From mboxrd@z Thu Jan 1 00:00:00 1970 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=-12.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 C5EE3C388F7 for ; Sun, 8 Nov 2020 01:19:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7CBC520885 for ; Sun, 8 Nov 2020 01:19:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="X1YLamVB" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728752AbgKHBTx (ORCPT ); Sat, 7 Nov 2020 20:19:53 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57602 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726060AbgKHBTx (ORCPT ); Sat, 7 Nov 2020 20:19:53 -0500 Received: from mail-ej1-x643.google.com (mail-ej1-x643.google.com [IPv6:2a00:1450:4864:20::643]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C4941C0613D2 for ; Sat, 7 Nov 2020 17:19:52 -0800 (PST) Received: by mail-ej1-x643.google.com with SMTP id cw8so7243168ejb.8 for ; Sat, 07 Nov 2020 17:19:52 -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=jKETXCOxbuPiYDn4OL3cUM1t7GC6XVLA7eZ9dGAEPbM=; b=X1YLamVBVgxymqFzTFoDqI7/8cducrhgc8AockGhEue56JFDEPoZy5sLPoQyTenay+ 5NZ1KD96SJuBWIm9XRu/zzetG1MYDw9AcWBxXM1+KUXeLFQB/6thS8idOafqC1hDZBCt PrOk3h6G9YEZ2D3SVPyfXlFz3Dch5y44W1Btl7hQ3E3KxpKuTniDOMaUoM2TQqkCq6ze f742jRRKwUrgy6vvf5r36+wMOAJ6ZlsiTFZNfdjoERmsBi4g4o4LBbDJx6I6fp63CN2w 6+KYFzCsObWbCY4mFCVRFOvVO2Flp6bsPj9dWaoHfHVHgX4fuJ+ccphrlwfqsT3RSsJO B+Ug== 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=jKETXCOxbuPiYDn4OL3cUM1t7GC6XVLA7eZ9dGAEPbM=; b=M+BK/Oy9nosAjsGt5ZsV3wON7iA1XAFztBpuv3XoZMRGor2zxOWhGuctDSv1jAfri3 3yVuT/AjkLjR448OYEJ4211aphqV2Iw81Rtt2Np3GQzUDLNkY72r2S0Ex7rc7nShQE31 hP7nOaSwIzq8Wh/PD6vyu/pE9lPp/ift1qTI4wxsEsuAJD+MB32IGcpbaWlr9KjAkCo5 p0dxUSAjhKqMhUCTDeOVspXhoNZLloHLC4fSYaTPtPNp9Y+6LgjHOq5pdXjG1vkvriun HNsNYZQRa9hRFBG+b/ZnLuY5W5u5eekeWb9jK08SEgdFWfRI8hc556wvwki7q42NkBTM uHXA== X-Gm-Message-State: AOAM533qsmcxTtn7bTUgThjK85/h/C7GN51LfjDOCA+/l/jjC3FbefSv tCdLTn4c+y6Hu5gtLoNvoMbX1P0B8WY= X-Google-Smtp-Source: ABdhPJwrEJrJrasZgIEmNKcJtHwglcxSdPeZIci44Dy56kk8LFVWTugA55lSeT61LThLQaChvFcwaA== X-Received: by 2002:a17:906:6d99:: with SMTP id h25mr8841408ejt.281.1604798391270; Sat, 07 Nov 2020 17:19:51 -0800 (PST) Received: from localhost.localdomain ([2a02:a03f:b7fe:f700:fce6:5cb0:27db:5e8c]) by smtp.gmail.com with ESMTPSA id t22sm4545127edq.64.2020.11.07.17.19.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 07 Nov 2020 17:19:50 -0800 (PST) From: Luc Van Oostenryck To: linux-sparse@vger.kernel.org Cc: Luc Van Oostenryck Subject: [PATCH 08/16] cmp: canonicalize unsigned compare with UMAX or UMAX-1 Date: Sun, 8 Nov 2020 02:19:38 +0100 Message-Id: <20201108011939.94252-9-luc.vanoostenryck@gmail.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201108011939.94252-1-luc.vanoostenryck@gmail.com> References: <20201108011939.94252-1-luc.vanoostenryck@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-sparse@vger.kernel.org Unsigned compares with UMAX (or UMAX-1) are equivalent to equality tests. These are preferable since it's easier to reason about them in other simplifications. So canonicalize these compares to equality tests. Signed-off-by: Luc Van Oostenryck --- simplify.c | 8 ++++++++ validation/optim/set-uimm2.c | 1 - 2 files changed, 8 insertions(+), 1 deletion(-) diff --git a/simplify.c b/simplify.c index 160a6ab15e7f..7921300f7280 100644 --- a/simplify.c +++ b/simplify.c @@ -1090,6 +1090,8 @@ static int simplify_compare_constant(struct instruction *insn, long long value) return replace_with_pseudo(insn, value_pseudo(0)); if (value == 1) // (x < 1) --> (x == 0) return replace_binop_value(insn, OP_SET_EQ, 0); + else if (value == bits) // (x < ~0) --> (x != ~0) + return replace_binop_value(insn, OP_SET_NE, value); else // (x < y) --> (x <= (y-1)) changed |= replace_binop_value(insn, OP_SET_BE, value - 1); break; @@ -1098,6 +1100,8 @@ static int simplify_compare_constant(struct instruction *insn, long long value) return replace_with_pseudo(insn, value_pseudo(1)); if (value == 1) // (x >= 1) --> (x != 0) return replace_binop_value(insn, OP_SET_NE, 0); + else if (value == bits) // (x >= ~0) --> (x == ~0) + return replace_binop_value(insn, OP_SET_EQ, value); else // (x >= y) --> (x > (y-1) changed |= replace_binop_value(insn, OP_SET_A, value - 1); break; @@ -1106,12 +1110,16 @@ static int simplify_compare_constant(struct instruction *insn, long long value) return replace_opcode(insn, OP_SET_EQ); if (value == bits) // (x <= ~0) --> 1 return replace_with_pseudo(insn, value_pseudo(1)); + if (value == (bits - 1)) // (x <= ~1) --> (x != ~0) + return replace_binop_value(insn, OP_SET_NE, bits); break; case OP_SET_A: if (!value) // (x > 0) --> (x != 0) return replace_opcode(insn, OP_SET_NE); if (value == bits) // (x > ~0) --> 0 return replace_with_pseudo(insn, value_pseudo(0)); + if (value == (bits - 1)) // (x > ~1) --> (x == ~0) + return replace_binop_value(insn, OP_SET_EQ, bits); break; } return changed; diff --git a/validation/optim/set-uimm2.c b/validation/optim/set-uimm2.c index efa326f532ce..9138ae7276e7 100644 --- a/validation/optim/set-uimm2.c +++ b/validation/optim/set-uimm2.c @@ -6,7 +6,6 @@ static _Bool setgt_umax(unsigned int a) { return (a > ~1) == (a == ~0); } /* * check-name: set-uimm2 * check-command: test-linearize $file - * check-known-to-fail * * check-output-ignore * check-output-returns: 1 -- 2.29.2