Optimization

[LinqLover]

Do a systematic optimization by using the TimeProfileBrowser and try to improve performance. Implement #13 before.

[LinqLover]

Possible topics for optimization (only implement if benchmarks have proven demand!):

• Use array lookup in overrides of #doPrimitive:method:receiver:args:
• Cache Simulator >> #requiredCapabilities? (prototypical implementation lies in TraceDebugger.image)
• Speed up SimulationContext>>#copyFrom: during customization which is currently enumerating instance variables manually

[LinqLover]

General performance insights (to be documented somewhere):

• Simulator overhead is added on-demand only if a capability is actually overridden
• A bottleneck of Simulator >> #evaluate: & Co. is runSimulated:* which adds overhead for checking the context at each step and leaving the simulation in case of a non-local return (and is not optimized for message inlining). If these properties are not used, a faster simulation would be possible via Process>>#runUntil:.

Confusions (to be reproduced!):

• Why is runSimulated: faster on SimulationContext than on Context? Is this related to context marriage (VM)?
• Why is TestSimulatorUnoptimized sometimes faster than Simulator?