:  (TextAttribute newFrom: strm)]
                                ]
                ].
        values add: attrList asArray.
        ^ self runs: runs asArray values: (values copyFrom: 1 to: runs size) asArray
 "
 RunArray scanFrom: (ReadStream on: '(14 50 312)f1,f1b,f1LInteger +;i')
 "!

Item was removed:
- ----- Method: Set>>includes2: (in category 'testing') -----
- includes2: anObject - -       ^((array at: (self scanFor: anObject)) == nil) not!

Item was changed:
 ----- Method: WeakIdentityDictionary>>includesKey: (in category 'testing') -----
 includesKey: key
        "Answer whether the receiver has a key equal to the argument, key."

+       (array at: (self scanFor: key))
+               ifNil: [
+                       "it just has been reclaimed"
+                       ^false]
+               ifNotNil: [ :element |
+                       element == vacuum
+                               ifTrue: [ ^false ]
+                               ifFalse: [ ^true ] ]!
-       ^(array at: (self scanFor: key))
-               ifNil:
-                       ["it just has been reclaimed"
-                       false]
-               ifNotNil: [:element | element ~~ vacuum]!

Item was changed:
 ----- Method: WeakSet>>includes: (in category 'testing') -----
 includes: anObject

        (array at: (self scanFor: anObject))
                ifNil: [ ^false ]
+               ifNotNil: [ :object |
+                       object == flag
+                               ifTrue: [ ^false ]
+                               ifFalse: [ ^true ] ]!
-               ifNotNil: [ :object | ^object ~~ flag ]!

Hi Eliot,

I tried to change the selector in the special objects array, but it didn't help. I get the same numbers as before.

Here's what I did:
First, I changed #blockCopy to: #~~ in SmalltalkImage >> #recreateSpecialObjectsArray.
Then, I evaluated the following snippet in a workspace:

senders := SystemNavigation default allCallsOn: #~~.
Smalltalk recreateSpecialObjectsArray.
senders
         do: [ :methodReference |
                | class |
                class := methodReference actualClass.
                class recompile: methodReference selector from: class ]
        displayingProgress: 'Recompiling...'.

And finally I ran the benchmark.

However, now #blockCopy: will just behave as #~~ should. And, it gives the same number as #==. So, I suppose there are few other places to change to get the right behavior (Compiler, Encoder, Whatever).

However, what's really interesting is how the JIT behaves in this case:
#== alone is about 1.43x slower than #== + #ifTrue:ifFalse: in this test.

Levente

On Tue, 28 Feb 2017, Eliot Miranda wrote:

Hi Levente,
On Tue, Feb 28, 2017 at 10:44 AM, Levente Uzonyi <[hidden email]> wrote:
      In case someone would like to defend the performance of #~~ and #notNil, here's a little benchmark I just wrote:

      | base ifNilIfNotNil notIdentical notEqual notNil |
      Smalltalk garbageCollect.
      base := (1 to: 5) collect: [ :run |
              [ 1 to: 100000000 do: [ :i | ] ] timeToRun ].

      ifNilIfNotNil := (1 to: 5) collect: [ :run |
              [ 1 to: 100000000 do: [ :i | i ifNil: [ false ] ifNotNil: [ true ] ] ] timeToRun ].

      notIdentical := (1 to: 5) collect: [ :run |
              [ 1 to: 100000000 do: [ :i | i ~~ nil ] ] timeToRun ].

      notEqual := (1 to: 5) collect: [ :run |
              [ 1 to: 100000000 do: [ :i | i ~= nil ] ] timeToRun ].


      notNil := (1 to: 5) collect: [ :run |
              [ 1 to: 100000000 do: [ :i | i notNil ] ] timeToRun ].

