Hi, this fixes two bugs in tree-ssa-loop-im.cc. First is that cap probability is not reliable, but it is constructed with adjusted quality. Second is that sometimes the conditional has wrong joiner BB count. This is visible on testsuite/gcc.dg/pr102385.c however the testcase triggers another profile update bug in pcom, so I will update it in followup patch.
gcc/ChangeLog: * tree-ssa-loop-im.cc (execute_sm_if_changed): Turn cap probability to guessed; fix count of new_bb. diff --git a/gcc/tree-ssa-loop-im.cc b/gcc/tree-ssa-loop-im.cc index f5b01e986ae..268f466bdc9 100644 --- a/gcc/tree-ssa-loop-im.cc +++ b/gcc/tree-ssa-loop-im.cc @@ -2059,7 +2059,8 @@ execute_sm_if_changed (edge ex, tree mem, tree tmp_var, tree flag, nbbs++; } - profile_probability cap = profile_probability::always ().apply_scale (2, 3); + profile_probability cap + = profile_probability::guessed_always ().apply_scale (2, 3); if (flag_probability.initialized_p ()) ; @@ -2103,6 +2104,8 @@ execute_sm_if_changed (edge ex, tree mem, tree tmp_var, tree flag, old_dest = ex->dest; new_bb = split_edge (ex); + if (append_cond_position) + new_bb->count += last_cond_fallthru->count (); then_bb = create_empty_bb (new_bb); then_bb->count = new_bb->count.apply_probability (flag_probability); if (irr)