Change the predicate stuff to use costs instead; now you can use when clauses

on leaves. Remove an iburg premature optimisation (required for above).

diff --git a/util/mcgg/iburg.c b/util/mcgg/iburg.c
index cae03e5..9d5d3f0 100644 (file)
--- a/util/mcgg/iburg.c
+++ b/util/mcgg/iburg.c
@@ -24,6 +24,7 @@ static void print(char* fmt, ...);
 static void ckreach(Nonterm p);
 static void emitclosure(Nonterm nts);
 static void emitcost(Tree t, char* v);
+static void emitcostcalc(Rule r);
 static void emitdefs(Nonterm nts, int ntnumber);
 static void emitfuncs(void);
 static void emitheader(void);
@@ -34,7 +35,6 @@ static void emitnts(Rule rules, int nrules);
 static void emitrecord(char* pre, Rule r, int cost);
 static void emitrule(Nonterm nts);
 static void emitpredicatedefinitions(Rule rules);
-static void emitpredicatecall(Rule rule);
 static void emitstate(Term terms, Nonterm start, int ntnumber);
 static void emitstring(Rule rules);
 static void emitstruct(Nonterm nts, int ntnumber);
@@ -283,9 +283,6 @@ Rule rule(char* id, Tree pattern, int ern, Stringlist when, int cost)
        Rule *q;
        Term p = pattern->op;
 
-       if (when && (p->arity == 0))
-               yyerror("can't have a when clause on leaf nodes");
-
        nrules++;
        r->when = when;
        r->lhs = nonterm(id);
@@ -421,11 +418,6 @@ static void emitcase(Term p, int ntnumber)
        {
                case 0:
                case -1:
-                       if (!Tflag)
-                       {
-                               emitleaf(p, ntnumber);
-                               return;
-                       }
                        break;
                case 1:
                        print("%2assert(l);\n");
@@ -442,26 +434,21 @@ static void emitcase(Term p, int ntnumber)
                {
                        case 0:
                        case -1:
-                               print("%2if (");
-                               emitpredicatecall(r);
-                               print(")\n%2{%1/* %R */\n%3c = ", r);
+                               print("%2{%1/* %R */\n%3c = ", r);
+                               emitcostcalc(r);
                                break;
                        case 1:
                                if (r->pattern->nterms > 1)
                                {
                                        print("%2if (%1/* %R */\n", r);
                                        emittest(r->pattern->left, "l", " ");
-                                       print("%3&& ");
-                                       emitpredicatecall(r);
-                                       print("\n");
                                        print("%2) {\n%3c = ");
                                }
                                else
                                {
-                                       print("%2if (");
-                                       emitpredicatecall(r);
-                                       print(")\n%2{%1/* %R */\n%3c = ", r);
+                                       print("%2{%1/* %R */\n%3c = ", r);
                                }
+                               emitcostcalc(r);
                                emitcost(r->pattern->left, "l");
                                break;
                        case 2:
@@ -471,17 +458,13 @@ static void emitcase(Term p, int ntnumber)
                                        emittest(r->pattern->left, "l",
                                            r->pattern->right->nterms ? " && " : " ");
                                        emittest(r->pattern->right, "r", " ");
-                                       print("%3&& ");
-                                       emitpredicatecall(r);
-                                       print("\n");
                                        print("%2) {\n%3c = ");
                                }
                                else
                                {
-                                       print("%2if (");
-                                       emitpredicatecall(r);
-                                       print(")\n%2{%1/* %R */\n%3c = ", r);
+                                       print("%2{%1/* %R */\n%3c = ", r);
                                }
+                               emitcostcalc(r);
                                emitcost(r->pattern->left, "l");
                                emitcost(r->pattern->right, "r");
                                break;
@@ -668,46 +651,6 @@ static void closure(int cost[], Rule rule[], Nonterm p, int c)
                }
 }
 
