From patchwork Tue Aug 8 23:06:31 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luc Van Oostenryck X-Patchwork-Id: 9889241 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id F33E160363 for ; Tue, 8 Aug 2017 23:07:04 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E5DB22891C for ; Tue, 8 Aug 2017 23:07:04 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DABCD28958; Tue, 8 Aug 2017 23:07:04 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.3 required=2.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_HI, RCVD_IN_SORBS_SPAM, T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 83D712891C for ; Tue, 8 Aug 2017 23:07:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751989AbdHHXHC (ORCPT ); Tue, 8 Aug 2017 19:07:02 -0400 Received: from mail-wm0-f67.google.com ([74.125.82.67]:35567 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752495AbdHHXG7 (ORCPT ); Tue, 8 Aug 2017 19:06:59 -0400 Received: by mail-wm0-f67.google.com with SMTP id r77so4920375wmd.2 for ; Tue, 08 Aug 2017 16:06:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=nV/9S1PzRVDrul1HFZfM1QICZpMBYt1EZ9Ag8AJLSvI=; b=DK9zUpKV8o+xcsHwAoRxupxE0MUlxQoo1/zlMTJgZ8OpSbu4tyZyQOq17/xPzZRXvM ZLB66Pq0u7Fvg0WwVrcnjnlSBd9MxNfNlGDzHSJ2uBfAj2P9SpQLTdnKwNAsjHvw0Huc ZQIL6zSgoOL9Vyi3ZhvI+uoisXtgtXx3e5aYZOBcRabp/hLBYn4dv2HEnR7yY5AEaSPy OB1VJGQ8owiCi4nGMY0xtMvlk4IEctOZTpKQ5m5HbfxY6wHTxP7ZbK5cAE7V5GCsMEbt 89Zk4GrSG1yY/JdgxDBFFhwapr6Pxe2VB8WuJfUitdVwIJTqdtG/CWmw1idLFJZAG0E8 eMiw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=nV/9S1PzRVDrul1HFZfM1QICZpMBYt1EZ9Ag8AJLSvI=; b=Y5l7Ct1s5e6L1TkPKm2WMTJpMPkNQn2tkYGz4f1e6T/s9fXMBZVCVny8hwNnVnFAZS xXkdXP0GYb7vxVaD/n91qkDULNtnaoDh3W2lzxTVeYr/6Pe7FbfVlzSf/5jGZyV4QwZ3 YtBV7+H96V64Tp+QvVLPbSPRVfz6mqEs05hxyLuat0hfqX3c3xElapu9SJzOTEF/FAqD hWz5IIbFHVWA0HhZO00YrRLOkOUDob4rpOYajdM+vdcUPE5mNv1tdTO/1d6euKD0irV+ IRB3IR3fom9dD/m7PaeWCBlVt6ftx4srIaYbtYfRLcTpKAkpE/0rcy8j859BaagzjwQR 6JCw== X-Gm-Message-State: AHYfb5i9OKCoSJjDBXegGBO2tQyugZIz+FeQgCm4czvjlSMrnjVzqO3x cNc7YA6QLJIz3K+AjHA= X-Received: by 10.80.164.18 with SMTP id u18mr5909756edb.250.1502233617333; Tue, 08 Aug 2017 16:06:57 -0700 (PDT) Received: from localhost.localdomain ([2a02:a03f:4076:600:6494:649b:1a34:f1b]) by smtp.gmail.com with ESMTPSA id n15sm1133490edb.87.2017.08.08.16.06.56 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 08 Aug 2017 16:06:56 -0700 (PDT) From: Luc Van Oostenryck To: linux-sparse@vger.kernel.org Cc: Christopher Li , Linus Torvalds , Dibyendu Majumdar , Luc Van Oostenryck Subject: [PATCH v3 5/8] simplify ((A & M') | B ) & M when M' & M == 0 Date: Wed, 9 Aug 2017 01:06:31 +0200 Message-Id: <20170808230634.16227-6-luc.vanoostenryck@gmail.com> X-Mailer: git-send-email 2.13.2 In-Reply-To: <20170808230634.16227-1-luc.vanoostenryck@gmail.com> References: <20170808230634.16227-1-luc.vanoostenryck@gmail.com> Sender: