a simple optimization added

diff --git a/util/LLgen/src/gencode.c b/util/LLgen/src/gencode.c
index 35b32ac..5162947 100644 (file)
--- a/util/LLgen/src/gencode.c
+++ b/util/LLgen/src/gencode.c
@@ -547,6 +547,19 @@ alternation(pp, safety, mustscan, mustpop, lb)
        if (unsafe && hulp1 == lb) {
                fprintf(f,"L_%d: \n", hulp1);
        }
+       if (safety == SAFE) {
+               /* check if we can avoid to generate the switch */
+               for (;;) {
+                       if (g_gettype(p) == EORULE) return;
+                       l = g_getlink(p);
+                       if (l->l_flag & COND) break;
+                       if ((g_gettype(l->l_rule) != TERMINAL &&
+                            g_gettype(l->l_rule) != LITERAL) ||
+                           g_gettype(l->l_rule+1) != EORULE) break;
+                       p++;
+               }
+               p = pp;
+       }
        while (g_gettype(p) != EORULE) {
                l = g_getlink(p);
                if (l->l_flag & COND) {