re PR ipa/65270 (issues with merging memory accesses from different code paths)

re PR ipa/65270 (issues with merging memory accesses from different code paths)

2015-03-09  Richard Biener  <rguenther@suse.de>

	PR middle-end/65270
	* tree-core.h (enum operand_equal_flag): Add OEP_ADDRESS_OF.
	* fold-const.c (operand_equal_p): When recursing for ADDR_EXPRs
	operand set OEP_ADDRESS_OF.  Clear it when recursing to non-bases
	of that.  When comparing dereferences compare alignment.
	When comparing MEM_REFs or TARGET_MEM_REFs compare dependence info.

	* gcc.dg/torture/pr65270-1.c: New testcase.
	* gcc.dg/torture/pr65270-2.c: Likewise.

From-SVN: r221281