Version abc60220

1 files changed, 810 insertions, 0 deletions

diff --git a/src/misc/espresso/cvrin.c b/src/misc/espresso/cvrin.c
new file mode 100644
index 00000000..7790b38b
--- /dev/null
+++ b/src/misc/espresso/cvrin.c
@@ -0,0 +1,810 @@
+/*
+ * Revision Control Information
+ *
+ * $Source$
+ * $Author$
+ * $Revision$
+ * $Date$
+ *
+ */
+/*
+    module: cvrin.c
+    purpose: cube and cover input routines
+*/
+
+#include "espresso.h"
+
+static bool line_length_error;
+static int lineno;
+
+void skip_line(fpin, fpout, echo)
+register FILE *fpin, *fpout;
+register bool echo;
+{
+    register int ch;
+    while ((ch=getc(fpin)) != EOF && ch != '\n')
+    if (echo)
+        putc(ch, fpout);
+    if (echo)
+    putc('\n', fpout);
+    lineno++;
+}
+
+char *get_word(fp, word)
+register FILE *fp;
+register char *word;
+{
+    register int ch, i = 0;
+    while ((ch = getc(fp)) != EOF && isspace(ch))
+    ;
+    word[i++] = ch;
+    while ((ch = getc(fp)) != EOF && ! isspace(ch))
+    word[i++] = ch;
+    word[i++] = '\0';
+    return word;
+}
+
+/*
+ *  Yes, I know this routine is a mess
+ */
+void read_cube(fp, PLA)
+register FILE *fp;
+pPLA PLA;
+{
+    register int var, i;
+    pcube cf = cube.temp[0], cr = cube.temp[1], cd = cube.temp[2];
+    bool savef = FALSE, saved = FALSE, saver = FALSE;
+    char token[256];             /* for kiss read hack */
+    int varx, first, last, offset;    /* for kiss read hack */
+
+    set_clear(cf, cube.size);
+
+    /* Loop and read binary variables */
+    for(var = 0; var < cube.num_binary_vars; var++)
+    switch(getc(fp)) {
+        case EOF:
+        goto bad_char;
+        case '\n':
+        if (! line_length_error)
+            (void) fprintf(stderr, "product term(s) %s\n",
+            "span more than one line (warning only)");
+        line_length_error = TRUE;
+        lineno++;
+        var--;
+        break;
+        case ' ': case '|': case '\t':
+        var--;
+        break;
+        case '2': case '-':
+        set_insert(cf, var*2+1);
+        case '0':
+        set_insert(cf, var*2);
+        break;
+        case '1':
+        set_insert(cf, var*2+1);
+        break;
+        case '?':
+        break;
+        default:
+        goto bad_char;
+    }
+
+
+    /* Loop for the all but one of the multiple-valued variables */    
+    for(var = cube.num_binary_vars; var < cube.num_vars-1; var++)
+
+    /* Read a symbolic multiple-valued variable */
+    if (cube.part_size[var] < 0) {
+        (void) fscanf(fp, "%s", token);
+        if (equal(token, "-") || equal(token, "ANY")) {
+        if (kiss && var == cube.num_vars - 2) {
+            /* leave it empty */
+        } else {
+            /* make it full */
+            set_or(cf, cf, cube.var_mask[var]);
+        }
+        } else if (equal(token, "~")) {
+        ;
+        /* leave it empty ... (?) */
+        } else {
+        if (kiss && var == cube.num_vars - 2)
+            varx = var - 1, offset = ABS(cube.part_size[var-1]);
+        else
+            varx = var, offset = 0;
+        /* Find the symbolic label in the label table */
+        first = cube.first_part[varx];
+        last = cube.last_part[varx];
+        for(i = first; i <= last; i++)
+            if (PLA->label[i] == (char *) NULL) {
+            PLA->label[i] = util_strsav(token);    /* add new label */
+            set_insert(cf, i+offset);
+            break;
+            } else if (equal(PLA->label[i], token)) {
+            set_insert(cf, i+offset);    /* use column i */
+            break;
+            }
+        if (i > last) {
+            (void) fprintf(stderr,
+"declared size of variable %d (counting from variable 0) is too small\n", var);
+            exit(-1);
+        }
+        }
+    
+    } else for(i = cube.first_part[var]; i <= cube.last_part[var]; i++)
+        switch (getc(fp)) {
