From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 2153) id 55597382A21D; Thu, 15 Dec 2022 08:28:06 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 55597382A21D DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1671092886; bh=JowHTW9DXwFNhOZR0D/uvCPGYimsL9d7jiR7l47PqTI=; h=From:To:Subject:Date:From; b=SLgmdxV9kWm2xHRUiYdU8e5Mq20Tta4NvbCHUqXcq0A/nWyIH0LXb+oNbLxeQqO/J E5qhEUWVcBl+lOF0eNwMBYvP5nVezD7+L9ap0YnujUrUXQrYDohhCa02qfsl+pyvD1 laXvmOcoioMhNRzqtnaS8yvDsBrtNPWNw0m7kHRM= MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" From: Jakub Jelinek To: gcc-cvs@gcc.gnu.org Subject: [gcc r13-4713] into-ssa: Fix emitting debug stmts after asm goto [PR108095] X-Act-Checkin: gcc X-Git-Author: Jakub Jelinek X-Git-Refname: refs/heads/master X-Git-Oldrev: 4ef521bbc63f8a3883d507a8b6c1f95f442df3fe X-Git-Newrev: bf3ce6f84a7a994a0fc87419b383b9ce4efed442 Message-Id: <20221215082806.55597382A21D@sourceware.org> Date: Thu, 15 Dec 2022 08:28:06 +0000 (GMT) List-Id: https://gcc.gnu.org/g:bf3ce6f84a7a994a0fc87419b383b9ce4efed442 commit r13-4713-gbf3ce6f84a7a994a0fc87419b383b9ce4efed442 Author: Jakub Jelinek Date: Thu Dec 15 09:26:44 2022 +0100 into-ssa: Fix emitting debug stmts after asm goto [PR108095] The following testcase ICEs, because ccp1 replaced s.0_1 = &s; __asm__ goto("" : "=r" MEM[(T *)s.0_1] : : : "lab" lab); with __asm__ goto("" : "=r" s : : : "lab" lab); and because s is no longer addressable, we are rewriting it into ssa and want __asm__ goto("" : "=r" s_7 : : : "lab" lab); plus debug stmt # DEBUG s => s_7 The code assumes that there is at most one non-EH edge in that case, but with the addition of outputs to asm goto that is no longer the case, we can have many outgoing edges. The patch keeps the checking assertion that there is at most one such edge for everything but asm goto, but moves the addition of the debug stmt into the loop, so that it can be added on all edges where it is possible, not just one of them. Furthermore, looking at gsi_insert_on_edge_immediate -> gimple_find_edge_insert_loc, the conditions to insert stmt there to the destination block are if (single_pred_p (dest) && gimple_seq_empty_p (phi_nodes (dest)) && dest != EXIT_BLOCK_PTR_FOR_FN (cfun)) (plus there is code to insert it in the previous block but that is never true when the pred is known to be stmt_ends_bb_p), while mayube_register_def was just checking if (ef && single_pred_p (ef->dest) && ef->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)) so if for whatever reason ef->dest had any PHIs, we'd split the edge for -g and not for -g0, something we must avoid for -fcompare-debug stability. So, I've added the no phi_nodes check too. 2022-12-15 Jakub Jelinek PR tree-optimization/108095 * tree-into-ssa.cc (maybe_register_def): Insert debug stmt on all non-EH edges from asm goto if they have a single predecessor rather than asserting there is at most one such edge. Test whether there are no PHI nodes next to the single predecessor test. * gcc.dg/pr108095.c: New test. Diff: --- gcc/testsuite/gcc.dg/pr108095.c | 15 ++++++++++ gcc/tree-into-ssa.cc | 64 ++++++++++++++++++++++++----------------- 2 files changed, 53 insertions(+), 26 deletions(-) diff --git a/gcc/testsuite/gcc.dg/pr108095.c b/gcc/testsuite/gcc.dg/pr108095.c new file mode 100644 index 00000000000..fb76caae72e --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr108095.c @@ -0,0 +1,15 @@ +/* PR tree-optimization/108095 */ +/* { dg-do compile } */ +/* { dg-options "-Os -g" } */ + +int v; +typedef unsigned T; + +void +foo (void) +{ + unsigned s; + asm goto ("" : "=r" (*(T *) &s) : : : lab); + v = 0; +lab: +} diff --git a/gcc/tree-into-ssa.cc b/gcc/tree-into-ssa.cc index 9a2417d2b0b..ebe7e699277 100644 --- a/gcc/tree-into-ssa.cc +++ b/gcc/tree-into-ssa.cc @@ -1934,9 +1934,8 @@ maybe_register_def (def_operand_p def_p, gimple *stmt, tree tracked_var = target_for_debug_bind (sym); if (tracked_var) { - gimple *note = gimple_build_debug_bind (tracked_var, def, stmt); - /* If stmt ends the bb, insert the debug stmt on the single - non-EH edge from the stmt. */ + /* If stmt ends the bb, insert the debug stmt on the non-EH + edge(s) from the stmt. */ if (gsi_one_before_end_p (gsi) && stmt_ends_bb_p (stmt)) { basic_block bb = gsi_bb (gsi); @@ -1945,33 +1944,46 @@ maybe_register_def (def_operand_p def_p, gimple *stmt, FOR_EACH_EDGE (e, ei, bb->succs) if (!(e->flags & EDGE_EH)) { - gcc_checking_assert (!ef); + /* asm goto can have multiple non-EH edges from the + stmt. Insert on all of them where it is + possible. */ + gcc_checking_assert (!ef || (gimple_code (stmt) + == GIMPLE_ASM)); ef = e; + /* If there are other predecessors to ef->dest, then + there must be PHI nodes for the modified + variable, and therefore there will be debug bind + stmts after the PHI nodes. The debug bind notes + we'd insert would force the creation of a new + block (diverging codegen) and be redundant with + the post-PHI bind stmts, so don't add them. + + As for the exit edge, there wouldn't be redundant + bind stmts, but there wouldn't be a PC to bind + them to either, so avoid diverging the CFG. */ + if (e + && single_pred_p (e->dest) + && gimple_seq_empty_p (phi_nodes (e->dest)) + && e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)) + { + /* If there were PHI nodes in the node, we'd + have to make sure the value we're binding + doesn't need rewriting. But there shouldn't + be PHI nodes in a single-predecessor block, + so we just add the note. */ + gimple *note + = gimple_build_debug_bind (tracked_var, def, + stmt); + gsi_insert_on_edge_immediate (ef, note); + } } - /* If there are other predecessors to ef->dest, then - there must be PHI nodes for the modified - variable, and therefore there will be debug bind - stmts after the PHI nodes. The debug bind notes - we'd insert would force the creation of a new - block (diverging codegen) and be redundant with - the post-PHI bind stmts, so don't add them. - - As for the exit edge, there wouldn't be redundant - bind stmts, but there wouldn't be a PC to bind - them to either, so avoid diverging the CFG. */ - if (ef && single_pred_p (ef->dest) - && ef->dest != EXIT_BLOCK_PTR_FOR_FN (cfun)) - { - /* If there were PHI nodes in the node, we'd - have to make sure the value we're binding - doesn't need rewriting. But there shouldn't - be PHI nodes in a single-predecessor block, - so we just add the note. */ - gsi_insert_on_edge_immediate (ef, note); - } } else - gsi_insert_after (&gsi, note, GSI_SAME_STMT); + { + gimple *note + = gimple_build_debug_bind (tracked_var, def, stmt); + gsi_insert_after (&gsi, note, GSI_SAME_STMT); + } } }