Add label predicates

* include/lightning.h, lib/lightning.c: Add three predicates
	to query information about labels. jit_forward_p(label)
	will return non zero if the label is "forward", that is
	need a call to jit_link(label), jit_indirect_p(label)
	that returns non zero if the label was created with the
	jit_indirect() call, and jit_target_p(label) that will
	return non zero if there is at least one jump patched
	to land at that label.

ChangeLog

@@ -1,3 +1,14 @@
+2014-10-21 Paulo Andrade <pcpa@gnu.org>
+
+	* include/lightning.h, lib/lightning.c: Add three predicates
+	to query information about labels. jit_forward_p(label)
+	will return non zero if the label is "forward", that is
+	need a call to jit_link(label), jit_indirect_p(label)
+	that returns non zero if the label was created with the
+	jit_indirect() call, and jit_target_p(label) that will
+	return non zero if there is at least one jump patched
+	to land at that label.
+
 2014-10-18 Paulo Andrade <pcpa@gnu.org>
 
 	* check/range.ok, check/range.tst: New test case designed

include/lightning.h

@@ -864,6 +864,12 @@ extern jit_node_t *_jit_label(jit_state_t*);
 extern jit_node_t *_jit_forward(jit_state_t*);
 extern jit_node_t *_jit_indirect(jit_state_t*);
 extern void _jit_link(jit_state_t*, jit_node_t*);
+#define jit_forward_p(u)	_jit_forward_p(_jit,u)
+extern jit_bool_t _jit_forward_p(jit_state_t*,jit_node_t*);
+#define jit_indirect_p(u)	_jit_indirect_p(_jit,u)
+extern jit_bool_t _jit_indirect_p(jit_state_t*,jit_node_t*);
+#define jit_target_p(u)		_jit_target_p(_jit,u)
+extern jit_bool_t _jit_target_p(jit_state_t*,jit_node_t*);
 
 extern void _jit_prolog(jit_state_t*);
 

lib/lightning.c

@@ -1127,6 +1127,24 @@ _jit_link(jit_state_t *_jit, jit_node_t *node)
     ++_jitc->blocks.offset;
 }
 
+jit_bool_t
+_jit_forward_p(jit_state_t *_jit, jit_node_t *node)
+{
+    return (node->code == jit_code_label && !node->next && node != _jitc->tail);
+}
+
+jit_bool_t
+_jit_indirect_p(jit_state_t *_jit, jit_node_t *node)
+{
+    return (node->code == jit_code_label && !!(node->flag & jit_flag_use));
+}
+
+jit_bool_t
+_jit_target_p(jit_state_t *_jit, jit_node_t *node)
+{
+    return (node->code == jit_code_label && !!node->link);
+}
+
 void
 _jit_prepare(jit_state_t *_jit)
 {