+        case EOF:
+            goto bad_char;
+        case '\n':
+            if (! line_length_error)
+            (void) fprintf(stderr, "product term(s) %s\n",
+                "span more than one line (warning only)");
+            line_length_error = TRUE;
+            lineno++;
+            i--;
+            break;
+        case ' ': case '|': case '\t':
+            i--;
+            break;
+        case '1':
+            set_insert(cf, i);
+        case '0':
+            break;
+        default:
+            goto bad_char;
+        }
+
+    /* Loop for last multiple-valued variable */
+    if (kiss) {
+    saver = savef = TRUE;
+    (void) set_xor(cr, cf, cube.var_mask[cube.num_vars - 2]);
+    } else
+    set_copy(cr, cf);
+    set_copy(cd, cf);
+    for(i = cube.first_part[var]; i <= cube.last_part[var]; i++)
+    switch (getc(fp)) {
+        case EOF:
+        goto bad_char;
+        case '\n':
+        if (! line_length_error)
+            (void) fprintf(stderr, "product term(s) %s\n",
+            "span more than one line (warning only)");
+        line_length_error = TRUE;
+        lineno++;
+        i--;
+        break;
+        case ' ': case '|': case '\t':
+        i--;
+        break;
+        case '4': case '1':
+        if (PLA->pla_type & F_type)
+            set_insert(cf, i), savef = TRUE;
+        break;
+        case '3': case '0':
+        if (PLA->pla_type & R_type)
+            set_insert(cr, i), saver = TRUE;
+        break;
+        case '2': case '-':
+        if (PLA->pla_type & D_type)
+            set_insert(cd, i), saved = TRUE;
+        case '~':
+        break;
+        default:
+        goto bad_char;
+    }
+    if (savef) PLA->F = sf_addset(PLA->F, cf);
+    if (saved) PLA->D = sf_addset(PLA->D, cd);
+    if (saver) PLA->R = sf_addset(PLA->R, cr);
+    return;
+
+bad_char:
+    (void) fprintf(stderr, "(warning): input line #%d ignored\n", lineno);
+    skip_line(fp, stdout, TRUE);
+    return;
+}
+void parse_pla(fp, PLA)
+IN FILE *fp;
+INOUT pPLA PLA;
+{
+    int i, var, ch, np, last;
+    char word[256];
+
+    lineno = 1;
+    line_length_error = FALSE;
+
+loop:
+    switch(ch = getc(fp)) {
+    case EOF:
+        return;
+
+    case '\n':
+        lineno++;
+
+    case ' ': case '\t': case '\f': case '\r':
+        break;
+
+    case '#':
+        (void) ungetc(ch, fp);
+        skip_line(fp, stdout, echo_comments);
+        break;
+
+    case '.':
+        /* .i gives the cube input size (binary-functions only) */
+        if (equal(get_word(fp, word), "i")) {
+        if (cube.fullset != NULL) {
+            (void) fprintf(stderr, "extra .i ignored\n");
+            skip_line(fp, stdout, /* echo */ FALSE);
+        } else {
+            if (fscanf(fp, "%d", &cube.num_binary_vars) != 1)
+            fatal("error reading .i");
+            cube.num_vars = cube.num_binary_vars + 1;
+            cube.part_size = ALLOC(int, cube.num_vars);
+        }
+
+        /* .o gives the cube output size (binary-functions only) */
+        } else if (equal(word, "o")) {
+        if (cube.fullset != NULL) {
+            (void) fprintf(stderr, "extra .o ignored\n");
+            skip_line(fp, stdout, /* echo */ FALSE);
+        } else {
+            if (cube.part_size == NULL)
+            fatal(".o cannot appear before .i");
+            if (fscanf(fp, "%d", &(cube.part_size[cube.num_vars-1]))!=1)
+            fatal("error reading .o");
+            cube_setup();
+            PLA_labels(PLA);
+        }
+
+        /* .mv gives the cube size for a multiple-valued function */
+        } else if (equal(word, "mv")) {
+        if (cube.fullset != NULL) {
+            (void) fprintf(stderr, "extra .mv ignored\n");
+            skip_line(fp, stdout, /* echo */ FALSE);
+        } else {
+            if (cube.part_size != NULL)
