[{"id":3680791,"web_url":"http://patchwork.ozlabs.org/comment/3680791/","msgid":"","list_archive_url":null,"date":"2026-04-22T18:11:37","subject":"Re: [PATCH v1 0/2] WIP: more_constexpr_stable_algorithms","submitter":{"id":93212,"url":"http://patchwork.ozlabs.org/api/people/93212/","name":"Lichenor Forgejo Bot via Sourceware Forge","email":"forge-bot+forge-bot@forge-stage.sourceware.org"},"content":"Sent patch series version 1 containing 2 patches to gcc-patches mailing list .\n[Cover letter](https://inbox.sourceware.org/gcc-patches/bmm.hhuo2dtkd4.gcc.gcc-TEST.peppe.44.1.0@forge-stage.sourceware.org)\n\n--\nhttps://forge.sourceware.org/gcc/gcc-TEST/pulls/44#issuecomment-5619","headers":{"Return-Path":"","X-Original-To":["incoming@patchwork.ozlabs.org","gcc-patches@gcc.gnu.org"],"Delivered-To":["patchwork-incoming@legolas.ozlabs.org","gcc-patches@gcc.gnu.org"],"Authentication-Results":["legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=gcc.gnu.org\n (client-ip=2620:52:6:3111::32; helo=vm01.sourceware.org;\n envelope-from=gcc-patches-bounces~incoming=patchwork.ozlabs.org@gcc.gnu.org;\n receiver=patchwork.ozlabs.org)","sourceware.org; dmarc=none (p=none dis=none)\n header.from=forge-stage.sourceware.org","sourceware.org;\n spf=pass smtp.mailfrom=forge-stage.sourceware.org","server2.sourceware.org;\n arc=none smtp.remote-ip=38.145.34.39"],"Received":["from vm01.sourceware.org (vm01.sourceware.org\n [IPv6:2620:52:6:3111::32])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\t key-exchange x25519 server-signature ECDSA (secp384r1) server-digest SHA384)\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4g16yc11wzz1y2d\n\tfor ; Thu, 23 Apr 2026 04:22:32 +1000 (AEST)","from vm01.sourceware.org (localhost [127.0.0.1])\n\tby sourceware.org (Postfix) with ESMTP id 24D974422B5F\n\tfor ; Wed, 22 Apr 2026 18:22:30 +0000 (GMT)","from forge-stage.sourceware.org (vm08.sourceware.org [38.145.34.39])\n by sourceware.org (Postfix) with ESMTPS id B38404BBCDDA\n for ; Wed, 22 Apr 2026 18:11:48 +0000 (GMT)","from forge-stage.sourceware.org (localhost [IPv6:::1])\n (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n key-exchange x25519 server-signature ECDSA (prime256v1) server-digest SHA256)\n (No client certificate requested)\n by forge-stage.sourceware.org (Postfix) with ESMTPS id A8B2A43416\n for ; Wed, 22 Apr 2026 18:11:38 +0000 (UTC)"],"DKIM-Filter":["OpenDKIM Filter v2.11.0 sourceware.org 24D974422B5F","OpenDKIM Filter v2.11.0 sourceware.org B38404BBCDDA"],"DMARC-Filter":"OpenDMARC Filter v1.4.2 sourceware.org B38404BBCDDA","ARC-Filter":"OpenARC Filter v1.0.0 sourceware.org B38404BBCDDA","ARC-Seal":"i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1776881508; cv=none;\n b=ilPiK0fcKK0WSQGPgKPUOxMI8cTfMJrUlAictB1Cwdw17jqHnQKVqqcxAobsuonAau/p3rDNEse1hZiq+1Ycdv6BvAdzE47oIV2tSdKnPzeKVsGKgwKS1AIvLZX1/v1P9P2izi+OH7zfh3A57DwcYJE6vSvhcxwb8x31+LejmP4=","ARC-Message-Signature":"i=1; a=rsa-sha256; d=sourceware.org; s=key;\n t=1776881508; c=relaxed/simple;\n bh=FDPI18hdIIqGixL/kAx2S+oK6H/ShVg0shNxVq4O+S8=;\n