220 37040 <53F0ECAD-6569-42FA-9675-1FB73DFAC6EA@apple.com> article Path: news.gmane.org!.POSTED!not-for-mail From: JF Bastien Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: More conservative version of P0907 "Signed Integers are Two's Complement" Date: Fri, 23 Feb 2018 14:11:51 -0800 Lines: 158 Approved: news@gmane.org Message-ID: <53F0ECAD-6569-42FA-9675-1FB73DFAC6EA@apple.com> References: Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: multipart/alternative; boundary="Boundary_(ID_MZ2pPvhCsRoA2CLuNCqMtA)" X-Trace: blaine.gmane.org 1519423793 14895 195.159.176.226 (23 Feb 2018 22:09:53 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Fri, 23 Feb 2018 22:09:53 +0000 (UTC) Cc: ISO C++ Standard - Future Proposals To: Arthur O'Dwyer Original-X-From: std-proposals+bncBAABBKNDYLKAKGQEDSUTA4Q@isocpp.org Fri Feb 23 23:09:49 2018 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-pf0-f198.google.com ([209.85.192.198]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1epLXI-0003NE-EZ for gclcip-std-proposals@m.gmane.org; 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[17.151.62.26]) by mx.google.com with ESMTPS id bb8-v6si2399622plb.719.2018.02.23.14.11.52 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 23 Feb 2018 14:11:52 -0800 (PST) Received-SPF: pass (google.com: domain of jfbastien@apple.com designates 17.151.62.26 as permitted sender) client-ip=17.151.62.26; Original-Received: from relay6.apple.com (relay6.apple.com [17.128.113.90]) (using TLS with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mail-in4.apple.com (Apple Secure Mail Relay) with SMTP id 47.3F.07147.8A1909A5; Fri, 23 Feb 2018 14:11:52 -0800 (PST) X-AuditID: 11973e12-d46b29e000001beb-81-5a9091a829d6 Original-Received: from nwk-mmpp-sz09.apple.com (nwk-mmpp-sz09.apple.com [17.128.115.80]) by relay6.apple.com (Apple SCV relay) with SMTP id 48.93.23861.8A1909A5; Fri, 23 Feb 2018 14:11:52 -0800 (PST) Original-Received: from jfbastien.apple.com (jfbastien.apple.com [17.202.48.12]) by nwk-mmpp-sz09.apple.com (Oracle Communications Messaging Server 8.0.2.2.20180130 64bit (built Jan 30 2018)) with ESMTPSA id <0P4M00AQHIZSB600@nwk-mmpp-sz09.apple.com>; Fri, 23 Feb 2018 14:11:52 -0800 (PST) Original-Sender: jfbastien@apple.com In-reply-to: X-Mailer: Apple Mail (2.3445.6.11) X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFrrALMWRmVeSWpSXmKPExsUi2FAYpbti4oQog0OrJSyerlzBYvH1epQD k8fOWXfZPSa+n8kSwBTFZZOSmpNZllqkb5fAlTF70w7Ggje2FZvn7WRtYJxm0sXIySEhYCLR 1HSPqYuRi0NIYDWTxMVPyxlhEv17H7FDJA4ySszbN5cNJMErICjxY/I9li5GDg5mgTCJbZM5 IWoWMEnc+NvEBFIjLCAt8e3gJjCbTUBN4u7tz8wQvTYSx898YIOoiZCY+6KZHcRmEVCVWN67 H8zmFAiWmL18HlgNs4CTxNq1c5hBdokI6ElMOmQMEhYSCJA4+ugjM8SdShLv3y5hBblBQmAK m8TiL++YJjAKzUJy6iyEUyFMdYkpU3JngS3Qlnjy7gIrhK0msfD3IiZk8QWMbKsYhXITM3N0 M/NM9BILCnJS9ZLzczcxgqJgup3QDsZTq6wOMQpwMCrx8G6QnBAlxJpYVlyZe4hRmoNFSZy3 Kbc/SkggPbEkNTs1tSC1KL6oNCe1+BAjEwenVAOjatb+GZe6/3pW/mX9sVwu0fHAt4Nac6cV Rly7yznl79GrB15eLPjxoDj8jNAnVhe/O9yv4vb4+AYxuMyRD5mnsLV25l9Ou5n2K5jvTFt/ y2/WmlSFFU2qH5I1/k/d+vS4vvCXCU8DPuQdrxZf7tEQrLf92D1d04z915SO3Dux6guLG8u9 2QVvu5VYijMSDbWYi4oTATeRp/RjAgAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFjrMLMWRmVeSWpSXmKPExsUi2FAcoLti4oQog037RC2erlzBYvH1epQD k8fOWXfZPSa+n8kSwBTFZZOSmpNZllqkb5fAlTF70w7Ggje2FZvn7WRtYJxm0sXIySEhYCLR v/cRexcjF4eQwEFGiXn75rKBJHgFBCV+TL7H0sXIwcEsECaxbTInRM0CJokbf5uYQGqEBaQl vh3cBGazCahJ3L39mRmi10bi+JkPbBA1ERJzXzSzg9gsAqoSy3v3g9mcAsESs5fPA6thFnCS WLt2DjPILhEBPYlJh4xBwkICARJHH31khrhTSeL92yWsExj5ZyG5bhbCdRCmusSUKbmzwGZq Szx5d4EVwlaTWPh7EROy+AJGtlWMAkWpOYmVZnqJBQU5qXrJ+bmbGMFBWxi1g7FhudUhRgEO RiUe3gjxCVFCrIllxZW5hxglOJiVRHjndQCFeFMSK6tSi/Lji0pzUosPMUpzsCiJ8zZ69EYJ CaQnlqRmp6YWpBbBZJk4OKUaGHNl5lWvKxRKDqpV9GUyn3xRzXvqr9cm6x6tP5qV2q4X5JTg 2/ThW27KbGHNSw/+x4qwsClOfKX7tNPiTsBF34/NsZtULy9dl1fa90hO9UaGverin5sYjm/l bLeydEis5RQ6fJ7nrbP9M93pFk13HNqO7XaUbl69+/F3BpUoFuPbSRNNPDymKrEUZyQaajEX FScCAKKolKBWAgAA X-Original-Sender: jfbastien@apple.com X-Original-Authentication-Results: mx.google.com; dkim=pass header.i=@apple.com header.s=mailout2048s header.b=SLYYYA/9; spf=pass (google.com: domain of jfbastien@apple.com designates 17.151.62.26 as permitted sender) smtp.mailfrom=jfbastien@apple.