Version abc60220

1 files changed, 680 insertions, 0 deletions

diff --git a/src/misc/espresso/compl.c b/src/misc/espresso/compl.c
new file mode 100644
index 00000000..8f1c6606
--- /dev/null
+++ b/src/misc/espresso/compl.c
@@ -0,0 +1,680 @@
+/*
+ * Revision Control Information
+ *
+ * $Source$
+ * $Author$
+ * $Revision$
+ * $Date$
+ *
+ */
+/*
+ *  module: compl.c
+ *  purpose: compute the complement of a multiple-valued function
+ *
+ *  The "unate recursive paradigm" is used.  After a set of special
+ *  cases are examined, the function is split on the "most active
+ *  variable".  These two halves are complemented recursively, and then
+ *  the results are merged.
+ *
+ *  Changes (from Version 2.1 to Version 2.2)
+ *      1. Minor bug in compl_lifting -- cubes in the left half were
+ *      not marked as active, so that when merging a leaf from the left
+ *      hand side, the active flags were essentially random.  This led
+ *      to minor impredictability problem, but never affected the
+ *      accuracy of the results.
+ */
+
+#include "espresso.h"
+
+#define USE_COMPL_LIFT            0
+#define USE_COMPL_LIFT_ONSET        1
+#define USE_COMPL_LIFT_ONSET_COMPLEX    2
+#define NO_LIFTING            3
+
+static bool compl_special_cases();
+static pcover compl_merge();
+static void compl_d1merge();
+static pcover compl_cube();
+static void compl_lift();
+static void compl_lift_onset();
+static void compl_lift_onset_complex();
+static bool simp_comp_special_cases();
+static bool simplify_special_cases();
+
+
+/* complement -- compute the complement of T */
+pcover complement(T)
+pcube *T;            /* T will be disposed of */
+{
+    register pcube cl, cr;
+    register int best;
+    pcover Tbar, Tl, Tr;
+    int lifting;
+    static int compl_level = 0;
+
+    if (debug & COMPL)
+    debug_print(T, "COMPLEMENT", compl_level++);
+
+    if (compl_special_cases(T, &Tbar) == MAYBE) {
+
+    /* Allocate space for the partition cubes */
+    cl = new_cube();
+    cr = new_cube();
+    best = binate_split_select(T, cl, cr, COMPL);
+
+    /* Complement the left and right halves */
+    Tl = complement(scofactor(T, cl, best));
+    Tr = complement(scofactor(T, cr, best));
+
+    if (Tr->count*Tl->count > (Tr->count+Tl->count)*CUBELISTSIZE(T)) {
+        lifting = USE_COMPL_LIFT_ONSET;
+    } else {
+        lifting = USE_COMPL_LIFT;
+    }
+    Tbar = compl_merge(T, Tl, Tr, cl, cr, best, lifting);
+
+    free_cube(cl);
+    free_cube(cr);
+    free_cubelist(T);
+    }
+
+    if (debug & COMPL)
+    debug1_print(Tbar, "exit COMPLEMENT", --compl_level);
+    return Tbar;
+}
+
+static bool compl_special_cases(T, Tbar)
+pcube *T;            /* will be disposed if answer is determined */
+pcover *Tbar;            /* returned only if answer determined */
+{
+    register pcube *T1, p, ceil, cof=T[0];
+    pcover A, ceil_compl;
+
+    /* Check for no cubes in the cover */
+    if (T[2] == NULL) {
+    *Tbar = sf_addset(new_cover(1), cube.fullset);
+    free_cubelist(T);
+    return TRUE;
+    }
+
+    /* Check for only a single cube in the cover */
+    if (T[3] == NULL) {
+    *Tbar = compl_cube(set_or(cof, cof, T[2]));
+    free_cubelist(T);
+    return TRUE;
+    }
+
+    /* Check for a row of all 1's (implies complement is null) */
