src/misc/espresso/espresso.c File Reference

#include "espresso.h"

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Functions
pcover	espresso (pcover F, pcover D1, pcover R)

---

Function Documentation

pcover espresso	(	pcover	F,
		pcover	D1,
		pcover	R
	)

Definition at line 50 of file espresso.c.

{
    pcover E, D, Fsave;
    pset last, p;
    cost_t cost, best_cost;

begin:
    Fsave = sf_save(F);         /* save original function */
    D = sf_save(D1);            /* make a scratch copy of D */

    /* Setup has always been a problem */
    if (recompute_onset) {
        EXEC(E = simplify(cube1list(F)),     "SIMPLIFY   ", E);
        free_cover(F);
        F = E;
    }
    cover_cost(F, &cost);
    if (unwrap_onset && (cube.part_size[cube.num_vars - 1] > 1)
      && (cost.out != cost.cubes*cube.part_size[cube.num_vars-1])
      && (cost.out < 5000))
        EXEC(F = sf_contain(unravel(F, cube.num_vars - 1)), "SETUP      ", F);

    /* Initial expand and irredundant */
    foreach_set(F, last, p) {
        RESET(p, PRIME);
    }
    EXECUTE(F = expand(F, R, FALSE), EXPAND_TIME, F, cost);
    EXECUTE(F = irredundant(F, D), IRRED_TIME, F, cost);

    if (! single_expand) {
        if (remove_essential) {
            EXECUTE(E = essential(&F, &D), ESSEN_TIME, E, cost);
        } else {
            E = new_cover(0);
        }

        cover_cost(F, &cost);
        do {

            /* Repeat inner loop until solution becomes "stable" */
            do {
                copy_cost(&cost, &best_cost);
                EXECUTE(F = reduce(F, D), REDUCE_TIME, F, cost);
                EXECUTE(F = expand(F, R, FALSE), EXPAND_TIME, F, cost);
                EXECUTE(F = irredundant(F, D), IRRED_TIME, F, cost);
            } while (cost.cubes < best_cost.cubes);

            /* Perturb solution to see if we can continue to iterate */
            copy_cost(&cost, &best_cost);
            if (use_super_gasp) {
                F = super_gasp(F, D, R, &cost);
                if (cost.cubes >= best_cost.cubes)
                    break;
            } else {
                F = last_gasp(F, D, R, &cost);
            }

        } while (cost.cubes < best_cost.cubes ||
            (cost.cubes == best_cost.cubes && cost.total < best_cost.total));

        /* Append the essential cubes to F */
        F = sf_append(F, E);                /* disposes of E */
        if (trace) size_stamp(F, "ADJUST     ");
    }

    /* Free the D which we used */
    free_cover(D);

    /* Attempt to make the PLA matrix sparse */
    if (! skip_make_sparse) {
        F = make_sparse(F, D1, R);
    }

    /*
     *  Check to make sure function is actually smaller !!
     *  This can only happen because of the initial unravel.  If we fail,
     *  then run the whole thing again without the unravel.
     */
    if (Fsave->count < F->count) {
        free_cover(F);
        F = Fsave;
        unwrap_onset = FALSE;
        goto begin;
    } else {
        free_cover(Fsave);
    }

    return F;
}