Date: Mon, 13 Jun 2016 16:48:27 +0000 (UTC) From: Ian Lepore <ian@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r301872 - head/sys/arm/include Message-ID: <201606131648.u5DGmRFb089449@repo.freebsd.org>
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Author: ian Date: Mon Jun 13 16:48:27 2016 New Revision: 301872 URL: https://svnweb.freebsd.org/changeset/base/301872 Log: Do not define __NO_STRICT_ALIGNMENT for armv6. While the requirements are no longer natural-alignment strict, there are still some restrictions. FreeBSD network code assumes data is naturally-aligned or is running on a platform with no restrictions; pointers are not annotated to indicate the data pointed to may be packed or unaligned. The clang optimizer can sometimes combine the load or store of a pair of adjacent 32-bit values into a single doubleword load/store, and that operation requires at least 4-byte alignment. __NO_STRICT_ALIGNMENT can lead to tcp headers being only 2-byte aligned. Note that alignment faults remain disabled on armv6, this change reverts only the defining of the symbol which leads to some overly-agressive code shortcuts when building common/shared drivers and network code for arm. Approved by: re(kib) Modified: head/sys/arm/include/_types.h Modified: head/sys/arm/include/_types.h ============================================================================== --- head/sys/arm/include/_types.h Mon Jun 13 11:19:06 2016 (r301871) +++ head/sys/arm/include/_types.h Mon Jun 13 16:48:27 2016 (r301872) @@ -43,10 +43,6 @@ #error this file needs sys/cdefs.h as a prerequisite #endif -#if __ARM_ARCH >= 6 -#define __NO_STRICT_ALIGNMENT -#endif - /* * Basic types upon which most other types are built. */
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