[PATCH][mem-ref2] Document MEM_REF in generic.texi

[Richard Guenther]

Committed.

2010-06-28  Richard Guenther  <rguenther@suse.de>

	* doc/generic.texi (References to storage): Document MEM_REF.

Index: gcc/doc/generic.texi
===================================================================
*** gcc/doc/generic.texi	(revision 161482)
--- gcc/doc/generic.texi	(working copy)
*************** target system bytes are not the same wid
*** 1116,1121 ****
--- 1116,1122 ----
  @subsection References to storage
  @tindex ADDR_EXPR
  @tindex INDIRECT_REF
+ @tindex MEM_REF
  @tindex ARRAY_REF
  @tindex ARRAY_RANGE_REF
  @tindex TARGET_MEM_REF
*************** These nodes are used to represent the ob
*** 1176,1181 ****
--- 1177,1189 ----
  The operand is the pointer being dereferenced; it will always have
  pointer or reference type.
  
+ @item MEM_REF
+ These nodes are used to represent the object pointed to by a pointer
+ offset by a constant.
+ The first operand is the pointer being dereferenced; it will always have
+ pointer or reference type.  The second operand is a pointer constant.
+ It's type is specifying the type to be used for type-based alias analysis.
+ 
  @item COMPONENT_REF
  These nodes represent non-static data member accesses.  The first
  operand is the object (rather than a pointer to it); the second operand