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Compile matches on literal values.

--- a/8/simp.c

+++ b/8/simp.c

@@ -358,6 +358,33 @@

     simp(s, lend);              /* exit */

 }

+static void simpmatch(Simp *s, Node *n)

+{

+    Node *end, *cur, *next; /* labels */

+    Node *val, *cond; /* intermediates */

+    Node *m;

+    size_t i;

+

+    end = genlbl();

+    val = rval(s, n->matchstmt.val); /* FIXME: don't recompute, even if pure */

+    for (i = 0; i < n->matchstmt.nmatches; i++) {

+        m = n->matchstmt.matches[i];

+

+        if (exprop(m->match.pat) != Olit)

+            die("Unsupported non-lit pat");

+        cond = mkexpr(m->line, Oeq, val, m->match.pat, NULL);

+

+        cur = genlbl();

+        next = genlbl();

+        cjmp(s, cond, cur, next);

+        append(s, cur);

+        simp(s, m->match.block);

+        jmp(s, end);

+        append(s, next);

+    }

+    append(s, end);

+}

+

 static void simpblk(Simp *s, Node *n)

 {

     size_t i;

@@ -801,15 +828,12 @@

         return NULL;

     r = NULL;

     switch (n->type) {

-        case Nblock:

-            simpblk(s, n);

-            break;

-        case Nifstmt:

-            simpif(s, n);

-            break;

-        case Nloopstmt:

-            simploop(s, n);

-            break;

+        case Nlit:       r = n;                 break;

+        case Nlbl:       append(s, n);          break;

+        case Nblock:     simpblk(s, n);         break;

+        case Nifstmt:    simpif(s, n);          break;

+        case Nloopstmt:  simploop(s, n);        break;

+        case Nmatchstmt: simpmatch(s, n);       break;

         case Nexpr:

             r = rval(s, n);

             if (r)

@@ -819,9 +843,7 @@

                 append(s, s->incqueue[i]);

             lfree(&s->incqueue, &s->nqueue);

             break;

-        case Nlit:

-            r = n;

-            break;

+

         case Ndecl:

             declarelocal(s, n);

             if (n->decl.init) {

@@ -832,9 +854,6 @@

                 t->expr.did = n->decl.did;

                 simp(s, u);

             }

-            break;

-        case Nlbl:

-            append(s, n);

             break;

         default:

             die("Bad node passsed to simp()");

--- a/parse/gram.y

+++ b/parse/gram.y

@@ -577,7 +577,7 @@

         | Tendln {$$ = NULL;}

         ;

-pat     : literal {$$ = $1;}

+pat     : literal {$$ = mkexpr($1->line, Olit, $1, NULL);}

         ;

 block   : blockbody Tendblk