Nicolas Cellier uploaded a new version of Compiler to project The Trunk:
http://source.squeak.org/trunk/Compiler-nice.224.mcz

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

Name: Compiler-nice.224
Author: nice
Time: 20 February 2012, 10:56:20.223 pm
UUID: 15070f34-9c69-4407-a041-7659522fc95a
Ancestors: Compiler-nice.223

Just for fun, fix http://code.google.com/p/pharo/issues/detail?id=4915
The inlined and non inlined versions of to:do: should answer the same result.

Implementation notes:
This happens to be the receiver of to:do:, and thus the initial value of the loop index.
So we can trivially
- push the value of init statement on the stack,
- remove the final nil that was pushed forValue,
- and leave the rest of code generation unchanged

=============== Diff against Compiler-nice.223 ===============

Item was changed:
  ----- Method: MessageNode>>emitCodeForToDo:encoder:value: (in category 'code generation') -----
  emitCodeForToDo: stack encoder: encoder value: forValue 
  	" var := rcvr. L1: [var <= arg1] Bfp(L2) [block body. var := var + inc] Jmp(L1) L2: "
  	| loopSize initStmt limitInit test block incStmt blockSize |
  	initStmt := arguments at: 4.
  	limitInit := arguments at: 7.
  	test := arguments at: 5.
  	block := arguments at: 3.
  	incStmt := arguments at: 6.
  	blockSize := sizes at: 1.
  	loopSize := sizes at: 2.
  	limitInit == nil
  		ifFalse: [limitInit emitCodeForEffect: stack encoder: encoder].
+ 		
+ 	"This will return the receiver of to:do: which is the initial value of the loop"
+ 	forValue
+ 		ifTrue: [initStmt emitCodeForValue: stack encoder: encoder.]
+ 		ifFalse: [initStmt emitCodeForEffect: stack encoder: encoder].
- 	initStmt emitCodeForEffect: stack encoder: encoder.
  	test emitCodeForValue: stack encoder: encoder.
  	self emitCodeForBranchOn: false dist: blockSize pop: stack encoder: encoder.
  	pc := encoder methodStreamPosition.
  	block emitCodeForEvaluatedEffect: stack encoder: encoder.
  	incStmt emitCodeForEffect: stack encoder: encoder.
+ 	self emitCodeForJump: 0 - loopSize encoder: encoder.!
- 	self emitCodeForJump: 0 - loopSize encoder: encoder.
- 	forValue ifTrue: [encoder genPushSpecialLiteral: nil. stack push: 1]!

Item was changed:
  ----- Method: MessageNode>>sizeCodeForToDo:value: (in category 'code generation') -----
  sizeCodeForToDo: encoder value: forValue 
  	" var := rcvr. L1: [var <= arg1] Bfp(L2) [block body. var := var + inc] Jmp(L1) L2: "
  	| loopSize initStmt test block incStmt blockSize initSize limitInit |
  	block := arguments at: 3.
  	initStmt := arguments at: 4.
  	test := arguments at: 5.
  	incStmt := arguments at: 6.
  	limitInit := arguments at: 7.
+ 	initSize := forValue
+ 		ifTrue: [initStmt sizeCodeForValue: encoder.]
+ 		ifFalse: [initStmt sizeCodeForEffect: encoder].
- 	initSize := initStmt sizeCodeForEffect: encoder.
  	limitInit == nil ifFalse:
  		[initSize := initSize + (limitInit sizeCodeForEffect: encoder)].
  	blockSize := (block sizeCodeForEvaluatedEffect: encoder)
  			+ (incStmt sizeCodeForEffect: encoder)
  			+ (encoder sizeJumpLong: -1).
  	loopSize := (test sizeCodeForValue: encoder)
  			+ (self sizeCode: encoder forBranchOn: false dist: blockSize)
  			+ blockSize.
  	sizes := Array with: blockSize with: loopSize.
  	^initSize
+ 	+ loopSize!
- 	+ loopSize
- 	+ (forValue ifTrue: [encoder sizePushSpecialLiteral: nil] ifFalse: [0])!