The Trunk: Compiler-eem.242.mcz

Eliot Miranda uploaded a new version of Compiler to project The Trunk:
http://source.squeak.org/trunk/Compiler-eem.242.mcz

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

Name: Compiler-eem.242
Author: eem
Time: 9 November 2012, 2:22:42.152 pm
UUID: 1f233dff-53b6-4ddd-977f-66550a4f0269
Ancestors: Compiler-eem.241

Further fix decompilation of to:do: loops now they return
their receiver.  Fixes the case where the loop is the last
statement in an ifTrue:ifFalse: branch, e.g. the recompilation
of Object>>#veryDeepCopyWith:.

=============== Diff against Compiler-eem.241 ===============

Item was changed:
  ----- Method: Decompiler>>convertToDoLoop (in category 'private') -----
  convertToDoLoop
  "If statements contains the pattern
  var := startExpr.
  [var <= limit] whileTrue: [...statements... var := var + incConst]
  then replace this by
  startExpr to: limit by: incConst do: [:var | ...statements...]"
  | initStmt toDoStmt limitStmt |
  (stack notEmpty
  and: [stack last isAssignmentNode])
  ifTrue:
  [initStmt := stack last.
  (toDoStmt := statements last toDoFromWhileWithInit: initStmt) ifNil:
  [^self].
  stack removeLast; addLast: toDoStmt.
  statements removeLast]
  ifFalse:
  [statements size < 2 ifTrue:
  [^self].
  initStmt := statements at: statements size-1.
  (toDoStmt := statements last toDoFromWhileWithInit: initStmt) ifNil:
  [^self].
  statements removeLast; removeLast; addLast: toDoStmt].
  initStmt variable scope: -1.  "Flag arg as block temp"
 
  "Attempt further conversion of the pattern
  limitVar := limitExpr.
  startExpr to: limitVar by: incConst do: [:var | ...statements...]
  to
+ startExpr to: limitExpr by: incConst do: [:var | ...statements...].
+ The complication here is that limitVar := limitExpr's value may be used, in which case it'll
+ be statements last, or may not be used, in which case it'll be statements nextToLast."
- startExpr to: limitExpr by: incConst do: [:var | ...statements...]"
  statements size < 2 ifTrue: [^ self].
+ limitStmt := statements last.
- limitStmt := statements at: statements size-1.
  ((limitStmt isMemberOf: AssignmentNode)
  and: [limitStmt variable isTemp
+ and: [limitStmt variable == toDoStmt arguments first]]) ifFalse:
+ [limitStmt := statements at: statements size-1.
+ ((limitStmt isMemberOf: AssignmentNode)
+ and: [limitStmt variable isTemp
+ and: [limitStmt variable == toDoStmt arguments first]]) ifFalse:
+ [^self]].
+
+ (self blockScopeRefersOnlyOnceToTemp: limitStmt variable fieldOffset) ifFalse:
+ [^self].
- and: [limitStmt variable == toDoStmt arguments first
- and: [self blockScopeRefersOnlyOnceToTemp: limitStmt variable fieldOffset]]])
- ifFalse: [^ self].
  toDoStmt arguments at: 1 put: limitStmt value.
  limitStmt variable scope: -2.  "Flag limit var so it won't print"
+ statements last == limitStmt
+ ifTrue: [statements removeLast]
+ ifFalse: [statements removeLast; removeLast; addLast: toDoStmt]!
- statements removeLast; removeLast; addLast: toDoStmt
-
- !