+    for(T1 = T+2; (p = *T1++) != NULL; ) {
+    if (full_row(p, cof)) {
+        *Tbar = new_cover(0);
+        free_cubelist(T);
+        return TRUE;
+    }
+    }
+
+    /* Check for a column of all 0's which can be factored out */
+    ceil = set_save(cof);
+    for(T1 = T+2; (p = *T1++) != NULL; ) {
+    INLINEset_or(ceil, ceil, p);
+    }
+    if (! setp_equal(ceil, cube.fullset)) {
+    ceil_compl = compl_cube(ceil);
+    (void) set_or(cof, cof, set_diff(ceil, cube.fullset, ceil));
+    set_free(ceil);
+    *Tbar = sf_append(complement(T), ceil_compl);
+    return TRUE;
+    }
+    set_free(ceil);
+
+    /* Collect column counts, determine unate variables, etc. */
+    massive_count(T);
+
+    /* If single active variable not factored out above, then tautology ! */
+    if (cdata.vars_active == 1) {
+    *Tbar = new_cover(0);
+    free_cubelist(T);
+    return TRUE;
+
+    /* Check for unate cover */
+    } else if (cdata.vars_unate == cdata.vars_active) {
+    A = map_cover_to_unate(T);
+    free_cubelist(T);
+    A = unate_compl(A);
+    *Tbar = map_unate_to_cover(A);
+    sf_free(A);
+    return TRUE;
+
+    /* Not much we can do about it */
+    } else {
+    return MAYBE;
+    }
+}
+
+/*
+ *  compl_merge -- merge the two cofactors around the splitting
+ *  variable
+ *
+ *  The merge operation involves intersecting each cube of the left
+ *  cofactor with cl, and intersecting each cube of the right cofactor
+ *  with cr.  The union of these two covers is the merged result.
+ *
+ *  In order to reduce the number of cubes, a distance-1 merge is
+ *  performed (note that two cubes can only combine distance-1 in the
+ *  splitting variable).  Also, a simple expand is performed in the
+ *  splitting variable (simple implies the covering check for the
+ *  expansion is not full containment, but single-cube containment).
+ */
+
+static pcover compl_merge(T1, L, R, cl, cr, var, lifting)
+pcube *T1;            /* Original ON-set */
+pcover L, R;            /* Complement from each recursion branch */
+register pcube cl, cr;        /* cubes used for cofactoring */
+int var;            /* splitting variable */
+int lifting;            /* whether to perform lifting or not */
+{
+    register pcube p, last, pt;
+    pcover T, Tbar;
+    pcube *L1, *R1;
+
+    if (debug & COMPL) {
+    (void) printf("compl_merge: left %d, right %d\n", L->count, R->count);
+    (void) printf("%s (cl)\n%s (cr)\nLeft is\n", pc1(cl), pc2(cr));
+    cprint(L);
+    (void) printf("Right is\n");
+    cprint(R);
+    }
+
+    /* Intersect each cube with the cofactored cube */
+    foreach_set(L, last, p) {
+    INLINEset_and(p, p, cl);
+    SET(p, ACTIVE);
+    }
+    foreach_set(R, last, p) {
+    INLINEset_and(p, p, cr);
+    SET(p, ACTIVE);
+    }
+
+    /* Sort the arrays for a distance-1 merge */
+    (void) set_copy(cube.temp[0], cube.var_mask[var]);
+    qsort((char *) (L1 = sf_list(L)), L->count, sizeof(pset), (int (*)()) d1_order);
+    qsort((char *) (R1 = sf_list(R)), R->count, sizeof(pset), (int (*)()) d1_order);
+
+    /* Perform distance-1 merge */
+    compl_d1merge(L1, R1);
+
+    /* Perform lifting */
+    switch(lifting) {
+    case USE_COMPL_LIFT_ONSET:
+        T = cubeunlist(T1);
+        compl_lift_onset(L1, T, cr, var);
