diff options
| author | Joern Rennecke <joern.rennecke@embecosm.com> | 2012-04-28 01:56:54 +0000 |
|---|---|---|
| committer | Maxim Kuvyrkov <mkuvyrkov@gcc.gnu.org> | 2012-04-28 01:56:54 +0000 |
| commit | fa06ad0d58e8981afc7dd0e8965505bab04a5320 (patch) | |
| tree | fa87f8c36fc8d168b8c0ab80f20d01bb470d9374 /gcc/tree-ssa-pre.c | |
| parent | 52556f04772d3841a6042d2029cf7d0f5e8d5342 (diff) | |
| download | gcc-fa06ad0d58e8981afc7dd0e8965505bab04a5320.zip gcc-fa06ad0d58e8981afc7dd0e8965505bab04a5320.tar.gz gcc-fa06ad0d58e8981afc7dd0e8965505bab04a5320.tar.bz2 | |
re PR tree-optimization/38785 (huge performance regression on EEMBC bitmnp01)
PR tree-optimization/38785
* common.opt (ftree-partial-pre): New option.
* doc/invoke.texi: Document it.
* opts.c (default_options_table): Initialize flag_tree_partial_pre.
* tree-ssa-pre.c (do_partial_partial_insertion): Insert only if it will
benefit speed path.
(execute_pre): Use flag_tree_partial_pre.
Co-Authored-By: Maxim Kuvyrkov <maxim@codesourcery.com>
Co-Authored-By: Steven Bosscher <steven@gcc.gnu.org>
From-SVN: r186928
Diffstat (limited to 'gcc/tree-ssa-pre.c')
| -rw-r--r-- | gcc/tree-ssa-pre.c | 48 |
1 files changed, 40 insertions, 8 deletions
diff --git a/gcc/tree-ssa-pre.c b/gcc/tree-ssa-pre.c index e3e55ef..a89856a 100644 --- a/gcc/tree-ssa-pre.c +++ b/gcc/tree-ssa-pre.c @@ -3774,20 +3774,51 @@ do_partial_partial_insertion (basic_block block, basic_block dom) } else avail[bprime->index] = edoubleprime; - } /* If we can insert it, it's not the same value already existing along every predecessor, and it's defined by some predecessor, it is partially redundant. */ - if (!cant_insert && by_all && dbg_cnt (treepre_insert)) + if (!cant_insert && by_all) { - pre_stats.pa_insert++; - if (insert_into_preds_of_block (block, get_expression_id (expr), - avail)) - new_stuff = true; - } + edge succ; + bool do_insertion = false; + + /* Insert only if we can remove a later expression on a path + that we want to optimize for speed. + The phi node that we will be inserting in BLOCK is not free, + and inserting it for the sake of !optimize_for_speed successor + may cause regressions on the speed path. */ + FOR_EACH_EDGE (succ, ei, block->succs) + { + if (bitmap_set_contains_value (PA_IN (succ->dest), val)) + { + if (optimize_edge_for_speed_p (succ)) + do_insertion = true; + } + } + + if (!do_insertion) + { + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, "Skipping partial partial redundancy " + "for expression "); + print_pre_expr (dump_file, expr); + fprintf (dump_file, " (%04d), not partially anticipated " + "on any to be optimized for speed edges\n", val); + } + } + else if (dbg_cnt (treepre_insert)) + { + pre_stats.pa_insert++; + if (insert_into_preds_of_block (block, + get_expression_id (expr), + avail)) + new_stuff = true; + } + } free (avail); } } @@ -4948,7 +4979,8 @@ execute_pre (bool do_fre) { unsigned int todo = 0; - do_partial_partial = optimize > 2 && optimize_function_for_speed_p (cfun); + do_partial_partial = + flag_tree_partial_pre && optimize_function_for_speed_p (cfun); /* This has to happen before SCCVN runs because loop_optimizer_init may create new phis, etc. */ |