Decompiler issues

> Hi,
>
>
> I recently ran into a new decompiler issue which doesn't allow the debugger
> to open. Details here: http://bugs.squeak.org/view.php?id=7467
>
> So I thought it's time to revisit my decision of making DecompilerTests a
> subclass of LongTestCase, because I'm pretty sure noone is running these
> tests. According to my measurements 60-70% of their runtime is spent with
> garbage collecting. DecompilerTests >> #decompileClassesSelect: forces a
> full GC for every class in the image (>2000 in a clear trunk image). Is this
> GC still necessary?
>
> There are also two new methods besides EventSensor >> #eventTickler which
> give a Syntax Error when running these tests. The new methods are
> SHMCClassDefinition >> #withAllSuperclasses and SHMCClassDefinition >>
> #allInstVarNames.
> This problem occurs when a temporary is declared in an inlined block which
> is the receiver of #whileTrue, #whileTrue:, #whileFalse or #whileFalse and
> the variable is also referenced from a normal block.
> For example:
>        [
>                | foo |
>                [ foo := false ] value ] whileTrue
> will be decompiled as: [[_r1 := false] value] whileTrue.
>
> A lot of decompiler tests are failing, because the temporaries are indexed
> in a different order during the second decompilation.
>
> I hope someone with enough knowledge will fix these issues.
>

> 2010/3/1 Levente Uzonyi <[hidden email]>:
>> Hi,
>>
>>
>> I recently ran into a new decompiler issue which doesn't allow the debugger
>> to open. Details here: http://bugs.squeak.org/view.php?id=7467
>>
>> So I thought it's time to revisit my decision of making DecompilerTests a
>> subclass of LongTestCase, because I'm pretty sure noone is running these
>> tests. According to my measurements 60-70% of their runtime is spent with
>> garbage collecting. DecompilerTests >> #decompileClassesSelect: forces a
>> full GC for every class in the image (>2000 in a clear trunk image). Is this
>> GC still necessary?
>>
>> There are also two new methods besides EventSensor >> #eventTickler which
>> give a Syntax Error when running these tests. The new methods are
>> SHMCClassDefinition >> #withAllSuperclasses and SHMCClassDefinition >>
>> #allInstVarNames.
>> This problem occurs when a temporary is declared in an inlined block which
>> is the receiver of #whileTrue, #whileTrue:, #whileFalse or #whileFalse and
>> the variable is also referenced from a normal block.
>> For example:
>>        [
>>                | foo |
>>                [ foo := false ] value ] whileTrue
>> will be decompiled as: [[_r1 := false] value] whileTrue.
>>
>> A lot of decompiler tests are failing, because the temporaries are indexed
>> in a different order during the second decompilation.
>>
>> I hope someone with enough knowledge will fix these issues.
>>
>
> I have no special knowledge.
> The code is quite complex (measured with # of instVars, # of methods,
> and # line of codes in certain methods).
> But, thanks you provided a good test case.
>
> The first problem I see right from beginning is the order of trailer temp names:
> trailer tempNames -> '[input i index1 ps k count (digits)[each (digits)]]'
> I guess parentheses (digits) expresses a copiedValue.
>
> Let explore the byte codes to see if it fits:
>
> '1 0' readStream
> 81 <22> pushConstant: '1 0'
> 82 <D1> send: readStream
>
> [:input: | ...] block argument
> 83 <8F 01 00 67> closureNumCopied: 0 numArgs: 1 bytes 87 to 189
> 87      <73> pushConstant: nil => i
> 88      <73> pushConstant: nil => index1
> 89      <73> pushConstant: nil => ps
> 90      <73> pushConstant: nil => k
> 91      <73> pushConstant: nil => count
> 92      <73> pushConstant: nil => UNUSED SLOT ?????
> 93      <73> pushConstant: nil => copiedValues #( digits )
> 94      <10> pushTemp: 0               ( input )
> 95      <DE> send: skipSeparators
> 96      <87> pop
> 97      <50> pushLit: Integer
> 98      <10> pushTemp: 0              ( input )
> 99      <EF> send: readFrom:
> 100     <69> popIntoTemp: 1          ( i := )
> 101     <11> pushTemp: 1             ( i )
> 102     <75> pushConstant: 0
> 103     <B6> send: =
>
> whileFalse: [...
