2007-12-05 Harsha Jagasia <harsha.jagasia@amd.com>

2007-12-05  Harsha Jagasia <harsha.jagasia@amd.com>

	* tree-vectorizer.c (slpeel_add_loop_guard): Gimplify the condition.
	(set_prologue_iterations): New. Set the prologue iterations to total
	number of scalar iterations if the cost model check indicates that
	scalar code should be generated.
	(slpeel_tree_peel_loop_to_edge): Add a new parameter and code for
	generating the cost condition for epilog. Call
	set_prologue_iterations to generate cost condition for prolog.
	(new_loop_vec_info): Initialize LOOP_VINFO_NITERS_UNCHANGED.
	* tree-vectorizer.h (LOOP_VINFO_NITERS_UNCHANGED): New.
	(slpeel_tree_peel_loop_to_edge): Update declaration.
	(set_prologue_iterations): New declaration.
	* tree-vect-analyze.c (vect_analyze_loop_form): Update
	LOOP_VINFO_NITERS_UNCHANGED.
	* tree-vect-transform.c
	(vect_estimate_min_profitable_iters): Add new parameter and
	code to  check if run time cost model test is needed.
	Remove code that adds builtin vectorization cost to scalar
	outside cost for the run time cost model test. If run time
	cost model test is needed add the appropriate guard cost to
	the scalar outside cost. The guard cost depends on whether
	the guard is generated at versioning or at prolog generation
	or at epilog generation. Change cost model equation to include
	scalar outside cost.
	(conservative_cost_threshold): New. Return the less conservative
	profitability threshold between the cost model threshold and the
	user defined vectorization threshold.
	(vect_do_peeling_for_loop_bound): Call conservative_cost_threshold.
	(vect_do_peeling_for_alignment): Same.
	(vect_loop_versioning): Same.
	(vect_create_cond_for_align_checks): ANDs the cost model condition
	with the alignment condition.
	(vect_transform_loop): Call loop versioning only when there is a
	misalignment or an aliasing problem.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@130651 138bc75d-0d04-0410-961f-82ee72b054a4