Compiler heuristics

[Igor Stasenko]

It's a theoretical question, rather than practical concerning Exupery,
but i'd like to know, what you know/thinking about special compiler
heuristics concerning simplifying expressions, when do inlining.

The problem, in basic can be demonstrated by following example.

Suppose you having a code:

mainMethod
   object = 0 ifTrue: [ object method1 ] ifFalse: [ object method2]

and now method bodies:

method1
   object = 0 ifTrue: [ do something] ifFalse: [ do something else ]

method2
   object ~= 0 ifTrue: [ do something] ifFalse: [ do something else ]

Now, the question is, when you inlining method1/2 into mainMethod
you can see, that tests in inlined methods become redundant.
If we inline both methods, code will look like:

mainMethod
   object = 0 ifTrue: [
       object = 0 ifTrue: [ do something]
       ifFalse: [ do something else ]  ]
   ifFalse: [
       object ~= 0 ifTrue: [ do something]
       ifFalse: [ do something else ] ]

Is there any techniques, which can help in removing such redundancy,
when analyzing code by compiler?

-- 
Best regards,
Igor Stasenko AKA sig.