This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]
Other format:	[Raw text]

Re: PATCH: Add -mcrc32

From: "H.J. Lu" <hjl dot tools at gmail dot com>
To: Uros Bizjak <ubizjak at gmail dot com>
Cc: gcc-patches at gcc dot gnu dot org
Date: Wed, 10 Jun 2009 08:25:36 -0700
Subject: Re: PATCH: Add -mcrc32
References: <20090610111832.GA10143@lucon.org> <4A2FC95C.1060801@gmail.com>

On Wed, Jun 10, 2009 at 7:55 AM, Uros Bizjak<ubizjak@gmail.com> wrote:
> On 06/10/2009 01:18 PM, H.J. Lu wrote:
>
>> Linux kernel is compiled with -mno-sse. It wants crc32 integer
>> instructions
>> without enabling SSE4. ?OK for trunk?
>>
>
> Hm, don't they use asm directly? IIRC, kernel people hate __builtin_X stuff.
>

Gcc generates better codes with built-in functions than asm. See:

__builtin_unreachable:

http://gcc.gnu.org/ml/gcc-patches/2009-06/msg00317.html

is another example.


-- 
H.J.

References:
- PATCH: Add -mcrc32
  - From: H.J. Lu
- Re: PATCH: Add -mcrc32
  - From: Uros Bizjak

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]