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 [170.10.133.124]) by sourceware.org (Postfix) with ESMTPS id 07E093858CDA for ; Mon, 25 Jul 2022 21:34:25 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 07E093858CDA Received: from mail-ej1-f70.google.com (mail-ej1-f70.google.com [209.85.218.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-658-G_82R1X2MnSvQcd2ih_iYw-1; Mon, 25 Jul 2022 17:34:23 -0400 X-MC-Unique: G_82R1X2MnSvQcd2ih_iYw-1 Received: by mail-ej1-f70.google.com with SMTP id gt38-20020a1709072da600b0072f21d7d12dso3512302ejc.7 for ; Mon, 25 Jul 2022 14:34:22 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=K7xSgmhbUD5VmOeJaCBAulPt2sB8bVtrV0Wvf6OyP0E=; b=4qxEuKbsAjkREu7VXv5NFEIByadCPsa4+Gb6Jvt9AWrAjVIqUgD7W4HYk5qn3ktwcq 6VGK8AdeVEMev70l83EcMWn9vBDKpAZ/EwsChGVj1Lldq4bbiBF2UD9T5ApHFwaM2IB5 U8eyAYo7as0jMJZ+xC4taH28tlPt2I3yMvtBOZxypqTvzLue4QXn0pU0lcDGDEen3cpe sKIkexI4HOfnTzGraMU0nOH+ACgYW3ik4SfmzB6CsDVXS+RtDDVt6/0aM+PXfJgH+ACY Rvl0/505b5RTAAVxJAn2qvm5BkAlZ8A+krh4UsjBLJXH6hfolKuTDvYNVzW4viY3+NFs AO6A== X-Gm-Message-State: AJIora/GcsRi1u9DbgIF70Om427g6dNWPV38P6nof+tggXs9mnOWsFaQ aDQtjBO+8JtPSsgt6GH3WHatKQRnlFeGfYrzSTJ4Eq1CEq12XmR4A7aMxUVg7yIQmI0bCRkK+MX cp5xzZwfFuYeOR01lhmHPAn5OFlx6VtU= X-Received: by 2002:a05:6402:378f:b0:43a:d3f5:79f2 with SMTP id et15-20020a056402378f00b0043ad3f579f2mr15326618edb.338.1658784861611; Mon, 25 Jul 2022 14:34:21 -0700 (PDT) X-Google-Smtp-Source: AGRyM1uDcPFCAQk1voAt5dkNqAB8+eTx81lHNUNZR4y8lPZcl1rpMXhsBmuji/B6cudQEFtsHxjHNYRW47G2Vg1JF+Q= X-Received: by 2002:a05:6402:378f:b0:43a:d3f5:79f2 with SMTP id et15-20020a056402378f00b0043ad3f579f2mr15326603edb.338.1658784861341; Mon, 25 Jul 2022 14:34:21 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Jonathan Wakely Date: Mon, 25 Jul 2022 22:34:10 +0100 Message-ID: Subject: Re: First-time contributor -- speeding up `std::unique_ptr` compilation To: Vittorio Romeo Cc: "libstdc++" X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: multipart/mixed; boundary="0000000000006b6aa205e4a7f2e0" X-Spam-Status: No, score=-13.0 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, SPF_HELO_NONE, SPF_NONE, TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: