Re: [sdcc-devel] adding a annotation to the ast

[Emanuel P. <ema...@gm...>]

Dear Kim (and other coleagues),

PCAF is a framework based on Coloured Petri Net modeling language (CPN) tha=
t
is adopted for supporting simulation and analysis. As result, it is possibl=
e
to explore scenarios of code execution according to the occurrence
probabilities of external events. Nowadays, the flow of code execution is
assumed to be fifty-fifty in a conditional jump instruction in the asm code=
;
our approach is to insert a more realistic value of probability.
For example, the instruction <@70@> after a conditional jump means that thi=
s
jump has got 70% of chance to execute.

The proposed approach (begin the analysis in C code) offers three basic
contributions:
(i)code modeling, a probabilistic model for scenarios exploration being
presented,
(ii) formalism, a formal and widespread modeling language (CPN) being
applied, with previously validated engines and algorithms for simulation;
(iii) flexibility, the proposed approach enabling modeling of different
micro-controllers at different abstraction levels.

For more references about this project, please see:
1. Oliveira J=FAnior, M. N. Analyzing Compiler Optimization Focusing Energy
Consumption: A Coloured Petri Net Approach.
2. Oliveira J=FAnior, M. N., et al. Towards a Software Power Cost Analysis
Framework Using Colored Petri Net.
3. Oliveira J=FAnior, M. N., et al. A Retargetable Environment for Power-Aw=
are
Code Evaluation: An Approach based on Coloured Petri Net.

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=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D

> The later syntax would allow you to change the definition of an
> expression and pass the @70 and @80 in with the expression to the next
> level.
> If you could pass them on down in the expression, when it comes time to
> generate the iCode, generate a branch icode for bne a,5 and insert an
> inlineasm iCode with @70 right behind it.  Then in gen.c  , the backend
> will have to be modified so that if it sees a branch followed by an
> inline asm with  ;<@INT@>, it knows to put that on the same line as the
> last emit went on, which means you'll have to watch the '\n's on the
> emits.

in other words, are you suggesting us to do something like:
relational_expr '<' shift_expr  {
    $$ =3D (port->lt_nge ?
          newNode('!',newNode(GE_OP,$1,$3),NULL) :
          newNode('<', $1,$3));
   }
| relational_expr '<' shift_expr '@' CONSTANT   {
      ast *ex;
      ex =3D (port->lt_nge ?
          newNode('!',newNode(GE_OP,$1,$3),NULL) :
          newNode('<', $1,$3));
      ex->values.probability =3D newAst_VALUE($5);
      $$ =3D ex;
   }
...
?

 great thanks
 Emanuel Pessoa
Computer Engineering student
State University of Pernambuco - Recife - Brasil