+        compl_lift_onset(R1, T, cl, var);
+        free_cover(T);
+        break;
+    case USE_COMPL_LIFT_ONSET_COMPLEX:
+        T = cubeunlist(T1);
+        compl_lift_onset_complex(L1, T, var);
+        compl_lift_onset_complex(R1, T, var);
+        free_cover(T);
+        break;
+    case USE_COMPL_LIFT:
+        compl_lift(L1, R1, cr, var);
+        compl_lift(R1, L1, cl, var);
+        break;
+    case NO_LIFTING:
+        break;
+    default:
+        ;
+    }
+    FREE(L1);
+    FREE(R1);
+
+    /* Re-create the merged cover */
+    Tbar = new_cover(L->count + R->count);
+    pt = Tbar->data;
+    foreach_set(L, last, p) {
+    INLINEset_copy(pt, p);
+    Tbar->count++;
+    pt += Tbar->wsize;
+    }
+    foreach_active_set(R, last, p) {
+    INLINEset_copy(pt, p);
+    Tbar->count++;
+    pt += Tbar->wsize;
+    }
+
+    if (debug & COMPL) {
+    (void) printf("Result %d\n", Tbar->count);
+    if (verbose_debug)
+        cprint(Tbar);
+    }
+
+    free_cover(L);
+    free_cover(R);
+    return Tbar;
+}
+
+/*
+ *  compl_lift_simple -- expand in the splitting variable using single
+ *  cube containment against the other recursion branch to check
+ *  validity of the expansion, and expanding all (or none) of the
+ *  splitting variable.
+ */
+static void compl_lift(A1, B1, bcube, var)
+pcube *A1, *B1, bcube;
+int var;
+{
+    register pcube a, b, *B2, lift=cube.temp[4], liftor=cube.temp[5];
+    pcube mask = cube.var_mask[var];
+
+    (void) set_and(liftor, bcube, mask);
+
+    /* for each cube in the first array ... */
+    for(; (a = *A1++) != NULL; ) {
+    if (TESTP(a, ACTIVE)) {
+
+        /* create a lift of this cube in the merging coord */
+        (void) set_merge(lift, bcube, a, mask);
+
+        /* for each cube in the second array */
+        for(B2 = B1; (b = *B2++) != NULL; ) {
+        INLINEsetp_implies(lift, b, /* when_false => */ continue);
+        /* when_true => fall through to next statement */
+
+        /* cube of A1 was contained by some cube of B1, so raise */
+        INLINEset_or(a, a, liftor);
+        break;
+        }
+    }
+    }
+}
+
+
+
+/*
+ *  compl_lift_onset -- expand in the splitting variable using a
+ *  distance-1 check against the original on-set; expand all (or
+ *  none) of the splitting variable.  Each cube of A1 is expanded
+ *  against the original on-set T.
+ */
+static void compl_lift_onset(A1, T, bcube, var)
+pcube *A1;
+pcover T;
+pcube bcube;
+int var;
+{
+    register pcube a, last, p, lift=cube.temp[4], mask=cube.var_mask[var];
+
+    /* for each active cube from one branch of the complement */
+    for(; (a = *A1++) != NULL; ) {
+    if (TESTP(a, ACTIVE)) {
+
+        /* create a lift of this cube in the merging coord */
+        INLINEset_and(lift, bcube, mask);    /* isolate parts to raise */
+        INLINEset_or(lift, a, lift);    /* raise these parts in a */
+
+        /* for each cube in the ON-set, check for intersection */
+        foreach_set(T, last, p) {
+        if (cdist0(p, lift)) {
+            goto nolift;
+        }
+        }
+        INLINEset_copy(a, lift);        /* save the raising */
+        SET(a, ACTIVE);
+nolift : ;
+    }
+    }
+}
+
+/*
+ *  compl_lift_complex -- expand in the splitting variable, but expand all
+ *  parts which can possibly expand.
