Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751419AbdFETHV (ORCPT ); Mon, 5 Jun 2017 15:07:21 -0400 Received: from mail.kernel.org ([198.145.29.99]:44762 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751395AbdFETHS (ORCPT ); Mon, 5 Jun 2017 15:07:18 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5DDA423A50 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=atull@kernel.org From: Alan Tull To: Greg Kroah-Hartman Cc: linux-kernel@vger.kernel.org, linux-fpga@vger.kernel.org, Moritz Fischer , delicious.quinoa@gmail.com, Joshua Clayton , Alan Tull Subject: [PATCH 08/10] lib: add bitrev8x4() Date: Mon, 5 Jun 2017 14:07:39 -0500 Message-Id: <20170605190741.10508-9-atull@kernel.org> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170605190741.10508-1-atull@kernel.org> References: <20170605190741.10508-1-atull@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1459 Lines: 57 From: Joshua Clayton Add a function to reverse bytes within a 32 bit word. Operate on a u32 rather than individual bytes. Signed-off-by: Joshua Clayton Signed-off-by: Alan Tull --- include/linux/bitrev.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/include/linux/bitrev.h b/include/linux/bitrev.h index fb790b8449c1..b97be27e5a85 100644 --- a/include/linux/bitrev.h +++ b/include/linux/bitrev.h @@ -29,6 +29,8 @@ static inline u32 __bitrev32(u32 x) #endif /* CONFIG_HAVE_ARCH_BITREVERSE */ +#define __bitrev8x4(x) (__bitrev32(swab32(x))) + #define __constant_bitrev32(x) \ ({ \ u32 __x = x; \ @@ -50,6 +52,15 @@ static inline u32 __bitrev32(u32 x) __x; \ }) +#define __constant_bitrev8x4(x) \ +({ \ + u32 __x = x; \ + __x = ((__x & (u32)0xF0F0F0F0UL) >> 4) | ((__x & (u32)0x0F0F0F0FUL) << 4); \ + __x = ((__x & (u32)0xCCCCCCCCUL) >> 2) | ((__x & (u32)0x33333333UL) << 2); \ + __x = ((__x & (u32)0xAAAAAAAAUL) >> 1) | ((__x & (u32)0x55555555UL) << 1); \ + __x; \ +}) + #define __constant_bitrev8(x) \ ({ \ u8 __x = x; \ @@ -75,6 +86,14 @@ static inline u32 __bitrev32(u32 x) __bitrev16(__x); \ }) +#define bitrev8x4(x) \ +({ \ + u32 __x = x; \ + __builtin_constant_p(__x) ? \ + __constant_bitrev8x4(__x) : \ + __bitrev8x4(__x); \ + }) + #define bitrev8(x) \ ({ \ u8 __x = x; \ -- 2.11.0