recursivness.cpp File Reference

Annotate a signal expression with recursivness information. More...

#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <limits.h>
#include "recursivness.hh"

Go to the source code of this file.

Functions
static int	annotate (Tree env, Tree sig)
	Annotate a signal with recursivness.
static int	position (Tree env, Tree t, int p)
	return the position of a signal in the current recursive environment
void	recursivnessAnnotation (Tree sig)
	Annotate a signal with recursivness.
int	getRecursivness (Tree sig)
	Return the recursivness of a previously annotated signal.

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Detailed Description

Annotate a signal expression with recursivness information.

Recursiveness indicates the amount of recursive dependencies of a signal. A closed signal has a recursivness of 0 because is has no recursive dependencies. This means that the succesive samples of this signal can be computed in parallel. In a signal of type .(...F(x)...), F(x) has a recursivness of 1. In a signal of type .(... .(...F(x)...G(y)...)...) F(x) has a recursivness of 2 while G(y) has a recursivness of 1.

Definition in file recursivness.cpp.

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Function Documentation

static int annotate	(	Tree	env,
		Tree	sig
	)			[static]

Annotate a signal with recursivness.

Parameters:

	env	the current environment
	sig	signal to annotate

Returns:

recursivness of the signal

Definition at line 81 of file recursivness.cpp.

References position().

Referenced by recursivnessAnnotation().

{
    Tree tr, var, body;

    if (getProperty(sig, RECURSIVNESS, tr)) {
        return tree2int(tr);    // already annotated
    } else if (isRec(sig, var, body)) {
        int p = position(env, sig);
        if (p > 0) {
            return p;   // we are inside \x.(...)
        } else {
            int r = annotate(cons(sig, env), body) - 1;
            if (r<0) r=0;
            setProperty(sig, RECURSIVNESS, tree(r));
            return r;
        }
    } else {
        int rmax = 0;
        vector<Tree> v; getSubSignals(sig, v);
        for (unsigned int i=0; i<v.size(); i++) {
            int r = annotate(env, v[i]);
            if (r>rmax) rmax=r;
        }
        setProperty(sig, RECURSIVNESS, tree(rmax));
        return rmax;
    }
}

int getRecursivness

(

Tree

sig

)

Return the recursivness of a previously annotated signal.

An error is generated if the signal has no recursivness property

Parameters:

sig

signal

Returns:

recursivness of the signal

Definition at line 64 of file recursivness.cpp.

Referenced by OccMarkup::incOcc().

{
    Tree tr;
    if ( ! getProperty(sig, RECURSIVNESS, tr)) {
        cerr << "Error in getRecursivness of " << *sig << endl;
        exit(1);
    }
    return tree2int(tr);
}

static int position	(	Tree	env,
		Tree	t,
		int	p
	)			[static]

return the position of a signal in the current recursive environment

Parameters:

	env	the current recursive environment of the signal
	t	signal we want to know the position

Returns:

the position in the recursive environment

Definition at line 117 of file recursivness.cpp.

Referenced by annotate().

{
    if (isNil(env)) return 0;   // was not in the environment
    if (hd(env) == t) return p;
    else return position (tl(env), t, p+1);
}

void recursivnessAnnotation

(

Tree

sig

)

Annotate a signal with recursivness.

Should be used before calling getRecursivness

Parameters:

sig

signal to annotate

Definition at line 51 of file recursivness.cpp.

References annotate().

{
    annotate(nil, sig);
}