h=Subject:From:To:Date:Message-ID:MIME-Version;\n b=nKdYsaCf74wwKgv+hxTT9bZfrAlNMdlagWnhUtQDqmo/fM5lBZ8GkuPDbLZNE5KyPefjhKwFWQg86CypuECRgvV3F8RGzj/cO8QnZzcyFHmC1CQhbndYZSWYJb52e+KS90gdB6IlZBS+5kgcGInruwxMTVHoqPnMt1ldhEtwgr0=","ARC-Authentication-Results":"i=1; server2.sourceware.org","Subject":"Re: [PATCH v1 0/2] WIP: more_constexpr_stable_algorithms","From":"Lichenor Forgejo Bot via Sourceware Forge\n ","To":"gcc-patches mailing list ","Date":"Wed, 22 Apr 2026 18:11:37 +0000","Message-ID":"\n ","In-Reply-To":"\n ","X-Mailer":"batrachomyomachia","X-Requested-Reviewer":"redi","X-Pull-Request-Organization":"gcc","X-Pull-Request-Repository":"gcc-TEST","X-Pull-Request":"https://forge.sourceware.org/gcc/gcc-TEST/pulls/44","X-Comment":"\n https://forge.sourceware.org/gcc/gcc-TEST/pulls/44#issuecomment-5619","Content-Type":"text/plain; charset=\"utf-8\"","Content-Transfer-Encoding":"quoted-printable","MIME-Version":"1.0","X-BeenThere":"gcc-patches@gcc.gnu.org","X-Mailman-Version":"2.1.30","Precedence":"list","List-Id":"Gcc-patches mailing list ","List-Unsubscribe":",\n ","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n ","Errors-To":"gcc-patches-bounces~incoming=patchwork.ozlabs.org@gcc.gnu.org"}},{"id":3680793,"web_url":"http://patchwork.ozlabs.org/comment/3680793/","msgid":"","list_archive_url":null,"date":"2026-04-22T18:11:10","subject":"Re: [PATCH v1 0/2] WIP: more_constexpr_stable_algorithms","submitter":{"id":93212,"url":"http://patchwork.ozlabs.org/api/people/93212/","name":"Lichenor Forgejo Bot via Sourceware Forge","email":"forge-bot+forge-bot@forge-stage.sourceware.org"},"content":"\nVersion 1 of this pull request has been stored. It includes the following commits:\n- libstdc++: add constexpr inplace_merge - 5989657326b5a977257f8139ae024dd18e27cb01\n- libstdc++: add constexpr stable_partition - bfb9835a6472095f7e80eb19c7074686efd4bc96\n\n\n--\nhttps://forge.sourceware.org/gcc/gcc-TEST/pulls/44#issuecomment-5617","headers":{"Return-Path":"","X-Original-To":["incoming@patchwork.ozlabs.org","gcc-patches@gcc.gnu.org"],"Delivered-To":["patchwork-incoming@legolas.ozlabs.org","gcc-patches@gcc.gnu.org"],"Authentication-Results":["legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=gcc.gnu.org\n (client-ip=2620:52:6:3111::32; helo=vm01.sourceware.org;\n envelope-from=gcc-patches-bounces~incoming=patchwork.ozlabs.org@gcc.gnu.org;\n receiver=patchwork.ozlabs.org)","sourceware.org; dmarc=none (p=none dis=none)\n header.from=forge-stage.sourceware.org","sourceware.org;\n spf=pass smtp.mailfrom=forge-stage.sourceware.org","server2.sourceware.org;\n arc=none smtp.remote-ip=38.145.34.39"],"Received":["from vm01.sourceware.org (vm01.sourceware.org\n [IPv6:2620:52:6:3111::32])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\t key-exchange x25519 server-signature ECDSA (secp384r1) server-digest SHA384)\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4g16zk6xYYz1y2d\n\tfor ; Thu, 23 Apr 2026 04:23:30 +1000 (AEST)","from vm01.sourceware.org (localhost [127.0.0.1])\n\tby sourceware.org (Postfix) with ESMTP id F1254442331F\n\tfor ; Wed, 22 Apr 2026 18:23:28 +0000 (GMT)","from forge-stage.sourceware.org (vm08.sourceware.org [38.145.34.39])\n by sourceware.org (Postfix) with ESMTPS id AD30A4BBCDBA\n for ; Wed, 22 Apr 2026 18:11:48 +0000 (GMT)","from forge-stage.sourceware.org (localhost [IPv6:::1])\n (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n key-exchange x25519 server-signature ECDSA (prime256v1) server-digest SHA256)\n (No client certificate requested)\n by forge-stage.sourceware.org (Postfix) with ESMTPS id 9670E43414\n for ; Wed, 22 Apr 2026 18:11:38 +0000 (UTC)"],"DKIM-Filter":["OpenDKIM Filter v2.11.0 sourceware.org F1254442331F","OpenDKIM Filter v2.11.0 sourceware.org AD30A4BBCDBA"],"DMARC-Filter":"OpenDMARC Filter v1.4.2 sourceware.org AD30A4BBCDBA","ARC-Filter":"OpenARC Filter v1.0.0 sourceware.org AD30A4BBCDBA","ARC-Seal":"i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1776881508; cv=none;\n b=K2XNe4ZlYAS+sByMTUDS3MpdILZmtq3uFw442THX1s2OA3jijTPbXGY6ajvXDhrceHVogxS0RUIGQ+HnxvTUmn2ICcjHqrdTQpgFReufnpMXg0cHb0p0azbpj1M3a6lW6tO5IL1tSkOyYLhX1RT4ccziKe+In156pnSfJI0AiU4=","ARC-Message-Signature":"i=1; a=rsa-sha256; d=sourceware.org; s=key;\n t=1776881508; c=relaxed/simple;\n bh=erSVTb67kwkS2bVU3kQQFiY3GtHZfc4lN5CbTXf1BOM=;\n h=Subject:From:To:Date:Message-ID:MIME-Version;\n b=wDabKHJU/6KrPadMSYwG2b+dF/7L/skjBNO9dKYo+XfRg0LIXxgiyIeX+/3qNXq1iD7C/RMNo9mzowRjtpq6kAStVXRbj405RGdy9tq/Hepx+R0Ot/2qUfXHObM2P4oVVJCL1btOmZ/A9rni3uc7aAa+gvgY2f+df8iRq7SI7ek=","ARC-Authentication-Results":"i=1; server2.sourceware.org","Subject":"Re: [PATCH v1 0/2] WIP: more_constexpr_stable_algorithms","From":"Lichenor Forgejo Bot via Sourceware Forge\n ","To":"gcc-patches mailing list ","Date":"Wed, 22 Apr 2026 18:11:10 +0000","Message-ID":"\n ","In-Reply-To":"\n ","X-Mailer":"batrachomyomachia","X-Requested-Reviewer":"redi","X-Pull-Request-Organization":"gcc","X-Pull-Request-Repository":"gcc-TEST","X-Pull-Request":"https://forge.sourceware.org/gcc/gcc-TEST/pulls/44","X-Comment":"\n https://forge.sourceware.org/gcc/gcc-TEST/pulls/44#issuecomment-5617","Content-Type":"text/plain; charset=\"utf-8\"","Content-Transfer-Encoding":"quoted-printable","MIME-Version":"1.0","X-BeenThere":"gcc-patches@gcc.gnu.org","X-Mailman-Version":"2.1.30","Precedence":"list","List-Id":"Gcc-patches mailing list ","List-Unsubscribe":",\n ","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n ","Errors-To":"gcc-patches-bounces~incoming=patchwork.ozlabs.org@gcc.gnu.org"}},{"id":3680794,"web_url":"http://patchwork.ozlabs.org/comment/3680794/","msgid":"","list_archive_url":null,"date":"2026-04-22T18:12:13","subject":"[SUMMARY] Re: [PATCH v1 0/2] WIP: more_constexpr_stable_algorithms","submitter":{"id":93222,"url":"http://patchwork.ozlabs.org/api/people/93222/","name":"peppe via Sourceware Forge","email":"forge-bot+peppe@forge-stage.sourceware.org"},"content":"This is a summary of discussions relative to the merge request created by (peppe) titled\nWIP: more_constexpr_stable_algorithms\nsince its creation.