* tree-ssa-loop-ivcanon.c: New file.

	* tree-ssa-loop-manip.c (create_iv): New function.
	* Makefile.in (tree-ssa-loop-ivcanon.o): Add.
	(tree-ssa-loop.o, tree-ssa-loop-manip.o): Add SCEV_H dependency.
	* cfgloop.c (mark_single_exit_loops): New function.
	(verify_loop_structure): Verify single-exit loops.
	* cfgloop.h (struct loop): Add single_exit field.
	(LOOPS_HAVE_MARKED_SINGLE_EXITS): New constant.
	(mark_single_exit_loops): Declare.
	(tree_num_loop_insns): Declare.
	* cfgloopmanip.c (update_single_exits_after_duplication): New function.
	(duplicate_loop_to_header_edge): Use it.
	* common.opt (fivcanon): New flag.
	* timevar.def (TV_TREE_LOOP_IVCANON, TV_COMPLETE_UNROLL): New timevars.
	* tree-cfg.c (tree_find_edge_insert_loc): Return newly created block.
	(bsi_commit_edge_inserts_1): Pass null to tree_find_edge_insert_loc.
	(bsi_insert_on_edge_immediate): New function.
	* tree-flow.h (bsi_insert_on_edge_immediate,
	canonicalize_induction_variables, tree_unroll_loops_completely,
	create_iv): Declare.
	* tree-optimize.c (init_tree_optimization_passes): Add
	pass_iv_canon and pass_complete_unroll.
	* tree-pass.h (pass_iv_canon, pass_complete_unroll): Declare.
	* tree-scalar-evolution.c (get_loop_exit_condition,
	get_exit_conditions_rec, number_of_iterations_in_loop,
	scev_initialize): Use single_exit information.
	* tree-ssa-loop-niter.c (number_of_iterations_cond): Record
	missing assumptions.
	(loop_niter_by_eval):  Return number of iterations as unsigned
	int.
	* tree-ssa-loop.c (tree_ssa_loop_init): Mark single exit loops.
	(tree_ssa_loop_ivcanon, gate_tree_ssa_loop_ivcanon, pass_iv_canon,
	tree_complete_unroll, gate_tree_complete_unroll, pass_complete_unroll):
	New passes.
	(tree_ssa_loop_done): Call free_numbers_of_iterations_estimates.
	* tree-ssanames.c (make_ssa_name): Allow creating ssa name before
	the defining statement is ready.
	* tree-vectorizer.c (vect_create_iv_simple): Removed.
	(vect_create_index_for_array_ref, vect_transform_loop_bound):
	Use create_iv.
	(vect_transform_loop_bound): Use single_exit information.
	(vect_analyze_loop_form): Cleanup bogus tests.
	(vectorize_loops): Do not call flow_loop_scan.
	* tree.h (may_negate_without_overflow_p): Declare.
	* fold-const.c (may_negate_without_overflow_p): Split out from ...
	(negate_expr_p): ... this function.
	(tree_expr_nonzero_p): Handle overflowed constants correctly.
	* doc/invoke.texi (-fivcanon): Document.
	* doc/passes.texi: Document canonical induction variable creation.

	* gcc.dg/tree-ssa/loop-1.c: New test.


git-svn-id: https://gcc.gnu.org/svn/gcc/trunk@86516 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 8 insertions, 1 deletions

diff --git a/gcc/cfgloop.h b/gcc/cfgloop.h
index c2be07dc8f2..367851ebd36 100644
--- a/gcc/cfgloop.h
+++ b/gcc/cfgloop.h
@@ -185,6 +185,10 @@ struct loop
 
   /* Upper bound on number of iterations of a loop.  */
   struct nb_iter_bound *bounds;
+
+  /* If not NULL, loop has just single exit edge stored here (edges to the
+     EXIT_BLOCK_PTR do not count.  */
+  edge single_exit;
 };
 
 /* Flags for state of loop structure.  */
@@ -192,7 +196,8 @@ enum
 {
   LOOPS_HAVE_PREHEADERS = 1,
   LOOPS_HAVE_SIMPLE_LATCHES = 2,
-  LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS = 4
+  LOOPS_HAVE_MARKED_IRREDUCIBLE_REGIONS = 4,
+  LOOPS_HAVE_MARKED_SINGLE_EXITS = 8
 };
 
 /* Structure to hold CFG information about natural loops within a function.  */
@@ -258,6 +263,7 @@ extern void flow_loop_dump (const struct loop *, FILE *,
 extern int flow_loop_scan (struct loop *, int);
 extern void flow_loop_free (struct loop *);
 void mark_irreducible_loops (struct loops *);
+void mark_single_exit_loops (struct loops *);
 extern void create_loop_notes (void);
 
 /* Loop data structure manipulation/querying.  */
@@ -268,6 +274,7 @@ extern bool flow_loop_nested_p	(const struct loop *, const struct loop *);
 extern bool flow_bb_inside_loop_p (const struct loop *, const basic_block);
 extern struct loop * find_common_loop (struct loop *, struct loop *);
 struct loop *superloop_at_depth (struct loop *, unsigned);
+extern unsigned tree_num_loop_insns (struct loop *);
 extern int num_loop_insns (struct loop *);
 extern int average_num_loop_insns (struct loop *);
 extern unsigned get_loop_level (const struct loop *);