[PATCH][1/2] Fix PR44688, set and preserve the maximum iterations of vectorizer prologue loops
Richard Guenther
rguenther@suse.de
Wed Apr 18 11:30:00 GMT 2012
Finally.
Boostrapped and tested on x86_64-unknown-linux-gnu, applied to trunk.
Richard.
2012-04-18 Richard Guenther <rguenther@suse.de>
PR tree-optimization/44688
* cfgloop.h (record_niter_bound): Declare.
* tree-ssa-loop-niter.c (record_niter_bound): Export.
Update the estimation with the upper bound here...
(estimate_numbers_of_iterations_loop): ... instead of here.
Do not forcefully reset a recorded upper bound.
* tree-vect-loop-manip.c (vect_do_peeling_for_alignment):
Record the maximum number of loop iterations of the
prologue loop.
Index: gcc/tree-ssa-loop-niter.c
===================================================================
*** gcc/tree-ssa-loop-niter.c.orig 2012-04-18 10:55:55.000000000 +0200
--- gcc/tree-ssa-loop-niter.c 2012-04-18 11:39:25.368167852 +0200
*************** derive_constant_upper_bound_ops (tree ty
*** 2494,2505 ****
of iterations. UPPER is true if we are sure the loop iterates at most
I_BOUND times. */
! static void
record_niter_bound (struct loop *loop, double_int i_bound, bool realistic,
bool upper)
{
! /* Update the bounds only when there is no previous estimation, or when the current
! estimation is smaller. */
if (upper
&& (!loop->any_upper_bound
|| double_int_ucmp (i_bound, loop->nb_iterations_upper_bound) < 0))
--- 2494,2505 ----
of iterations. UPPER is true if we are sure the loop iterates at most
I_BOUND times. */
! void
record_niter_bound (struct loop *loop, double_int i_bound, bool realistic,
bool upper)
{
! /* Update the bounds only when there is no previous estimation, or when the
! current estimation is smaller. */
if (upper
&& (!loop->any_upper_bound
|| double_int_ucmp (i_bound, loop->nb_iterations_upper_bound) < 0))
*************** record_niter_bound (struct loop *loop, d
*** 2514,2519 ****
--- 2514,2527 ----
loop->any_estimate = true;
loop->nb_iterations_estimate = i_bound;
}
+
+ /* If an upper bound is smaller than the realistic estimate of the
+ number of iterations, use the upper bound instead. */
+ if (loop->any_upper_bound
+ && loop->any_estimate
+ && double_int_ucmp (loop->nb_iterations_upper_bound,
+ loop->nb_iterations_estimate) < 0)
+ loop->nb_iterations_estimate = loop->nb_iterations_upper_bound;
}
/* Records that AT_STMT is executed at most BOUND + 1 times in LOOP. IS_EXIT
*************** estimate_numbers_of_iterations_loop (str
*** 2962,2969 ****
/* Give up if we already have tried to compute an estimation. */
if (loop->estimate_state != EST_NOT_COMPUTED)
return;
loop->estimate_state = EST_AVAILABLE;
! loop->any_upper_bound = false;
loop->any_estimate = false;
exits = get_loop_exit_edges (loop);
--- 2970,2978 ----
/* Give up if we already have tried to compute an estimation. */
if (loop->estimate_state != EST_NOT_COMPUTED)
return;
+
loop->estimate_state = EST_AVAILABLE;
! /* Force estimate compuation but leave any existing upper bound in place. */
loop->any_estimate = false;
exits = get_loop_exit_edges (loop);
*************** estimate_numbers_of_iterations_loop (str
*** 2994,3007 ****
bound = gcov_type_to_double_int (nit);
record_niter_bound (loop, bound, true, false);
}
-
- /* If an upper bound is smaller than the realistic estimate of the
- number of iterations, use the upper bound instead. */
- if (loop->any_upper_bound
- && loop->any_estimate
- && double_int_ucmp (loop->nb_iterations_upper_bound,
- loop->nb_iterations_estimate) < 0)
- loop->nb_iterations_estimate = loop->nb_iterations_upper_bound;
}
/* Sets NIT to the estimated number of executions of the latch of the
--- 3003,3008 ----
Index: gcc/tree-vect-loop-manip.c
===================================================================
*** gcc/tree-vect-loop-manip.c.orig 2012-04-17 12:59:22.000000000 +0200
--- gcc/tree-vect-loop-manip.c 2012-04-18 11:39:25.368167852 +0200
*************** vect_do_peeling_for_alignment (loop_vec_
*** 2167,2172 ****
--- 2167,2173 ----
struct loop *new_loop;
unsigned int th = 0;
int min_profitable_iters;
+ int max_iter;
if (vect_print_dump_info (REPORT_DETAILS))
fprintf (vect_dump, "=== vect_do_peeling_for_alignment ===");
*************** vect_do_peeling_for_alignment (loop_vec_
*** 2192,2197 ****
--- 2193,2203 ----
#ifdef ENABLE_CHECKING
slpeel_verify_cfg_after_peeling (new_loop, loop);
#endif
+ max_iter = MAX (LOOP_VINFO_VECT_FACTOR (loop_vinfo) - 1, (int) th);
+ record_niter_bound (new_loop, shwi_to_double_int (max_iter), false, true);
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Setting upper bound of nb iterations for prologue "
+ "loop to %d\n", max_iter);
/* Update number of times loop executes. */
n_iters = LOOP_VINFO_NITERS (loop_vinfo);
Index: gcc/cfgloop.h
===================================================================
*** gcc/cfgloop.h.orig 2012-04-18 10:55:55.000000000 +0200
--- gcc/cfgloop.h 2012-04-18 11:39:49.936166250 +0200
*************** extern unsigned expected_loop_iterations
*** 279,284 ****
--- 279,285 ----
extern rtx doloop_condition_get (rtx);
void estimate_numbers_of_iterations_loop (struct loop *);
+ void record_niter_bound (struct loop *, double_int, bool, 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 *);
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