From patchwork Tue Nov 8 12:53:48 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Richard Biener X-Patchwork-Id: 60200 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 2A3373858417 for ; Tue, 8 Nov 2022 12:54:21 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 2A3373858417 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1667912061; bh=UM7owphI3lOTENpp3ZiSX+U1WRhvl2GOrjvBUGawdFg=; h=Date:To:cc:Subject:List-Id:List-Unsubscribe:List-Archive: List-Post:List-Help:List-Subscribe:From:Reply-To:From; b=VsLOmXT+0XuvTA+f7GOarQusK9E2bDC2tu3iLjdOgWCjGJ8K06HYn3XRxRfoQgkDx 2P/welJoorlgmZatVG3PYkj2v7sESPo2jcqZpkEQ78YgZ6hXkKz3v6KMA2cw0TT3Cj yM+SywjthHIPRlYcNVK414Ug9x7eGQ4NX7/Z+eGo= X-Original-To: gcc-patches@gcc.gnu.org Delivered-To: gcc-patches@gcc.gnu.org Received: from smtp-out1.suse.de (smtp-out1.suse.de [IPv6:2001:67c:2178:6::1c]) by sourceware.org (Postfix) with ESMTPS id 057213858C53 for ; Tue, 8 Nov 2022 12:53:50 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 057213858C53 Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id D80E821B46; Tue, 8 Nov 2022 12:53:48 +0000 (UTC) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id BFC2213398; Tue, 8 Nov 2022 12:53:48 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id V/6ZLVxRamMQbgAAMHmgww (envelope-from ); Tue, 08 Nov 2022 12:53:48 +0000 Date: Tue, 8 Nov 2022 13:53:48 +0100 (CET) To: gcc-patches@gcc.gnu.org cc: Jakub Jelinek Subject: [PATCH][v2] tree-optimization/107389 - honor __builtin_assume_alignment at -O0 MIME-Version: 1.0 Message-Id: <20221108125348.BFC2213398@imap2.suse-dmz.suse.de> X-Spam-Status: No, score=-10.2 required=5.0 tests=BAYES_00, DKIM_INVALID, DKIM_SIGNED, GIT_PATCH_0, KAM_DMARC_STATUS, KAM_NUMSUBJECT, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: gcc-patches@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Patchwork-Original-From: Richard Biener via Gcc-patches From: Richard Biener Reply-To: Richard Biener Errors-To: gcc-patches-bounces+patchwork=sourceware.org@gcc.gnu.org Sender: "Gcc-patches" The following makes sure to set alignment information on the LHS of __builtin_assume_alignment calls even when not optimizing so uses as arguments to builtin functions like memcpy or __atomic_load_n can be reflected at RTL expansion time. Bootstrap and regtest running on x86_64-unknown-linux-gnu, OK? Thanks, Richard. PR tree-optimization/107389 * gimple-low.cc (lower_builtin_assume_aligned): New. (lower_stmt): Call it. * gcc.dg/pr107389.c: New testcase. --- gcc/gimple-low.cc | 41 +++++++++++++++++++++++++++++++++ gcc/testsuite/gcc.dg/pr107389.c | 13 +++++++++++ 2 files changed, 54 insertions(+) create mode 100644 gcc/testsuite/gcc.dg/pr107389.c diff --git a/gcc/gimple-low.cc b/gcc/gimple-low.cc index 512aa9feada..f9bcb772163 100644 --- a/gcc/gimple-low.cc +++ b/gcc/gimple-low.cc @@ -84,6 +84,7 @@ static void lower_try_catch (gimple_stmt_iterator *, struct lower_data *); static void lower_gimple_return (gimple_stmt_iterator *, struct lower_data *); static void lower_builtin_setjmp (gimple_stmt_iterator *); static void lower_builtin_posix_memalign (gimple_stmt_iterator *); +static void lower_builtin_assume_aligned (gimple_stmt_iterator *); /* Lower the body of current_function_decl from High GIMPLE into Low @@ -768,6 +769,13 @@ lower_stmt (gimple_stmt_iterator *gsi, struct lower_data *data) lower_builtin_posix_memalign (gsi); return; } + else if (DECL_FUNCTION_CODE (decl) == BUILT_IN_ASSUME_ALIGNED + && !optimize) + { + lower_builtin_assume_aligned (gsi); + data->cannot_fallthru = false; + return; + } } if (decl && (flags_from_decl_or_type (decl) & ECF_NORETURN)) @@ -1310,6 +1318,39 @@ lower_builtin_posix_memalign (gimple_stmt_iterator *gsi) gsi_insert_after (gsi, stmt, GSI_NEW_STMT); gsi_insert_after (gsi, gimple_build_label (noalign_label), GSI_NEW_STMT); } + +/* Lower calls to __builtin_assume_aligned when not optimizing. */ + +static void +lower_builtin_assume_aligned (gimple_stmt_iterator *gsi) +{ + gcall *call = as_a (gsi_stmt (*gsi)); + + tree lhs = gimple_call_lhs (call); + if (!lhs || !POINTER_TYPE_P (TREE_TYPE (lhs))) + return; + + tree align = gimple_call_arg (call, 1); + tree misalign = (gimple_call_num_args (call) > 2 + ? gimple_call_arg (call, 2) : NULL_TREE); + if (!tree_fits_uhwi_p (align) + || (misalign && !tree_fits_uhwi_p (misalign))) + return; + + unsigned aligni = TREE_INT_CST_LOW (align); + unsigned misaligni = misalign ? TREE_INT_CST_LOW (misalign) : 0; + if (aligni <= 1 + || (aligni & (aligni - 1)) != 0 + || (misaligni & ~(aligni - 1)) != 0) + return; + + /* For lowering we simply transfer alignment information to the + result and leave the call otherwise unchanged, it will be elided + at RTL expansion time. */ + ptr_info_def *pi = get_ptr_info (lhs); + set_ptr_info_alignment (pi, aligni, misaligni); + gsi_next (gsi); +} /* Record the variables in VARS into function FN. */ diff --git a/gcc/testsuite/gcc.dg/pr107389.c b/gcc/testsuite/gcc.dg/pr107389.c new file mode 100644 index 00000000000..deb63380704 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr107389.c @@ -0,0 +1,13 @@ +/* { dg-do compile } */ +/* { dg-options "-fdump-tree-optimized-alias" } */ + +unsigned foo (void *p) +{ + unsigned i; + __builtin_memcpy (&i, __builtin_assume_aligned (p, 4), sizeof (unsigned)); + return i; +} + +/* Even when not optimizing we should have alignment info on the temporary + feeding the memcpy. */ +/* { dg-final { scan-tree-dump "ALIGN = 4" "optimized" } } */