besched: Add and use sched_foreach_reverse_safe().

[libfirm] / ir / be / besched.h

diff --git a/ir/be/besched.h b/ir/be/besched.h
index aa8c314..eb7907d 100644 (file)
--- a/ir/be/besched.h
+++ b/ir/be/besched.h
@@ -188,6 +188,16 @@ static inline bool sched_comes_after(const ir_node *n1, const ir_node *n2)
 #define sched_foreach_safe(block, irn) \
        for (ir_node *irn, *irn##__next = sched_first(block); !sched_is_end(irn = irn##__next) ? irn##__next = sched_next(irn), 1 : 0;)
 
+/**
+ * A shorthand macro for reversely iterating over a schedule while the current
+ * node may be removed or replaced.
+ *
+ * @param block  The block.
+ * @param irn    A ir node pointer used as an iterator.
+ */
+#define sched_foreach_reverse_safe(block, irn) \
+       for (ir_node *irn, *irn##__prev = sched_last(block); !sched_is_begin(irn = irn##__prev) ? irn##__prev = sched_prev(irn), 1 : 0;)
+
 /**
  * Type for a function scheduling a graph
  */