|Interprocedural SSA form? email@example.com (Edsko de Vries) (2005-06-02)|
|Re: Interprocedural SSA form? firstname.lastname@example.org (Jeremy Singer) (2005-06-02)|
|Re: Interprocedural SSA form? email@example.com (Florian Liekweg) (2005-06-02)|
|Re: Interprocedural SSA form? firstname.lastname@example.org (Matthias Blume) (2005-06-04)|
|Re: Interprocedural SSA form? email@example.com (Jeremy Singer) (2005-06-04)|
|From:||Matthias Blume <firstname.lastname@example.org>|
|Date:||4 Jun 2005 15:07:11 -0400|
|Posted-Date:||04 Jun 2005 15:07:11 EDT|
Florian Liekweg <email@example.com> writes:
> Edsko de Vries wrote:
>> When writing a compiler based around SSA, is every procedure converted
>> to SSA form individually, or is it possible to create some sort of
>> "super control flow graph" that incorporates procedures, and convert
>> the entire thing to SSA form? ...
> Hi, Edsko,
> this depends on what You are planning to do on the interprocedural
> representation. For a whole-program analysis, we have found the
> following idea(s) useful:
> * Formal arguments in procedure f are nothing more than Phi-Functions
> for the actual parameters given to calls to f in other procedures.
> * Return instructions (with a value) are 'inverse' to the argument
> Phi's in the sense that the return value of a call to f can be
> now written as an access to the return value of f.
> * For a program analysis, you will probably take into account that
> analysis information gathered for a return instruction must be
> filtered: if g calls f, and accesses the return instruction of g,
> it may only pick up information computed from values prpagated into
> f from g. (if this is omitted, you propagate information along
> unrealizable paths, e.g. g and g' both call f, and g' values are
> propagated int the call to f, through f, and back ... into g'.)
> With the first two points done before an analysis is started, and
> the analysis itself extended by the third point, you get an inter-
> procedural analysis 'for free'.
This begins to sound a lot like CPS (continuation-passing style), and
that should come as no surprise:
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