From: "H. Peter Anvin" <hpa@zytor.com>
To: Andi Kleen <ak@linux.intel.com>
Cc: linux-kernel@vger.kernel.org, linux-kbuild@vger.kernel.org,
x86@kernel.org
Subject: Re: [PATCH 02/17] x86, lto: Disable fancy hweight optimizations for LTO v2
Date: Sat, 08 Feb 2014 13:43:29 -0800 [thread overview]
Message-ID: <bbf468ff-4a69-4e51-afc4-d894f459ded7@email.android.com> (raw)
In-Reply-To: <20140208202124.GK12219@tassilo.jf.intel.com>
That's fine.
On February 8, 2014 12:21:24 PM PST, Andi Kleen <ak@linux.intel.com> wrote:
>On Sat, Feb 08, 2014 at 10:52:07AM -0800, H. Peter Anvin wrote:
>> On 02/08/2014 12:01 AM, Andi Kleen wrote:
>> > The fancy x86 hweight uses different compiler options for the
>> > hweight file. This does not work with LTO. Just disable the
>optimization
>> > with LTO
>>
>> No, I'm going to NAK this. This means not using the POPCNT
>instruction
>> if LTO is enabled, and that really isn't an acceptable option.
>
>I thought the use was obscure?
>
>Ok, suppose can just disable LTO for the file.
>The only drawback is that the functions will not be optimized away when
>not used, as they'll need to be __visible.
>
>-Andi
--
Sent from my mobile phone. Please pardon brevity and lack of formatting.
next prev parent reply other threads:[~2014-02-08 21:44 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-08 8:01 [PATCH 01/17] x86, lto: Disable LTO for the x86 VDSO Andi Kleen
2014-02-08 8:01 ` [PATCH 02/17] x86, lto: Disable fancy hweight optimizations for LTO v2 Andi Kleen
2014-02-08 18:52 ` H. Peter Anvin
2014-02-08 20:21 ` Andi Kleen
2014-02-08 21:43 ` H. Peter Anvin [this message]
2014-02-08 8:01 ` [PATCH 03/17] lto: Make asmlinkage __visible Andi Kleen
2014-02-08 8:01 ` [PATCH 04/17] lto, workaround: Add workaround for initcall reordering Andi Kleen
2014-02-08 8:01 ` [PATCH 05/17] lto: Handle LTO common symbols in module loader Andi Kleen
2014-02-12 1:04 ` Rusty Russell
2014-02-08 8:01 ` [PATCH 06/17] lto: Disable LTO for sys_ni Andi Kleen
2014-02-08 8:01 ` [PATCH 07/17] Kbuild, lto, workaround: Don't warn for initcall_reference in modpost Andi Kleen
2014-02-08 8:01 ` [PATCH 08/17] Kbuild, lto: Drop .number postfixes " Andi Kleen
2014-02-08 8:01 ` [PATCH 09/17] Kbuild, lto: add ld-version and ld-ifversion macros Andi Kleen
2014-02-08 8:01 ` [PATCH 10/17] Kbuild, lto: Add a gcc-ld script to let run gcc as ld Andi Kleen
2014-02-08 8:01 ` [PATCH 11/17] Kbuild, lto: Disable LTO for asm-offsets.c Andi Kleen
2014-02-08 8:01 ` [PATCH 12/17] Kbuild, lto: Set TMPDIR for LTO Andi Kleen
2014-02-14 4:26 ` H. Peter Anvin
2014-02-08 8:01 ` [PATCH 13/17] Kbuild, lto: Handle basic LTO in modpost Andi Kleen
2014-02-08 8:01 ` [PATCH 14/17] Kbuild, lto: Add Link Time Optimization support Andi Kleen
2014-02-14 4:28 ` H. Peter Anvin
2014-02-14 14:36 ` Andi Kleen
2014-02-14 16:25 ` H. Peter Anvin
2014-02-08 8:01 ` [PATCH 15/17] Kbuild, lto: Add LTO build Documentation Andi Kleen
2014-02-08 8:01 ` [PATCH 16/17] lto: Mark spinlocks noinline when inline spinlocks are disabled Andi Kleen
2014-02-08 8:01 ` [PATCH 17/17] lto, module: Warn about modules that are not fully LTOed Andi Kleen
2014-02-12 1:13 ` Rusty Russell
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