From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f44.google.com (mail-wm1-f44.google.com [209.85.128.44]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1923422301 for ; Sat, 7 Feb 2026 23:50:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.44 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770508223; cv=none; b=M4pZ8bhee3v0BBlwXrW4BL5rEa4Yd7203MahwZLsq0fr4l9GlS6hoGrBZH8gsU8QSeGnjUak96UKxwYEcj0BwG9aF1TSXtcop4qpWe1a232kExAoBWAcgEOdRF1M1RI331Zqz8Ltkg7oY0Co0lMSinKIhDK+El5mKeokV0k4lVc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770508223; c=relaxed/simple; bh=fT+TSNOBpNOhyzShZ48NwbeARUV59gSKO83og8bHf0M=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=bW3KEZ1HLS5D/jy6m6mQkScYTm8SBOzqVK3OOfToMTBZZxLwFdEByjI2cNDbY4heBXohpKwRn35H/KiIVDi0zsCI9pzesJdvPt7N6C+yN0320DYf5nh2ksRy0PHWB2p4wzLwy4F9bhna8lLiZ6amDU4vp+tbFJ4dA7mVKIavXjk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=kUmoNZF3; arc=none smtp.client-ip=209.85.128.44 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="kUmoNZF3" Received: by mail-wm1-f44.google.com with SMTP id 5b1f17b1804b1-480706554beso20005565e9.1 for ; Sat, 07 Feb 2026 15:50:22 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1770508221; x=1771113021; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:from:to:cc:subject:date :message-id:reply-to; bh=eoYx0PxhvmuOAhutxH3fXLMhD7k2Bc8M1Df20D/G3kQ=; b=kUmoNZF3qunaYCns1BvK9ybH18Bmaf5YY3SySGdKW+tDEIMbV/NI6vV43D1Qzcy5Ed o+kY3SoK/kiDTcC0GaBZHLX9MtXDxruWZwsw5SIZlKDTjFxaBbvSxUOMd332lLYRwnOo GxgWwWoIjTNJDUv4nm6U2SDnNfinm8vfbN5Tev8BJ63UcHJZpQkJ1rrxoKdjszBNKu3Z 6MGv3utdwxpOSKD6T5A2RndlEhCBgcQorIjzZoqZUakGCbGBnWnOu8eEqwXLTGJa9BRT 3U2DOj0Qo8sHyyKdNiqmI9ylkn7Q7S6e5K4X9aW0gp2EeiRw3PnmSdWK7VBdSY7v5YiH TJOQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1770508221; x=1771113021; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=eoYx0PxhvmuOAhutxH3fXLMhD7k2Bc8M1Df20D/G3kQ=; b=TMmrm8CLnxz4bB55OI1ZGeO8mQuKQMNFQbK5Y298G1YDukLxVWkpSJtBnQtdJd6qJB cjRRLJlbFGlx0NROId02vE4DdsOvsNkj0cQREujqPZb9TkfGHYgPVs3byJJPyNn0icYq F7Qs3AvBZzU1qeihvlWGtzTYmpWtue6WYSmueK61CDv8LZdQNJTbE6dTAWo99HPjbu84 vMQ7foRXFP/yJiVuWDvyB8PaBYXhTRYy54OSI3gLAA4VgLHxgzdR/CdmeZSXA5PgCNvR T804IOT5BqIezH3jYdIHyT8Um7gyaaG57c+XrxMwJpOo0kn+SqNP/7m/t2/o7lxEPspY 5rkA== X-Forwarded-Encrypted: i=1; AJvYcCXyzCFPBFJfaZcaTu9b+0UmITbrj8h/7zxgTN6RYFAzPvwlWy/2r0GICU/S0ml0ixEzF+WQdQuARfX0x0U=@vger.kernel.org X-Gm-Message-State: AOJu0YyHEW9HURGSUmtYTyjtd+PPLjif5iLz3ZK9n/q40pZAAwWHwc/T 61EXsH3Eq4o9XYkiQ6NyCJQj2iT/WeEmRxeMbY/cS5G8xWLS4kIdytIw X-Gm-Gg: AZuq6aK8bbTmcXi2gta+mmq10/hkGU78aKFUfbo9/BcIjQHiRQrZTIKcgd6PmI8yr9t ZqQIWhlmE6hLVT9MMJwcva/Kqrp2/u1hjMI4uK5RCmKniDa5OXkpkpsdc/CBbPZboDdLQpTb2OV