Hi Honza and all,
I updated the patch a little as below. Bootstrap and regtest are ok
on powerpc64le.
Is OK for trunk?
Thanks for comments.
Jiufu
diff --git a/gcc/cfgloopmanip.c b/gcc/cfgloopmanip.c
index 727e951..ded0046 100644
--- a/gcc/cfgloopmanip.c
+++ b/gcc/cfgloopmanip.c
@@ -31,6 +31,7 @@ along with GCC; see the file COPYING3. If not see
#include "gimplify-me.h"
#include "tree-ssa-loop-manip.h"
#include "dumpfile.h"
+#include "cfgrtl.h"
static void copy_loops_to (class loop **, int,
class loop *);
@@ -1258,14 +1259,30 @@ duplicate_loop_to_header_edge (class loop *loop, edge e,
/* If original loop is executed COUNT_IN times, the unrolled
loop will account SCALE_MAIN_DEN times. */
scale_main = count_in.probability_in (scale_main_den);
+
+ /* If we are guessing at the number of iterations and count_in
+ becomes unrealistically small, reset probability. */
+ if (!(count_in.reliable_p () || loop->any_estimate))
+ {
+ profile_count new_count_in = count_in.apply_probability
(scale_main);
+ profile_count preheader_count = loop_preheader_edge (loop)->count
();
+ if (new_count_in.apply_scale (1, 10) < preheader_count)
+ scale_main = profile_probability::likely ();
+ }
+
scale_act = scale_main * prob_pass_main;
}
else
{
+ profile_count new_loop_count;
profile_count preheader_count = e->count ();
- for (i = 0; i < ndupl; i++)
- scale_main = scale_main * scale_step[i];
scale_act = preheader_count.probability_in (count_in);
+ /* Compute final preheader count after peeling NDUPL copies. */
+ for (i = 0; i < ndupl; i++)
+ preheader_count = preheader_count.apply_probability (scale_step[i]);
+ /* Subtract out exit(s) from peeled copies. */
+ new_loop_count = count_in - (e->count () - preheader_count);
+ scale_main = new_loop_count.probability_in (count_in);
}
}
@@ -1381,6 +1398,38 @@ duplicate_loop_to_header_edge (class loop *loop, edge e,
scale_bbs_frequencies (new_bbs, n, scale_act);
scale_act = scale_act * scale_step[j];
}
+
+ /* Need to update PROB of exit edge and corresponding COUNT. */
+ if (orig && is_latch && (!bitmap_bit_p (wont_exit, j + 1))
+ && bbs_to_scale)
+ {
+ edge new_exit = new_spec_edges[SE_ORIG];
+ profile_count new_count_in = new_exit->src->count;
+ profile_count preheader_count = loop_preheader_edge (loop)->count ();
+ edge e;
+ edge_iterator ei;
+
+ FOR_EACH_EDGE (e, ei, new_exit->src->succs)
+ if (e != new_exit)
+ break;
+
+ gcc_assert (e && e != new_exit);
+
+ new_exit->probability = preheader_count.probability_in (new_count_in);
+ e->probability = new_exit->probability.invert ();
+
+ profile_count new_latch_count
+ = new_exit->src->count.apply_probability (e->probability);
+ profile_count old_latch_count = e->dest->count;
+
+ EXECUTE_IF_SET_IN_BITMAP (bbs_to_scale, 0, i, bi)
+ scale_bbs_frequencies_profile_count (new_bbs + i, 1,
+ new_latch_count,
+ old_latch_count);
+
+ if (current_ir_type () != IR_GIMPLE)
+ update_br_prob_note (e->src);
+ }
}
free (new_bbs);
free (orig_loops);
diff --git a/gcc/testsuite/gcc.dg/pr68212.c b/gcc/testsuite/gcc.dg/pr68212.c
new file mode 100644
index 0000000..f3b7c22
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr68212.c
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fno-tree-vectorize -funroll-loops --param
max-unroll-times=4 -fdump-rtl-alignments" } */
+
+void foo(long int *a, long int *b, long int n)
+{
+ long int i;
+
+ for (i = 0; i < n; i++)
+ a[i] = *b;
+}
+
+/* { dg-final { scan-rtl-dump-times "internal loop alignment added" 1
"alignments"} } */
+
--
2.7.4