-/* emitleaf - emit state code for a leaf */
-static void emitleaf(Term p, int ntnumber)
-{
-       int i;
-       Rule r;
-       static int* cost;
-       static Rule* rule;
-
-       if (cost == NULL)
-       {
-               cost = calloc(ntnumber+1, sizeof *cost);
-               rule = calloc(ntnumber+1, sizeof *rule);
-       }
-       for (i = 0; i <= ntnumber; i++)
-       {
-               cost[i] = maxcost;
-               rule[i] = NULL;
-       }
-       for (r = p->rules; r; r = r->next)
-               if (r->pattern->left == NULL && r->pattern->right == NULL)
-               {
-                       cost[r->lhs->number] = r->cost;
-                       rule[r->lhs->number] = r;
-                       closure(cost, rule, r->lhs, r->cost);
-               }
-       print("%2{\n%3static struct %Pstate z = { %d, 0, 0,\n%4{%10,\n", p->esn);
-       for (i = 1; i <= ntnumber; i++)
-               if (cost[i] < maxcost)
-                       print("%5%d,%1/* %R */\n", cost[i], rule[i]);
-               else
-                       print("%5%d,\n", cost[i]);
-       print("%4},{\n");
-       for (i = 1; i <= ntnumber; i++)
-               if (rule[i])
-                       print("%5%d,%1/* %R */\n", rule[i]->packed, rule[i]);
-               else
-                       print("%50,\n");
-       print("%4}\n%3};\n%3return (STATE_TYPE)&z;\n%2}\n");
-}
-
 /* computents - fill in bp with burm_nts vector for tree t */
 static char* computents(Tree t, char* bp)
 {
@@ -815,13 +758,11 @@ static void emitpredicatedefinitions(Rule r)
        }
 }
 
-/* emitpredicatecall - emit a call to a predicate */
-static void emitpredicatecall(Rule r)
+/* emitcost - emit a cost calculation via a predicate */
+static void emitcostcalc(Rule r)
 {
        if (r->when)
-               print("%Ppredicate_%d(node)", r->ern);
-       else
-               print("1");
+               print("!%Ppredicate_%d(node) ? %d : ", r->ern, maxcost);
 }
 
 /* emitstate - emit state function */
@@ -837,15 +778,17 @@ static void emitstate(Term terms, Nonterm start, int ntnumber)
              "%1struct %Pstate* r = (struct %Pstate *)right;\n"
                  "\n"
                  "%1assert(sizeof (STATE_TYPE) >= sizeof (void *));\n%1");
-       if (!Tflag)
-               print("if (%Parity[op] > 0) ");
-       print("{\n%2p = ALLOC(sizeof *p);\n"
-             "%2%Passert(p, PANIC(\"ALLOC returned NULL in %Pstate\\n\"));\n"
-             "%2p->op = op;\n%2p->left = l;\n%2p->right = r;\n%2p->rule.%P%S = 0;\n",
+       print("%1p = ALLOC(sizeof *p);\n"
+             "%1%Passert(p, PANIC(\"ALLOC returned NULL in %Pstate\\n\"));\n"
+             "%1p->op = op;\n"
+                 "%1p->left = l;\n"
+                 "%1p->right = r;\n"
+                 "%1p->rule.%P%S = 0;\n",
            start);
        for (i = 1; i <= ntnumber; i++)
-               print("%2p->cost[%d] =\n", i);
-       print("%3%d;\n%1}\n%1switch (op) {\n", maxcost);
+               print("%1p->cost[%d] =\n", i);
+       print("%2%d;\n"
+                 "%1switch (op) {\n", maxcost);
        for (p = terms; p; p = p->link)
                emitcase(p, ntnumber);
        print("%1default:\n"

diff --git a/util/mcgg/mcgg_generated_footer.h b/util/mcgg/mcgg_generated_footer.h
index 986ecd2..8205439 100644 (file)
--- a/util/mcgg/mcgg_generated_footer.h
+++ b/util/mcgg/mcgg_generated_footer.h
@@ -32,7 +32,10 @@ int main(void) {
        NODEPTR_TYPE p;
 
        p = tree(STORE,
-                       tree(LABEL, 0, 0),
+                       tree(ADD,
+                               tree(LABEL, 0, 0),
+                               tree(CONST, 0, 0)
+                       ),
                        tree(ADD,
                                tree(LOAD,
                                        tree(LABEL, 0, 0),