diff options
| author | Drahflow <drahflow@gmx.de> | 2013-01-23 12:58:22 +0100 |
|---|---|---|
| committer | Drahflow <drahflow@gmx.de> | 2013-01-23 12:58:22 +0100 |
| commit | 6da4d865cd7d8051c8609e90b43a55fd26a74582 (patch) | |
| tree | 1dc00c1c446fd253c40ea1c3b9817b92da982c09 /notes | |
| parent | aba7b3fa8bd92c66760009d0a2762df3539c36cd (diff) | |
Some thoughts about the optimizer
Diffstat (limited to 'notes')
| -rw-r--r-- | notes | 40 |
1 files changed, 40 insertions, 0 deletions
@@ -192,3 +192,43 @@ Small set in between bit 63-60: 0 1 1 1 bit 59: reserved for GC * [ <object pointer> ]* + + += Musings About The Optimizer = + +Main problem: How do we find out if the names mean what we believe they do? + +== Runtime Checking == +* Optimize for the _current_ values of names +* Check whether changes have occured + * maybe some kind of version numbering in the scopes ++ semantically identical to fully dynamic scopes +- slow + +== Dynamic / Static / Constant Scopes, Guessing == +* A scope can be static (i.e. names don't change activation mode and no new names) +* A scope can be constant (i.e. names don't change values and it is static) +* The compiler guesses what is correct + * The user can override +* Conflicting runtime-changes raise errors ++ should be doable as long as no joker redefines =, defv, deff ++ should result in fast code for most methods +- surprising runtime errors + +== Dynamic / Static / Constant Scopes, User Specified == +* A scope can be static (i.e. names don't change activation mode and no new names) +* A scope can be constant (i.e. names don't change values and it is static) +* Default scopes are dynamic, but the user can specify otherwise +- many methods would not get optimized because the user forgot to flag the scope + +== Dynamic / Static / Constant Names == +* A name can be static (i.e. it is never overwritten after being resolved in a child scope and remains at the same scope index) +* A name can be constant (i.e. its value never changes after being resolved in a child scope) +* An optimized version of the code can be generated whenever it is called (using current name values) ++ fine grained control, sensible defaults possible +- even more assignment semantics + +== Sticky Resolution == +* Active names are considered constant after being resolved for the first time +* Passive names are considered static after being resolved for the first time +- fails to correctly handle the { =*array ... } use case |