Implement and use the %retload/real opcode.

tgt-vvp/eval_real.c

@@ -297,6 +297,16 @@ static void draw_signal_real_real(ivl_expr_t expr)
 {
       ivl_signal_t sig = ivl_expr_signal(expr);
 
+	/* Special Case: If the signal is the return value of the function,
+	   then use a different opcode to get the value. */
+      if (signal_is_return_value(sig)) {
+	    assert(ivl_signal_dimensions(sig) == 0);
+	    fprintf(vvp_out, "    %%retload/real 0; Load %s (draw_signal_real_real)\n",
+		    ivl_signal_basename(sig));
+	    return;
+      }
+
+
       if (ivl_signal_dimensions(sig) == 0) {
 	    fprintf(vvp_out, "    %%load/real v%p_0;\n", sig);
 	    return;

vvp/opcodes.txt

@@ -1025,6 +1025,7 @@ that contains the actual offset. In this case, flag-4 is tested, and
 if not 1, the assign is suppressed.
 
 * %retload/vec4 <index>
+* %retload/real <index>
 
 Read a value from the indexed function argument. The value is read
 from the argument and pushed to the appropriate stack.

vvp/vthread.cc

@@ -5049,8 +5049,13 @@ bool of_RET_VEC4(vthread_t thr, vvp_code_t cp)
  */
 bool of_RETLOAD_REAL(vthread_t thr, vvp_code_t cp)
 {
-	// NOT IMPLEMENTED
-      assert(0);
+      size_t index = cp->number;
+
+      assert(index >= 0 && index < thr->args_real.size());
+      unsigned depth = thr->args_real[index];
+	// Use the depth to extract the values from the stack
+	// of the parent thread.
+      thr->push_real(thr->parent->peek_real(depth));
       return true;
 }