diff options
| author | Jan Hubicka <hubicka@ucw.cz> | 2017-11-17 18:44:41 +0100 |
|---|---|---|
| committer | Jan Hubicka <hubicka@gcc.gnu.org> | 2017-11-17 17:44:41 +0000 |
| commit | db16c1841a09f60bbdf2bb825e7e790a437f83c7 (patch) | |
| tree | 0b8ddecbdf0968c20f67c16dec7dae40527dba93 /gcc/tree-tailcall.c | |
| parent | 3860f31db1e1b155532fb96a3e703b6b9e780753 (diff) | |
tree-tailcall.c (eliminate_tail_call): Be more careful about not disturbin profile of entry block.
* tree-tailcall.c (eliminate_tail_call): Be more careful about not
disturbin profile of entry block.
From-SVN: r254887
Diffstat (limited to 'gcc/tree-tailcall.c')
| -rw-r--r-- | gcc/tree-tailcall.c | 14 |
1 files changed, 11 insertions, 3 deletions
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)), |