Reimplement interchange heuristic.

Reimplement interchange heuristic.

2009-08-11  Sebastian Pop  <sebastian.pop@amd.com>
	    Pranav Garg  <pranav.garg2107@gmail.com>

	* graphite-interchange.c (gather_access_strides): Removed.
	(ppl_max_for_le): New.
	(build_linearized_memory_access): New.
	(memory_stride_in_loop): New.
	(pbb_interchange_profitable_p): Reimplemented.
	* graphite-ppl.h (ppl_new_id_map): New.
	(ppl_interchange): New.

	* testsuite/gcc.dg/graphite/interchange-6.c: XFAILed.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@150692 138bc75d-0d04-0410-961f-82ee72b054a4