h/8gOt0xnhYasymMSZCGJg4ho7Y6P2rbvP/fEwaekulOPjj3OEMyIScO3R+vWvodbgKMpyxW4Lr VrHA/0JVWBmRqSNP8za8NTaGndF6Y54z2WzzS+yo2YHW/gl602FDbK8r5eT/YZx6pCmDiiuJiBX G27/n8Mrsg71Jg06ZwOH3HsOc94gWKngAhSvqiQevT9DD/Z14o5hflgW3wEIE2zO/9cLfY1okQE L/KK7rgD0b4mP06DEQ0KdSXIrxLhUuXgZ566z0xCqvJniPaQRH853DSigZGhALF69xHN0wwpUCr lrBHIkb2T5IBOS+3pwljHeavdZjLY2e7oXjVON5qfcGKIZCyVKJ6OX X-Received: by 2002:a05:600c:1390:b0:477:5ad9:6df1 with SMTP id 5b1f17b1804b1-483201dc4bamr96810895e9.3.1770508221361; Sat, 07 Feb 2026 15:50:21 -0800 (PST) Received: from pumpkin (82-69-66-36.dsl.in-addr.zen.co.uk. [82.69.66.36]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-483203e126dsm105989055e9.2.2026.02.07.15.50.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 07 Feb 2026 15:50:21 -0800 (PST) Date: Sat, 7 Feb 2026 23:50:19 +0000 From: David Laight To: Willy Tarreau Cc: Thomas =?UTF-8?B?V2Vpw59zY2h1aA==?= , linux-kernel@vger.kernel.org, Cheng Li Subject: Re: [PATCH v2 next 05/11] tools/nolibc/printf: Simplify __nolibc_printf() Message-ID: <20260207235019.40f82fca@pumpkin> In-Reply-To: References: <20260206191121.3602-1-david.laight.linux@gmail.com> <20260206191121.3602-6-david.laight.linux@gmail.com> X-Mailer: Claws Mail 4.1.1 (GTK 3.24.38; arm-unknown-linux-gnueabihf) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Sat, 7 Feb 2026 21:05:42 +0100 Willy Tarreau wrote: > On Fri, Feb 06, 2026 at 07:11:15PM +0000, david.laight.linux@gmail.com wrote: > > From: David Laight > > > > Move the check for the length modifiers into the format processing > > between the field width and conversion specifier. > > This lets the loop be simplified and a 'fast scan' for a format start > > used. > > > > If an error is detected (eg an invalid conversion specifier) then > > copy the invalid format to the output buffer. > > > > Reduces code size by about 10% on x86-64. > > I'm surprised, because for me it's the opposite: > > $ size hello-patch* > text data bss dec hex filename > 1859 48 24 1931 78b hello-patch1 > 2071 48 24 2143 85f hello-patch2 > 2091 48 24 2163 873 hello-patch3 > 2422 48 24 2494 9be hello-patch4 > > The whole program grew by almost 16%, and that's a 30% increase since > the first patch. This is with gcc 15 -Oz. aarch64 however decreased by > 15 bytes since previous patch. > > I have not figured what makes this change yet, I'm still digging. Running scripts/bloat-o-meter will give more detail. > Willy I'm using gcc 12.2 and just running 'make O=xxx' for the test program. The object looks like what I'd expect, so might be -O2. Is it constant folding the #defines. For me it generating the (1 << (c & 31)) & 0xxxxx as you might hope. David