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authorhubicka <hubicka@138bc75d-0d04-0410-961f-82ee72b054a4>2016-05-20 13:19:59 +0000
committerhubicka <hubicka@138bc75d-0d04-0410-961f-82ee72b054a4>2016-05-20 13:19:59 +0000
commita42877ad844b48f45b96abf81a7b51457326a1e3 (patch)
tree5a59e9c33670e77c59db2200ae49b413088be4c9 /gcc/cfgloopanal.c
parent22e0b7be8596b0d40c6f856dd08c5dcda94bd2cd (diff)
downloadgcc-a42877ad844b48f45b96abf81a7b51457326a1e3.tar.gz
* cfgloop.h (expected_loop_iterations_unbounded,
expected_loop_iterations): Unconstify. * cfgloopanal.c (expected_loop_iterations_unbounded): Sanity check the profile with known upper bound; return 3 when profile is absent. (expected_loop_iterations): Update. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@236511 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/cfgloopanal.c')
-rw-r--r--gcc/cfgloopanal.c35
1 files changed, 25 insertions, 10 deletions
diff --git a/gcc/cfgloopanal.c b/gcc/cfgloopanal.c
index 4d35820b729..938ac43879a 100644
--- a/gcc/cfgloopanal.c
+++ b/gcc/cfgloopanal.c
@@ -231,14 +231,20 @@ average_num_loop_insns (const struct loop *loop)
value. */
gcov_type
-expected_loop_iterations_unbounded (const struct loop *loop)
+expected_loop_iterations_unbounded (struct loop *loop)
{
edge e;
edge_iterator ei;
-
- if (loop->latch->count || loop->header->count)
+ gcov_type expected;
+
+
+ /* Average loop rolls about 3 times. If we have no profile at all, it is
+ best we can do. */
+ if (profile_status_for_fn (cfun) == PROFILE_ABSENT)
+ expected = 3;
+ else if (loop->latch->count || loop->header->count)
{
- gcov_type count_in, count_latch, expected;
+ gcov_type count_in, count_latch;
count_in = 0;
count_latch = 0;
@@ -253,8 +259,6 @@ expected_loop_iterations_unbounded (const struct loop *loop)
expected = count_latch * 2;
else
expected = (count_latch + count_in - 1) / count_in;
-
- return expected;
}
else
{
@@ -270,17 +274,28 @@ expected_loop_iterations_unbounded (const struct loop *loop)
freq_in += EDGE_FREQUENCY (e);
if (freq_in == 0)
- return freq_latch * 2;
-
- return (freq_latch + freq_in - 1) / freq_in;
+ {
+ /* If we have no profile at all, expect 3 iterations. */
+ if (!freq_latch)
+ expected = 3;
+ else
+ expected = freq_latch * 2;
+ }
+ else
+ expected = (freq_latch + freq_in - 1) / freq_in;
}
+
+ HOST_WIDE_INT max = get_max_loop_iterations_int (loop);
+ if (max != -1 && max < expected)
+ return max;
+ return expected;
}
/* Returns expected number of LOOP iterations. The returned value is bounded
by REG_BR_PROB_BASE. */
unsigned
-expected_loop_iterations (const struct loop *loop)
+expected_loop_iterations (struct loop *loop)
{
gcov_type expected = expected_loop_iterations_unbounded (loop);
return (expected > REG_BR_PROB_BASE ? REG_BR_PROB_BASE : expected);