+            fatal("cannot mix .i and .mv");
+            if (fscanf(fp,"%d %d",
+            &cube.num_vars,&cube.num_binary_vars) != 2)
+             fatal("error reading .mv");
+            if (cube.num_binary_vars < 0)
+fatal("num_binary_vars (second field of .mv) cannot be negative");
+            if (cube.num_vars < cube.num_binary_vars)
+            fatal(
+"num_vars (1st field of .mv) must exceed num_binary_vars (2nd field of .mv)");
+            cube.part_size = ALLOC(int, cube.num_vars);
+            for(var=cube.num_binary_vars; var < cube.num_vars; var++)
+            if (fscanf(fp, "%d", &(cube.part_size[var])) != 1)
+                fatal("error reading .mv");
+            cube_setup();
+            PLA_labels(PLA);
+        }
+
+        /* .p gives the number of product terms -- we ignore it */
+        } else if (equal(word, "p"))
+        (void) fscanf(fp, "%d", &np);
+        /* .e and .end specify the end of the file */
+        else if (equal(word, "e") || equal(word,"end")) {
+        if (cube.fullset == NULL) {
+            /* fatal("unknown PLA size, need .i/.o or .mv");*/
+                } else if (PLA->F == NULL) {
+                    PLA->F = new_cover(10);
+                    PLA->D = new_cover(10);
+                    PLA->R = new_cover(10);
+                }
+        return;
+        }
+        /* .kiss turns on the kiss-hack option */
+        else if (equal(word, "kiss"))
+        kiss = TRUE;
+
+        /* .type specifies a logical type for the PLA */
+        else if (equal(word, "type")) {
+        (void) get_word(fp, word);
+        for(i = 0; pla_types[i].key != 0; i++)
+            if (equal(pla_types[i].key + 1, word)) {
+            PLA->pla_type = pla_types[i].value;
+            break;
+            }
+        if (pla_types[i].key == 0)
+            fatal("unknown type in .type command");
+
+        /* parse the labels */
+        } else if (equal(word, "ilb")) {
+        if (cube.fullset == NULL)
+            fatal("PLA size must be declared before .ilb or .ob");
+        if (PLA->label == NULL)
+            PLA_labels(PLA);
+        for(var = 0; var < cube.num_binary_vars; var++) {
+            (void) get_word(fp, word);
+            i = cube.first_part[var];
+            PLA->label[i+1] = util_strsav(word);
+            PLA->label[i] = ALLOC(char, strlen(word) + 6);
+            (void) sprintf(PLA->label[i], "%s.bar", word);
+        }
+        } else if (equal(word, "ob")) {
+        if (cube.fullset == NULL)
+            fatal("PLA size must be declared before .ilb or .ob");
+        if (PLA->label == NULL)
+            PLA_labels(PLA);
+        var = cube.num_vars - 1;
+        for(i = cube.first_part[var]; i <= cube.last_part[var]; i++) {
+            (void) get_word(fp, word);
+            PLA->label[i] = util_strsav(word);
+        }
+        /* .label assigns labels to multiple-valued variables */
+        } else if (equal(word, "label")) {
+        if (cube.fullset == NULL)
+            fatal("PLA size must be declared before .label");
+        if (PLA->label == NULL)
+            PLA_labels(PLA);
+        if (fscanf(fp, "var=%d", &var) != 1)
+            fatal("Error reading labels");
+        for(i = cube.first_part[var]; i <= cube.last_part[var]; i++) {
+            (void) get_word(fp, word);
+            PLA->label[i] = util_strsav(word);
+        }
+
+        } else if (equal(word, "symbolic")) {
+        symbolic_t *newlist, *p1;
+        if (read_symbolic(fp, PLA, word, &newlist)) {
+            if (PLA->symbolic == NIL(symbolic_t)) {
+            PLA->symbolic = newlist;
+            } else {
+            for(p1=PLA->symbolic;p1->next!=NIL(symbolic_t);
+                p1=p1->next){
+            }
+            p1->next = newlist;
+            }
+        } else {
+            fatal("error reading .symbolic");
