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| 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 | |
| parent | 3860f31db1e1b155532fb96a3e703b6b9e780753 (diff) | |
| download | gcc-db16c1841a09f60bbdf2bb825e7e790a437f83c7.zip gcc-db16c1841a09f60bbdf2bb825e7e790a437f83c7.tar.gz gcc-db16c1841a09f60bbdf2bb825e7e790a437f83c7.tar.bz2 | |
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
| -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 c24c0a5..5ab422c 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 0e63714..212519c 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)), |