From 8d71d7cd025d5b0b62a8cb9fd99c38f1b37fcc7d Mon Sep 17 00:00:00 2001 From: Jan Hubicka Date: Fri, 16 Jun 2017 21:02:11 +0200 Subject: [PATCH] predict.c (force_edge_cold): Handle declaring edges impossible more aggresively. * predict.c (force_edge_cold): Handle declaring edges impossible more aggresively. From-SVN: r249276 --- gcc/ChangeLog | 5 +++++ gcc/predict.c | 33 ++++++++++++++++++++++++++++++++- 2 files changed, 37 insertions(+), 1 deletion(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 44ef8579998..b22b567358e 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +2017-06-16 Jan Hubicka + + * predict.c (force_edge_cold): Handle declaring edges impossible + more aggresively. + 2017-06-16 Jan Hubicka * tree-ssa-loop-ivcanon.c (remove_exits_and_undefined_stmts): Update diff --git a/gcc/predict.c b/gcc/predict.c index 1cb7dc50103..60d1a094d10 100644 --- a/gcc/predict.c +++ b/gcc/predict.c @@ -3968,6 +3968,7 @@ force_edge_cold (edge e, bool impossible) profile_count old_count = e->count; int old_probability = e->probability; int prob_scale = REG_BR_PROB_BASE; + bool uninitialized_exit = false; /* If edge is already improbably or cold, just return. */ if (e->probability <= (impossible ? PROB_VERY_UNLIKELY : 0) @@ -3978,6 +3979,8 @@ force_edge_cold (edge e, bool impossible) { if (e2->count.initialized_p ()) count_sum += e2->count; + else + uninitialized_exit = true; prob_sum += e2->probability; } @@ -3989,7 +3992,7 @@ force_edge_cold (edge e, bool impossible) = MIN (e->probability, impossible ? 0 : PROB_VERY_UNLIKELY); if (impossible) e->count = profile_count::zero (); - if (old_probability) + else if (old_probability) e->count = e->count.apply_scale (e->probability, old_probability); else e->count = e->count.apply_scale (1, REG_BR_PROB_BASE); @@ -4016,6 +4019,34 @@ force_edge_cold (edge e, bool impossible) else { e->probability = REG_BR_PROB_BASE; + if (e->src->count == profile_count::zero ()) + return; + if (count_sum == profile_count::zero () && !uninitialized_exit + && impossible) + { + bool found = false; + for (gimple_stmt_iterator gsi = gsi_start_bb (e->src); + !gsi_end_p (gsi); gsi_next (&gsi)) + { + if (stmt_can_terminate_bb_p (gsi_stmt (gsi))) + { + found = true; + break; + } + } + if (!found) + { + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, + "Making bb %i impossible and dropping count to 0.\n", + e->src->index); + e->count = profile_count::zero (); + e->src->count = profile_count::zero (); + FOR_EACH_EDGE (e2, ei, e->src->preds) + force_edge_cold (e2, impossible); + return; + } + } /* If we did not adjusting, the source basic block has no likely edeges leaving other direction. In that case force that bb cold, too. -- 2.30.2