On Thu, Oct 23, 2008 at 10:46 AM, Martin Schindewolf <[EMAIL PROTECTED]> wrote: > Hi all, > > how is the must-alias information represented in mainline? > Is there something like DEF-USE chains for virtual operands? > How can I access this kind of information and where should I look for some > examples how to use it? > Thank you very much!
There is only may-alias information explicitely represented, by virtue of the virtual operands USE-DEF/DEF-USE chains. You have to verify must-alias relation yourself, which is eased by several helper functions, most notable get_ref_base_and_extent () which dissects a memory reference into a base, offset range and access size. You can compare the base for equality using the operand_equal_p function. For pointer bases you can also access points-to information present in the SSA_NAME_PTR_INFO structure. On the alias-improvements branch we hopefully will end up with more specific interfaces to query must-alias information. Richard.
