This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
[PATCH] Use all bells and whistles for number of iteration analysis in VRP
- From: Richard Guenther <rguenther at suse dot de>
- To: gcc-patches at gcc dot gnu dot org
- Date: Tue, 17 Apr 2012 16:02:55 +0200 (CEST)
- Subject: [PATCH] Use all bells and whistles for number of iteration analysis in VRP
This patch reverts the change originally done when adding
number-of-iteration analysis uses to VRP, to have a flag
to toggle whether to derive number of iterations from undefined
behavior. To be able to do so one error in VRP has to be fixed - we
have to check for the number of stmt executions, not for the number
of latch block executions. Otherwise we miscompile IRA during bootstrap.
Bootstrap and regtest ongoing on x86_64-unknown-linux-gnu.
With this I can finally make the max loop bound preserved and
set it from loop version producers. Yay.
Richard.
2012-04-17 Richard Guenther <rguenther@suse.de>
* cfgloop.h (estimate_numbers_of_iterations_loop): Remove
use_undefined_p parameter.
* tree-flow.h (estimate_numbers_of_iterations): Likewise.
* tree-ssa-loop-niter.c (estimate_numbers_of_iterations_loop):
Likewise.
(estimate_numbers_of_iterations): Likewise.
(estimated_loop_iterations): Adjust.
(max_loop_iterations): Likewise.
(scev_probably_wraps_p): Likewise.
* tree-ssa-loop.c (tree_ssa_loop_bounds): Likewise.
* tree-vrp.c (adjust_range_with_scev): Use max_stmt_executions,
not max_loop_iterations.
(execute_vrp): Remove explicit number of iterations estimation.
Index: gcc/cfgloop.h
===================================================================
*** gcc/cfgloop.h (revision 186526)
--- gcc/cfgloop.h (working copy)
*************** gcov_type expected_loop_iterations_unbou
*** 278,284 ****
extern unsigned expected_loop_iterations (const struct loop *);
extern rtx doloop_condition_get (rtx);
! void estimate_numbers_of_iterations_loop (struct loop *, bool);
bool estimated_loop_iterations (struct loop *, double_int *);
bool max_loop_iterations (struct loop *, double_int *);
HOST_WIDE_INT estimated_loop_iterations_int (struct loop *);
--- 278,284 ----
extern unsigned expected_loop_iterations (const struct loop *);
extern rtx doloop_condition_get (rtx);
! void estimate_numbers_of_iterations_loop (struct loop *);
bool estimated_loop_iterations (struct loop *, double_int *);
bool max_loop_iterations (struct loop *, double_int *);
HOST_WIDE_INT estimated_loop_iterations_int (struct loop *);
Index: gcc/tree-flow.h
===================================================================
*** gcc/tree-flow.h (revision 186527)
--- gcc/tree-flow.h (working copy)
*************** bool number_of_iterations_exit (struct l
*** 685,691 ****
tree find_loop_niter (struct loop *, edge *);
tree loop_niter_by_eval (struct loop *, edge);
tree find_loop_niter_by_eval (struct loop *, edge *);
! void estimate_numbers_of_iterations (bool);
bool scev_probably_wraps_p (tree, tree, gimple, struct loop *, bool);
bool convert_affine_scev (struct loop *, tree, tree *, tree *, gimple, bool);
--- 685,691 ----
tree find_loop_niter (struct loop *, edge *);
tree loop_niter_by_eval (struct loop *, edge);
tree find_loop_niter_by_eval (struct loop *, edge *);
! void estimate_numbers_of_iterations (void);
bool scev_probably_wraps_p (tree, tree, gimple, struct loop *, bool);
bool convert_affine_scev (struct loop *, tree, tree *, tree *, gimple, bool);
Index: gcc/tree-ssa-loop-niter.c
===================================================================
*** gcc/tree-ssa-loop-niter.c (revision 186527)
--- gcc/tree-ssa-loop-niter.c (working copy)
*************** gcov_type_to_double_int (gcov_type val)
*** 2950,2956 ****
is true also use estimates derived from undefined behavior. */
void
! estimate_numbers_of_iterations_loop (struct loop *loop, bool use_undefined_p)
{
VEC (edge, heap) *exits;
tree niter, type;
--- 2950,2956 ----
is true also use estimates derived from undefined behavior. */
void
! estimate_numbers_of_iterations_loop (struct loop *loop)
{
VEC (edge, heap) *exits;
tree niter, type;
