re PR rtl-optimization/55342 ([LRA,x86] Non-optimal code for simple loop with LRA)

re PR rtl-optimization/55342 ([LRA,x86] Non-optimal code for simple loop with LRA)

2013-07-05  Vladimir Makarov  <vmakarov@redhat.com>

	PR rtl-optimization/55342
	* lra-int.h (lra_subreg_reload_pseudos): New.
	* lra.c: Add undoing optional reloads to the block diagram.
	(lra_subreg_reload_pseudos): New.
	(lra_optional_reload_pseudos): Change comments.
	(lra): Init and clear lra_subreg_reload_pseudos.  Clear
	lra_optional_reload_pseudos after undo transformations.
	* lra-assigns.c (pseudo_prefix_title): New.
	(lra_setup_reg_renumber): Use it.
	(spill_for): Ditto.  Check subreg reload pseudos too.
	(assign_by_spills): Consider subreg reload pseudos too.
	* lra-constraints.c (simplify_operand_subreg): Use
	lra_subreg_reload_pseudos instead of lra_optional_reload_pseudos.
	(curr_insn_transform): Recognize and do optional reloads.
	(undo_optional_reloads): New.
	(lra_undo_inheritance): Call undo_optional_reloads.

2013-07-05  Vladimir Makarov  <vmakarov@redhat.com>

	PR rtl-optimization/55342
	* gcc.target/i386/pr55342.c: New.

From-SVN: r200723