      {
              #ifNilIfNotNil -> ifNilIfNotNil.
              #notIdentical -> notIdentical.
              #notEqual -> notEqual.
              #notNil -> notNil
      }
              replace: [ :each |
                      each key -> (each value average - base average) asFloat ];
              sort: #value ascending

      "{#ifNilIfNotNil->73.6 . #notNil->336.8 . #notIdentical->511.6 . #notEqual->3354.0}"

      So it's 4.5x faster than #notNil and 7x faster than #~~ on 64-bit Spur on Linux. Once we have jitted #~~, I'll change the code again.


IIRC, all one needs to get jitted #~~ is to store #~~ in place of blockCopy: in the specialSelectors array and recompile all senders of #~~.  You may need to collect all senders of #~~ before you make the
swap since putting it in the specialSelectors array may confuse allReferencesTo: et al.

      Levente


      On Tue, 28 Feb 2017, [hidden email] wrote:

            Levente Uzonyi uploaded a new version of Collections to project The Trunk:
            http://source.squeak.org/trunk/Collections-ul.739.mcz

            ==================== Summary ====================

            Name: Collections-ul.739
            Author: ul
            Time: 28 February 2017, 7:34:55.711173 pm
            UUID: 66c6ecf2-71bf-4e7d-80e6-5ace72fa19ba
            Ancestors: Collections-ul.738

            - use micro optimization for #~~ and #notNil in common collection methods
            - reuse one of the OrderedCollections in RunArray >> #scanFrom:
            - two other minor tweaks in KeyedSet
            - removed accidentally commited Set >> #includes2:

            =============== Diff against Collections-ul.738 ===============

            Item was changed:
             ----- Method: Dictionary>>includesKey: (in category 'testing') -----
             includesKey: key
                    "Answer whether the receiver has a key equal to the argument, key."

            +       (array at: (self scanFor: key)) ifNil: [ ^false ] ifNotNil: [ ^true ]!
            -        ^(array at: (self scanFor: key)) notNil!

            Item was changed:
             ----- Method: KeyedSet>>includesKey: (in category 'testing') -----
             includesKey: key

            +       (array at: (self scanFor: key)) ifNil: [ ^false ] ifNotNil: [ ^true ]!
            -       ^ (array at: (self scanFor: key)) notNil!

            Item was changed:
             ----- Method: KeyedSet>>remove:ifAbsent: (in category 'removing') -----
             remove: oldObject ifAbsent: aBlock

                    | index |
                    index := self scanFor: (keyBlock value: oldObject).
            +       (array at: index) ifNil: [ ^ aBlock value ].
            -       (array at: index) == nil ifTrue: [ ^ aBlock value ].
                    array at: index put: nil.
                    tally := tally - 1.
                    self fixCollisionsFrom: index.
                    ^ oldObject!

            Item was changed:
             ----- Method: KeyedSet>>removeKey:ifAbsent: (in category 'removing') -----
             removeKey: key ifAbsent: aBlock

                    | index obj |
                    index := self scanFor: key.
            +       obj := (array at: index) ifNil: [ ^ aBlock value ].
            -       (obj := array at: index) == nil ifTrue: [ ^ aBlock value ].
                    array at: index put: nil.
                    tally := tally - 1.
                    self fixCollisionsFrom: index.
                    ^ obj enclosedSetElement!

