From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1666) id 9EC723858C56; Wed, 4 May 2022 07:52:14 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 9EC723858C56 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" From: Richard Biener To: gcc-cvs@gcc.gnu.org Subject: [gcc r13-99] debug/105158 - improve debug stmt retaining for forwarder removal X-Act-Checkin: gcc X-Git-Author: Richard Biener X-Git-Refname: refs/heads/master X-Git-Oldrev: c4ae175881f773383f392ee39bad4ac1c0fa53ca X-Git-Newrev: 1ba68f78c9d2510eb095f7d8a90c87cd5fd4183d Message-Id: <20220504075214.9EC723858C56@sourceware.org> Date: Wed, 4 May 2022 07:52:14 +0000 (GMT) X-BeenThere: gcc-cvs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-cvs mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 04 May 2022 07:52:14 -0000 https://gcc.gnu.org/g:1ba68f78c9d2510eb095f7d8a90c87cd5fd4183d commit r13-99-g1ba68f78c9d2510eb095f7d8a90c87cd5fd4183d Author: Richard Biener Date: Tue Apr 5 15:23:54 2022 +0200 debug/105158 - improve debug stmt retaining for forwarder removal Currently when we cannot move debug stmt from a forwarder to the destination block we drop/reset them. But in some cases as for the testcase we can move them to the predecessor when that has a single successor and we can insert after the last stmt of the block. That allows us to preserve debug info here. 2022-04-05 Richard Biener PR debug/105158 * tree-cfgcleanup.cc (move_debug_stmts_from_forwarder): Move debug stmts to the predecessor if moving to the destination is not possible. (remove_forwarder_block): Adjust. (remove_forwarder_block_with_phi): Likewise. Diff: --- gcc/tree-cfgcleanup.cc | 31 ++++++++++++++++++++++++++----- 1 file changed, 26 insertions(+), 5 deletions(-) diff --git a/gcc/tree-cfgcleanup.cc b/gcc/tree-cfgcleanup.cc index 6c05ef2464e..893619eaaa4 100644 --- a/gcc/tree-cfgcleanup.cc +++ b/gcc/tree-cfgcleanup.cc @@ -468,15 +468,34 @@ phi_alternatives_equal (basic_block dest, edge e1, edge e2) return true; } -/* Move debug stmts from the forwarder block SRC to DEST. */ +/* Move debug stmts from the forwarder block SRC to DEST or PRED. */ static void -move_debug_stmts_from_forwarder (basic_block src, basic_block dest, - bool dest_single_pred_p) +move_debug_stmts_from_forwarder (basic_block src, + basic_block dest, bool dest_single_pred_p, + basic_block pred, bool pred_single_succ_p) { if (!MAY_HAVE_DEBUG_STMTS) return; + /* If we cannot move to the destination but to the predecessor do that. */ + if (!dest_single_pred_p && pred_single_succ_p) + { + gimple_stmt_iterator gsi_to = gsi_last_bb (pred); + if (gsi_end_p (gsi_to) || !stmt_ends_bb_p (gsi_stmt (gsi_to))) + { + for (gimple_stmt_iterator gsi = gsi_after_labels (src); + !gsi_end_p (gsi);) + { + gimple *debug = gsi_stmt (gsi); + gcc_assert (is_gimple_debug (debug)); + gsi_move_after (&gsi, &gsi_to); + } + return; + } + } + + /* Else move to DEST or drop/reset them. */ gimple_stmt_iterator gsi_to = gsi_after_labels (dest); for (gimple_stmt_iterator gsi = gsi_after_labels (src); !gsi_end_p (gsi);) { @@ -627,7 +646,8 @@ remove_forwarder_block (basic_block bb) /* Move debug statements. Reset them if the destination does not have a single predecessor. */ - move_debug_stmts_from_forwarder (bb, dest, dest_single_pred_p); + move_debug_stmts_from_forwarder (bb, dest, dest_single_pred_p, + pred, pred && single_succ_p (pred)); bitmap_set_bit (cfgcleanup_altered_bbs, dest->index); @@ -1309,7 +1329,8 @@ remove_forwarder_block_with_phi (basic_block bb) /* Move debug statements. Reset them if the destination does not have a single predecessor. */ - move_debug_stmts_from_forwarder (bb, dest, dest_single_pred_p); + move_debug_stmts_from_forwarder (bb, dest, dest_single_pred_p, + pred, pred && single_succ_p (pred)); /* Update the dominators. */ dombb = get_immediate_dominator (CDI_DOMINATORS, bb);