From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.136]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 50EEC30F9A for ; Mon, 16 Oct 2023 16:55:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="H1t7Ipid" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1697475310; x=1729011310; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=JgZclxzvXH6brVhcVWQRFhTS/icokSmMXi/raH9oYiU=; b=H1t7IpidKYLcsVd2KlFcPqUcM1Lc/UWssDsb71ecYFMB35bMThd2Zjvp Lj3TPZOISp24uJJ/9UGORa6Sw5DbN32DGzFVFZyjd0G3RKlm9WlGQB4Mn a/ajOfehkg2AZsrEhIglqjdO08YE0ZRuh6QbMD4t5LuiQZ1aSUKJl6l5G GHhMkyfEGZTqG1coAujGkHwglieh3IYt4FMHlFc+GgkjxaxFPCx4eX2eh Prz1Vc77OXHOHe+VhBZ3Lf6LSwzAMzolT+tTxCUoSV+6eVYRMtMmOGcuE YXs4A2QQV3WnGlrvSUd3Iq1zs/ujMDrlcO/GCpRA6zAJQ9c7JnBvpCBsL g==; X-IronPort-AV: E=McAfee;i="6600,9927,10865"; a="364937334" X-IronPort-AV: E=Sophos;i="6.03,229,1694761200"; d="scan'208";a="364937334" Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Oct 2023 09:55:09 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10865"; a="826084549" X-IronPort-AV: E=Sophos;i="6.03,229,1694761200"; d="scan'208";a="826084549" Received: from newjersey.igk.intel.com ([10.102.20.203]) by fmsmga004.fm.intel.com with ESMTP; 16 Oct 2023 09:55:06 -0700 From: Alexander Lobakin To: Yury Norov Cc: Alexander Lobakin , Andy Shevchenko , Rasmus Villemoes , Alexander Potapenko , Jakub Kicinski , Eric Dumazet , David Ahern , Przemek Kitszel , Simon Horman , netdev@vger.kernel.org, linux-btrfs@vger.kernel.org, dm-devel@redhat.com, ntfs3@lists.linux.dev, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 12/13] lib/bitmap: add compile-time test for __assign_bit() optimization Date: Mon, 16 Oct 2023 18:52:46 +0200 Message-ID: <20231016165247.14212-13-aleksander.lobakin@intel.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20231016165247.14212-1-aleksander.lobakin@intel.com> References: <20231016165247.14212-1-aleksander.lobakin@intel.com> Precedence: bulk X-Mailing-List: ntfs3@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Commit dc34d5036692 ("lib: test_bitmap: add compile-time optimization/evaluations assertions") initially missed __assign_bit(), which led to that quite a time passed before I realized it doesn't get optimized at compilation time. Now that it does, add test for that just to make sure nothing will break one day. To make things more interesting, use bitmap_complement() and bitmap_full(), thus checking their compile-time evaluation as well. And remove the misleading comment mentioning the workaround removed recently in favor of adding the whole file to GCov exceptions. Reviewed-by: Przemek Kitszel Signed-off-by: Alexander Lobakin --- lib/test_bitmap.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/lib/test_bitmap.c b/lib/test_bitmap.c index 910457662322..a005fcd70ed7 100644 --- a/lib/test_bitmap.c +++ b/lib/test_bitmap.c @@ -1193,14 +1193,7 @@ static void __init test_bitmap_const_eval(void) * in runtime. */ - /* - * Equals to `unsigned long bitmap[1] = { GENMASK(6, 5), }`. - * Clang on s390 optimizes bitops at compile-time as intended, but at - * the same time stops treating @bitmap and @bitopvar as compile-time - * constants after regular test_bit() is executed, thus triggering the - * build bugs below. So, call const_test_bit() there directly until - * the compiler is fixed. - */ + /* Equals to `unsigned long bitmap[1] = { GENMASK(6, 5), }` */ bitmap_clear(bitmap, 0, BITS_PER_LONG); if (!test_bit(7, bitmap)) bitmap_set(bitmap, 5, 2); @@ -1232,6 +1225,15 @@ static void __init test_bitmap_const_eval(void) /* ~BIT(25) */ BUILD_BUG_ON(!__builtin_constant_p(~var)); BUILD_BUG_ON(~var != ~BIT(25)); + + /* ~BIT(25) | BIT(25) == ~0UL */ + bitmap_complement(&var, &var, BITS_PER_LONG); + __assign_bit(25, &var, true); + + /* !(~(~0UL)) == 1 */ + res = bitmap_full(&var, BITS_PER_LONG); + BUILD_BUG_ON(!__builtin_constant_p(res)); + BUILD_BUG_ON(!res); } /* -- 2.41.0