            Item was changed:
             ----- Method: RunArray class>>scanFrom: (in category 'instance creation') -----
             scanFrom: strm
                    "Read the style section of a fileOut or sources file.  nextChunk has already been done.  We need to return a RunArray of TextAttributes of various kinds.  These are written by
            the implementors of writeScanOn:"
                    | runs values attrList char |
                    (strm peekFor: $( ) ifFalse: [^ nil].
                    runs := OrderedCollection new.
                    [strm skipSeparators.
                     strm peekFor: $)] whileFalse:
                            [runs add: (Number readFrom: strm)].
                    values := OrderedCollection new.        "Value array"
                    attrList := OrderedCollection new.      "Attributes list"
                    [(char := strm peek) == nil] whileFalse: [
                            (char isSeparator or: [ char = $!! ])
                                    ifTrue: [ "n.b. Skip $!! to meet expectations of RunArrayTest>>testScanFromTrailer.
                                                    The example string used in that test does not seem to match the implemention
                                                    of the fileOut serialization, but the test may be right and the implementation
                                                    wrong. In any case, relax the parsing here to meet the test expectations, and to
                                                    be more consistent with the original version of this method that assumed any
                                                    unexpected charater to be a separator. -dtl Jan 2014"
                                            strm next "space, cr do nothing"]
                                    ifFalse: [char == $,
                                                    ifTrue: [strm next.
                                                            values add: attrList asArray.
            +                                               attrList reset ]
            -                                               attrList := OrderedCollection new]
                                                    ifFalse: [attrList add:  (TextAttribute newFrom: strm)]
                                            ]
                            ].
                    values add: attrList asArray.
                    ^ self runs: runs asArray values: (values copyFrom: 1 to: runs size) asArray
             "
             RunArray scanFrom: (ReadStream on: '(14 50 312)f1,f1b,f1LInteger +;i')
             "!

            Item was removed:
            - ----- Method: Set>>includes2: (in category 'testing') -----
            - includes2: anObject - -       ^((array at: (self scanFor: anObject)) == nil) not!

            Item was changed:
             ----- Method: WeakIdentityDictionary>>includesKey: (in category 'testing') -----
             includesKey: key
                    "Answer whether the receiver has a key equal to the argument, key."

            +       (array at: (self scanFor: key))
            +               ifNil: [
            +                       "it just has been reclaimed"
            +                       ^false]
            +               ifNotNil: [ :element |
            +                       element == vacuum
            +                               ifTrue: [ ^false ]
            +                               ifFalse: [ ^true ] ]!
            -       ^(array at: (self scanFor: key))
            -               ifNil:
            -                       ["it just has been reclaimed"
            -                       false]
            -               ifNotNil: [:element | element ~~ vacuum]!

            Item was changed:
             ----- Method: WeakSet>>includes: (in category 'testing') -----
             includes: anObject

                    (array at: (self scanFor: anObject))
                            ifNil: [ ^false ]
            +               ifNotNil: [ :object |
            +                       object == flag
            +                               ifTrue: [ ^false ]
            +                               ifFalse: [ ^true ] ]!
            -               ifNotNil: [ :object | ^object ~~ flag ]!





--
_,,,^..^,,,_
best, Eliot

Hi Levente,

On Tue, Feb 28, 2017 at 2:43 PM, Levente Uzonyi <[hidden email]> wrote:

Hi Eliot,

I tried to change the selector in the special objects array, but it didn't help. I get the same numbers as before.

Here's what I did:
First, I changed #blockCopy to: #~~ in SmalltalkImage >> #recreateSpecialObjectsArray.
Then, I evaluated the following snippet in a workspace:

senders := SystemNavigation default allCallsOn: #~~.
Smalltalk recreateSpecialObjectsArray.
senders
         do: [ :methodReference |
                | class |
                class := methodReference actualClass.
                class recompile: methodReference selector from: class ]
        displayingProgress: 'Recompiling...'.

And finally I ran the benchmark.

However, now #blockCopy: will just behave as #~~ should. And, it gives the same number as #==. So, I suppose there are few other places to change to get the right behavior (Compiler, Encoder, Whatever).

I forgot to tell you that you need to do 

    VariableNode initialize.  Decompiler initialize

See variableNode class>>#initialize.  This fills StdSelectors, a class var of ParseNode, with the special selectors.  Sorry!

However, what's really interesting is how the JIT behaves in this case:
#== alone is about 1.43x slower than #== + #ifTrue:ifFalse: in this test.

Yes, I chose to only inline when a comparison operator is followed by a conditional branch.  So any of #= #~= #== #~~ #> #< #>= #<= if used to compute a value will be compiled into a real send  That could be a mistake.  Let me know if you think it will be critical to performance.  The notion is that inlining the branch saves a lot (reifying the result, testing the result for being true, false or something else), but inlining just to obtain the result saves only the inline cached send overhead.  That could be the wrong call, but that's what I decided to do back in 2009.