+        }
+
+        } else if (equal(word, "symbolic-output")) {
+        symbolic_t *newlist, *p1;
+        if (read_symbolic(fp, PLA, word, &newlist)) {
+            if (PLA->symbolic_output == NIL(symbolic_t)) {
+            PLA->symbolic_output = newlist;
+            } else {
+            for(p1=PLA->symbolic_output;p1->next!=NIL(symbolic_t);
+                p1=p1->next){
+            }
+            p1->next = newlist;
+            }
+        } else {
+            fatal("error reading .symbolic-output");
+        }
+        
+        /* .phase allows a choice of output phases */
+        } else if (equal(word, "phase")) {
+        if (cube.fullset == NULL)
+            fatal("PLA size must be declared before .phase");
+        if (PLA->phase != NULL) {
+            (void) fprintf(stderr, "extra .phase ignored\n");
+            skip_line(fp, stdout, /* echo */ FALSE);
+        } else {
+            do ch = getc(fp); while (ch == ' ' || ch == '\t');
+            (void) ungetc(ch, fp);
+            PLA->phase = set_save(cube.fullset);
+            last = cube.last_part[cube.num_vars - 1];
+            for(i=cube.first_part[cube.num_vars - 1]; i <= last; i++)
+            if ((ch = getc(fp)) == '0')
+                set_remove(PLA->phase, i);
+            else if (ch != '1')
+                fatal("only 0 or 1 allowed in phase description");
+        }
+
+        /* .pair allows for bit-pairing input variables */
+        } else if (equal(word, "pair")) {
+        int j;
+        if (PLA->pair != NULL) {
+            (void) fprintf(stderr, "extra .pair ignored\n");
+        } else {
+            ppair pair;
+            PLA->pair = pair = ALLOC(pair_t, 1);
+            if (fscanf(fp, "%d", &(pair->cnt)) != 1)
+            fatal("syntax error in .pair");
+            pair->var1 = ALLOC(int, pair->cnt);
+            pair->var2 = ALLOC(int, pair->cnt);
+            for(i = 0; i < pair->cnt; i++) {
+            (void) get_word(fp, word);
+            if (word[0] == '(') (void) strcpy(word, word+1);
+            if (label_index(PLA, word, &var, &j)) {
+                pair->var1[i] = var+1;
+            } else {
+                fatal("syntax error in .pair");
+            }
+
+            (void) get_word(fp, word);
+            if (word[strlen(word)-1] == ')') {
+                word[strlen(word)-1]='\0';
+            }
+            if (label_index(PLA, word, &var, &j)) {
+                pair->var2[i] = var+1;
+            } else {
+                fatal("syntax error in .pair");
+            }
+            }
+        }
+        
+        } else {
+        if (echo_unknown_commands)
+            printf("%c%s ", ch, word);
+        skip_line(fp, stdout, echo_unknown_commands);
+        }
+        break;
+    default:
+        (void) ungetc(ch, fp);
+        if (cube.fullset == NULL) {
+/*        fatal("unknown PLA size, need .i/.o or .mv");*/
+        if (echo_comments)
+            putchar('#');
+        skip_line(fp, stdout, echo_comments);
+        break;
+        }
+        if (PLA->F == NULL) {
+        PLA->F = new_cover(10);
+        PLA->D = new_cover(10);
+        PLA->R = new_cover(10);
+        }
+        read_cube(fp, PLA);
+    }
+    goto loop;
+}
+/*
+    read_pla -- read a PLA from a file
+
+    Input stops when ".e" is encountered in the input file, or upon reaching
+    end of file.
+
+    Returns the PLA in the variable PLA after massaging the "symbolic"
+    representation into a positional cube notation of the ON-set, OFF-set,
+    and the DC-set.
+
+    needs_dcset and needs_offset control the computation of the OFF-set
+    and DC-set (i.e., if either needs to be computed, then it will be
+    computed via complement only if the corresponding option is TRUE.)
+    pla_type specifies the interpretation to be used when reading the
+    PLA.
