Improved code generation for sets somewhat

diff --git a/lang/m2/comp/code.c b/lang/m2/comp/code.c
index 6972b0e..ab12389 100644 (file)
--- a/lang/m2/comp/code.c
+++ b/lang/m2/comp/code.c
@@ -137,13 +137,21 @@ CodeExpr(nd, ds, true_label, false_label)
        case Set: {
                register unsigned i = (unsigned) (tp->tp_size) / (int) word_size;
                register arith *st = nd->nd_set + i;
+               int null_set = 1;
 
                ds->dsg_kind = DSG_LOADED;
                for (; i; i--) { 
-                       C_loc(*--st);
+                       if (*--st != 0) null_set = 0;
+               }
+               if (! null_set) {
+                       i = (unsigned) (tp->tp_size) / (int) word_size;
+                       st = nd->nd_set + i;
+                       for (; i; i--) { 
+                               C_loc(*--st);
+                       }
                }
                FreeSet(nd->nd_set);
-               CodeSet(nd);
+               CodeSet(nd, null_set);
                }
                break;
 
@@ -992,7 +1000,7 @@ CodeUoper(nd)
        }
 }
 
-CodeSet(nd)
+CodeSet(nd, null_set)
        register t_node *nd;
 {
        register t_type *tp = nd->nd_type;
@@ -1001,18 +1009,23 @@ CodeSet(nd)
        while (nd) {
                assert(nd->nd_class == Link && nd->nd_symb == ',');
 
-               if (nd->nd_LEFT) CodeEl(nd->nd_LEFT, tp);
+               if (nd->nd_LEFT) {
+                       CodeEl(nd->nd_LEFT, tp, null_set);
+                       null_set = 0;
+               }
                nd = nd->nd_RIGHT;
        }
+       if (null_set) C_zer(tp->tp_size);
 }
 
-CodeEl(nd, tp)
+CodeEl(nd, tp, null_set)
        register t_node *nd;
        register t_type *tp;
 {
        register t_type *eltype = ElementType(tp);
 
        if (nd->nd_class == Link && nd->nd_symb == UPTO) {
+               if (null_set) C_zer(tp->tp_size);
                C_loc(tp->set_low);
                C_loc(tp->tp_size);     /* push size */
                if (eltype->tp_fund == T_SUBRANGE) {
@@ -1028,7 +1041,7 @@ CodeEl(nd, tp)
                C_loc(tp->set_low);
                C_sbi(word_size);
                C_set(tp->tp_size);
-               C_ior(tp->tp_size);
+               if (! null_set) C_ior(tp->tp_size);
        }
 }