diff options
Diffstat (limited to 'gcc/cfgloopanal.c')
| -rw-r--r-- | gcc/cfgloopanal.c | 35 |
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); |