> 104     <A8 52> jumpTrue: 188
> 106     <8A 01> push: (Array new: 1)
> 108     <6F> popIntoTemp: 7         ( #( digits ) ) copiedValues... Note
> that this is at rank 8, not 7 as expected from trailer tempNames...
> 109     <76> pushConstant: 1
> 110     <6C> popIntoTemp: 4        ( k :=)
> 111     <75> pushConstant: 0
> 112     <6D> popIntoTemp: 5        ( count := )
> 113     <44> pushLit: Array
> 114     <25> pushConstant: 10
> 115     <75> pushConstant: 0
> 116     <F3> send: new:withAll:
> 117     <8E 00 07> popIntoTemp: 0 inVectorAt: 7  ( digits := )
>
> 120     <15> pushTemp: 5            ( count )
> 121     <11> pushTemp: 1            ( i )
> 122     <B2> send: <
>
> whileTrue: [
> 123     <AC 3A> jumpFalse: 183
> 125     <14> pushTemp: 4            ( k )
> 126     <D6> send: printString
> 127     <6B> popIntoTemp: 3        ( ps := )
> 128     <13> pushTemp: 3
> 129     <2C> pushConstant: $1
> 130     <EB> send: indexOf:
> 131     <81 42> storeIntoTemp: 2  ( index1 := )
> 133     <75> pushConstant: 0
> 134     <B6> send: =
> 135     <99> jumpFalse: 138
> 136     <71> pushConstant: true
> 137     <95> jumpTo: 144
> 138     <13> pushTemp: 3
> 139     <2A> pushConstant: $3
> 140     <12> pushTemp: 2            ( index1 )
> 141     <F9> send: indexOf:startingAt:
> 142     <75> pushConstant: 0
> 143     <B6> send: =
>
> ifTrue: [
> 144     <AC 1F> jumpFalse: 177
> 146     <15> pushTemp: 5            ( count )
> 147     <76> pushConstant: 1
> 148     <B0> send: +
> 149     <6D> popIntoTemp: 5        ( count := )
> 150     <13> pushTemp: 3            ( ps )
> 151     <17> pushTemp: 7            ( #( digits) )
> 152     <8F 11 00 13> closureNumCopied: 1 numArgs: 1 bytes 156 to 174
> 156             <8C 00 01> pushTemp: 0 inVectorAt: 1  ( digits )
> 159             <10> pushTemp: 0                                ( each )
> 160             <D7> send: asciiValue
> 161             <28> pushConstant: 47
> 162             <B1> send: -
> 163             <8C 00 01> pushTemp: 0 inVectorAt: 1  ( digits )
> 166             <10> pushTemp: 0                               ( each )
> 167             <D7> send: asciiValue
> 168             <28> pushConstant: 47
> 169             <B1> send: -
> 170             <C0> send: at:
> 171             <76> pushConstant: 1
> 172             <B0> send: +
> 173             <C1> send: at:put:
> 174             <7D> blockReturn
> 175     <CB> send: do:
> 176     <87> pop
> 177     <14> pushTemp: 4       ( k )
> 178     <76> pushConstant: 1
> 179     <B0> send: +
> 180     <6C> popIntoTemp: 4   ( k := )
> 181     <A3 C1> jumpTo: 120
> 183     <70> self
> 184     <DD> send: halt
> 185     <87> pop
> 186     <A3 A2> jumpTo: 94
> 188     <73> pushConstant: nil
> 189     <7D> blockReturn
> 190 <E0> send: in:
> 191 <7C> returnTop
>
> What look *** STRANGE *** is the UNUSED slot reserved in [:input | ...
> ] temp vector...
>
>
> Now decompiling in initSymbols: >>
> mapFromBlockStartsIn:toTempVarsFrom:constructor:
>
> I got this map: there are only 3 blocks: (the other onesare inlined)
> - the whole method (startpc=81)
> - the [:input | ...] block (startpc=87)
> - the [:each | ...] block (startpc=156)
>
> And the temps names are (for each block indexed by start pc)
> a Dictionary(
>    81->#()
>    87->#(
>           #('input' 1)
>           #('i' 2)
>           #('index1' 3)
>           #('ps' 4)
>           #('k' 5)
>           #('count' 6)
>           #('digits' #(7 1)))
>    156->#(
>           #('each' 1)
>           #('digits' #(2 1))) )
> I think we got a problem here... digits should be #(8 1) to fit the
> compiled code and the UNUSED slot...