\n\nDescription: Completing P2562R1 for C++26.\n\nThe full and up to date discussion can be found at https://forge.sourceware.org/gcc/gcc-TEST/pulls/44\n\nThe merge request has been closed without being merged directly on the forge repository.\n\n\nOn 2025-03-14 23:50:14+00:00, (peppe) wrote:\n\nHi,\n\nFor me this is kind of a test of Forgejo's support for commit chains. I'm not sure if it's actually able to let people review on a commit-by-commit basis (*including* the commit messages); and let people push new versions of individual commits in a PR (by amending and force-pushing the branch again), while detecting changes correctly...\n\n\n\nOn 2025-03-15 00:04:06+00:00, (peppe) commented on the code:\n\n\n> +++ libstdc++-v3/include/bits/stl_algo.h\n> @@ -1524,0 +1533,4 @@\n> +\t\t\t\t\t\t&__buf,\n> +\t\t\t\t\t\t_DistanceType(1));\n> + }\n> +#endif\nI'm torn on the approach here.\n\nstable_partition always allocates memory through _Temporary_buffer. I guess this is the reason why the algorithm is not available on freestanding. \n\nThe 1-object buffer seems to be OK for the purpose of the inner call to `__stable_partition_adaptive`, although it doesn't sound very efficient. (I'm still able to partition a vector of 20k elements during constant evaluation, though.)\n\nSome ideas:\n\n* Should I use a smarter stack-based buffer? Basically, instead of allocating only 1 object on the stack, allocate as many as necessary but up to a maximum of X _bytes_ (256?). \n* Given the current naive solution (or the smarter one), should this function now be available in freestanding?\n* I think I could go for making `_Temporary_buffer` available in constexpr, but I'd like that to happen for GCC 16 if you don't mind. That could possibly lead to even remove these `if consteval` paths I've just added around. (However it wouldn't make this usable in freestanding, not sure how pressing that is as a goal.)\n\nOn 2025-03-27 10:32:06+00:00, Jonathan Wakely (redi) approved the changes:\n\n\n\n\nOn 2026-04-22 18:11:10+00:00, Lichenor Forgejo Bot (forge-bot) wrote:\n\n\nVersion 1 of this pull request has been stored. It includes the following commits:\n- libstdc++: add constexpr inplace_merge - 5989657326b5a977257f8139ae024dd18e27cb01\n- libstdc++: add constexpr stable_partition - bfb9835a6472095f7e80eb19c7074686efd4bc96\n\n\n\nOn 2026-04-22 18:11:37+00:00, Lichenor Forgejo Bot (forge-bot) wrote:\n\nSent patch series version 1 containing 2 patches to gcc-patches mailing list .\n[Cover letter](https://inbox.sourceware.org/gcc-patches/bmm.hhuo2dtkd4.gcc.gcc-TEST.peppe.44.1.0@forge-stage.sourceware.org)","headers":{"Return-Path":"","X-Original-To":["incoming@patchwork.ozlabs.org","gcc-patches@gcc.gnu.org"],"Delivered-To":["patchwork-incoming@legolas.ozlabs.org","gcc-patches@gcc.gnu.org"],"Authentication-Results":["legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=gcc.gnu.org\n (client-ip=2620:52:6:3111::32; helo=vm01.sourceware.org;\n envelope-from=gcc-patches-bounces~incoming=patchwork.ozlabs.org@gcc.gnu.org;\n