* cfgloop.h: Include vec-prim.h.

	(enum li_flags): Remove LI_ONLY_OLD.
	(loop_iterator): Changed.
	(fel_next, fel_init): Iterate over loop tree.
	(FOR_EACH_LOOP_BREAK): New macro.
	* loop-unswitch.c (unswitch_loops): Do not pass LI_ONLY_OLD to
	FOR_EACH_LOOP.
	* tree-ssa-loop-unswitch.c (tree_ssa_unswitch_loops): Ditto.
	* modulo-sched.c (sms_schedule): Ditto.
	* tree-vectorizer.c (vectorize_loops): Ditto.
	* doc/loop.texi: Update information on loop numbering and behavior of
	FOR_EACH_LOOP wrto new loops.
	* tree-scalar-evolution.c (compute_overall_effect_of_inner_loop,
	add_to_evolution_1): Test nestedness of loops instead of comparing
	their numbers.
	* tree-chrec.c (chrec_fold_plus_poly_poly,
	chrec_fold_multiply_poly_poly, chrec_evaluate,
	hide_evolution_in_other_loops_than_loop, chrec_component_in_loop_num,
	reset_evolution_in_loop): Ditto.
	* Makefile.in (CFGLOOP_H): Add vecprim.h dependency.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@121422 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 11 insertions, 4 deletions

diff --git a/gcc/doc/loop.texi b/gcc/doc/loop.texi
index fade89d32e8..e486b0c5d10 100644
--- a/gcc/doc/loop.texi
+++ b/gcc/doc/loop.texi
@@ -64,17 +64,24 @@ function.  Each of the loops is represented in a @code{struct loop}
 structure.  Each loop is assigned an index (@code{num} field of the
 @code{struct loop} structure), and the pointer to the loop is stored in
 the corresponding field of the @code{larray} vector in the loops
-structure.  Index of a sub-loop is always greater than the index of its
-super-loop.  The indices do not have to be continuous, there may be
+structure.  The indices do not have to be continuous, there may be
 empty (@code{NULL}) entries in the @code{larray} created by deleting
-loops.  The index of a loop never changes.
+loops.  Also, there is no guarantee on the relative order of a loop
+and its subloops in the numbering.  The index of a loop never changes.
 
 The entries of the @code{larray} field should not be accessed directly.
 The function @code{get_loop} returns the loop description for a loop with
 the given index.  @code{number_of_loops} function returns number of
 loops in the function.  To traverse all loops, use @code{FOR_EACH_LOOP}
 macro.  The @code{flags} argument of the macro is used to determine
-the direction of traversal and the set of loops visited.
+the direction of traversal and the set of loops visited.  Each loop is
+guaranteed to be visited exactly once, regardless of the changes to the
+loop tree, and the loops may be removed during the traversal.  The newly
+created loops are never traversed, if they need to be visited, this
+must be done separately after their creation.  The @code{FOR_EACH_LOOP}
+macro allocates temporary variables.  If the @code{FOR_EACH_LOOP} loop
+were ended using break or goto, they would not be released;
+@code{FOR_EACH_LOOP_BREAK} macro must be used instead.
 
 Each basic block contains the reference to the innermost loop it belongs
 to (@code{loop_father}).  For this reason, it is only possible to have