From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Original-To: caml-list@sympa.inria.fr Delivered-To: caml-list@sympa.inria.fr Received: from mail4-relais-sop.national.inria.fr (mail4-relais-sop.national.inria.fr [192.134.164.105]) by sympa.inria.fr (Postfix) with ESMTPS id 1FC7A7ED5C for ; Wed, 8 Aug 2012 20:23:25 +0200 (CEST) Received-SPF: None (mail4-smtp-sop.national.inria.fr: no sender authenticity information available from domain of jesper.louis.andersen@gmail.com) identity=pra; client-ip=209.85.214.182; receiver=mail4-smtp-sop.national.inria.fr; envelope-from="jesper.louis.andersen@gmail.com"; x-sender="jesper.louis.andersen@gmail.com"; x-conformance=sidf_compatible Received-SPF: Pass (mail4-smtp-sop.national.inria.fr: domain of jesper.louis.andersen@gmail.com designates 209.85.214.182 as permitted sender) identity=mailfrom; client-ip=209.85.214.182; receiver=mail4-smtp-sop.national.inria.fr; envelope-from="jesper.louis.andersen@gmail.com"; x-sender="jesper.louis.andersen@gmail.com"; x-conformance=sidf_compatible; x-record-type="v=spf1" Received-SPF: None (mail4-smtp-sop.national.inria.fr: no sender authenticity information available from domain of postmaster@mail-ob0-f182.google.com) identity=helo; client-ip=209.85.214.182; receiver=mail4-smtp-sop.national.inria.fr; envelope-from="jesper.louis.andersen@gmail.com"; x-sender="postmaster@mail-ob0-f182.google.com"; x-conformance=sidf_compatible X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AhgCAOmtIlDRVda2kGdsb2JhbABFhgGzVQgiAQEBAQkJDQcUBCOCIAEBAQMBEgIPHQEbHQEDAQsGBQsPAiYCAiIBEQEFARwGEwgah1sBAwYGnFAJA4tUT4JxhU0KGScNV4hxAQUMgRWJcYVOgRIDlUmOMj6EAA X-IronPort-AV: E=Sophos;i="4.77,734,1336341600"; d="scan'208";a="152709101" Received: from mail-ob0-f182.google.com ([209.85.214.182]) by mail4-smtp-sop.national.inria.fr with ESMTP/TLS/RC4-SHA; 08 Aug 2012 20:23:24 +0200 Received: by obbun3 with SMTP id un3so2846830obb.27 for ; Wed, 08 Aug 2012 11:23:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-type; bh=mdfqTspogc1XQbh4l7wHotM4MwMU8v9pYtNQwg1I2gs=; b=c2AS5H00JeBSbW5Pzt3TUXvadx6saaGdlmrT3C4iCg0OcgHQjqQRFfOOxJMn8jNAjF dVEuCLbM9xp+CyWs62WSMfsKoisTpX3Xjq9C+lTXcBXgRL6L2l1Z6yffDsPm9kH+sKW7 iU5iIGyTYFzssL6deRWVCGUc31Wa8johTNlG2zpy22si2LeVeAwzkIA2ZTlHPDJ5Ny0O pYEEvlGpvjqcUcDCi8LEx0Ybb5FZ4ac7p/bGpYSPuCbPzJuzyyIS/9/6wQxcUtO+ULfS XPOkVEL0aDM9j59NN18lAfZrAageqawjUIrXK90vGuzrYlWxI2cN/ZDIaiQdepNW2Pji 2vjQ== Received: by 10.182.177.7 with SMTP id cm7mr1869184obc.17.1344450202861; Wed, 08 Aug 2012 11:23:22 -0700 (PDT) MIME-Version: 1.0 Received: by 10.182.231.33 with HTTP; Wed, 8 Aug 2012 11:22:52 -0700 (PDT) In-Reply-To: <5022A9FE.4050006@frisch.fr> References: <501F9855.6080709@frisch.fr> <501F9DB9.2050805@frisch.fr> <501FAB4A.107@frisch.fr> <5022A9FE.4050006@frisch.fr> From: Jesper Louis Andersen Date: Wed, 8 Aug 2012 20:22:52 +0200 Message-ID: To: Alain Frisch Cc: Dmitry Bely , caml-list@inria.fr Content-Type: text/plain; charset=UTF-8 Subject: Re: [Caml-list] Compiler bug? On Wed, Aug 8, 2012 at 8:03 PM, Alain Frisch wrote: > I'm not sure, someone else would have to reply! I guess that these > registers are supposed to be preserved by the callee in the x64 ABI (and > obviously, they don't hold pointers to OCaml values, so they don't have to > be tracked by the GC). Also, the GC itself will not be using Floating Point code at all, so we can save a lot by not saving/restoring these values on the stack. It is akin to what the Linux kernel does: trap on the first FP instruction and only then do work to save/restore the FP context - but here we know a priori we never will access FP. By doing so we can cut the time to the GC call down - and reap the benefits by having a faster GC cycle. -- J.