+ *  T is the original ON-set
+ *  A1 is either the left or right cofactor
+ */
+static void compl_lift_onset_complex(A1, T, var)
+pcube *A1;            /* array of pointers to new result */
+pcover T;            /* original ON-set */
+int var;            /* which variable we split on */
+{
+    register int dist;
+    register pcube last, p, a, xlower;
+
+    /* for each cube in the complement */
+    xlower = new_cube();
+    for(; (a = *A1++) != NULL; ) {
+
+    if (TESTP(a, ACTIVE)) {
+
+        /* Find which parts of the splitting variable are forced low */
+        INLINEset_clear(xlower, cube.size);
+        foreach_set(T, last, p) {
+        if ((dist = cdist01(p, a)) < 2) {
+            if (dist == 0) {
+            fatal("compl: ON-set and OFF-set are not orthogonal");
+            } else {
+            (void) force_lower(xlower, p, a);
+            }
+        }
+        }
+
+        (void) set_diff(xlower, cube.var_mask[var], xlower);
+        (void) set_or(a, a, xlower);
+        free_cube(xlower);
+    }
+    }
+}
+
+
+
+/*
+ *  compl_d1merge -- distance-1 merge in the splitting variable
+ */
+static void compl_d1merge(L1, R1)
+register pcube *L1, *R1;
+{
+    register pcube pl, pr;
+
+    /* Find equal cubes between the two cofactors */
+    for(pl = *L1, pr = *R1; (pl != NULL) && (pr != NULL); )
+    switch (d1_order(L1, R1)) {
+        case 1:
+        pr = *(++R1); break;            /* advance right pointer */
+        case -1:
+        pl = *(++L1); break;            /* advance left pointer */
+        case 0:
+        RESET(pr, ACTIVE);
+        INLINEset_or(pl, pl, pr);
+        pr = *(++R1);
+        default:
+        ;
+    }
+}
+
+
+
+/* compl_cube -- return the complement of a single cube (De Morgan's law) */
+static pcover compl_cube(p)
+register pcube p;
+{
+    register pcube diff=cube.temp[7], pdest, mask, full=cube.fullset;
+    int var;
+    pcover R;
+
+    /* Allocate worst-case size cover (to avoid checking overflow) */
+    R = new_cover(cube.num_vars);
+
+    /* Compute bit-wise complement of the cube */
+    INLINEset_diff(diff, full, p);
+
+    for(var = 0; var < cube.num_vars; var++) {
+    mask = cube.var_mask[var];
+    /* If the bit-wise complement is not empty in var ... */
+    if (! setp_disjoint(diff, mask)) {
+        pdest = GETSET(R, R->count++);
+        INLINEset_merge(pdest, diff, full, mask);
+    }
+    }
+    return R;
+}
+
+/* simp_comp -- quick simplification of T */
+void simp_comp(T, Tnew, Tbar)
+pcube *T;            /* T will be disposed of */
+pcover *Tnew;
+pcover *Tbar;
+{
+    register pcube cl, cr;
+    register int best;
+    pcover Tl, Tr, Tlbar, Trbar;
+    int lifting;
+    static int simplify_level = 0;
+
+    if (debug & COMPL)
+    debug_print(T, "SIMPCOMP", simplify_level++);
+
+    if (simp_comp_special_cases(T, Tnew, Tbar) == MAYBE) {
+
+    /* Allocate space for the partition cubes */
+    cl = new_cube();
+    cr = new_cube();
+    best = binate_split_select(T, cl, cr, COMPL);
+
+    /* Complement the left and right halves */
+    simp_comp(scofactor(T, cl, best), &Tl, &Tlbar);
+    simp_comp(scofactor(T, cr, best), &Tr, &Trbar);
