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=-19.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 B8154C433B4 for ; Fri, 14 May 2021 10:04:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9F182613BC for ; Fri, 14 May 2021 10:04:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232871AbhENKF1 (ORCPT ); Fri, 14 May 2021 06:05:27 -0400 Received: from mail.kernel.org ([198.145.29.99]:59442 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230326AbhENKFY (ORCPT ); Fri, 14 May 2021 06:05:24 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8FCA6613BC; Fri, 14 May 2021 10:04:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1620986653; bh=cCVVu+62kA2pXYPTc6FjelykeA3Lz1iR9GcRa0bvZ+0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Mrb4cX8JGEo6YhS2lWZqeQfpB0XaIgV/M2wRMQPF+XrF/24xEgD1w8712MTzypyh1 5nwfzFFnMKLsizZaTAqLDmRgF9DHsPJCuq56qOhXyjkJu+f4YoHaaPyjpcE92g8zDW KHm4fyhb22gKrnZjv7THODKqSHh42FqpgstOMB3b29ETIS5IaaLqCcrHuVfmIf10x3 yaDySR/yjWGCuqyMTRColt6PSseJNxdAetcSo3Cz16k/JNhLOaOJowDifZuXQ8q+Zw 57HdfecvPHAlBPZESMxdkz106d0cdnTQ2ShxgC2aHd+r43vL5A0PYVG4qKR/LpT/44 Y4BSPjQkndCdw== From: Arnd Bergmann To: linux-arch@vger.kernel.org Cc: Linus Torvalds , Vineet Gupta , Arnd Bergmann , Russell King , Nathan Chancellor , Nick Desaulniers , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com Subject: [PATCH v2 06/13] asm-generic: unaligned: remove byteshift helpers Date: Fri, 14 May 2021 12:00:54 +0200 Message-Id: <20210514100106.3404011-7-arnd@kernel.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210514100106.3404011-1-arnd@kernel.org> References: <20210514100106.3404011-1-arnd@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Arnd Bergmann In theory, compilers should be able to work this out themselves so we can use a simpler version based on the swab() helpers. I have verified that this works on all supported compiler versions (gcc-4.9 and up, clang-10 and up). Looking at the object code produced by gcc-11, I found that the impact is mostly a change in inlining decisions that lead to slightly larger code. In other cases, this version produces explicit byte swaps in place of separate byte access, or comparing against pre-swapped constants. While the source code is clearly simpler, I have not seen an indication of the new version actually producing better code on Arm, so maybe we want to skip this after all. From what I can tell, gcc recognizes the byteswap pattern in the byteshift.h header and can turn it into explicit instructions, but it does not turn a __builtin_bswap32() back into individual bytes when that would result in better output, e.g. when storing a byte-reversed constant. Suggested-by: Linus Torvalds Signed-off-by: Arnd Bergmann --- arch/arm/include/asm/unaligned.h | 2 - include/asm-generic/unaligned.h | 2 - include/linux/unaligned/be_byteshift.h | 71 -------------------------- include/linux/unaligned/be_struct.h | 30 +++++++++++ include/linux/unaligned/le_byteshift.h | 71 -------------------------- include/linux/unaligned/le_struct.h | 30 +++++++++++ 6 files changed, 60 insertions(+), 146 deletions(-) delete mode 100644 include/linux/unaligned/be_byteshift.h delete mode 100644 include/linux/unaligned/le_byteshift.h diff --git a/arch/arm/include/asm/unaligned.h b/arch/arm/include/asm/unaligned.h index ab905ffcf193..3c5248fb4cdc 100644 --- a/arch/arm/include/asm/unaligned.h +++ b/arch/arm/include/asm/unaligned.h @@ -10,13 +10,11 @@ #if defined(__LITTLE_ENDIAN) # include -# include # include # define get_unaligned __get_unaligned_le # define put_unaligned __put_unaligned_le #elif defined(__BIG_ENDIAN) # include -# include # include # define get_unaligned __get_unaligned_be # define put_unaligned __put_unaligned_be diff --git a/include/asm-generic/unaligned.h b/include/asm-generic/unaligned.h index 374c940e9be1..d79df721ae60 100644 --- a/include/asm-generic/unaligned.h +++ b/include/asm-generic/unaligned.h @@ -16,7 +16,6 @@ #if defined(__LITTLE_ENDIAN) # ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS # include -# include # endif # include # define get_unaligned __get_unaligned_le @@ -24,7 +23,6 @@ #elif defined(__BIG_ENDIAN) # ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS # include -# include # endif # include # define get_unaligned __get_unaligned_be diff --git a/include/linux/unaligned/be_byteshift.h b/include/linux/unaligned/be_byteshift.h deleted file mode 100644 index c43ff5918c8a..000000000000 --- a/include/linux/unaligned/be_byteshift.h +++ /dev/null @@ -1,71 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -#ifndef _LINUX_UNALIGNED_BE_BYTESHIFT_H -#define _LINUX_UNALIGNED_BE_BYTESHIFT_H - -#include - -static inline u16 __get_unaligned_be16(const u8 *p) -{ - return p[0] << 8 | p[1]; -} - -static inline u32 __get_unaligned_be32(const u8 *p) -{ - return p[0] << 24 | p[1] << 16 | p[2] << 8 | p[3]; -} - -static inline u64 __get_unaligned_be64(const u8 *p) -{ - return (u64)__get_unaligned_be32(p) << 32 | - __get_unaligned_be32(p + 4); -} - -static inline void __put_unaligned_be16(u16 val, u8 *p) -{ - *p++ = val >> 8; - *p++ = val; -} - -static inline void __put_unaligned_be32(u32 val, u8 *p) -{ - __put_unaligned_be16(val >> 16, p); - __put_unaligned_be16(val, p + 2); -} - -static inline void __put_unaligned_be64(u64 val, u8 *p) -{ - __put_unaligned_be32(val >> 32, p); - __put_unaligned_be32(val, p + 4); -} - -static inline u16 get_unaligned_be16(const void *p) -{ - return __get_unaligned_be16(p); -} - -static inline u32 get_unaligned_be32(const void *p) -{ - return __get_unaligned_be32(p); -} - -static inline u64 get_unaligned_be64(const void *p) -{ - return __get_unaligned_be64(p); -} - -static inline void put_unaligned_be16(u16 val, void *p) -{ - __put_unaligned_be16(val, p); -} - -static inline void put_unaligned_be32(u32 val, void *p) -{ - __put_unaligned_be32(val, p); -} - -static inline void put_unaligned_be64(u64 val, void *p) -{ - __put_unaligned_be64(val, p); -} - -#endif /* _LINUX_UNALIGNED_BE_BYTESHIFT_H */ diff --git a/include/linux/unaligned/be_struct.h b/include/linux/unaligned/be_struct.h index 15ea503a13fc..76d9fe297c33 100644 --- a/include/linux/unaligned/be_struct.h +++ b/include/linux/unaligned/be_struct.h @@ -34,4 +34,34 @@ static inline void put_unaligned_be64(u64 val, void *p) __put_unaligned_cpu64(val, p); } +static inline u16 get_unaligned_le16(const void *p) +{ + return swab16(__get_unaligned_cpu16((const u8 *)p)); +} + +static inline u32 get_unaligned_le32(const void *p) +{ + return swab32(__get_unaligned_cpu32((const u8 *)p)); +} + +static inline u64 get_unaligned_le64(const void *p) +{ + return swab64(__get_unaligned_cpu64((const u8 *)p)); +} + +static inline void put_unaligned_le16(u16 val, void *p) +{ + __put_unaligned_cpu16(swab16(val), p); +} + +static inline void put_unaligned_le32(u32 val, void *p) +{ + __put_unaligned_cpu32(swab32(val), p); +} + +static inline void put_unaligned_le64(u64 val, void *p) +{ + __put_unaligned_cpu64(swab64(val), p); +} + #endif /* _LINUX_UNALIGNED_BE_STRUCT_H */ diff --git a/include/linux/unaligned/le_byteshift.h b/include/linux/unaligned/le_byteshift.h deleted file mode 100644 index 2248dcb0df76..000000000000 --- a/include/linux/unaligned/le_byteshift.h +++ /dev/null @@ -1,71 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -#ifndef _LINUX_UNALIGNED_LE_BYTESHIFT_H -#define _LINUX_UNALIGNED_LE_BYTESHIFT_H - -#include - -static inline u16 __get_unaligned_le16(const u8 *p) -{ - return p[0] | p[1] << 8; -} - -static inline u32 __get_unaligned_le32(const u8 *p) -{ - return p[0] | p[1] << 8 | p[2] << 16 | p[3] << 24; -} - -static inline u64 __get_unaligned_le64(const u8 *p) -{ - return (u64)__get_unaligned_le32(p + 4) << 32 | - __get_unaligned_le32(p); -} - -static inline void __put_unaligned_le16(u16 val, u8 *p) -{ - *p++ = val; - *p++ = val >> 8; -} - -static inline void __put_unaligned_le32(u32 val, u8 *p) -{ - __put_unaligned_le16(val >> 16, p + 2); - __put_unaligned_le16(val, p); -} - -static inline void __put_unaligned_le64(u64 val, u8 *p) -{ - __put_unaligned_le32(val >> 32, p + 4); - __put_unaligned_le32(val, p); -} - -static inline u16 get_unaligned_le16(const void *p) -{ - return __get_unaligned_le16(p); -} - -static inline u32 get_unaligned_le32(const void *p) -{ - return __get_unaligned_le32(p); -} - -static inline u64 get_unaligned_le64(const void *p) -{ - return __get_unaligned_le64(p); -} - -static inline void put_unaligned_le16(u16 val, void *p) -{ - __put_unaligned_le16(val, p); -} - -static inline void put_unaligned_le32(u32 val, void *p) -{ - __put_unaligned_le32(val, p); -} - -static inline void put_unaligned_le64(u64 val, void *p) -{ - __put_unaligned_le64(val, p); -} - -#endif /* _LINUX_UNALIGNED_LE_BYTESHIFT_H */ diff --git a/include/linux/unaligned/le_struct.h b/include/linux/unaligned/le_struct.h index 9977987883a6..22f90a4afaa5 100644 --- a/include/linux/unaligned/le_struct.h +++ b/include/linux/unaligned/le_struct.h @@ -34,4 +34,34 @@ static inline void put_unaligned_le64(u64 val, void *p) __put_unaligned_cpu64(val, p); } +static inline u16 get_unaligned_be16(const void *p) +{ + return swab16(__get_unaligned_cpu16((const u8 *)p)); +} + +static inline u32 get_unaligned_be32(const void *p) +{ + return swab32(__get_unaligned_cpu32((const u8 *)p)); +} + +static inline u64 get_unaligned_be64(const void *p) +{ + return swab64(__get_unaligned_cpu64((const u8 *)p)); +} + +static inline void put_unaligned_be16(u16 val, void *p) +{ + __put_unaligned_cpu16(swab16(val), p); +} + +static inline void put_unaligned_be32(u32 val, void *p) +{ + __put_unaligned_cpu32(swab32(val), p); +} + +static inline void put_unaligned_be64(u64 val, void *p) +{ + __put_unaligned_cpu64(swab64(val), p); +} + #endif /* _LINUX_UNALIGNED_LE_STRUCT_H */ -- 2.29.2