linux-sparse-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sparse@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This is specially usefull when A is in fact undefined. Reported-by: Dibyendu Majumdar Signed-off-by: Luc Van Oostenryck --- simplify.c | 42 +++++++++++++++++++++- validation/optim/store-load-bitfield.c | 66 ++++++++++++++++++++++++++++++++++ 2 files changed, 107 insertions(+), 1 deletion(-) create mode 100644 validation/optim/store-load-bitfield.c diff --git a/simplify.c b/simplify.c index 8b63bcaff..9893613da 100644 --- a/simplify.c +++ b/simplify.c @@ -502,6 +502,46 @@ static int simplify_seteq_setne(struct instruction *insn, long long value) } } +static int simplify_and_or_mask(struct instruction *insn, pseudo_t and, pseudo_t other, unsigned long long mask) +{ + struct instruction *def = and->def; + pseudo_t old; + + if (!constant(def->src2)) + return 0; + if (def->src2->value & mask) + return 0; + old = insn->src1; + use_pseudo(insn, other, &insn->src1); + remove_usage(old, &insn->src1); + return REPEAT_CSE; +} + +static int simplify_constant_mask(struct instruction *insn, unsigned long long mask) +{ + struct instruction *left; + pseudo_t src1, src2; + + switch (def_opcode(insn->src1)) { + case OP_OR: + // Let's handle ((A & M') | B ) & M + // or (B | (A & M')) & M + // when M' & M == 0 + left = insn->src1->def; + src1 = left->src1; + src2 = left->src2; + if (def_opcode(src1) == OP_AND) + return simplify_and_or_mask(insn, src1, src2, mask); + if (def_opcode(src2) == OP_AND) + return simplify_and_or_mask(insn, src2, src1, mask); + break; + + default: + break; + } + return 0; +} + static int simplify_constant_rightside(struct instruction *insn) { long long value = insn->src2->value; @@ -546,7 +586,7 @@ static int simplify_constant_rightside(struct instruction *insn) case OP_AND: if (!value) return replace_with_pseudo(insn, insn->src2); - return 0; + return simplify_constant_mask(insn, value); case OP_SET_NE: case OP_SET_EQ: diff --git a/validation/optim/store-load-bitfield.c b/validation/optim/store-load-bitfield.c new file mode 100644 index 000000000..b74022602 --- /dev/null +++ b/validation/optim/store-load-bitfield.c @@ -0,0 +1,66 @@ +int ufoo(int a) +{ + struct u { + unsigned int :2; + unsigned int a:3; + } bf; + + bf.a = a; + return bf.a; +} + +int sfoo(int a) +{ + struct s { + signed int :2; + signed int a:3; + } bf; + + bf.a = a; + return bf.a; +} + +int xfoo(int a) +{ + struct x { + int :2; + int a:3; // unsigned ! + } bf; + + bf.a = a; + return bf.a; +} + + +/* + * check-name: optim store/load bitfields + * check-command: test-linearize -Wno-decl $file + * + * check-output-start +ufoo: +.L0: + + scast.3 %r2 <- (32) %arg1 + and.32 %r9 <- %r2, $7 + ret.32 %r9 + + +sfoo: +.L2: + + scast.3 %r13 <- (32) %arg1 + and.32 %r20 <- %r13, $7 + scast.32 %r21 <- (3) %r20 + ret.32 %r21 + + +xfoo: +.L4: + + scast.3 %r24 <- (32) %arg1 + and.32 %r31 <- %r24, $7 + ret.32 %r31 + + + * check-output-end + */