From owner-svn-src-all@freebsd.org Wed Oct 23 16:41:32 2019 Return-Path: <owner-svn-src-all@freebsd.org> Delivered-To: svn-src-all@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 8FC811579A3; Wed, 23 Oct 2019 16:41:32 +0000 (UTC) (envelope-from jhb@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) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 46yx3J3Fn0z4L6P; Wed, 23 Oct 2019 16:41:32 +0000 (UTC) (envelope-from jhb@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 53F16275FE; Wed, 23 Oct 2019 16:41:32 +0000 (UTC) (envelope-from jhb@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id x9NGfWen031408; Wed, 23 Oct 2019 16:41:32 GMT (envelope-from jhb@FreeBSD.org) Received: (from jhb@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id x9NGfWeU031407; Wed, 23 Oct 2019 16:41:32 GMT (envelope-from jhb@FreeBSD.org) Message-Id: <201910231641.x9NGfWeU031407@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: jhb set sender to jhb@FreeBSD.org using -f From: John Baldwin <jhb@FreeBSD.org> Date: Wed, 23 Oct 2019 16:41:32 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r353931 - head/sys/riscv/include X-SVN-Group: head X-SVN-Commit-Author: jhb X-SVN-Commit-Paths: head/sys/riscv/include X-SVN-Commit-Revision: 353931 X-SVN-Commit-Repository: base 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: 2.1.29 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" <svn-src-all.freebsd.org> List-Unsubscribe: <https://lists.freebsd.org/mailman/options/svn-src-all>, <mailto:svn-src-all-request@freebsd.org?subject=unsubscribe> List-Archive: <http://lists.freebsd.org/pipermail/svn-src-all/> List-Post: <mailto:svn-src-all@freebsd.org> List-Help: <mailto:svn-src-all-request@freebsd.org?subject=help> List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/svn-src-all>, <mailto:svn-src-all-request@freebsd.org?subject=subscribe> X-List-Received-Date: Wed, 23 Oct 2019 16:41:32 -0000 Author: jhb Date: Wed Oct 23 16:41:31 2019 New Revision: 353931 URL: https://svnweb.freebsd.org/changeset/base/353931 Log: Fix atomic_*cmpset32 on riscv64 with clang. The lr.w instruction used to read the value from memory sign-extends the value read from memory. GCC sign-extends the 32-bit comparison value passed in whereas clang currently does not. As a result, if the value being compared has the MSB set, the comparison fails for matching 32-bit values when compiled with clang. Use a cast to explicitly sign-extend the unsigned comparison value. This works with both GCC and clang. There is commentary in the RISC-V spec that suggests that GCC's approach is more correct, but it is not clear if the commentary in the RISC-V spec is binding. Reviewed by: mhorne Obtained from: Axiado MFC after: 2 weeks Sponsored by: DARPA Differential Revision: https://reviews.freebsd.org/D22084 Modified: head/sys/riscv/include/atomic.h Modified: head/sys/riscv/include/atomic.h ============================================================================== --- head/sys/riscv/include/atomic.h Wed Oct 23 16:06:47 2019 (r353930) +++ head/sys/riscv/include/atomic.h Wed Oct 23 16:41:31 2019 (r353931) @@ -182,7 +182,7 @@ atomic_cmpset_32(volatile uint32_t *p, uint32_t cmpval "bnez %1, 0b\n" "1:" : "=&r" (tmp), "=&r" (res), "+A" (*p) - : "rJ" (cmpval), "rJ" (newval) + : "rJ" ((long)(int32_t)cmpval), "rJ" (newval) : "memory"); return (!res); @@ -207,7 +207,7 @@ atomic_fcmpset_32(volatile uint32_t *p, uint32_t *cmpv "sw %0, %3\n" /* Save old value */ "2:" : "=&r" (tmp), "=&r" (res), "+A" (*p), "+A" (*cmpval) - : "rJ" (*cmpval), "rJ" (newval) + : "rJ" ((long)(int32_t)*cmpval), "rJ" (newval) : "memory"); return (!res);