Levente

On Tue, 28 Feb 2017, Eliot Miranda wrote:

Hi Levente,
On Tue, Feb 28, 2017 at 10:44 AM, Levente Uzonyi <[hidden email]> wrote:
      In case someone would like to defend the performance of #~~ and #notNil, here's a little benchmark I just wrote:

      | base ifNilIfNotNil notIdentical notEqual notNil |
      Smalltalk garbageCollect.
      base := (1 to: 5) collect: [ :run |
              [ 1 to: 100000000 do: [ :i | ] ] timeToRun ].

      ifNilIfNotNil := (1 to: 5) collect: [ :run |
              [ 1 to: 100000000 do: [ :i | i ifNil: [ false ] ifNotNil: [ true ] ] ] timeToRun ].

      notIdentical := (1 to: 5) collect: [ :run |
              [ 1 to: 100000000 do: [ :i | i ~~ nil ] ] timeToRun ].

      notEqual := (1 to: 5) collect: [ :run |
              [ 1 to: 100000000 do: [ :i | i ~= nil ] ] timeToRun ].


      notNil := (1 to: 5) collect: [ :run |
              [ 1 to: 100000000 do: [ :i | i notNil ] ] timeToRun ].

      {
              #ifNilIfNotNil -> ifNilIfNotNil.
              #notIdentical -> notIdentical.
              #notEqual -> notEqual.
              #notNil -> notNil
      }
              replace: [ :each |
                      each key -> (each value average - base average) asFloat ];
              sort: #value ascending

      "{#ifNilIfNotNil->73.6 . #notNil->336.8 . #notIdentical->511.6 . #notEqual->3354.0}"

      So it's 4.5x faster than #notNil and 7x faster than #~~ on 64-bit Spur on Linux. Once we have jitted #~~, I'll change the code again.


IIRC, all one needs to get jitted #~~ is to store #~~ in place of blockCopy: in the specialSelectors array and recompile all senders of #~~.  You may need to collect all senders of #~~ before you make the
swap since putting it in the specialSelectors array may confuse allReferencesTo: et al.

      Levente


      On Tue, 28 Feb 2017, [hidden email] wrote:

            Levente Uzonyi uploaded a new version of Collections to project The Trunk:
            http://source.squeak.org/trunk/Collections-ul.739.mcz

            ==================== Summary ====================

            Name: Collections-ul.739
            Author: ul
            Time: 28 February 2017, 7:34:55.711173 pm
            UUID: 66c6ecf2-71bf-4e7d-80e6-5ace72fa19ba
            Ancestors: Collections-ul.738

            - use micro optimization for #~~ and #notNil in common collection methods
            - reuse one of the OrderedCollections in RunArray >> #scanFrom:
            - two other minor tweaks in KeyedSet
            - removed accidentally commited Set >> #includes2:

            =============== Diff against Collections-ul.738 ===============

            Item was changed:
             ----- Method: Dictionary>>includesKey: (in category 'testing') -----
             includesKey: key
                    "Answer whether the receiver has a key equal to the argument, key."

            +       (array at: (self scanFor: key)) ifNil: [ ^false ] ifNotNil: [ ^true ]!
            -        ^(array at: (self scanFor: key)) notNil!

            Item was changed:
             ----- Method: KeyedSet>>includesKey: (in category 'testing') -----
             includesKey: key

            +       (array at: (self scanFor: key)) ifNil: [ ^false ] ifNotNil: [ ^true ]!
            -       ^ (array at: (self scanFor: key)) notNil!

            Item was changed:
             ----- Method: KeyedSet>>remove:ifAbsent: (in category 'removing') -----
             remove: oldObject ifAbsent: aBlock

                    | index |
                    index := self scanFor: (keyBlock value: oldObject).
            +       (array at: index) ifNil: [ ^ aBlock value ].
            -       (array at: index) == nil ifTrue: [ ^ aBlock value ].
                    array at: index put: nil.
                    tally := tally - 1.
                    self fixCollisionsFrom: index.
                    ^ oldObject!