+
+    lifting = USE_COMPL_LIFT;
+    *Tnew = compl_merge(T, Tl, Tr, cl, cr, best, lifting);
+
+    lifting = USE_COMPL_LIFT;
+    *Tbar = compl_merge(T, Tlbar, Trbar, cl, cr, best, lifting);
+
+    /* All of this work for nothing ? Let's hope not ... */
+    if ((*Tnew)->count > CUBELISTSIZE(T)) {
+        sf_free(*Tnew);
+        *Tnew = cubeunlist(T);
+    }
+
+    free_cube(cl);
+    free_cube(cr);
+    free_cubelist(T);
+    }
+
+    if (debug & COMPL) {
+    debug1_print(*Tnew, "exit SIMPCOMP (new)", simplify_level);
+    debug1_print(*Tbar, "exit SIMPCOMP (compl)", simplify_level);
+    simplify_level--;
+    }
+}
+
+static bool simp_comp_special_cases(T, Tnew, Tbar)
+pcube *T;            /* will be disposed if answer is determined */
+pcover *Tnew;            /* returned only if answer determined */
+pcover *Tbar;            /* returned only if answer determined */
+{
+    register pcube *T1, p, ceil, cof=T[0];
+    pcube last;
+    pcover A;
+
+    /* Check for no cubes in the cover (function is empty) */
+    if (T[2] == NULL) {
+    *Tnew = new_cover(1);
+    *Tbar = sf_addset(new_cover(1), cube.fullset);
+    free_cubelist(T);
+    return TRUE;
+    }
+
+    /* Check for only a single cube in the cover */
+    if (T[3] == NULL) {
+    (void) set_or(cof, cof, T[2]);
+    *Tnew = sf_addset(new_cover(1), cof);
+    *Tbar = compl_cube(cof);
+    free_cubelist(T);
+    return TRUE;
+    }
+
+    /* Check for a row of all 1's (function is a tautology) */
+    for(T1 = T+2; (p = *T1++) != NULL; ) {
+    if (full_row(p, cof)) {
+        *Tnew = sf_addset(new_cover(1), cube.fullset);
+        *Tbar = new_cover(1);
+        free_cubelist(T);
+        return TRUE;
+    }
+    }
+
+    /* Check for a column of all 0's which can be factored out */
+    ceil = set_save(cof);
+    for(T1 = T+2; (p = *T1++) != NULL; ) {
+    INLINEset_or(ceil, ceil, p);
+    }
+    if (! setp_equal(ceil, cube.fullset)) {
+    p = new_cube();
+    (void) set_diff(p, cube.fullset, ceil);
+    (void) set_or(cof, cof, p);
+    set_free(p);
+    simp_comp(T, Tnew, Tbar);
+
+    /* Adjust the ON-set */
+    A = *Tnew;
+    foreach_set(A, last, p) {
+        INLINEset_and(p, p, ceil);
+    }
+
+    /* Compute the new complement */
+    *Tbar = sf_append(*Tbar, compl_cube(ceil));
+    set_free(ceil);
+    return TRUE;
+    }
+    set_free(ceil);
+
+    /* Collect column counts, determine unate variables, etc. */
+    massive_count(T);
+
+    /* If single active variable not factored out above, then tautology ! */
+    if (cdata.vars_active == 1) {
+    *Tnew = sf_addset(new_cover(1), cube.fullset);
+    *Tbar = new_cover(1);
+    free_cubelist(T);
+    return TRUE;
+
+    /* Check for unate cover */
+    } else if (cdata.vars_unate == cdata.vars_active) {
+    /* Make the cover minimum by single-cube containment */
+    A = cubeunlist(T);
+    *Tnew = sf_contain(A);
+
+    /* Now form a minimum representation of the complement */
+    A = map_cover_to_unate(T);
+    A = unate_compl(A);
+    *Tbar = map_unate_to_cover(A);
+    sf_free(A);
+    free_cubelist(T);
+    return TRUE;
+
+    /* Not much we can do about it */
