From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41633) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bmRqv-0002IX-O7 for qemu-devel@nongnu.org; Tue, 20 Sep 2016 16:41:18 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bmRqq-0004Kt-Qw for qemu-devel@nongnu.org; Tue, 20 Sep 2016 16:41:16 -0400 Received: from mail-yw0-x22d.google.com ([2607:f8b0:4002:c05::22d]:36836) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bmRqq-0004KU-LQ for qemu-devel@nongnu.org; Tue, 20 Sep 2016 16:41:12 -0400 Received: by mail-yw0-x22d.google.com with SMTP id t67so20799847ywg.3 for ; Tue, 20 Sep 2016 13:41:12 -0700 (PDT) Sender: Richard Henderson References: <1473945360-13663-1-git-send-email-pbonzini@redhat.com> From: Richard Henderson Message-ID: <98a4be9e-8e90-b2b9-9b66-ab673c94e2c6@twiddle.net> Date: Tue, 20 Sep 2016 13:41:08 -0700 MIME-Version: 1.0 In-Reply-To: <1473945360-13663-1-git-send-email-pbonzini@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] tcg: try sti when moving a constant into a dead memory temp List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini , qemu-devel@nongnu.org On 09/15/2016 06:16 AM, Paolo Bonzini wrote: > This comes from free from unifying tcg_reg_alloc_mov and > tcg_reg_alloc_movi's handling of TEMP_VAL_CONST. It triggers > often on moves to cc_dst, such as the following translation > of "sub $0x3c,%esp": > > before: after: > subl $0x3c,%ebp subl $0x3c,%ebp > movl %ebp,0x10(%r14) movl %ebp,0x10(%r14) > movl $0x3c,%ebx movl $0x3c,0x2c(%r14) > movl %ebx,0x2c(%r14) What's the input here? From just this snippet it looks as if we should have converted both of them to an immediate store. r~