From owner-svn-src-all@FreeBSD.ORG Sun Jun 30 10:38:21 2013 Return-Path: Delivered-To: svn-src-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by hub.freebsd.org (Postfix) with ESMTP id 2FA56EE8; Sun, 30 Jun 2013 10:38:21 +0000 (UTC) (envelope-from ed@FreeBSD.org) Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:1900:2254:2068::e6a:0]) by mx1.freebsd.org (Postfix) with ESMTP id 083F71AA5; Sun, 30 Jun 2013 10:38:21 +0000 (UTC) Received: from svn.freebsd.org ([127.0.1.70]) by svn.freebsd.org (8.14.7/8.14.7) with ESMTP id r5UAcKs9048232; Sun, 30 Jun 2013 10:38:20 GMT (envelope-from ed@svn.freebsd.org) Received: (from ed@localhost) by svn.freebsd.org (8.14.7/8.14.5/Submit) id r5UAcKbX048231; Sun, 30 Jun 2013 10:38:20 GMT (envelope-from ed@svn.freebsd.org) Message-Id: <201306301038.r5UAcKbX048231@svn.freebsd.org> From: Ed Schouten Date: Sun, 30 Jun 2013 10:38:20 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r252413 - head/sys/sys X-SVN-Group: head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 30 Jun 2013 10:38:21 -0000 Author: ed Date: Sun Jun 30 10:38:20 2013 New Revision: 252413 URL: http://svnweb.freebsd.org/changeset/base/252413 Log: Make atomic_fetch_add() and atomic_fetch_sub() work for pointers with GCC 4.2. According to the standard, atomic_fetch_*() has to behave identical to regular arithmetic. This means that for pointer types, we have to apply the stride when doing addition/subtraction. The GCC documentation seems to imply this is done for __sync_*() as well. Unfortunately, both tests and Googling seems to reveal this is not really the case. Fix this by performing the multiplication with the stride manually. Modified: head/sys/sys/stdatomic.h Modified: head/sys/sys/stdatomic.h ============================================================================== --- head/sys/sys/stdatomic.h Sun Jun 30 08:59:33 2013 (r252412) +++ head/sys/sys/stdatomic.h Sun Jun 30 10:38:20 2013 (r252413) @@ -281,6 +281,8 @@ typedef _Atomic(__uintmax_t) atomic_uin #define atomic_store_explicit(object, desired, order) \ __atomic_store_n(&(object)->__val, desired, order) #else +#define __atomic_apply_stride(object, operand) \ + (((__typeof__((object)->__val))0) + (operand)) #define atomic_compare_exchange_strong_explicit(object, expected, \ desired, success, failure) __extension__ ({ \ __typeof__(expected) __ep = (expected); \ @@ -313,13 +315,15 @@ __extension__ ({ \ }) #endif #define atomic_fetch_add_explicit(object, operand, order) \ - ((void)(order), __sync_fetch_and_add(&(object)->__val, operand)) + ((void)(order), __sync_fetch_and_add(&(object)->__val, \ + __atomic_apply_stride(object, operand))) #define atomic_fetch_and_explicit(object, operand, order) \ ((void)(order), __sync_fetch_and_and(&(object)->__val, operand)) #define atomic_fetch_or_explicit(object, operand, order) \ ((void)(order), __sync_fetch_and_or(&(object)->__val, operand)) #define atomic_fetch_sub_explicit(object, operand, order) \ - ((void)(order), __sync_fetch_and_sub(&(object)->__val, operand)) + ((void)(order), __sync_fetch_and_sub(&(object)->__val, \ + __atomic_apply_stride(object, operand))) #define atomic_fetch_xor_explicit(object, operand, order) \ ((void)(order), __sync_fetch_and_xor(&(object)->__val, operand)) #define atomic_load_explicit(object, order) \