1 files changed, 170 insertions, 0 deletions
diff --git a/src/misc/espresso/primes.c b/src/misc/espresso/primes.c
new file mode 100644
index 00000000..3e40da27
--- /dev/null
+++ b/src/misc/espresso/primes.c
@@ -0,0 +1,170 @@
+/*
+ * Revision Control Information
+ *
+ * $Source$
+ * $Author$
+ * $Revision$
+ * $Date$
+ *
+ */
+#include "espresso.h"
+
+static bool primes_consensus_special_cases();
+static pcover primes_consensus_merge();
+static pcover and_with_cofactor(); 
+
+
+/* primes_consensus -- generate primes using consensus */
+pcover primes_consensus(T)
+pcube *T;            /* T will be disposed of */
+{
+    register pcube cl, cr;
+    register int best;
+    pcover Tnew, Tl, Tr;
+
+    if (primes_consensus_special_cases(T, &Tnew) == MAYBE) {
+    cl = new_cube();
+    cr = new_cube();
+    best = binate_split_select(T, cl, cr, COMPL);
+
+    Tl = primes_consensus(scofactor(T, cl, best));
+    Tr = primes_consensus(scofactor(T, cr, best));
+    Tnew = primes_consensus_merge(Tl, Tr, cl, cr);
+
+    free_cube(cl);
+    free_cube(cr);
+    free_cubelist(T);
+    }
+
+    return Tnew;
+}
+
+static bool 
+primes_consensus_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 = primes_consensus(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;
+    }
+}
+
+static pcover 
+primes_consensus_merge(Tl, Tr, cl, cr)
+pcover Tl, Tr;
+pcube cl, cr;
+{
+    register pcube pl, pr, lastl, lastr, pt;
+    pcover T, Tsave;
+
+    Tl = and_with_cofactor(Tl, cl);
+    Tr = and_with_cofactor(Tr, cr);
+
+    T = sf_new(500, Tl->sf_size);
+    pt = T->data;
+    Tsave = sf_contain(sf_join(Tl, Tr));
+
+    foreach_set(Tl, lastl, pl) {
+    foreach_set(Tr, lastr, pr) {
+        if (cdist01(pl, pr) == 1) {
+        consensus(pt, pl, pr);
+        if (++T->count >= T->capacity) {
+            Tsave = sf_union(Tsave, sf_contain(T));
+            T = sf_new(500, Tl->sf_size);
+            pt = T->data;
+        } else {
+            pt += T->wsize;
+        }
+        }
+    }
+    }
+    free_cover(Tl);
+    free_cover(Tr);
+
+    Tsave = sf_union(Tsave, sf_contain(T));
+    return Tsave;
+}
+
+
+static pcover
+and_with_cofactor(A, cof)
+pset_family A;
+register pset cof;
+{
+    register pset last, p;
+
+    foreach_set(A, last, p) {
+    INLINEset_and(p, p, cof);
+    if (cdist(p, cube.fullset) > 0) {
+        RESET(p, ACTIVE);
+    } else {
+        SET(p, ACTIVE);
+    }
+    }
+    return sf_inactive(A);
+}