>
> the tempVector has just 7 slots:
>    {{input} . {i} . {index1} . {ps} . {k} . {count} . {{digits}}}
> later replaced with:
>    {{input} . {i} . {index1} . {ps} . {k} . {count} . {_r7}}
>
> Then, when decompiling:
> 108     <6F> popIntoTemp: 7         ( #( digits ) ) copiedValues... Note
> that this is at rank 8, not 7 as expected from trailer tempNames...
> the assertion fails because we only have 7 temps vars and try to
> assign temp of rank 8...
>
> Now, just have to discover how the UNUSED slot was ever compiled...
>

> Eliot might be more efficient than me...
>
> Nicolas
>
>>
>> Cheers,
>> Levente
>>
>>
>

> 2010/3/1 Nicolas Cellier <[hidden email]>:
>> 2010/3/1 Levente Uzonyi <[hidden email]>:
>>> Hi,
>>>
>>>
>>> I recently ran into a new decompiler issue which doesn't allow the debugger
>>> to open. Details here: http://bugs.squeak.org/view.php?id=7467
>>>
>>> So I thought it's time to revisit my decision of making DecompilerTests a
>>> subclass of LongTestCase, because I'm pretty sure noone is running these
>>> tests. According to my measurements 60-70% of their runtime is spent with
>>> garbage collecting. DecompilerTests >> #decompileClassesSelect: forces a
>>> full GC for every class in the image (>2000 in a clear trunk image). Is this
>>> GC still necessary?
>>>
>>> There are also two new methods besides EventSensor >> #eventTickler which
>>> give a Syntax Error when running these tests. The new methods are
>>> SHMCClassDefinition >> #withAllSuperclasses and SHMCClassDefinition >>
>>> #allInstVarNames.
>>> This problem occurs when a temporary is declared in an inlined block which
>>> is the receiver of #whileTrue, #whileTrue:, #whileFalse or #whileFalse and
>>> the variable is also referenced from a normal block.
>>> For example:
>>>        [
>>>                | foo |
>>>                [ foo := false ] value ] whileTrue
>>> will be decompiled as: [[_r1 := false] value] whileTrue.
>>>
>>> A lot of decompiler tests are failing, because the temporaries are indexed
>>> in a different order during the second decompilation.
>>>
>>> I hope someone with enough knowledge will fix these issues.
>>>
>>
>> I have no special knowledge.
>> The code is quite complex (measured with # of instVars, # of methods,
>> and # line of codes in certain methods).
>> But, thanks you provided a good test case.
>>
>> The first problem I see right from beginning is the order of trailer temp names:
>> trailer tempNames -> '[input i index1 ps k count (digits)[each (digits)]]'
>> I guess parentheses (digits) expresses a copiedValue.
>>
>> Let explore the byte codes to see if it fits:
>>
>> '1 0' readStream
>> 81 <22> pushConstant: '1 0'
>> 82 <D1> send: readStream
>>
>> [:input: | ...] block argument
>> 83 <8F 01 00 67> closureNumCopied: 0 numArgs: 1 bytes 87 to 189
>> 87      <73> pushConstant: nil => i
>> 88      <73> pushConstant: nil => index1
>> 89      <73> pushConstant: nil => ps
>> 90      <73> pushConstant: nil => k
>> 91      <73> pushConstant: nil => count
>> 92      <73> pushConstant: nil => UNUSED SLOT ?????
>> 93      <73> pushConstant: nil => copiedValues #( digits )
>> 94      <10> pushTemp: 0               ( input )
>> 95      <DE> send: skipSeparators
>> 96      <87> pop
>> 97      <50> pushLit: Integer
>> 98      <10> pushTemp: 0              ( input )
>> 99      <EF> send: readFrom:
>> 100     <69> popIntoTemp: 1          ( i := )
>> 101     <11> pushTemp: 1             ( i )
>> 102     <75> pushConstant: 0
>> 103     <B6> send: =
>>
>> whileFalse: [...
>> 104     <A8 52> jumpTrue: 188
>> 106     <8A 01> push: (Array new: 1)
>> 108     <6F> popIntoTemp: 7         ( #( digits ) ) copiedValues... Note
>> that this is at rank 8, not 7 as expected from trailer tempNames...
