diff options
| -rw-r--r-- | gcc/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/tree-tailcall.c | 14 |
2 files changed, 16 insertions, 3 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index c24c0a5f343..5ab422c917a 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,5 +1,10 @@ 2017-11-17 Jan Hubicka <hubicka@ucw.cz> + * tree-tailcall.c (eliminate_tail_call): Be more careful about not + disturbin profile of entry block. + +2017-11-17 Jan Hubicka <hubicka@ucw.cz> + * ipa-fnsummary.c (estimate_node_size_and_time): Be more tolerant for roundoff errors. diff --git a/gcc/tree-tailcall.c b/gcc/tree-tailcall.c index 0e637147e8c..212519cdfd7 100644 --- a/gcc/tree-tailcall.c +++ b/gcc/tree-tailcall.c @@ -889,10 +889,18 @@ eliminate_tail_call (struct tailcall *t) /* Number of executions of function has reduced by the tailcall. */ e = single_succ_edge (gsi_bb (t->call_gsi)); - decrease_profile (EXIT_BLOCK_PTR_FOR_FN (cfun), e->count ()); - decrease_profile (ENTRY_BLOCK_PTR_FOR_FN (cfun), e->count ()); + + profile_count count = e->count (); + + /* When profile is inconsistent and the recursion edge is more frequent + than number of executions of functions, scale it down, so we do not end + up with 0 executions of entry block. */ + if (count >= ENTRY_BLOCK_PTR_FOR_FN (cfun)->count) + count = ENTRY_BLOCK_PTR_FOR_FN (cfun)->count.apply_scale (7, 8); + decrease_profile (EXIT_BLOCK_PTR_FOR_FN (cfun), count); + decrease_profile (ENTRY_BLOCK_PTR_FOR_FN (cfun), count); if (e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)) - decrease_profile (e->dest, e->count ()); + decrease_profile (e->dest, count); /* Replace the call by a jump to the start of function. */ e = redirect_edge_and_branch (single_succ_edge (gsi_bb (t->call_gsi)), |