From patchwork Tue Jan 26 22:04:30 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luc Van Oostenryck X-Patchwork-Id: 12048809 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2CC48C433DB for ; Wed, 27 Jan 2021 03:46:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E2548206B5 for ; Wed, 27 Jan 2021 03:46:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237072AbhA0DqB (ORCPT ); Tue, 26 Jan 2021 22:46:01 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58790 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728170AbhAZWF0 (ORCPT ); Tue, 26 Jan 2021 17:05:26 -0500 Received: from mail-wr1-x42e.google.com (mail-wr1-x42e.google.com [IPv6:2a00:1450:4864:20::42e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 51709C061794 for ; Tue, 26 Jan 2021 14:04:46 -0800 (PST) Received: by mail-wr1-x42e.google.com with SMTP id d16so17426742wro.11 for ; Tue, 26 Jan 2021 14:04:46 -0800 (PST) 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 :mime-version:content-transfer-encoding; bh=kgm7kxF29Ax0Vo6bQpRB0+xryXYstzCCJl7s01b9uBM=; b=UtBavKqqWrhcWOl80vDMmhHzFAJ/4+i0+qnox2WivFJ9yZLIZKEmI1WJqwRkE5pGfi 4N6rVQdaz3f6+7piTa20Hk7WZ7xm8F0lqvifmCHqrqmN+BmKdZeti5qgqhY7v9sF4uNJ rsd7hceSYezCOWLezL3x6EmBiJNi189L1eiLajPDu6nd5DYOwqKqBB95l+IPIF7o1U7x NI4xVG2ryU53f1cjl6x6rXpXYp5V5ONJrWb1StPmgBZjz3mPbaS/BWL8ZdC7b46T44q4 RC02zs9gY2rvqcaguVfGtp5fuIl5PaH/O/AuKUxcqMP9GvqHUa4czlucFdvfzh/RmGRY sMwA== 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:mime-version:content-transfer-encoding; bh=kgm7kxF29Ax0Vo6bQpRB0+xryXYstzCCJl7s01b9uBM=; b=h42IH9wXKRimh6+WMPhwIXFP/xxvkxIBdhcGdRZNRklpUFop1pjqRDuFKP50Op5a7G 7mcLmJmJMsRpXT3hx+oSe0ekurkX1bvOfz3B6D2RulZpIPLvY3LcYBGlIMZL3NPnqD20 qn93A5snAqBSksqgqQBbcvC7+x7JOZlzBhBA0qc6qgqnugMRoeXI4HRKYcHbddenBKvb XneBtxVJxaHq+Qfk8N0pVPYohuc+JNDASnyXoumNqR5ks8wqat2OkOQx072VKzXVW+tQ +1++2xrB+LHWCwf4QSjZSHSJra7m8n2ck/Nrpf4QZ+PWw3ogw8rdps6m6X75g8J/xM/4 wXNg== X-Gm-Message-State: AOAM533AADLjRULzqvdie9Zfs7v8nkfEpIutMdxjEi1f/3gd43KZS8m/ PAgyP8ugJVjhMirvtGKy1yV604gnNco= X-Google-Smtp-Source: ABdhPJxKT1nSKm3zR4eJ6MkQSTCytIkELUIPzSbtWfmKbhh6SrvYegOlTVRc95K4X7pC6txOrf851w== X-Received: by 2002:a5d:453b:: with SMTP id j27mr8305833wra.92.1611698685163; Tue, 26 Jan 2021 14:04:45 -0800 (PST) Received: from localhost.localdomain ([2a02:a03f:b7fe:f700:285a:40db:3257:f0fd]) by smtp.gmail.com with ESMTPSA id b132sm5268447wmh.21.2021.01.26.14.04.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 26 Jan 2021 14:04:44 -0800 (PST) From: Luc Van Oostenryck To: linux-sparse@vger.kernel.org Cc: Luc Van Oostenryck Subject: [PATCH 08/10] cmps: canonicalize signed compares with constant Date: Tue, 26 Jan 2021 23:04:30 +0100 Message-Id: <20210126220432.58265-9-luc.vanoostenryck@gmail.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210126220432.58265-1-luc.vanoostenryck@gmail.com> References: <20210126220432.58265-1-luc.vanoostenryck@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-sparse@vger.kernel.org Modify the constants to canonicalize (x < C) to (x <= (C-1)) and (x <= C) to (x > (C-1)). This choice is partially arbitrary but 1) it's the one with the smallest positive constants, 2) it eliminates all OP_SET_LT & OP_SET_GE with a constant. A disadvantage of this choice is that we lost some compares with 0: (x < 0) is now canonicalized into (x <= -1). Note: Another good choice would be to canonicalize using the smallest absolute constants. This would keep compares with 0 but would also keep the 4 kinds of comparison. Signed-off-by: Luc Van Oostenryck --- simplify.c | 2 ++ validation/optim/canonical-cmps.c | 1 - 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/simplify.c b/simplify.c index ad3adb11595e..b29f5d5b2444 100644 --- a/simplify.c +++ b/simplify.c @@ -1177,6 +1177,7 @@ static int simplify_compare_constant(struct instruction *insn, long long value) return replace_opcode(insn, OP_SET_NE); if (value == sign_bit(size) + 1)// (x < SMIN + 1) --> (x == SMIN) return replace_binop_value(insn, OP_SET_EQ, sign_bit(size)); + changed |= replace_binop_value(insn, OP_SET_LE, (value - 1) & bits); break; case OP_SET_LE: if (value == sign_mask(size)) // (x <= SMAX) --> 1 @@ -1193,6 +1194,7 @@ static int simplify_compare_constant(struct instruction *insn, long long value) return replace_opcode(insn, OP_SET_EQ); if (value == sign_bit(size) + 1)// (x >= SMIN + 1) --> (x != SMIN) return replace_binop_value(insn, OP_SET_NE, sign_bit(size)); + changed |= replace_binop_value(insn, OP_SET_GT, (value - 1) & bits); break; case OP_SET_GT: if (value == sign_mask(size)) // (x > SMAX) --> 0 diff --git a/validation/optim/canonical-cmps.c b/validation/optim/canonical-cmps.c index f42664b21e04..42801cdce520 100644 --- a/validation/optim/canonical-cmps.c +++ b/validation/optim/canonical-cmps.c @@ -10,7 +10,6 @@ _Bool ge_x(int a) { return (a >= 1234) == (a > 1233); } /* * check-name: canonical-cmps * check-command: test-linearize -Wno-decl $file - * check-known-to-fail * * check-output-ignore * check-output-returns: 1