>> 109     <76> pushConstant: 1
>> 110     <6C> popIntoTemp: 4        ( k :=)
>> 111     <75> pushConstant: 0
>> 112     <6D> popIntoTemp: 5        ( count := )
>> 113     <44> pushLit: Array
>> 114     <25> pushConstant: 10
>> 115     <75> pushConstant: 0
>> 116     <F3> send: new:withAll:
>> 117     <8E 00 07> popIntoTemp: 0 inVectorAt: 7  ( digits := )
>>
>> 120     <15> pushTemp: 5            ( count )
>> 121     <11> pushTemp: 1            ( i )
>> 122     <B2> send: <
>>
>> whileTrue: [
>> 123     <AC 3A> jumpFalse: 183
>> 125     <14> pushTemp: 4            ( k )
>> 126     <D6> send: printString
>> 127     <6B> popIntoTemp: 3        ( ps := )
>> 128     <13> pushTemp: 3
>> 129     <2C> pushConstant: $1
>> 130     <EB> send: indexOf:
>> 131     <81 42> storeIntoTemp: 2  ( index1 := )
>> 133     <75> pushConstant: 0
>> 134     <B6> send: =
>> 135     <99> jumpFalse: 138
>> 136     <71> pushConstant: true
>> 137     <95> jumpTo: 144
>> 138     <13> pushTemp: 3
>> 139     <2A> pushConstant: $3
>> 140     <12> pushTemp: 2            ( index1 )
>> 141     <F9> send: indexOf:startingAt:
>> 142     <75> pushConstant: 0
>> 143     <B6> send: =
>>
>> ifTrue: [
>> 144     <AC 1F> jumpFalse: 177
>> 146     <15> pushTemp: 5            ( count )
>> 147     <76> pushConstant: 1
>> 148     <B0> send: +
>> 149     <6D> popIntoTemp: 5        ( count := )
>> 150     <13> pushTemp: 3            ( ps )
>> 151     <17> pushTemp: 7            ( #( digits) )
>> 152     <8F 11 00 13> closureNumCopied: 1 numArgs: 1 bytes 156 to 174
>> 156             <8C 00 01> pushTemp: 0 inVectorAt: 1  ( digits )
>> 159             <10> pushTemp: 0                                ( each )
>> 160             <D7> send: asciiValue
>> 161             <28> pushConstant: 47
>> 162             <B1> send: -
>> 163             <8C 00 01> pushTemp: 0 inVectorAt: 1  ( digits )
>> 166             <10> pushTemp: 0                               ( each )
>> 167             <D7> send: asciiValue
>> 168             <28> pushConstant: 47
>> 169             <B1> send: -
>> 170             <C0> send: at:
>> 171             <76> pushConstant: 1
>> 172             <B0> send: +
>> 173             <C1> send: at:put:
>> 174             <7D> blockReturn
>> 175     <CB> send: do:
>> 176     <87> pop
>> 177     <14> pushTemp: 4       ( k )
>> 178     <76> pushConstant: 1
>> 179     <B0> send: +
>> 180     <6C> popIntoTemp: 4   ( k := )
>> 181     <A3 C1> jumpTo: 120
>> 183     <70> self
>> 184     <DD> send: halt
>> 185     <87> pop
>> 186     <A3 A2> jumpTo: 94
>> 188     <73> pushConstant: nil
>> 189     <7D> blockReturn
>> 190 <E0> send: in:
>> 191 <7C> returnTop
>>
>> What look *** STRANGE *** is the UNUSED slot reserved in [:input | ...
>> ] temp vector...
>>
>>
>> Now decompiling in initSymbols: >>
>> mapFromBlockStartsIn:toTempVarsFrom:constructor:
>>
>> I got this map: there are only 3 blocks: (the other onesare inlined)
>> - the whole method (startpc=81)
>> - the [:input | ...] block (startpc=87)
>> - the [:each | ...] block (startpc=156)
>>
>> And the temps names are (for each block indexed by start pc)
>> a Dictionary(
>>    81->#()
>>    87->#(
>>           #('input' 1)
>>           #('i' 2)
>>           #('index1' 3)
>>           #('ps' 4)
>>           #('k' 5)
>>           #('count' 6)
>>           #('digits' #(7 1)))
>>    156->#(
>>           #('each' 1)
>>           #('digits' #(2 1))) )
>> I think we got a problem here... digits should be #(8 1) to fit the
>> compiled code and the UNUSED slot...
