Reset link field to NULL on construction

[libfirm] / ir / ir / ircons.h

diff --git a/ir/ir/ircons.h b/ir/ir/ircons.h
index 0380d33..d284069 100644 (file)
--- a/ir/ir/ircons.h
+++ b/ir/ir/ircons.h
@@ -453,7 +453,12 @@
  *    --------------------------------------------
  *
  *    Creates a new Block with the given list of predecessors.  This block
- *    is mature.
+ *    is mature.  As other constructors calls optimization and vrfy for the
+ *    block.  If one of the predecessors is Unknown (as it has to be filled in
+ *    later) optimizations are skipped.  This is necessary to
+ *    construct Blocks in loops.  Leaving Unknown in the Block after finishing
+ *    the construction may have strange effects, especially for interprocedural
+ *    representation and analyses.
  *
  *
  *    CONTROL FLOW OPERATIONS
@@ -587,7 +592,7 @@
  *    datastructure don't use
  *      new_SymConst((type_or_id*)get_entity_ld_ident(ent), linkage_ptr_info);.
  *    Use a real const instead:
- *      new_Const(mode_P, tarval_p_from_entity(ent));
+ *      new_Const(mode_P_mach, tarval_p_from_entity(ent));
  *    This makes the Constant independent of name changes of the entity due to
  *    mangling.
  *
@@ -611,7 +616,7 @@
  *      attr.i.*type,    a pointer to a type_class.  The mode of the node is mode_Is.
  *        if it is linkage_ptr_info it contains
  *      attr.i.*ptrinfo,  an ident holding information for the linker.  The mode
- *        of the node is mode_P.
+ *        of the node is mode_P_mach.
  *
  *    ---------------
  *
@@ -840,6 +845,11 @@
  *
  *    Creates a Phi node. The in's order has to correspond to the order
  *    of in's of current_block.  This is not checked by the library!
+ *    If one of the predecessors is Unknown (as it has to be filled in
+ *    later) optimizations are skipped.  This is necessary to
+ *    construct Phi nodes in loops.  Leaving Unknown in the Phi after finishing
+ *    the construction may have strange effects, especially for interprocedural
+ *    representation and analyses.
  *
  *    Parameter
  *      arity            number of predecessors