            Item was changed:
             ----- Method: KeyedSet>>removeKey:ifAbsent: (in category 'removing') -----
             removeKey: key ifAbsent: aBlock

                    | index obj |
                    index := self scanFor: key.
            +       obj := (array at: index) ifNil: [ ^ aBlock value ].
            -       (obj := array at: index) == nil ifTrue: [ ^ aBlock value ].
                    array at: index put: nil.
                    tally := tally - 1.
                    self fixCollisionsFrom: index.
                    ^ obj enclosedSetElement!

            Item was changed:
             ----- Method: RunArray class>>scanFrom: (in category 'instance creation') -----
             scanFrom: strm
                    "Read the style section of a fileOut or sources file.  nextChunk has already been done.  We need to return a RunArray of TextAttributes of various kinds.  These are written by
            the implementors of writeScanOn:"
                    | runs values attrList char |
                    (strm peekFor: $( ) ifFalse: [^ nil].
                    runs := OrderedCollection new.
                    [strm skipSeparators.
                     strm peekFor: $)] whileFalse:
                            [runs add: (Number readFrom: strm)].
                    values := OrderedCollection new.        "Value array"
                    attrList := OrderedCollection new.      "Attributes list"
                    [(char := strm peek) == nil] whileFalse: [
                            (char isSeparator or: [ char = $!! ])
                                    ifTrue: [ "n.b. Skip $!! to meet expectations of RunArrayTest>>testScanFromTrailer.
                                                    The example string used in that test does not seem to match the implemention
                                                    of the fileOut serialization, but the test may be right and the implementation
                                                    wrong. In any case, relax the parsing here to meet the test expectations, and to
                                                    be more consistent with the original version of this method that assumed any
                                                    unexpected charater to be a separator. -dtl Jan 2014"
                                            strm next "space, cr do nothing"]
                                    ifFalse: [char == $,
                                                    ifTrue: [strm next.
                                                            values add: attrList asArray.
            +                                               attrList reset ]
            -                                               attrList := OrderedCollection new]
                                                    ifFalse: [attrList add:  (TextAttribute newFrom: strm)]
                                            ]
                            ].
                    values add: attrList asArray.
                    ^ self runs: runs asArray values: (values copyFrom: 1 to: runs size) asArray
             "
             RunArray scanFrom: (ReadStream on: '(14 50 312)f1,f1b,f1LInteger +;i')
             "!

            Item was removed:
            - ----- Method: Set>>includes2: (in category 'testing') -----
            - includes2: anObject - -       ^((array at: (self scanFor: anObject)) == nil) not!

            Item was changed:
             ----- Method: WeakIdentityDictionary>>includesKey: (in category 'testing') -----
             includesKey: key
                    "Answer whether the receiver has a key equal to the argument, key."

            +       (array at: (self scanFor: key))
            +               ifNil: [
            +                       "it just has been reclaimed"
            +                       ^false]
            +               ifNotNil: [ :element |
            +                       element == vacuum
            +                               ifTrue: [ ^false ]
            +                               ifFalse: [ ^true ] ]!
            -       ^(array at: (self scanFor: key))
            -               ifNil:
            -                       ["it just has been reclaimed"
            -                       false]
            -               ifNotNil: [:element | element ~~ vacuum]!

            Item was changed:
             ----- Method: WeakSet>>includes: (in category 'testing') -----
             includes: anObject

                    (array at: (self scanFor: anObject))
                            ifNil: [ ^false ]
            +               ifNotNil: [ :object |
            +                       object == flag
            +                               ifTrue: [ ^false ]
            +                               ifFalse: [ ^true ] ]!
            -               ifNotNil: [ :object | ^object ~~ flag ]!





--
_,,,^..^,,,_
best, Eliot

--

_,,,^..^,,,_

best, Eliot