From a41da6d838174be7fb529470fd9d04936783d3cb Mon Sep 17 00:00:00 2001 From: Staf Verhaegen Date: Sat, 16 May 2020 11:47:27 +0200 Subject: [PATCH] Re: [libre-riscv-dev] Introduction and Questions --- 30/6f69e812cb83cce4ac1f835857c5112198f48f | 102 ++++++++++++++++++++++ 1 file changed, 102 insertions(+) create mode 100644 30/6f69e812cb83cce4ac1f835857c5112198f48f diff --git a/30/6f69e812cb83cce4ac1f835857c5112198f48f b/30/6f69e812cb83cce4ac1f835857c5112198f48f new file mode 100644 index 0000000..2fd23c4 --- /dev/null +++ b/30/6f69e812cb83cce4ac1f835857c5112198f48f @@ -0,0 +1,102 @@ +Return-path: +Envelope-to: publicinbox@libre-riscv.org +Delivery-date: Sat, 16 May 2020 10:47:30 +0100 +Received: from localhost ([::1] helo=libre-riscv.org) + by libre-soc.org with esmtp (Exim 4.89) + (envelope-from ) + id 1jZtPl-0005pq-Qi; Sat, 16 May 2020 10:47:29 +0100 +Received: from vps2.stafverhaegen.be ([85.10.201.15]) + by libre-soc.org with esmtp (Exim 4.89) + (envelope-from ) id 1jZtPk-0005pk-Bd + for libre-riscv-dev@lists.libre-riscv.org; Sat, 16 May 2020 10:47:28 +0100 +Received: from hpdc7800 (hpdc7800 [10.0.0.1]) + by vps2.stafverhaegen.be (Postfix) with ESMTP id 063D111C04FF + for ; + Sat, 16 May 2020 11:47:27 +0200 (CEST) +Message-ID: +From: Staf Verhaegen +To: libre-riscv-dev@lists.libre-riscv.org +Date: Sat, 16 May 2020 11:47:27 +0200 +In-Reply-To: +References: + <747F8870-06C6-46A0-AFD9-D55289D4C41A@gatech.edu> + + <4BDA96A5-9063-42A6-9548-CAE3CBEBEBAC@gatech.edu> + + + + + + +Organization: FibraServi bvba +X-Mailer: Evolution 3.28.5 (3.28.5-8.el7) +Mime-Version: 1.0 +X-Content-Filtered-By: Mailman/MimeDel 2.1.23 +Subject: Re: [libre-riscv-dev] Introduction and Questions +X-BeenThere: libre-riscv-dev@lists.libre-riscv.org +X-Mailman-Version: 2.1.23 +Precedence: list +List-Id: Libre-RISCV General Development + +List-Unsubscribe: , + +List-Archive: +List-Post: +List-Help: +List-Subscribe: , + +Reply-To: Libre-RISCV General Development + +Content-Type: multipart/mixed; boundary="===============6853962972487324962==" +Errors-To: libre-riscv-dev-bounces@lists.libre-riscv.org +Sender: "libre-riscv-dev" + + +--===============6853962972487324962== +Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; + boundary="=-aNfOkJazDJL9i8Rts+Jp" + + +--=-aNfOkJazDJL9i8Rts+Jp +Content-Type: text/plain; charset="UTF-8" +Content-Transfer-Encoding: quoted-printable + +Jeremy Singher schreef op vr 15-05-2020 om 16:49 [-0700]: +>=20 +> >=20 +> > sigh over a year ago i understood this enough to be able to answer. +> > what we will have to do is simply ignore the optimisation opportunity. +>=20 +>=20 +> Hmmm, ignoring WAW will significantly limit the ability of the core to +> exploit ILP, which is one of the fundamental reasons for going OOO. + +I've wondered about this myself. Can you give concrete example of where +not supporting a WAW hazard blocks ILP ? +I am asking because just a WAW hazard could be easily avoided by a good +peep hole optimizer in software because it would see that the output of +the first write is never used. + +greets, +Staf. + + +--=-aNfOkJazDJL9i8Rts+Jp-- + + + +--===============6853962972487324962== +Content-Type: text/plain; charset="utf-8" +MIME-Version: 1.0 +Content-Transfer-Encoding: base64 +Content-Disposition: inline + +X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KbGlicmUtcmlz +Y3YtZGV2IG1haWxpbmcgbGlzdApsaWJyZS1yaXNjdi1kZXZAbGlzdHMubGlicmUtcmlzY3Yub3Jn +Cmh0dHA6Ly9saXN0cy5saWJyZS1yaXNjdi5vcmcvbWFpbG1hbi9saXN0aW5mby9saWJyZS1yaXNj +di1kZXYK + +--===============6853962972487324962==-- + + + -- 2.30.2