libstdc++@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libstdc++ mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 25 Jul 2022 21:34:27 -0000 --0000000000006b6aa205e4a7f2e0 Content-Type: text/plain; charset="UTF-8" On Sat, 25 Jun 2022 at 13:45, Vittorio Romeo wrote: > > Thank you, Jonathan, for the very thorough explanation and for pointing out that I completely forgot to consider ABI stability in this case. > > I still think that it might be worthwhile to attempt some work in this area as multiple projects I work on have various TUs using unique_ptr but not tuple. I will look into the refactoring you suggested. Something like this would avoid instantiating most of std::tuple while preserving ABI, but it doesn't seem to really make much difference to compilation time. --0000000000006b6aa205e4a7f2e0 Content-Type: text/x-patch; charset="US-ASCII"; name="unique_ptr.patch" Content-Disposition: attachment; filename="unique_ptr.patch" Content-Transfer-Encoding: base64 Content-ID: X-Attachment-Id: f_l619nj000 ZGlmZiAtLWdpdCBhL2xpYnN0ZGMrKy12My9pbmNsdWRlL2JpdHMvdW5pcXVlX3B0ci5oIGIvbGli c3RkYysrLXYzL2luY2x1ZGUvYml0cy91bmlxdWVfcHRyLmgKaW5kZXggZTFhZDc3MjFhNTkuLjc3 N2M3ZGVjMTVhIDEwMDY0NAotLS0gYS9saWJzdGRjKystdjMvaW5jbHVkZS9iaXRzL3VuaXF1ZV9w dHIuaAorKysgYi9saWJzdGRjKystdjMvaW5jbHVkZS9iaXRzL3VuaXF1ZV9wdHIuaApAQCAtMTcy LDcgKzE3Miw3IEBAIF9HTElCQ1hYX0JFR0lOX05BTUVTUEFDRV9WRVJTSU9OCiAKICAgICAgIF9f dW5pcV9wdHJfaW1wbCgpID0gZGVmYXVsdDsKICAgICAgIF9HTElCQ1hYMjNfQ09OU1RFWFBSCi0g ICAgICBfX3VuaXFfcHRyX2ltcGwocG9pbnRlciBfX3ApIDogX01fdCgpIHsgX01fcHRyKCkgPSBf X3A7IH0KKyAgICAgIF9fdW5pcV9wdHJfaW1wbChwb2ludGVyIF9fcCkgOiBfTV90KF9fcCkgeyB9 CiAKICAgICAgIHRlbXBsYXRlPHR5cGVuYW1lIF9EZWw+CiAJX0dMSUJDWFgyM19DT05TVEVYUFIK QEAgLTE5MywxMyArMTkzLDEzIEBAIF9HTElCQ1hYX0JFR0lOX05BTUVTUEFDRV9WRVJTSU9OCiAg ICAgICB9CiAKICAgICAgIF9HTElCQ1hYMjNfQ09OU1RFWFBSCi0gICAgICBwb2ludGVyJiAgIF9N X3B0cigpIG5vZXhjZXB0IHsgcmV0dXJuIHN0ZDo6Z2V0PDA+KF9NX3QpOyB9CisgICAgICBwb2lu dGVyJiAgIF9NX3B0cigpIG5vZXhjZXB0IHsgcmV0dXJuIF9NX3QuX01fcHRyKCk7IH0KICAgICAg IF9HTElCQ1hYMjNfQ09OU1RFWFBSCi0gICAgICBwb2ludGVyICAgIF9NX3B0cigpIGNvbnN0IG5v