*************** estimate_numbers_of_iterations_loop (str
*** 2984,2991 ****
}
VEC_free (edge, heap, exits);
! if (use_undefined_p)
! infer_loop_bounds_from_undefined (loop);
/* If we have a measured profile, use it to estimate the number of
iterations. */
--- 2984,2990 ----
}
VEC_free (edge, heap, exits);
! infer_loop_bounds_from_undefined (loop);
/* If we have a measured profile, use it to estimate the number of
iterations. */
*************** estimate_numbers_of_iterations_loop (str
*** 3013,3019 ****
bool
estimated_loop_iterations (struct loop *loop, double_int *nit)
{
! estimate_numbers_of_iterations_loop (loop, true);
if (!loop->any_estimate)
return false;
--- 3012,3018 ----
bool
estimated_loop_iterations (struct loop *loop, double_int *nit)
{
! estimate_numbers_of_iterations_loop (loop);
if (!loop->any_estimate)
return false;
*************** estimated_loop_iterations (struct loop *
*** 3028,3034 ****
bool
max_loop_iterations (struct loop *loop, double_int *nit)
{
! estimate_numbers_of_iterations_loop (loop, true);
if (!loop->any_upper_bound)
return false;
--- 3027,3033 ----
bool
max_loop_iterations (struct loop *loop, double_int *nit)
{
! estimate_numbers_of_iterations_loop (loop);
if (!loop->any_upper_bound)
return false;
*************** estimated_stmt_executions (struct loop *
*** 3155,3161 ****
/* Records estimates on numbers of iterations of loops. */
void
! estimate_numbers_of_iterations (bool use_undefined_p)
{
loop_iterator li;
struct loop *loop;
--- 3154,3160 ----
/* Records estimates on numbers of iterations of loops. */
void
! estimate_numbers_of_iterations (void)
{
loop_iterator li;
struct loop *loop;
*************** estimate_numbers_of_iterations (bool use
*** 3166,3172 ****
FOR_EACH_LOOP (li, loop, 0)
{
! estimate_numbers_of_iterations_loop (loop, use_undefined_p);
}
fold_undefer_and_ignore_overflow_warnings ();
--- 3165,3171 ----
FOR_EACH_LOOP (li, loop, 0)
{
! estimate_numbers_of_iterations_loop (loop);
}
fold_undefer_and_ignore_overflow_warnings ();
*************** scev_probably_wraps_p (tree base, tree s
*** 3362,3368 ****
valid_niter = fold_build2 (FLOOR_DIV_EXPR, unsigned_type, delta, step_abs);
! estimate_numbers_of_iterations_loop (loop, true);
for (bound = loop->bounds; bound; bound = bound->next)
{
if (n_of_executions_at_most (at_stmt, bound, valid_niter))
--- 3361,3367 ----
valid_niter = fold_build2 (FLOOR_DIV_EXPR, unsigned_type, delta, step_abs);
! estimate_numbers_of_iterations_loop (loop);
for (bound = loop->bounds; bound; bound = bound->next)
{
if (n_of_executions_at_most (at_stmt, bound, valid_niter))
Index: gcc/tree-ssa-loop.c
===================================================================
*** gcc/tree-ssa-loop.c (revision 186526)
--- gcc/tree-ssa-loop.c (working copy)
*************** tree_ssa_loop_bounds (void)
*** 420,426 ****
if (number_of_loops () <= 1)
return 0;
! estimate_numbers_of_iterations (true);
scev_reset ();
return 0;
}
--- 420,426 ----
if (number_of_loops () <= 1)
return 0;
! estimate_numbers_of_iterations ();
scev_reset ();
return 0;
}
Index: gcc/tree-vrp.c
===================================================================
*** gcc/tree-vrp.c (revision 186526)
--- gcc/tree-vrp.c (working copy)
*************** adjust_range_with_scev (value_range_t *v
*** 3420,3426 ****
{
double_int nit;
! if (max_loop_iterations (loop, &nit))
{
value_range_t maxvr = { VR_UNDEFINED, NULL_TREE, NULL_TREE, NULL };
double_int dtmp;
--- 3420,3426 ----
{
double_int nit;
! if (max_stmt_executions (loop, &nit))
{
value_range_t maxvr = { VR_UNDEFINED, NULL_TREE, NULL_TREE, NULL };
double_int dtmp;
*************** execute_vrp (void)
*** 8272,8283 ****
insert_range_assertions ();
- /* Estimate number of iterations - but do not use undefined behavior
- for this. We can't do this lazily as other functions may compute
- this using undefined behavior. */
- free_numbers_of_iterations_estimates ();
- estimate_numbers_of_iterations (false);
-
to_remove_edges = VEC_alloc (edge, heap, 10);
to_update_switch_stmts = VEC_alloc (switch_update, heap, 5);
threadedge_initialize_values ();
--- 8272,8277 ----