From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 4280 invoked by alias); 17 Dec 2015 18:09:33 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Received: (qmail 4265 invoked by uid 89); 17 Dec 2015 18:09:33 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.6 required=5.0 tests=AWL,BAYES_00,FREEMAIL_FROM,RCVD_IN_DNSWL_LOW,SPF_PASS autolearn=ham version=3.3.2 spammy=ubizjakgmailcom, ubizjak@gmail.com, our X-HELO: mail-qg0-f53.google.com Received: from mail-qg0-f53.google.com (HELO mail-qg0-f53.google.com) (209.85.192.53) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES128-GCM-SHA256 encrypted) ESMTPS; Thu, 17 Dec 2015 18:09:31 +0000 Received: by mail-qg0-f53.google.com with SMTP id c96so14059169qgd.3 for ; Thu, 17 Dec 2015 10:09:31 -0800 (PST) MIME-Version: 1.0 X-Received: by 10.140.169.139 with SMTP id p133mr55092891qhp.50.1450375769738; Thu, 17 Dec 2015 10:09:29 -0800 (PST) Received: by 10.55.181.70 with HTTP; Thu, 17 Dec 2015 10:09:29 -0800 (PST) In-Reply-To: References: <20151216232951.GA17976@intel.com> Date: Thu, 17 Dec 2015 18:09:00 -0000 Message-ID: Subject: Re: [PATCH] PR target/68937: i686: -fno-plt produces wrong code (maybe only with tailcall From: "H.J. Lu" To: Uros Bizjak Cc: "gcc-patches@gcc.gnu.org" Content-Type: text/plain; charset=UTF-8 X-IsSubscribed: yes X-SW-Source: 2015-12/txt/msg01806.txt.bz2 On Thu, Dec 17, 2015 at 8:11 AM, H.J. Lu wrote: > On Thu, Dec 17, 2015 at 7:50 AM, H.J. Lu wrote: >> On Thu, Dec 17, 2015 at 5:42 AM, Uros Bizjak wrote: >>> On Thu, Dec 17, 2015 at 2:00 PM, H.J. Lu wrote: >>>> On Thu, Dec 17, 2015 at 2:04 AM, Uros Bizjak wrote: >>>>> On Thu, Dec 17, 2015 at 12:29 AM, H.J. Lu wrote: >>>>>> Since sibcall never returns, we can only use call-clobbered register >>>>>> as GOT base. Otherwise, callee-saved register used as GOT base won't >>>>>> be properly restored. >>>>>> >>>>>> Tested on x86-64 with -m32. OK for trunk? >>>>> >>>>> You don't have to add explicit clobber for members of "CLOBBERED_REGS" >>>>> class, and register_no_elim_operand predicate should be used with "U" >>>>> constraint. Also, please introduce new predicate, similar to how >>>>> GOT_memory_operand is defined and handled. >>>>> >>>> >>>> Here is the updated patch. There is a predicate already, >>>> sibcall_memory_operand. It allows any registers to >>>> be as GOT base, which is the root of our problem. >>>> This patch removes GOT slot from it and handles >>>> sibcall over GOT slot with *sibcall_GOT_32 and >>>> *sibcall_value_GOT_32 patterns. Since I need to >>>> expose constraints on GOT base register to RA, >>>> I have to use 2 operands, GOT base and function >>>> symbol, to describe sibcall over 32-bit GOT slot. >>> >>> Please use >>> >>> (mem:SI (plus:SI >>> (match_operand:SI 0 "register_no_elim_operand" "U") >>> (match_operand:SI 1 "GOT32_symbol_operand"))) >>> ... >>> >>> to avoid manual rebuild of the operand. >>> >> >> Is this OK? >> > > An updated patch to allow sibcall_memory_operand for RTL > expansion. OK for trunk if there is no regression? > There is no regressions on x86-64 with -m32. OK for trunk? -- H.J.