From: Jan Hubicka Date: Fri, 17 Nov 2017 17:44:41 +0000 (+0100) Subject: tree-tailcall.c (eliminate_tail_call): Be more careful about not disturbin profile... X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=db16c1841a09f60bbdf2bb825e7e790a437f83c7;p=gcc.git 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 --- diff --git a/gcc/ChangeLog b/gcc/ChangeLog index c24c0a5f343..5ab422c917a 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +2017-11-17 Jan Hubicka + + * tree-tailcall.c (eliminate_tail_call): Be more careful about not + disturbin profile of entry block. + 2017-11-17 Jan Hubicka * ipa-fnsummary.c (estimate_node_size_and_time): Be more tolerant for 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)),