>>
>> the tempVector has just 7 slots:
>>    {{input} . {i} . {index1} . {ps} . {k} . {count} . {{digits}}}
>> later replaced with:
>>    {{input} . {i} . {index1} . {ps} . {k} . {count} . {_r7}}
>>
>> Then, when decompiling:
>> 108     <6F> popIntoTemp: 7         ( #( digits ) ) copiedValues... Note
>> that this is at rank 8, not 7 as expected from trailer tempNames...
>> the assertion fails because we only have 7 temps vars and try to
>> assign temp of rank 8...
>>
>> Now, just have to discover how the UNUSED slot was ever compiled...
>>
>
> Debugging this:
> Compiler evaluate: '''1 0'' readStream in: [ :input |
>    | i |
>    [
>    input skipSeparators.
>    i := Integer readFrom: input.
>    i = 0 ] whileFalse: [
>        | k count digits |
>        k := 1.
>        count := 0.
>        digits := Array new: 10 withAll: 0.
>        [ count < i ] whileTrue: [
>            | index1 ps |
>            ps := k printString.
>            ((index1 := ps indexOf: $1) = 0 or: [ (ps indexOf: $3
> startingAt: index1) = 0 ]) ifTrue: [
>                count := count + 1.
>                ps do: [ :each | digits at: each asciiValue - 47 put:
> (digits at: each asciiValue - 47) + 1 ] ].
>                k := k + 1 ].
>        self halt ] ] '
>
> Visibly, the digits temp has two slots reserved, one for itself, one
> for copiedValues <2-8>:
> encoder blockExtentsToLocal
> -> a Dictionary(
>     (0 to: 10)->#()
>     (2 to: 8)->{{input} . {i} . {index1} . {ps} . {k} . {count} .
> {digits} . {<2-8>}}
>     (4 to: 6)->{{each} . {<2-8>}} )
>

> Nicolas
>
>> Eliot might be more efficient than me...
>>
>> Nicolas
>>
>>>
>>> Cheers,
>>> Levente
>>>
>>>
>>
>

> 2010/3/1 Nicolas Cellier <[hidden email]>:
>> 2010/3/1 Nicolas Cellier <[hidden email]>:
>>> 2010/3/1 Levente Uzonyi <[hidden email]>:
>>>> Hi,
>>>>
>>>>
>>>> I recently ran into a new decompiler issue which doesn't allow the debugger
>>>> to open. Details here: http://bugs.squeak.org/view.php?id=7467
>>>>
>>>> So I thought it's time to revisit my decision of making DecompilerTests a
>>>> subclass of LongTestCase, because I'm pretty sure noone is running these
>>>> tests. According to my measurements 60-70% of their runtime is spent with
>>>> garbage collecting. DecompilerTests >> #decompileClassesSelect: forces a
>>>> full GC for every class in the image (>2000 in a clear trunk image). Is this
>>>> GC still necessary?
>>>>
>>>> There are also two new methods besides EventSensor >> #eventTickler which
>>>> give a Syntax Error when running these tests. The new methods are
>>>> SHMCClassDefinition >> #withAllSuperclasses and SHMCClassDefinition >>
>>>> #allInstVarNames.
>>>> This problem occurs when a temporary is declared in an inlined block which
>>>> is the receiver of #whileTrue, #whileTrue:, #whileFalse or #whileFalse and
>>>> the variable is also referenced from a normal block.
>>>> For example:
>>>>        [
>>>>                | foo |
>>>>                [ foo := false ] value ] whileTrue
>>>> will be decompiled as: [[_r1 := false] value] whileTrue.
>>>>
>>>> A lot of decompiler tests are failing, because the temporaries are indexed
>>>> in a different order during the second decompilation.
>>>>
>>>> I hope someone with enough knowledge will fix these issues.
>>>>
>>>
>>> I have no special knowledge.
>>> The code is quite complex (measured with # of instVars, # of methods,
>>> and # line of codes in certain methods).
>>> But, thanks you provided a good test case.
>>>
>>> The first problem I see right from beginning is the order of trailer temp names:
>>> trailer tempNames -> '[input i index1 ps k count (digits)[each (digits)]]'
>>> I guess parentheses (digits) expresses a copiedValue.
