From nobody Tue Apr 23 05:03:17 2024 X-Original-To: dev-commits-src-all@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4VNqks525Wz5JRPd; Tue, 23 Apr 2024 05:03:17 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4VNqks4DnVz4d6b; Tue, 23 Apr 2024 05:03:17 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1713848597; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=0jFi3KBnHGz4d6cNU1+t8yMbae6HN5ABsIehz4UbFVc=; b=kPvdlMpUWykwnmbsD2UzZtU3Uuxth9iqIH38TZ6Cn6KfE9rFAqntVolvMnRvzmsPbrq6Jv 7xbaArhRMIzQnCcgWRDJRkI55+qMOM0Oyb8FtxfXL22YTdGzPG7mYQF2vSHSxbSSoTQxjr OLL/8ACZeq2CNW1C6Rm5ArW1XBQB2seSHYbgFeKrT06lv7xTkoizscBd+7D5tvrMJrGg5s 4HdoyWWXX3xy5aV1Z2vlIqP9NBJvIkNow2qwiG8RoRYzr8Y+i5/ApjXldDtPxFQCX3hh4H jYY0TPk6FKzc56R2yxlfu1sD+uYjUTXhsFNtdQTeF4qAXdx2XdWjr2XAamyeiw== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1713848597; a=rsa-sha256; cv=none; b=lcOxIZHx+Rua8WeSw3jSv+yrsPGM3/QsPewnbG8Qcwk9Xj5C4DNj4DeU4xZjey31vm6iOr 9hS/zYO3eCu/GxGXOMPJya1DqZm7psYnFJjs8t7247shFhnuLCDOOKGBXf7X+/1ZZwHFjR svK1z2rOLWQI9D220RPBKwD5C/3h37aVDk30qpIsdR5lbhlXD5B67ZWv+8GunHFG2Ihye5 BOT7xd1GaeDdMVghud/AHsB01LG4PIV8+rJY4lCFiXrHd1F3iTw1ZpZpU8vGcDG3EQCsQW mmqGygNGJP+idK7yQJM5p+7Zu9CneC6Mv5yGK64POuEqj1B4IBgOeoMReUxbxg== ARC-Authentication-Results: i=1; mx1.freebsd.org; none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1713848597; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=0jFi3KBnHGz4d6cNU1+t8yMbae6HN5ABsIehz4UbFVc=; b=INJs4n+39M08SPNMijEuuMYe24xZEOoQ042ycwEG4xcCT9keiGd69vRACJQNB8HC0iaO7L 9i324Yo33AiNmSCb9hAX7/IburjAvwiYXK+dLtb2OHo1HvuzpEbkGt6cp7oSrqm9RjS426 npicX1Oqzq1w1mvOl5bRizLxEIv4T6ThO6FwGCbu04evYcYc0631ld00Nob4j1UpLOMSYv QqAgjapQABmpno0w4/X/4ZK1Tmxz9jmiZDZa1HQAO7G6hbpezazm6LnxAIQgxaYzErB6Xu z4bXrOVcdWJhDd6MuDeUSfcJYHsSNzZpu3kxFPVsuxM+z98zpyAYvxRG4bcGuA== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 4VNqks3rLhzJjL; Tue, 23 Apr 2024 05:03:17 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.17.1/8.17.1) with ESMTP id 43N53Hdn081672; Tue, 23 Apr 2024 05:03:17 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.17.1/8.17.1/Submit) id 43N53HWZ081669; Tue, 23 Apr 2024 05:03:17 GMT (envelope-from git) Date: Tue, 23 Apr 2024 05:03:17 GMT Message-Id: <202404230503.43N53HWZ081669@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: Warner Losh Subject: git: bac2eea13ae3 - main - swab.c(libc): use a simplified version of byte swapping List-Id: Commit messages for all branches of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-all List-Help: List-Post: List-Subscribe: List-Unsubscribe: X-BeenThere: dev-commits-src-all@freebsd.org Sender: owner-dev-commits-src-all@FreeBSD.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: imp X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: bac2eea13ae3e4dc8fd2aec261b2a18930138495 Auto-Submitted: auto-generated The branch main has been updated by imp: URL: https://cgit.FreeBSD.org/src/commit/?id=bac2eea13ae3e4dc8fd2aec261b2a18930138495 commit bac2eea13ae3e4dc8fd2aec261b2a18930138495 Author: rilysh AuthorDate: 2024-04-22 21:52:25 +0000 Commit: Warner Losh CommitDate: 2024-04-23 05:01:54 +0000 swab.c(libc): use a simplified version of byte swapping This version of swab function simplifies the logic of swapping adjacent bytes. Previous version of swab() used an arbitrary unrolling, which was relevant back in the day but unnecessary for modern compilers, as if the input size is known at compile time, they can do it automatically. This version of swab() is inspired by musl. A similar version can be found at: https://github.com/openbsd/src/blob/master/lib/libc/string/swab.c Signed-off-by: rilysh Reviewed by: imp Pull Request: https://github.com/freebsd/freebsd-src/pull/1086 --- lib/libc/string/swab.c | 58 ++++++++++---------------------------------------- 1 file changed, 11 insertions(+), 47 deletions(-) diff --git a/lib/libc/string/swab.c b/lib/libc/string/swab.c index e3765fa08d07..2b044d68ca46 100644 --- a/lib/libc/string/swab.c +++ b/lib/libc/string/swab.c @@ -1,35 +1,6 @@ /*- - * SPDX-License-Identifier: BSD-3-Clause - * - * Copyright (c) 1988, 1993 - * The Regents of the University of California. All rights reserved. - * - * This code is derived from software contributed to Berkeley by - * Jeffrey Mogul. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * 1. Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in the - * documentation and/or other materials provided with the distribution. - * 3. Neither the name of the University nor the names of its contributors - * may be used to endorse or promote products derived from this software - * without specific prior written permission. - * - * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND - * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE - * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE - * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE - * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL - * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS - * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) - * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT - * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY - * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF - * SUCH DAMAGE. + * SPDX-License-Identifier: BSD-2-Clause + * Copyright (c) 2024 rilysh */ #include @@ -37,22 +8,15 @@ void swab(const void * __restrict from, void * __restrict to, ssize_t len) { - unsigned char temp; - size_t n; - const unsigned char *fp; - unsigned char *tp; + const unsigned char *f = from; + unsigned char *t = to; - if (len <= 0) - return; - n = (size_t)len >> 1; - fp = (const unsigned char *)from; - tp = (unsigned char *)to; -#define STEP temp = *fp++,*tp++ = *fp++,*tp++ = temp - /* round to multiple of 8 */ - for (; n & 0x7; --n) - STEP; - for (n >>= 3; n > 0; --n) { - STEP; STEP; STEP; STEP; - STEP; STEP; STEP; STEP; + while (len > 1) { + t[0] = f[1]; + t[1] = f[0]; + + f += 2; + t += 2; + len -= 2; } }