From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 2153) id 0A7B83858C54; Mon, 5 Feb 2024 09:58:20 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 0A7B83858C54 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1707127101; bh=R/MUWviQLMInV24WOglH6MzIYPZN+KwVF8m3oGuv22c=; h=From:To:Subject:Date:From; b=MDS1jkyKDAmxhj35wRR+VPpQ8+BB9feLBdTF/MuMEIVfGuy9LzM0QY0IOkPk/0IQE /IAns0exNQeQSA9trF1rUFtVvi9YcICoYWEU7EwEAu7ciRWoEhj9sXVPWP6lklI23l qQ+fOrz4txJEPgJ+RCI7iuqYf5tn++uwLhEQpoZk= 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 r14-8798] lower-bitint: Remove single label _BitInt switches [PR113737] X-Act-Checkin: gcc X-Git-Author: Jakub Jelinek X-Git-Refname: refs/heads/master X-Git-Oldrev: d413df070ba5efadd2fb8b6c6aa6003b8cae617b X-Git-Newrev: dede174fbb57bdd3e26f322b6096d53edf0089c4 Message-Id: <20240205095821.0A7B83858C54@sourceware.org> Date: Mon, 5 Feb 2024 09:58:20 +0000 (GMT) List-Id: https://gcc.gnu.org/g:dede174fbb57bdd3e26f322b6096d53edf0089c4 commit r14-8798-gdede174fbb57bdd3e26f322b6096d53edf0089c4 Author: Jakub Jelinek Date: Mon Feb 5 10:57:39 2024 +0100 lower-bitint: Remove single label _BitInt switches [PR113737] The following testcase ICEs, because group_case_labels_stmt optimizes switch (a.0_7) [50.00%], case 0: [50.00%], case 2: [50.00%]> where L7 block starts with __builtin_unreachable (); to switch (a.0_7) [50.00%]> and single label GIMPLE_SWITCH is something the switch expansion refuses to lower: if (gimple_switch_num_labels (m_switch) == 1 || range_check_type (index_type) == NULL_TREE) return false; (range_check_type never returns NULL for BITINT_TYPE), but the gimple lowering pass relies on all large/huge _BitInt switches to be lowered by that pass. The following patch just removes those after making the single successor edge EDGE_FALLTHRU. I've done it even if !optimize just in case in case we'd end up with single case label from earlier passes. 2024-02-05 Jakub Jelinek PR tree-optimization/113737 * gimple-lower-bitint.cc (gimple_lower_bitint): If GIMPLE_SWITCH has just a single label, remove it and make single successor edge EDGE_FALLTHRU. * gcc.dg/bitint-84.c: New test. Diff: --- gcc/gimple-lower-bitint.cc | 9 ++++++++- gcc/testsuite/gcc.dg/bitint-84.c | 32 ++++++++++++++++++++++++++++++++ 2 files changed, 40 insertions(+), 1 deletion(-) diff --git a/gcc/gimple-lower-bitint.cc b/gcc/gimple-lower-bitint.cc index a7cc5cee07ba..e92f5731d9e2 100644 --- a/gcc/gimple-lower-bitint.cc +++ b/gcc/gimple-lower-bitint.cc @@ -5832,7 +5832,14 @@ gimple_lower_bitint (void) if (optimize) group_case_labels_stmt (swtch); - switch_statements.safe_push (swtch); + if (gimple_switch_num_labels (swtch) == 1) + { + single_succ_edge (bb)->flags |= EDGE_FALLTHRU; + gimple_stmt_iterator gsi = gsi_for_stmt (swtch); + gsi_remove (&gsi, true); + } + else + switch_statements.safe_push (swtch); } } diff --git a/gcc/testsuite/gcc.dg/bitint-84.c b/gcc/testsuite/gcc.dg/bitint-84.c new file mode 100644 index 000000000000..dffdf160a845 --- /dev/null +++ b/gcc/testsuite/gcc.dg/bitint-84.c @@ -0,0 +1,32 @@ +/* PR tree-optimization/113737 */ +/* { dg-do compile { target bitint } } */ +/* { dg-options "-O2 -std=c23" } */ + +#if __BITINT_MAXWIDTH__ >= 129 +_BitInt(129) a; +#else +_BitInt(63) a; +#endif + +int b[1], c; + +int +foo (void) +{ + switch (a) + case 0: + case 2: + return 1; + return 0; +} + +void +bar (int i) +{ + for (;; ++i) + { + c = b[i]; + if (!foo ()) + __asm__ (""); + } +}