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=apple.com Precedence: list Mailing-list: list std-proposals@isocpp.org; contact std-proposals+owners@isocpp.org List-ID: X-Spam-Checked-In-Group: std-proposals@isocpp.org X-Google-Group-Id: 399137483710 List-Post: , List-Help: , List-Archive: List-Subscribe: , List-Unsubscribe: , Xref: news.gmane.org gmane.comp.lang.c++.isocpp.proposals:37040 Archived-At: --Boundary_(ID_MZ2pPvhCsRoA2CLuNCqMtA) Content-type: text/plain; charset="UTF-8" Content-transfer-encoding: quoted-printable Hi Arthur, I=E2=80=99ll be in JAX and will definitely champion my own approach, but wi= ll make sure any other approaches are discussed thoroughly. I=E2=80=99ll th= en ask for direction polls from EWG, and will follow the proposed direction= in an updated paper. I=E2=80=99d therefore appreciate it if you instead had rationales for why y= ou=E2=80=99d take a different approach. I offered my rationale for going th= e direction I suggest, and the right thing to change people=E2=80=99s minds= is to offer compelling arguments to go in another direction. Ideally you= =E2=80=99d have data to back up any performance / bug finding / odd archite= cture claims. Do you think you have time to get this together before JAX? T= hat=E2=80=99s definitely something I=E2=80=99d present along my paper, thou= gh I might disagree. In the end I simply want two=E2=80=99s complement, and I see a few ways tha= t this play out with everyone liking the outcome. I just ask that oppositio= n comes with rationales, not =E2=80=9CI like my way better=E2=80=9D. :-) JF > On Feb 23, 2018, at 14:05, Arthur O'Dwyer wro= te: >=20 > The pre-JAX mailing contains this discussion-provoking paper by JF Bastie= n: > P0907R0 "Signed Integers are Two's Complement" >=20 > My understanding is that JF wants to use this "modest proposal" (for wrap= ping arithmetic on `int`, among other things) as a way to incite discussion= among the Committee. >=20 > I have created an as-yet-unofficial "conservative fork" of the proposal, = which removes the parts that I think are airballs, while leaving in much of= what I consider the good stuff =E2=80=94 notably, making signed-to-unsigne= d and unsigned-to-signed conversions well-defined in terms of two's complem= ent representations, and defining what happens when you bit-shift into or o= ut of the sign bit. > https://quuxplusone.github.io/draft/twosc-conservative.html >=20 > I hope that if the Committee asks JF to come back with a more conservativ= e proposal, the existence of my "conservative fork" will save time, possibl= y even allow further discussion later in the week at JAX. >=20 > I personally will not be at JAX, though. JF, will you be? Could I count = on you to... not to "champion" my unsubmitted paper, of course, but just to= be aware of it in case something like it is asked for by the Committee? I= mean, the worst-case, which I would like to avoid, is that JF's paper is r= ejected as too crazy and then the entire subject is tabled until Rapperswil= .. I would like to see some concrete progress in this department at JAX if h= umanly possible. >=20 > =E2=80=93Arthur >=20 > P.S. =E2=80=94 Also, if anyone on std-proposals has objections to the spe= cific diffs in my conservative proposal, I would like to know about it. I d= eliberately tried to remove any whiff of controversy from the diff. (This = is distinct from objecting to my presumptuousness or objecting to wasting t= he Committee's time. ;)) --=20 You received this message because you are subscribed to the Google Groups "= ISO C++ Standard - Future Proposals" group. To unsubscribe from this group and stop receiving emails from it, send an e= mail to std-proposals+unsubscribe@isocpp.org. To post to this group, send email to std-proposals@isocpp.org. To view this discussion on the web visit https://groups.google.com/a/isocpp= ..org/d/msgid/std-proposals/53F0ECAD-6569-42FA-9675-1FB73DFAC6EA%40apple.com= .. --Boundary_(ID_MZ2pPvhCsRoA2CLuNCqMtA) Content-type: text/html; charset="UTF-8" Content-transfer-encoding: quoted-printable Hi Arthur,
=
I=E2=80=99ll be in JAX and will defini= tely champion my own approach, but will make sure any other approaches are = discussed thoroughly. I=E2=80=99ll then ask for direction polls from EWG, a= nd will follow the proposed direction in an updated paper.

