From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by sourceware.org (Postfix) with ESMTPS id 10C683882648 for ; Thu, 13 Jun 2024 12:39:28 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 10C683882648 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=redhat.com ARC-Filter: OpenARC Filter v1.0.0 sourceware.org 10C683882648 Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1718282369; cv=none; b=MLjndDssoXTreM2aMlMvapuHzhJtLFtaz52lJv7AYfP6fAQ4SqHwkZ6h8S47TQUnIA8p7Un/a/VZ6xLSAp7YixLyC2Tjij7aY2WIq9LjvaCDetotR658JlHZOhqukmHos3q+i46aDDfRenWzdyTDYQ8liViFhEnU86nvCSzjtCg= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1718282369; c=relaxed/simple; bh=Rhym58xFFID43eCoZO/jPMI1EtfXxaFsBsO45zNJbYc=; h=DKIM-Signature:Date:From:To:Subject:Message-ID:MIME-Version; b=RaWr2gfMQHjPrPmoYUnFqXHaxDlMvC+a53gxA+Ig9ZfrV46On7ry1n84hLrHotT2h0gDmilt7rzMpVUrPugCMoAMHNgGHmp11fRD7Lu9TErDD6fhrrDmE1p23mdoBMfbyt4K8EKDNY+uBolsVsAJMkkMNyDos8kpc/wDBtNJEbs= ARC-Authentication-Results: i=1; server2.sourceware.org DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1718282367; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=fyQaQJoUplfP2Wtuq40oEekXZFbsq5fVEuDPLaMn86E=; b=Emd/Vwr33zvoWMsbDlN7XQml0vAFz4NBOL3sxFnGILi/Hxrg2+oQC+yL2xFiv7s1PgKNpf mFBgffG07T+WTYhUBxDYhGcPsVgFl6S8445Q70gY2KfgQeH+te5bkgiqBdeHBxWr9Q7qf9 7DRmsa2s4kW2LLHIw3+OE5Pg3VA4C3k= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-175--UweCcqBOBCL0QSIawRlqA-1; Thu, 13 Jun 2024 08:39:24 -0400 X-MC-Unique: -UweCcqBOBCL0QSIawRlqA-1 Received: from mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.40]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id CF449195608E; Thu, 13 Jun 2024 12:39:22 +0000 (UTC) Received: from localhost (unknown [10.39.192.128]) by mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 26165197C444; Thu, 13 Jun 2024 12:39:20 +0000 (UTC) Date: Thu, 13 Jun 2024 13:39:14 +0100 From: Jonathan Wakely To: Ken Matsui Cc: gcc-patches@gcc.gnu.org, libstdc++@gcc.gnu.org Subject: Re: [PATCH v26 10/13] libstdc++: Optimize std::decay compilation performance Message-ID: References: <20240510161405.194750-21-kmatsui@gcc.gnu.org> <20240511090130.248174-1-kmatsui@gcc.gnu.org> <20240511090130.248174-10-kmatsui@gcc.gnu.org> MIME-Version: 1.0 In-Reply-To: <20240511090130.248174-10-kmatsui@gcc.gnu.org> X-Clacks-Overhead: GNU Terry Pratchett X-Scanned-By: MIMEDefang 3.0 on 10.30.177.40 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline X-Spam-Status: No, score=-10.8 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,GIT_PATCH_0,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H4,RCVD_IN_MSPIKE_WL,RCVD_IN_SBL_CSS,SPF_HELO_NONE,SPF_NONE,TXREP,T_SCC_BODY_TEXT_LINE autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On 11/05/24 02:01 -0700, Ken Matsui wrote: >This patch optimizes the compilation performance of std::decay >by dispatching to the new __decay built-in trait. OK, thanks. >libstdc++-v3/ChangeLog: > > * include/std/type_traits (decay): Use __decay built-in trait. > >Signed-off-by: Ken Matsui >--- > libstdc++-v3/include/std/type_traits | 6 ++++++ > 1 file changed, 6 insertions(+) > >diff --git a/libstdc++-v3/include/std/type_traits b/libstdc++-v3/include/std/type_traits >index 824cad90a25..4cc587d4e08 100644 >--- a/libstdc++-v3/include/std/type_traits >+++ b/libstdc++-v3/include/std/type_traits >@@ -2316,6 +2316,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION > > /// @cond undocumented > >+#if _GLIBCXX_USE_BUILTIN_TRAIT(__decay) >+ template >+ struct decay >+ { using type = __decay(_Tp); }; >+#else > // Decay trait for arrays and functions, used for perfect forwarding > // in make_pair, make_tuple, etc. > template >@@ -2347,6 +2352,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION > template > struct decay<_Tp&&> > { using type = typename __decay_selector<_Tp>::type; }; >+#endif > > /// @cond undocumented > >-- >2.44.0 >