+
+    The phase of the output functions is adjusted according to the
+    global option "pos" or according to an imbedded .phase option in
+    the input file.  Note that either phase option implies that the
+    OFF-set be computed regardless of whether the caller needs it
+    explicitly or not.
+
+    Bit pairing of the binary variables is performed according to an
+    imbedded .pair option in the input file.
+
+    The global cube structure also reflects the sizes of the PLA which
+    was just read.  If these fields have already been set, then any
+    subsequent PLA must conform to these sizes.
+
+    The global flags trace and summary control the output produced
+    during the read.
+
+    Returns a status code as a result:
+    EOF (-1) : End of file reached before any data was read
+    > 0     : Operation successful
+*/
+
+int read_pla(fp, needs_dcset, needs_offset, pla_type, PLA_return)
+IN FILE *fp;
+IN bool needs_dcset, needs_offset;
+IN int pla_type;
+OUT pPLA *PLA_return;
+{
+    pPLA PLA;
+    int i, second, third;
+    long time;
+    cost_t cost;
+
+    /* Allocate and initialize the PLA structure */
+    PLA = *PLA_return = new_PLA();
+    PLA->pla_type = pla_type;
+
+    /* Read the pla */
+    time = ptime();
+    parse_pla(fp, PLA);
+
+    /* Check for nothing on the file -- implies reached EOF */
+    if (PLA->F == NULL) {
+    return EOF;
+    }
+
+    /* This hack merges the next-state field with the outputs */
+    for(i = 0; i < cube.num_vars; i++) {
+    cube.part_size[i] = ABS(cube.part_size[i]);
+    }
+    if (kiss) {
+    third = cube.num_vars - 3;
+    second = cube.num_vars - 2;
+    if (cube.part_size[third] != cube.part_size[second]) {
+        (void) fprintf(stderr," with .kiss option, third to last and second\n");
+        (void) fprintf(stderr, "to last variables must be the same size.\n");
+        return EOF;
+    }
+    for(i = 0; i < cube.part_size[second]; i++) {
+        PLA->label[i + cube.first_part[second]] =
+        util_strsav(PLA->label[i + cube.first_part[third]]);
+    }
+    cube.part_size[second] += cube.part_size[cube.num_vars-1];
+    cube.num_vars--;
+    setdown_cube();
+    cube_setup();
+    }
+
+    if (trace) {
+    totals(time, READ_TIME, PLA->F, &cost);
+    }
+
+    /* Decide how to break PLA into ON-set, OFF-set and DC-set */
+    time = ptime();
+    if (pos || PLA->phase != NULL || PLA->symbolic_output != NIL(symbolic_t)) {
+    needs_offset = TRUE;
+    }
+    if (needs_offset && (PLA->pla_type==F_type || PLA->pla_type==FD_type)) {
+    free_cover(PLA->R);
+    PLA->R = complement(cube2list(PLA->F, PLA->D));
+    } else if (needs_dcset && PLA->pla_type == FR_type) {
+    pcover X;
+    free_cover(PLA->D);
+    /* hack, why not? */
+    X = d1merge(sf_join(PLA->F, PLA->R), cube.num_vars - 1);
+    PLA->D = complement(cube1list(X));
+    free_cover(X);
+    } else if (PLA->pla_type == R_type || PLA->pla_type == DR_type) {
+    free_cover(PLA->F);
+    PLA->F = complement(cube2list(PLA->D, PLA->R));
+    }
+
+    if (trace) {
+    totals(time, COMPL_TIME, PLA->R, &cost);
+    }
+
+    /* Check for phase rearrangement of the functions */
+    if (pos) {
+    pcover onset = PLA->F;
+    PLA->F = PLA->R;
