From owner-svn-src-stable-12@freebsd.org Sat May 11 09:57:01 2019 Return-Path: Delivered-To: svn-src-stable-12@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 0A8521596FF3; Sat, 11 May 2019 09:57:01 +0000 (UTC) (envelope-from dim@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 4A5EA82F7A; Sat, 11 May 2019 09:57:00 +0000 (UTC) (envelope-from dim@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 B05EF19FD5; Sat, 11 May 2019 09:56:59 +0000 (UTC) (envelope-from dim@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id x4B9ux1l032812; Sat, 11 May 2019 09:56:59 GMT (envelope-from dim@FreeBSD.org) Received: (from dim@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id x4B9ux0r032811; Sat, 11 May 2019 09:56:59 GMT (envelope-from dim@FreeBSD.org) Message-Id: <201905110956.x4B9ux0r032811@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: dim set sender to dim@FreeBSD.org using -f From: Dimitry Andric Date: Sat, 11 May 2019 09:56:59 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-12@freebsd.org Subject: svn commit: r347486 - in stable: 11/contrib/llvm/lib/Target/ARM 12/contrib/llvm/lib/Target/ARM X-SVN-Group: stable-12 X-SVN-Commit-Author: dim X-SVN-Commit-Paths: in stable: 11/contrib/llvm/lib/Target/ARM 12/contrib/llvm/lib/Target/ARM X-SVN-Commit-Revision: 347486 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 4A5EA82F7A X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org X-Spamd-Result: default: False [-2.95 / 15.00]; local_wl_from(0.00)[FreeBSD.org]; NEURAL_HAM_MEDIUM(-1.00)[-0.995,0]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; NEURAL_HAM_SHORT(-0.95)[-0.950,0]; ASN(0.00)[asn:11403, ipnet:2610:1c1:1::/48, country:US] X-BeenThere: svn-src-stable-12@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: SVN commit messages for only the 12-stable src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 11 May 2019 09:57:01 -0000 Author: dim Date: Sat May 11 09:56:59 2019 New Revision: 347486 URL: https://svnweb.freebsd.org/changeset/base/347486 Log: MFC r347243: Pull in r360099 from upstream llvm trunk (by Eli Friedman): [ARM] Glue register copies to tail calls. This generally follows what other targets do. I don't completely understand why the special case for tail calls existed in the first place; even when the code was committed in r105413, call lowering didn't work in the way described in the comments. Stack protector lowering breaks if the register copies are not glued to a tail call: we have to insert the stack protector check before the tail call, and we choose the location based on the assumption that all physical register dependencies of a tail call are adjacent to the tail call. (See FindSplitPointForStackProtector.) This is sort of fragile, but I don't see any reason to break that assumption. I'm guessing nobody has seen this before just because it's hard to convince the scheduler to actually schedule the code in a way that breaks; even without the glue, the only computation that could actually be scheduled after the register copies is the computation of the call address, and the scheduler usually prefers to schedule that before the copies anyway. Fixes https://bugs.llvm.org/show_bug.cgi?id=41417 Differential Revision: https://reviews.llvm.org/D60427 This should fix several instances of "Bad machine code: Using an undefined physical register", when compiling ports such as multimedia/vlc, audio/alsa-lib and devel/avro-c for armv6, with -fstack-protector-strong. Reported by: jbeich PR: 237074, 237783, 237784 Modified: stable/12/contrib/llvm/lib/Target/ARM/ARMISelLowering.cpp Directory Properties: stable/12/ (props changed) Changes in other areas also in this revision: Modified: stable/11/contrib/llvm/lib/Target/ARM/ARMISelLowering.cpp Directory Properties: stable/11/ (props changed) Modified: stable/12/contrib/llvm/lib/Target/ARM/ARMISelLowering.cpp ============================================================================== --- stable/12/contrib/llvm/lib/Target/ARM/ARMISelLowering.cpp Sat May 11 09:12:13 2019 (r347485) +++ stable/12/contrib/llvm/lib/Target/ARM/ARMISelLowering.cpp Sat May 11 09:56:59 2019 (r347486) @@ -1984,32 +1984,10 @@ ARMTargetLowering::LowerCall(TargetLowering::CallLower // Build a sequence of copy-to-reg nodes chained together with token chain // and flag operands which copy the outgoing args into the appropriate regs. SDValue InFlag; - // Tail call byval lowering might overwrite argument registers so in case of - // tail call optimization the copies to registers are lowered later. - if (!isTailCall) - for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) { - Chain = DAG.getCopyToReg(Chain, dl, RegsToPass[i].first, - RegsToPass[i].second, InFlag); - InFlag = Chain.getValue(1); - } - - // For tail calls lower the arguments to the 'real' stack slot. - if (isTailCall) { - // Force all the incoming stack arguments to be loaded from the stack - // before any new outgoing arguments are stored to the stack, because the - // outgoing stack slots may alias the incoming argument stack slots, and - // the alias isn't otherwise explicit. This is slightly more conservative - // than necessary, because it means that each store effectively depends - // on every argument instead of just those arguments it would clobber. - - // Do not flag preceding copytoreg stuff together with the following stuff. - InFlag = SDValue(); - for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) { - Chain = DAG.getCopyToReg(Chain, dl, RegsToPass[i].first, - RegsToPass[i].second, InFlag); - InFlag = Chain.getValue(1); - } - InFlag = SDValue(); + for (unsigned i = 0, e = RegsToPass.size(); i != e; ++i) { + Chain = DAG.getCopyToReg(Chain, dl, RegsToPass[i].first, + RegsToPass[i].second, InFlag); + InFlag = Chain.getValue(1); } // If the callee is a GlobalAddress/ExternalSymbol node (quite common, every