Eliot Miranda uploaded a new version of Compiler to project The Trunk: http://source.squeak.org/trunk/Compiler-eem.395.mcz
==================== Summary ====================
Name: Compiler-eem.395 Author: eem Time: 15 October 2018, 12:37:16.203042 pm UUID: 2f7c8f3a-4e2d-413b-8651-b05b5683f89d Ancestors: Compiler-eem.394
Implement markerOrNil: for the SistaV1 bytecode set and firm up both implementations so that e.g. aMethod self fooClass new is not interpreted as a marker method (because #new is a special selector and hence does not cayse a literal to be allocated).
=============== Diff against Compiler-eem.394 ===============
Item was added: + ----- Method: EncoderForSistaV1 class>>markerOrNilFor: (in category 'compiled method support') ----- + markerOrNilFor: aMethod + "If aMethod is a marker method, answer the symbol used to mark it. Otherwise + answer nil. What is a marker method? It is method with body like + 'self subclassResponsibility' or '^ self subclassResponsibility' + used to indicate ('mark') a special property. + + Marker methods compile to two bytecode forms, this: + self + send: <literal 1> + pop + returnSelf + or this: + self + send: <literal 1> + returnTop" + | expectedHeaderPlusLliteralSize e byte | + expectedHeaderPlusLliteralSize := Smalltalk wordSize * 4. + ^(((e := aMethod endPC - expectedHeaderPlusLliteralSize) = 3 or: [e = 4]) + and: [aMethod numLiterals = 3 + and: [(aMethod at: expectedHeaderPlusLliteralSize + 1) = 16r4C "push self" + and: [(aMethod at: expectedHeaderPlusLliteralSize + 2) = 16r80 + and: [(byte := aMethod at: expectedHeaderPlusLliteralSize + 3) = 16rD8 or: [byte = 16r5C]]]]]) "pop or returnSelf" + ifTrue: [aMethod literalAt: 1]!
Item was changed: ----- Method: EncoderForV3 class>>markerOrNilFor: (in category 'compiled method support') ----- markerOrNilFor: aMethod "If aMethod is a marker method, answer the symbol used to mark it. Otherwise answer nil. What is a marker method? It is method with body like 'self subclassResponsibility' or '^ self subclassResponsibility' used to indicate ('mark') a special property.
Marker methods compile to two bytecode forms, this: self send: <literal 1> pop returnSelf or this: self send: <literal 1> returnTop" + | expectedHeaderPlusLliteralSize e byte | - | expectedHeaderPlusLliteralSize e | expectedHeaderPlusLliteralSize := Smalltalk wordSize * 4. ^(((e := aMethod endPC - expectedHeaderPlusLliteralSize) = 3 or: [e = 4]) and: [aMethod numLiterals = 3 + and: [(aMethod at: expectedHeaderPlusLliteralSize + 1) = 16r70 "push self" + and: [(aMethod at: expectedHeaderPlusLliteralSize + 2) = 16rD0 + and: [(byte := aMethod at: expectedHeaderPlusLliteralSize + 3) = 16r87 or: [byte = 16r78]]]]]) "pop or returnSelf" - and: [(aMethod at: expectedHeaderPlusLliteralSize + 1) = 16r70 "push self" - and: [(aMethod at: expectedHeaderPlusLliteralSize + 2) = 16rD0]]]) "send <literal 1>" ifTrue: [aMethod literalAt: 1]!