+    PLA->R = onset;
+    PLA->phase = new_cube();
+    set_diff(PLA->phase, cube.fullset, cube.var_mask[cube.num_vars-1]);
+    } else if (PLA->phase != NULL) {
+    (void) set_phase(PLA);
+    }
+
+    /* Setup minimization for two-bit decoders */
+    if (PLA->pair != (ppair) NULL) {
+    set_pair(PLA);
+    }
+
+    if (PLA->symbolic != NIL(symbolic_t)) {
+    EXEC(map_symbolic(PLA), "MAP-INPUT  ", PLA->F);
+    }
+    if (PLA->symbolic_output != NIL(symbolic_t)) {
+    EXEC(map_output_symbolic(PLA), "MAP-OUTPUT ", PLA->F);
+    if (needs_offset) {
+        free_cover(PLA->R);
+EXECUTE(PLA->R=complement(cube2list(PLA->F,PLA->D)), COMPL_TIME, PLA->R, cost);
+    }
+    }
+
+    return 1;
+}
+
+void PLA_summary(PLA)
+pPLA PLA;
+{
+    int var, i;
+    symbolic_list_t *p2;
+    symbolic_t *p1;
+
+    printf("# PLA is %s", PLA->filename);
+    if (cube.num_binary_vars == cube.num_vars - 1)
+    printf(" with %d inputs and %d outputs\n",
+        cube.num_binary_vars, cube.part_size[cube.num_vars - 1]);
+    else {
+    printf(" with %d variables (%d binary, mv sizes",
+        cube.num_vars, cube.num_binary_vars);
+    for(var = cube.num_binary_vars; var < cube.num_vars; var++)
+        printf(" %d", cube.part_size[var]);
+    printf(")\n");
+    }
+    printf("# ON-set cost is  %s\n", print_cost(PLA->F));
+    printf("# OFF-set cost is %s\n", print_cost(PLA->R));
+    printf("# DC-set cost is  %s\n", print_cost(PLA->D));
+    if (PLA->phase != NULL)
+    printf("# phase is %s\n", pc1(PLA->phase));
+    if (PLA->pair != NULL) {
+    printf("# two-bit decoders:");
+    for(i = 0; i < PLA->pair->cnt; i++)
+        printf(" (%d %d)", PLA->pair->var1[i], PLA->pair->var2[i]);
+    printf("\n");
+    }
+    if (PLA->symbolic != NIL(symbolic_t)) {
+    for(p1 = PLA->symbolic; p1 != NIL(symbolic_t); p1 = p1->next) {
+        printf("# symbolic: ");
+        for(p2=p1->symbolic_list; p2!=NIL(symbolic_list_t); p2=p2->next) {
+        printf(" %d", p2->variable);
+        }
+        printf("\n");
+    }
+    }
+    if (PLA->symbolic_output != NIL(symbolic_t)) {
+    for(p1 = PLA->symbolic_output; p1 != NIL(symbolic_t); p1 = p1->next) {
+        printf("# output symbolic: ");
+        for(p2=p1->symbolic_list; p2!=NIL(symbolic_list_t); p2=p2->next) {
+        printf(" %d", p2->pos);
+        }
+        printf("\n");
+    }
+    }
+    (void) fflush(stdout);
+}
+
+
+pPLA new_PLA()
+{
+    pPLA PLA;
+
+    PLA = ALLOC(PLA_t, 1);
+    PLA->F = PLA->D = PLA->R = (pcover) NULL;
+    PLA->phase = (pcube) NULL;
+    PLA->pair = (ppair) NULL;
+    PLA->label = (char **) NULL;
+    PLA->filename = (char *) NULL;
+    PLA->pla_type = 0;
+    PLA->symbolic = NIL(symbolic_t);
+    PLA->symbolic_output = NIL(symbolic_t);
+    return PLA;
+}
+
+
+PLA_labels(PLA)
+pPLA PLA;
+{
+    int i;
+
+    PLA->label = ALLOC(char *, cube.size);
+    for(i = 0; i < cube.size; i++)
+    PLA->label[i] = (char *) NULL;
+}
+
+
+void free_PLA(PLA)
+pPLA PLA;
+{
+    symbolic_list_t *p2, *p2next;
+    symbolic_t *p1, *p1next;
+    int i;
+
+    if (PLA->F != (pcover) NULL)
+    free_cover(PLA->F);
+    if (PLA->R != (pcover) NULL)
+    free_cover(PLA->R);
+    if (PLA->D != (pcover) NULL)
+    free_cover(PLA->D);
+    if (PLA->phase != (pcube) NULL)
