tree-ssa-loop-ivopts.c: New file.

	* tree-ssa-loop-ivopts.c: New file.
	* Makefile.in (tree-ssa-loop-ivopts.c): Add.
	* cfgloop.h (target_avail_regs, target_res_regs, target_small_cost,
	target_pres_cost, target_spill_cost): Declare.
	* cfgloopanal.c (avail_regs, res_regs, small_cost, pres_cost,
	spill_cost): Renamed to ...
	(target_avail_regs, target_res_regs, target_small_cost,
	target_pres_cost, target_spill_cost): ... and exported.
	(init_set_costs, global_cost_for_size): Work with renamed variables.
	* common.opt (flag_ivopts): New flag.
	* expr.c (expand_expr_real_1): Handle SSA_NAME case.  Handle
	REF_ORIGINAL.
	* gimplify.c (struct gimplify_ctx): Add into_ssa field.
	(internal_get_tmp_var, gimplify_modify_expr, gimplify_expr): Support
	generating SSA form.
	(force_gimple_operand): New function.
	* timevar.def (TV_TREE_LOOP_IVOPTS): New timevar.
	* tree-cfg.c (stmt_bsi): New function.
	* params.def (PARAM_IV_CONSIDER_ALL_CANDIDATES_BOUND,
	PARAM_IV_MAX_CONSIDERED_USES): New.
	* tree-flow.h (stmt_bsi, tree_ssa_iv_optimize, split_loop_exit_edge,
	bsi_insert_on_edge_immediate_loop. standard_iv_increment_position,
	ip_end_pos, ip_normal_pos, force_gimple_operand): Declare.
	* tree-gimple.c (is_gimple_formal_tmp_var): Accept ssa names.
	* tree-nested.c (build_addr): Export.
	* tree-optimize.c (init_tree_optimization_passes): Add
	pass_iv_optimize.
	* tree-pass.h (pass_iv_optimize): Declare.
	* tree-ssa-loop-im.c (for_each_index): Handle REALPART_EXPR and
	IMAGPART_EXPR.
	* tree-ssa-loop-manip.c (create_iv): Force the base to be acceptable
	as a phi node argument.
	(split_loop_exit_edge, bsi_insert_on_edge_immediate_loop,
	ip_end_pos, ip_normal_pos, standard_iv_increment_position): New
	functions.
	* tree-ssa-loop-niter.c (zero_p, unsigned_type_for): Export.
	* tree-ssa-loop.c (tree_ssa_loop_ivopts, gate_tree_ssa_loop_ivopts,
	pass_iv_optimize): New pass.
	* tree-ssa-operands.c (get_indirect_ref_operands): Handle REF_ORIGINAL.
	* tree-ssanames.c (release_ssa_name): Allow calling with var = NULL.
	* tree.c (build_int_cst_type, cst_and_fits_in_hwi): New functions.
	* tree.h (REF_ORIGINAL): New macro.
	(build_int_cst_type, unsigned_type_for, zero_p,
	cst_and_fits_in_hwi, build_addr): Declare.
	* doc/invoke.texi (-fivopts): Document.
	(PARAM_IV_CONSIDER_ALL_CANDIDATES_BOUND,
	PARAM_IV_MAX_CONSIDERED_USES): Document.
	* doc/passes.texi: Document induction variable optimizations pass.

	* gcc.dg/tree-ssa/loop-2.c: New test.
	* gcc.dg/tree-ssa/loop-3.c: New test.
	* gcc.dg/tree-ssa/loop-4.c: New test.
	* gcc.dg/tree-ssa/loop-5.c: New test.

From-SVN: r87100

1 files changed, 15 insertions, 1 deletions

diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 5c0030e..ade9d2c2 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -316,7 +316,7 @@ Objective-C and Objective-C++ Dialects}.
 -funroll-all-loops  -funroll-loops  -fpeel-loops @gol
 -funswitch-loops  -fold-unroll-loops  -fold-unroll-all-loops @gol
 -ftree-pre  -ftree-ccp  -ftree-dce -ftree-loop-optimize @gol
--ftree-loop-im -ftree-loop-ivcanon @gol
+-ftree-loop-im -ftree-loop-ivcanon -fivopts @gol
 -ftree-dominator-opts -ftree-dse -ftree-copyrename @gol
 -ftree-ch -ftree-sra -ftree-ter -ftree-lrs -ftree-fre -ftree-vectorize @gol
 --param @var{name}=@var{value}
@@ -4503,6 +4503,10 @@ determining number of iterations requires complicated analysis.  Later
 optimizations then may determine the number easily.  Useful especially
 in connection with unrolling.
 
+@item -fivopts
+Perform induction variable optimizations (strength reduction, induction
+variable merging and induction variable elimination) on trees.
+
 @item -ftree-sra
 Perform scalar replacement of aggregates.  This pass replaces structure
 references with scalars to prevent committing structures to memory too
@@ -5308,6 +5312,16 @@ The maximum number of branches unswitched in a single loop.
 @item lim-expensive
 The minimum cost of an expensive expression in the loop invariant motion.
 
+@item iv-consider-all-candidates-bound
+Bound on number of candidates for induction variables below that
+all candidates are considered for each use in induction variable
+optimizations.  Only the most relevant candidates are considered
+if there are more candidates, to avoid quadratic time complexity.
+
+@item iv-max-considered-uses
+The induction variable optimizations give up on loops that contain more
+induction variable uses.
+
 @item max-iterations-to-track
 
 The maximum number of iterations of a loop the brute force algorithm