>>>
>>> Let explore the byte codes to see if it fits:
>>>
>>> '1 0' readStream
>>> 81 <22> pushConstant: '1 0'
>>> 82 <D1> send: readStream
>>>
>>> [:input: | ...] block argument
>>> 83 <8F 01 00 67> closureNumCopied: 0 numArgs: 1 bytes 87 to 189
>>> 87      <73> pushConstant: nil => i
>>> 88      <73> pushConstant: nil => index1
>>> 89      <73> pushConstant: nil => ps
>>> 90      <73> pushConstant: nil => k
>>> 91      <73> pushConstant: nil => count
>>> 92      <73> pushConstant: nil => UNUSED SLOT ?????
>>> 93      <73> pushConstant: nil => copiedValues #( digits )
>>> 94      <10> pushTemp: 0               ( input )
>>> 95      <DE> send: skipSeparators
>>> 96      <87> pop
>>> 97      <50> pushLit: Integer
>>> 98      <10> pushTemp: 0              ( input )
>>> 99      <EF> send: readFrom:
>>> 100     <69> popIntoTemp: 1          ( i := )
>>> 101     <11> pushTemp: 1             ( i )
>>> 102     <75> pushConstant: 0
>>> 103     <B6> send: =
>>>
>>> whileFalse: [...
>>> 104     <A8 52> jumpTrue: 188
>>> 106     <8A 01> push: (Array new: 1)
>>> 108     <6F> popIntoTemp: 7         ( #( digits ) ) copiedValues... Note
>>> that this is at rank 8, not 7 as expected from trailer tempNames...
>>> 109     <76> pushConstant: 1
>>> 110     <6C> popIntoTemp: 4        ( k :=)
>>> 111     <75> pushConstant: 0
>>> 112     <6D> popIntoTemp: 5        ( count := )
>>> 113     <44> pushLit: Array
>>> 114     <25> pushConstant: 10
>>> 115     <75> pushConstant: 0
>>> 116     <F3> send: new:withAll:
>>> 117     <8E 00 07> popIntoTemp: 0 inVectorAt: 7  ( digits := )
>>>
>>> 120     <15> pushTemp: 5            ( count )
>>> 121     <11> pushTemp: 1            ( i )
>>> 122     <B2> send: <
>>>
>>> whileTrue: [
>>> 123     <AC 3A> jumpFalse: 183
>>> 125     <14> pushTemp: 4            ( k )
>>> 126     <D6> send: printString
>>> 127     <6B> popIntoTemp: 3        ( ps := )
>>> 128     <13> pushTemp: 3
>>> 129     <2C> pushConstant: $1
>>> 130     <EB> send: indexOf:
>>> 131     <81 42> storeIntoTemp: 2  ( index1 := )
>>> 133     <75> pushConstant: 0
>>> 134     <B6> send: =
>>> 135     <99> jumpFalse: 138
>>> 136     <71> pushConstant: true
>>> 137     <95> jumpTo: 144
>>> 138     <13> pushTemp: 3
>>> 139     <2A> pushConstant: $3
>>> 140     <12> pushTemp: 2            ( index1 )
>>> 141     <F9> send: indexOf:startingAt:
>>> 142     <75> pushConstant: 0
>>> 143     <B6> send: =
>>>
>>> ifTrue: [
>>> 144     <AC 1F> jumpFalse: 177
>>> 146     <15> pushTemp: 5            ( count )
>>> 147     <76> pushConstant: 1
>>> 148     <B0> send: +
>>> 149     <6D> popIntoTemp: 5        ( count := )
>>> 150     <13> pushTemp: 3            ( ps )
>>> 151     <17> pushTemp: 7            ( #( digits) )
>>> 152     <8F 11 00 13> closureNumCopied: 1 numArgs: 1 bytes 156 to 174
>>> 156             <8C 00 01> pushTemp: 0 inVectorAt: 1  ( digits )
>>> 159             <10> pushTemp: 0                                ( each )
>>> 160             <D7> send: asciiValue
>>> 161             <28> pushConstant: 47
>>> 162             <B1> send: -
>>> 163             <8C 00 01> pushTemp: 0 inVectorAt: 1  ( digits )
>>> 166             <10> pushTemp: 0                               ( each )
>>> 167             <D7> send: asciiValue
>>> 168             <28> pushConstant: 47
>>> 169             <B1> send: -
>>> 170             <C0> send: at:
>>> 171             <76> pushConstant: 1
>>> 172             <B0> send: +
>>> 173             <C1> send: at:put:
>>> 174             <7D> blockReturn
>>> 175     <CB> send: do:
>>> 176     <87> pop
>>> 177     <14> pushTemp: 4       ( k )
>>> 178     <76> pushConstant: 1
>>> 179     <B0> send: +
>>> 180     <6C> popIntoTemp: 4   ( k := )
>>> 181     <A3 C1> jumpTo: 120
>>> 183     <70> self
>>> 184     <DD> send: halt
>>> 185     <87> pop
>>> 186     <A3 A2> jumpTo: 94
>>> 188     <73> pushConstant: nil
>>> 189     <7D> blockReturn
>>> 190 <E0> send: in:
>>> 191 <7C> returnTop
>>>
>>> What look *** STRANGE *** is the UNUSED slot reserved in [:input | ...