+    free_cube(PLA->phase);
+    if (PLA->pair != (ppair) NULL) {
+    FREE(PLA->pair->var1);
+    FREE(PLA->pair->var2);
+    FREE(PLA->pair);
+    }
+    if (PLA->label != NULL) {
+    for(i = 0; i < cube.size; i++)
+        if (PLA->label[i] != NULL)
+        FREE(PLA->label[i]);
+    FREE(PLA->label);
+    }
+    if (PLA->filename != NULL) {
+    FREE(PLA->filename);
+    }
+    for(p1 = PLA->symbolic; p1 != NIL(symbolic_t); p1 = p1next) {
+    for(p2 = p1->symbolic_list; p2 != NIL(symbolic_list_t); p2 = p2next) {
+        p2next = p2->next;
+        FREE(p2);
+    }
+    p1next = p1->next;
+    FREE(p1);
+    }
+    PLA->symbolic = NIL(symbolic_t);
+    for(p1 = PLA->symbolic_output; p1 != NIL(symbolic_t); p1 = p1next) {
+    for(p2 = p1->symbolic_list; p2 != NIL(symbolic_list_t); p2 = p2next) {
+        p2next = p2->next;
+        FREE(p2);
+    }
+    p1next = p1->next;
+    FREE(p1);
+    }
+    PLA->symbolic_output = NIL(symbolic_t);
+    FREE(PLA);
+}
+
+
+int read_symbolic(fp, PLA, word, retval)
+FILE *fp;
+pPLA PLA;
+char *word;        /* scratch string for words */
+symbolic_t **retval;
+{
+    symbolic_list_t *listp, *prev_listp;
+    symbolic_label_t *labelp, *prev_labelp;
+    symbolic_t *newlist;
+    int i, var;
+
+    newlist = ALLOC(symbolic_t, 1);
+    newlist->next = NIL(symbolic_t);
+    newlist->symbolic_list = NIL(symbolic_list_t);
+    newlist->symbolic_list_length = 0;
+    newlist->symbolic_label = NIL(symbolic_label_t);
+    newlist->symbolic_label_length = 0;
+    prev_listp = NIL(symbolic_list_t);
+    prev_labelp = NIL(symbolic_label_t);
+
+    for(;;) {
+    (void) get_word(fp, word);
+    if (equal(word, ";"))
+        break;
+    if (label_index(PLA, word, &var, &i)) {
+        listp = ALLOC(symbolic_list_t, 1);
+        listp->variable = var;
+        listp->pos = i;
+        listp->next = NIL(symbolic_list_t);
+        if (prev_listp == NIL(symbolic_list_t)) {
+        newlist->symbolic_list = listp;
+        } else {
+        prev_listp->next = listp;
+        }
+        prev_listp = listp;
+        newlist->symbolic_list_length++;
+    } else {
+        return FALSE;
+    }
+    }
+
+    for(;;) {
+    (void) get_word(fp, word);
+    if (equal(word, ";"))
+        break;
+    labelp = ALLOC(symbolic_label_t, 1);
+    labelp->label = util_strsav(word);
+    labelp->next = NIL(symbolic_label_t);
+    if (prev_labelp == NIL(symbolic_label_t)) {
+        newlist->symbolic_label = labelp;
+    } else {
+        prev_labelp->next = labelp;
+    }
+    prev_labelp = labelp;
+    newlist->symbolic_label_length++;
+    }
+
+    *retval = newlist;
+    return TRUE;
+}
+
+
+int label_index(PLA, word, varp, ip)
+pPLA PLA;
+char *word;
+int *varp;
+int *ip;
+{
+    int var, i;
+
+    if (PLA->label == NIL(char *) || PLA->label[0] == NIL(char)) {
+    if (sscanf(word, "%d", varp) == 1) {
+        *ip = *varp;
+        return TRUE;
+    }
+    } else {
+    for(var = 0; var < cube.num_vars; var++) {
+        for(i = 0; i < cube.part_size[var]; i++) {
+        if (equal(PLA->label[cube.first_part[var]+i], word)) {
+            *varp = var;
+            *ip = i;
+            return TRUE;
+        }
+        }
+    }
+    }
+    return FALSE;
+}