From ec23e9e25eb64bb066dc408fd498861b8587bec8 Mon Sep 17 00:00:00 2001 From: Richard Biener Date: Thu, 9 Feb 2023 11:03:25 +0100 Subject: [PATCH] target/108738 - STV bitmap operations compile-time hog When the set of candidates becomes very large then repeated bit checks on it during the build of an actual chain can become slow because of the O(n) nature of bitmap tests. The following switches the candidates bitmaps to the tree representation before building the chains to get O(log n) amortized behavior. For the testcase at hand this improves STV time by 50%. PR target/108738 * config/i386/i386-features.cc (convert_scalars_to_vector): Switch candidates bitmaps to tree view before building the chains. --- gcc/config/i386/i386-features.cc | 49 +++++++++++++++++--------------- 1 file changed, 26 insertions(+), 23 deletions(-) diff --git a/gcc/config/i386/i386-features.cc b/gcc/config/i386/i386-features.cc index ec13d4e74898..9bd6d8677bb9 100644 --- a/gcc/config/i386/i386-features.cc +++ b/gcc/config/i386/i386-features.cc @@ -2283,30 +2283,33 @@ convert_scalars_to_vector (bool timode_p) fprintf (dump_file, "There are no candidates for optimization.\n"); for (unsigned i = 0; i <= 2; ++i) - while (!bitmap_empty_p (&candidates[i])) - { - unsigned uid = bitmap_first_set_bit (&candidates[i]); - scalar_chain *chain; - - if (cand_mode[i] == TImode) - chain = new timode_scalar_chain; - else - chain = new general_scalar_chain (cand_mode[i], cand_vmode[i]); - - /* Find instructions chain we want to convert to vector mode. - Check all uses and definitions to estimate all required - conversions. */ - chain->build (&candidates[i], uid); - - if (chain->compute_convert_gain () > 0) - converted_insns += chain->convert (); - else - if (dump_file) - fprintf (dump_file, "Chain #%d conversion is not profitable\n", - chain->chain_id); + { + bitmap_tree_view (&candidates[i]); + while (!bitmap_empty_p (&candidates[i])) + { + unsigned uid = bitmap_first_set_bit (&candidates[i]); + scalar_chain *chain; - delete chain; - } + if (cand_mode[i] == TImode) + chain = new timode_scalar_chain; + else + chain = new general_scalar_chain (cand_mode[i], cand_vmode[i]); + + /* Find instructions chain we want to convert to vector mode. + Check all uses and definitions to estimate all required + conversions. */ + chain->build (&candidates[i], uid); + + if (chain->compute_convert_gain () > 0) + converted_insns += chain->convert (); + else + if (dump_file) + fprintf (dump_file, "Chain #%d conversion is not profitable\n", + chain->chain_id); + + delete chain; + } + } if (dump_file) fprintf (dump_file, "Total insns converted: %d\n", converted_insns); -- 2.47.2