receiver=patchwork.ozlabs.org)","sourceware.org; dmarc=none (p=none dis=none)\n header.from=forge-stage.sourceware.org","sourceware.org;\n spf=pass smtp.mailfrom=forge-stage.sourceware.org","server2.sourceware.org;\n arc=none smtp.remote-ip=38.145.34.39"],"Received":["from vm01.sourceware.org (vm01.sourceware.org\n [IPv6:2620:52:6:3111::32])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\t key-exchange x25519 server-signature ECDSA (secp384r1) server-digest SHA384)\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4g170625S8z1y2d\n\tfor ; Thu, 23 Apr 2026 04:23:50 +1000 (AEST)","from vm01.sourceware.org (localhost [127.0.0.1])\n\tby sourceware.org (Postfix) with ESMTP id 72D83441F948\n\tfor ; Wed, 22 Apr 2026 18:23:48 +0000 (GMT)","from forge-stage.sourceware.org (vm08.sourceware.org [38.145.34.39])\n by sourceware.org (Postfix) with ESMTPS id 7B0184BBCDA3\n for ; Wed, 22 Apr 2026 18:12:13 +0000 (GMT)","from forge-stage.sourceware.org (localhost [IPv6:::1])\n (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n key-exchange x25519 server-signature ECDSA (prime256v1) server-digest SHA256)\n (No client certificate requested)\n by forge-stage.sourceware.org (Postfix) with ESMTPS id 4D60B4340C\n for ; Wed, 22 Apr 2026 18:12:13 +0000 (UTC)"],"DKIM-Filter":["OpenDKIM Filter v2.11.0 sourceware.org 72D83441F948","OpenDKIM Filter v2.11.0 sourceware.org 7B0184BBCDA3"],"DMARC-Filter":"OpenDMARC Filter v1.4.2 sourceware.org 7B0184BBCDA3","ARC-Filter":"OpenARC Filter v1.0.0 sourceware.org 7B0184BBCDA3","ARC-Seal":"i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1776881533; cv=none;\n b=GXS/WaGQ18+1wUdqjBKExP4WjxOI80buLAt3W1g0pEQdUhqP+g6M53cq8fdtbPnY6b2vJiZ1Q3xjQpF2rVPNop6gc18IOCnTa6yto2b8Qymj4Q0ihLawkp+bkJ2E0J2dWNHHlBZJG0mZExVP+fU3FUqqFTVgrGVccjkjhDokTgY=","ARC-Message-Signature":"i=1; a=rsa-sha256; d=sourceware.org; s=key;\n t=1776881533; c=relaxed/simple;\n bh=oHGOpAxipB+RIjhJB0v2S/jh2m+ztWEdc/WxKC5G1bY=;\n h=Subject:From:To:Message-ID:MIME-Version:Date;\n b=FTG6JIMXSeS4P7LY9vLoi2CemnM1GuOZApFAZgoizqVIJZImXtbfuNM3Oa94zM69vOQAko7LwIPvYtW8abHSU9Vct7I+BDqR2GRyZCvmaHlikTbsQPOO5gb6RKvDdaFv9ogVF5027Vk2XQVMPFIYgIz18P1zcQPapPaWjsR/Tak=","ARC-Authentication-Results":"i=1; server2.sourceware.org","Subject":"[SUMMARY] Re: [PATCH v1 0/2] WIP: more_constexpr_stable_algorithms","From":"peppe via Sourceware Forge ","To":"gcc-patches mailing list ","In-Reply-To":"\n ","Message-ID":"\n ","X-Mailer":"batrachomyomachia","X-Requested-Reviewer":"redi","X-Pull-Request-Organization":"gcc","X-Pull-Request-Repository":"gcc-TEST","X-Pull-Request":"https://forge.sourceware.org/gcc/gcc-TEST/pulls/44","Content-Type":"text/plain; charset=\"utf-8\"","Content-Transfer-Encoding":"quoted-printable","MIME-Version":"1.0","Date":"Wed, 22 Apr 2026 18:12:13 +0000 (UTC)","X-BeenThere":"gcc-patches@gcc.gnu.org","X-Mailman-Version":"2.1.30","Precedence":"list","List-Id":"Gcc-patches mailing list ","List-Unsubscribe":",\n ","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n ","Errors-To":"gcc-patches-bounces~incoming=patchwork.ozlabs.org@gcc.gnu.org"}}]