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

	* 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.

From-SVN: r86516

1 files changed, 7 insertions, 12 deletions

diff --git a/gcc/tree-scalar-evolution.c b/gcc/tree-scalar-evolution.c
index d56b672274b..79eb3a6db21 100644
--- a/gcc/tree-scalar-evolution.c
+++ b/gcc/tree-scalar-evolution.c
@@ -1001,18 +1001,17 @@ tree
 get_loop_exit_condition (struct loop *loop)
 {
   tree res = NULL_TREE;
+  edge exit_edge = loop->single_exit;
+
   
   if (dump_file && (dump_flags & TDF_DETAILS))
     fprintf (dump_file, "(get_loop_exit_condition \n  ");
   
-  if (loop->exit_edges)
+  if (exit_edge)
     {
-      edge exit_edge;
       tree expr;
       
-      exit_edge = loop->exit_edges[0];
       expr = last_stmt (exit_edge->src);
-      
       if (analyzable_condition (expr))
 	res = expr;
     }
@@ -1039,8 +1038,7 @@ get_exit_conditions_rec (struct loop *loop,
   get_exit_conditions_rec (loop->inner, exit_conditions);
   get_exit_conditions_rec (loop->next, exit_conditions);
   
-  flow_loop_scan (loop, LOOP_EXIT_EDGES);
-  if (loop->num_exits == 1)
+  if (loop->single_exit)
     {
       tree loop_condition = get_loop_exit_condition (loop);
       
@@ -2185,9 +2183,9 @@ number_of_iterations_in_loop (struct loop *loop)
   if (dump_file && (dump_flags & TDF_DETAILS))
     fprintf (dump_file, "(number_of_iterations_in_loop\n");
   
-  if (!loop->exit_edges)
+  exit = loop->single_exit;
+  if (!exit)
     goto end;
-  exit = loop->exit_edges[0];
 
   if (!number_of_iterations_exit (loop, exit, &niter_desc))
     goto end;
@@ -2458,10 +2456,7 @@ scev_initialize (struct loops *loops)
 
   for (i = 1; i < loops->num; i++)
     if (loops->parray[i])
-      {
-	flow_loop_scan (loops->parray[i], LOOP_EXIT_EDGES);
-	loops->parray[i]->nb_iterations = NULL_TREE;
-      }
+      loops->parray[i]->nb_iterations = NULL_TREE;
 }
 
 /* Cleans up the information cached by the scalar evolutions analysis.  */