From nobody Wed Feb 11 06:54:10 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A7103C76188 for ; Tue, 4 Apr 2023 22:14:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236477AbjDDWOY (ORCPT ); Tue, 4 Apr 2023 18:14:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46284 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229973AbjDDWOW (ORCPT ); Tue, 4 Apr 2023 18:14:22 -0400 Received: from mail-ej1-x634.google.com (mail-ej1-x634.google.com [IPv6:2a00:1450:4864:20::634]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 116BC40D9 for ; Tue, 4 Apr 2023 15:14:21 -0700 (PDT) Received: by mail-ej1-x634.google.com with SMTP id a640c23a62f3a-93df929479cso2753166b.3 for ; Tue, 04 Apr 2023 15:14:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1680646459; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=tWU46z+LxAZ1Ey10aQVV7RoKLINUb1ekhfE7aBIl2Ps=; b=L4+wRj6/x0iKLAqOjXV0y7hMh4azCyZamBDr8njWOhWQzudWScUkVwh8IAF52vxcI8 xyD9bv3a+6FFcxWPNXclggxwjVIkovF06vPQPlmN9KCyWnq+8R/ZnrzySv/Oldq9ydo0 QbUpQlg3y9orqTjrxODR/IkZNAo0ZQzQTwwCtKfhWBKj2fpodF6FbDYMuB5yR4lfnkPU uSJ/ZnXvMyh7O7T1k9oe5FnM0ZuKfl0PjidDkFmVdZTF1y50l1NY5cXiR1+HiUuZOrDi dSQc43O7veEpkQzrs+DxCdHp5dx9gQTprT7xkjQ2lc1T2EaNqo4JnL5Mtu6WArVz/7kH WIkw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1680646459; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=tWU46z+LxAZ1Ey10aQVV7RoKLINUb1ekhfE7aBIl2Ps=; b=Xqq/HXzNSvrGGvsuKoCoE2SHqDA3vgi3AXZ2vDVFy8ABBcZvItDJrT23TNVjWbpGUQ Q5Ls90Qhr0i3JFhBJ81BFDLK0J/J4SL4LCX9FCNR3iIK1/rQNqnwhJtIsIZWqbfyAkY1 cykX2S+kdiX7S9Kt7g/LoIKYxQwPxLLO3tBNWHpIxMpQz2l/oeUAfDsNgKdJ6Uk7Mncj TJAgLKmFZDzRNFc84W2vzdI52qKdAFFP50hruJJeZir31uA48c7mJ2+GHhGHjThdIpyP y3K4k46D5ifjtgx6JnztJyUA+LGGXDmmokXgNLg1UTumynD5zieQPLCrv5FJCO77fIly G9VQ== X-Gm-Message-State: AAQBX9ctyqXM3KYzCH/0t1BzJN1SC7uxM57TqkZfy+mIRwP9Wa+WDwmR YVC76tzP9h2PECEDZBOzj/787TZi6+4= X-Google-Smtp-Source: AKy350bvVO6MrW64LZ9jDBgS+4RnuM/Y3HVt0DwAgjbfv9AMuqLzhJxib25vlMyWVfLmEtZXgWW/0w== X-Received: by 2002:aa7:d8da:0:b0:4ac:b69a:2f06 with SMTP id k26-20020aa7d8da000000b004acb69a2f06mr197334eds.0.1680646459228; Tue, 04 Apr 2023 15:14:19 -0700 (PDT) Received: from noahgold-desk.intel.com ([192.55.54.55]) by smtp.gmail.com with ESMTPSA id t20-20020a50d714000000b005021d17d896sm6428256edi.21.2023.04.04.15.14.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 04 Apr 2023 15:14:18 -0700 (PDT) From: Noah Goldstein To: linux-kernel@vger.kernel.org Cc: goldstein.w.n@gmail.com, walken@google.com, akpm@linux-foundation.org Subject: [PATCH v1] lib/rbtree: Use '+' instead of '|' for setting color. Date: Tue, 4 Apr 2023 17:13:51 -0500 Message-Id: <20230404221350.3806566-1-goldstein.w.n@gmail.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" This has a slight benefit for x86 and has no effect on other targets. The benefit to x86 is it change the codegen for setting a node to block from `mov %r0, %r1; or $RB_BLACK, %r1` to `lea RB_BLACK(%r0), %r1` which saves an instructions. In all other cases it just replace ALU with ALU (or -> and) which perform the same on all machines I am aware of. Total instructions in rbtree.o: Before - 802 After - 782 so it saves about 20 `mov` instructions. Signed-off-by: Noah Goldstein --- include/linux/rbtree_augmented.h | 4 ++-- lib/rbtree.c | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/include/linux/rbtree_augmented.h b/include/linux/rbtree_augmen= ted.h index d1c53e9d8c75..7ee7ed5de722 100644 --- a/include/linux/rbtree_augmented.h +++ b/include/linux/rbtree_augmented.h @@ -156,13 +156,13 @@ RB_DECLARE_CALLBACKS(RBSTATIC, RBNAME, \ =20 static inline void rb_set_parent(struct rb_node *rb, struct rb_node *p) { - rb->__rb_parent_color =3D rb_color(rb) | (unsigned long)p; + rb->__rb_parent_color =3D rb_color(rb) + (unsigned long)p; } =20 static inline void rb_set_parent_color(struct rb_node *rb, struct rb_node *p, int color) { - rb->__rb_parent_color =3D (unsigned long)p | color; + rb->__rb_parent_color =3D (unsigned long)p + color; } =20 static inline void diff --git a/lib/rbtree.c b/lib/rbtree.c index c4ac5c2421f2..5114eda6309c 100644 --- a/lib/rbtree.c +++ b/lib/rbtree.c @@ -58,7 +58,7 @@ =20 static inline void rb_set_black(struct rb_node *rb) { - rb->__rb_parent_color |=3D RB_BLACK; + rb->__rb_parent_color +=3D RB_BLACK; } =20 static inline struct rb_node *rb_red_parent(struct rb_node *red) --=20 2.34.1