>>> ] temp vector...
>>>
>>>
>>> Now decompiling in initSymbols: >>
>>> mapFromBlockStartsIn:toTempVarsFrom:constructor:
>>>
>>> I got this map: there are only 3 blocks: (the other onesare inlined)
>>> - the whole method (startpc=81)
>>> - the [:input | ...] block (startpc=87)
>>> - the [:each | ...] block (startpc=156)
>>>
>>> And the temps names are (for each block indexed by start pc)
>>> a Dictionary(
>>>    81->#()
>>>    87->#(
>>>           #('input' 1)
>>>           #('i' 2)
>>>           #('index1' 3)
>>>           #('ps' 4)
>>>           #('k' 5)
>>>           #('count' 6)
>>>           #('digits' #(7 1)))
>>>    156->#(
>>>           #('each' 1)
>>>           #('digits' #(2 1))) )
>>> I think we got a problem here... digits should be #(8 1) to fit the
>>> compiled code and the UNUSED slot...
>>>
>>> the tempVector has just 7 slots:
>>>    {{input} . {i} . {index1} . {ps} . {k} . {count} . {{digits}}}
>>> later replaced with:
>>>    {{input} . {i} . {index1} . {ps} . {k} . {count} . {_r7}}
>>>
>>> Then, when decompiling:
>>> 108     <6F> popIntoTemp: 7         ( #( digits ) ) copiedValues... Note
>>> that this is at rank 8, not 7 as expected from trailer tempNames...
>>> the assertion fails because we only have 7 temps vars and try to
>>> assign temp of rank 8...
>>>
>>> Now, just have to discover how the UNUSED slot was ever compiled...
>>>
>>
>> Debugging this:
>> Compiler evaluate: '''1 0'' readStream in: [ :input |
>>    | i |
>>    [
>>    input skipSeparators.
>>    i := Integer readFrom: input.
>>    i = 0 ] whileFalse: [
>>        | k count digits |
>>        k := 1.
>>        count := 0.
>>        digits := Array new: 10 withAll: 0.
>>        [ count < i ] whileTrue: [
>>            | index1 ps |
>>            ps := k printString.
>>            ((index1 := ps indexOf: $1) = 0 or: [ (ps indexOf: $3
>> startingAt: index1) = 0 ]) ifTrue: [
>>                count := count + 1.
>>                ps do: [ :each | digits at: each asciiValue - 47 put:
>> (digits at: each asciiValue - 47) + 1 ] ].
>>                k := k + 1 ].
>>        self halt ] ] '
>>
>> Visibly, the digits temp has two slots reserved, one for itself, one
>> for copiedValues <2-8>:
>> encoder blockExtentsToLocal
>> -> a Dictionary(
>>     (0 to: 10)->#()
>>     (2 to: 8)->{{input} . {i} . {index1} . {ps} . {k} . {count} .
>> {digits} . {<2-8>}}
>>     (4 to: 6)->{{each} . {<2-8>}} )
>>
>
> BlockNode>>addRemoteTemp: aTempVariableNode rootNode: rootNode "<MethodNode>"
>        ...snip...
>        temporaries remove: aTempVariableNode ifAbsent: [self halt: 'debug me'].
>
> triggers the halt because temporaries isEmpty... in block node
> [
>    | k count digits |
>     k := 1.
> ...]
>
> temporaries isEmpty because block is optimized...
> So the block does not really exist, and the temps are stored in parent block...
> So when block is optimized, we should better not ask it to remove:
> aTempVariableNode, should we?
>

> Nicolas
>
>> Nicolas
>>
>>> Eliot might be more efficient than me...
>>>
>>> Nicolas
>>>
>>>>
>>>> Cheers,
>>>> Levente
>>>>
>>>>
>>>
>>
>