ZXhjZXB0IHsgcmV0dXJuIHN0ZDo6Z2V0PDA+KF9NX3QpOyB9CisgICAgICBwb2ludGVyICAgIF9N X3B0cigpIGNvbnN0IG5vZXhjZXB0IHsgcmV0dXJuIF9NX3QuX01fcHRyKCk7IH0KICAgICAgIF9H TElCQ1hYMjNfQ09OU1RFWFBSCi0gICAgICBfRHAmICAgICAgIF9NX2RlbGV0ZXIoKSBub2V4Y2Vw dCB7IHJldHVybiBzdGQ6OmdldDwxPihfTV90KTsgfQorICAgICAgX0RwJiAgICAgICBfTV9kZWxl dGVyKCkgbm9leGNlcHQgeyByZXR1cm4gX01fdC5fTV9kZWxldGVyKCk7IH0KICAgICAgIF9HTElC Q1hYMjNfQ09OU1RFWFBSCi0gICAgICBjb25zdCBfRHAmIF9NX2RlbGV0ZXIoKSBjb25zdCBub2V4 Y2VwdCB7IHJldHVybiBzdGQ6OmdldDwxPihfTV90KTsgfQorICAgICAgY29uc3QgX0RwJiBfTV9k ZWxldGVyKCkgY29uc3Qgbm9leGNlcHQgeyByZXR1cm4gX01fdC5fTV9kZWxldGVyKCk7IH0KIAog ICAgICAgX0dMSUJDWFgyM19DT05TVEVYUFIKICAgICAgIHZvaWQgcmVzZXQocG9pbnRlciBfX3Ap IG5vZXhjZXB0CkBAIC0yMjYsOSArMjI2LDM1IEBAIF9HTElCQ1hYX0JFR0lOX05BTUVTUEFDRV9W RVJTSU9OCiAJc3dhcCh0aGlzLT5fTV9wdHIoKSwgX19yaHMuX01fcHRyKCkpOwogCXN3YXAodGhp cy0+X01fZGVsZXRlcigpLCBfX3Jocy5fTV9kZWxldGVyKCkpOwogICAgICAgfQotCiAgICAgcHJp dmF0ZToKLSAgICAgIHR1cGxlPHBvaW50ZXIsIF9EcD4gX01fdDsKKyAgICAgIHN0cnVjdCBfVHVw bGUgOiBfSGVhZF9iYXNlPDEsIF9EcD4sIF9IZWFkX2Jhc2U8MCwgcG9pbnRlcj4KKyAgICAgIHsK Kwl1c2luZyBfUHRyX2Jhc2UgPSBfSGVhZF9iYXNlPDAsIHBvaW50ZXI+OworCXVzaW5nIF9EZWxf YmFzZSA9IF9IZWFkX2Jhc2U8MSwgX0RwPjsKKworCV9UdXBsZSgpID0gZGVmYXVsdDsKKwlfVHVw bGUoX1R1cGxlJiYpID0gZGVmYXVsdDsKKworCWNvbnN0ZXhwcgorCV9UdXBsZShwb2ludGVyIF9f cCkgOiBfUHRyX2Jhc2UoX19wKSB7IH0KKworCXRlbXBsYXRlPHR5cGVuYW1lIF9EZWw+CisJICBj b25zdGV4cHIKKwkgIF9UdXBsZShwb2ludGVyIF9fcCwgX0RlbCYmIF9fZCkKKwkgIDogX0RlbF9i YXNlKHN0ZDo6Zm9yd2FyZDxfRGVsPihfX2QpKSwgX1B0cl9iYXNlKF9fcCkKKwkgIHsgfQorCisJ Y29uc3RleHByIHBvaW50ZXImCisJX01fcHRyKCkgbm9leGNlcHQgeyByZXR1cm4gX1B0cl9iYXNl OjpfTV9oZWFkKCp0aGlzKTsgfQorCWNvbnN0ZXhwciBwb2ludGVyCisJX01fcHRyKCkgY29uc3Qg bm9leGNlcHQgeyByZXR1cm4gX1B0cl9iYXNlOjpfTV9oZWFkKCp0aGlzKTsgfQorCWNvbnN0ZXhw ciBfRHAmCisJX01fZGVsZXRlcigpIG5vZXhjZXB0IHsgcmV0dXJuIF9EZWxfYmFzZTo6X01faGVh ZCgqdGhpcyk7IH0KKwljb25zdGV4cHIgY29uc3QgX0RwJgorCV9NX2RlbGV0ZXIoKSBjb25zdCBu b2V4Y2VwdCB7IHJldHVybiBfRGVsX2Jhc2U6Ol9NX2hlYWQoKnRoaXMpOyB9CisgICAgICB9Owor CisgICAgICBfVHVwbGUgX01fdDsKICAgICB9OwogCiAgIC8vIERlZmluZXMgbW92ZSBjb25zdHJ1 Y3Rpb24gKyBhc3NpZ25tZW50IGFzIGVpdGhlciBkZWZhdWx0ZWQgb3IgZGVsZXRlZC4K --0000000000006b6aa205e4a7f2e0--