+    } else {
+    return MAYBE;
+    }
+}
+
+/* simplify -- quick simplification of T */
+pcover simplify(T)
+pcube *T;            /* T will be disposed of */
+{
+    register pcube cl, cr;
+    register int best;
+    pcover Tbar, Tl, Tr;
+    int lifting;
+    static int simplify_level = 0;
+
+    if (debug & COMPL) {
+    debug_print(T, "SIMPLIFY", simplify_level++);
+    }
+
+    if (simplify_special_cases(T, &Tbar) == MAYBE) {
+
+    /* Allocate space for the partition cubes */
+    cl = new_cube();
+    cr = new_cube();
+
+    best = binate_split_select(T, cl, cr, COMPL);
+
+    /* Complement the left and right halves */
+    Tl = simplify(scofactor(T, cl, best));
+    Tr = simplify(scofactor(T, cr, best));
+
+    lifting = USE_COMPL_LIFT;
+    Tbar = compl_merge(T, Tl, Tr, cl, cr, best, lifting);
+
+    /* All of this work for nothing ? Let's hope not ... */
+    if (Tbar->count > CUBELISTSIZE(T)) {
+        sf_free(Tbar);
+        Tbar = cubeunlist(T);
+    }
+
+    free_cube(cl);
+    free_cube(cr);
+    free_cubelist(T);
+    }
+
+    if (debug & COMPL) {
+    debug1_print(Tbar, "exit SIMPLIFY", --simplify_level);
+    }
+    return Tbar;
+}
+
+static bool simplify_special_cases(T, Tnew)
+pcube *T;            /* will be disposed if answer is determined */
+pcover *Tnew;            /* returned only if answer determined */
+{
+    register pcube *T1, p, ceil, cof=T[0];
+    pcube last;
+    pcover A;
+
+    /* Check for no cubes in the cover */
+    if (T[2] == NULL) {
+    *Tnew = new_cover(0);
+    free_cubelist(T);
+    return TRUE;
+    }
+
+    /* Check for only a single cube in the cover */
+    if (T[3] == NULL) {
+    *Tnew = sf_addset(new_cover(1), set_or(cof, cof, T[2]));
+    free_cubelist(T);
+    return TRUE;
+    }
+
+    /* Check for a row of all 1's (implies function is a tautology) */
+    for(T1 = T+2; (p = *T1++) != NULL; ) {
+    if (full_row(p, cof)) {
+        *Tnew = sf_addset(new_cover(1), cube.fullset);
+        free_cubelist(T);
+        return TRUE;
+    }
+    }
+
+    /* Check for a column of all 0's which can be factored out */
+    ceil = set_save(cof);
+    for(T1 = T+2; (p = *T1++) != NULL; ) {
+    INLINEset_or(ceil, ceil, p);
+    }
+    if (! setp_equal(ceil, cube.fullset)) {
+    p = new_cube();
+    (void) set_diff(p, cube.fullset, ceil);
+    (void) set_or(cof, cof, p);
+    free_cube(p);
+
+    A = simplify(T);
+    foreach_set(A, last, p) {
+        INLINEset_and(p, p, ceil);
+    }
+    *Tnew = A;
+    set_free(ceil);
+    return TRUE;
+    }
+    set_free(ceil);
+
+    /* Collect column counts, determine unate variables, etc. */
+    massive_count(T);
+
+    /* If single active variable not factored out above, then tautology ! */
+    if (cdata.vars_active == 1) {
+    *Tnew = sf_addset(new_cover(1), cube.fullset);
+    free_cubelist(T);
+    return TRUE;
+
+    /* Check for unate cover */
+    } else if (cdata.vars_unate == cdata.vars_active) {
+    A = cubeunlist(T);
+    *Tnew = sf_contain(A);
+    free_cubelist(T);
+    return TRUE;
+
+    /* Not much we can do about it */
+    } else {
+    return MAYBE;
+    }
+}