I=E2=80=99d therefore appreciate= it if you instead had rationales for why you=E2=80=99d take a different ap= proach. I offered my rationale for going the direction I suggest, and the r= ight thing to change people=E2=80=99s minds is to offer compelling argument= s to go in another direction. Ideally you=E2=80=99d have data to back up an= y performance / bug finding / odd architecture claims. Do you think you hav= e time to get this together before JAX? That=E2=80=99s definitely something= I=E2=80=99d present along my paper, though I might disagree.

In the end I simply want two= =E2=80=99s complement, and I see a few ways that this play out with everyon= e liking the outcome. I just ask that opposition comes with rationales, not= =E2=80=9CI like my way better=E2=80=9D. :-)

JF

On Feb 23, 2018,= at 14:05, Arthur O'Dwyer <arthur.j.odwyer@gmail.com> wrote:

The pre-JAX mailing contains this discussion-provoking paper by JF B= astien:
P0907R0 "Signed Integers are = Two's Complement"

My understanding is that JF wants to use this "modest proposal" (for = wrapping arithmetic on `int`, among other things) as a way to incite discus= sion among the Committee.

I have create= d an as-yet-unofficial "conservative fork" of the proposal, which removes t= he parts that I think are airballs, while leaving in much of what I conside= r the good stuff =E2=80=94 notably, making signed-to-unsigned and unsigned-= to-signed conversions well-defined in terms of two's complement representat= ions, and defining what happens when you bit-shift into or out of the sign = bit.
https://quuxplusone.github.io/draft/twosc= -conservative.html

<= /div>
I hope that if the Committee asks JF to come back with= a more conservative proposal, the existence of my "conservative fork" will= save time, possibly even allow further discussion later in the week at JAX= ..

= I personally will not be at JAX, though.  JF, will you be? Could I cou= nt on you to... not to "champion" my unsubmitted paper, of course, but just= to be aware of it in case something like it is asked for by the Committee?=   I mean, the worst-case, which I would like to avoid, is that JF's pa= per is rejected as too crazy and then the entire subject is tabled until Ra= pperswil. I would like to see some concrete progress in this department at = JAX if humanly possible.

=E2=80=93Arthur

P.S. =E2=80=94 Also, if anyone on std-proposals has objections to th= e specific diffs in my conservative proposal, I would like to know about it= .. I deliberately tried to remove any whiff of controversy from the diff. &n= bsp;(This is distinct from objecting to my presumptuousness or objecting to= wasting the Committee's time. ;))

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