From: Ulrich Drepper <drepper@redhat.com>
To: Linus Torvalds <torvalds@transmeta.com>
Cc: Andi Kleen <ak@muc.de>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Runtime memory barrier patching
Date: Mon, 21 Apr 2003 14:43:38 -0700 [thread overview]
Message-ID: <3EA4660A.6000506@redhat.com> (raw)
In-Reply-To: <Pine.LNX.4.44.0304211359430.17938-100000@home.transmeta.com>
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Linus Torvalds wrote:
> They may _work_ for intel, but quite frankly they suck for most Intel (and
> probably non-intel too) CPU's. Using prefixes tends to almost always mess
> up the instruction decoders on most CPU's out there.
Indeed, using prefixes is terrible. This is what is used in gas:
{0x90}; /* nop */
static const char f32_2[] =
{0x89,0xf6}; /* movl %esi,%esi */
static const char f32_3[] =
{0x8d,0x76,0x00}; /* leal 0(%esi),%esi */
static const char f32_4[] =
{0x8d,0x74,0x26,0x00}; /* leal 0(%esi,1),%esi */
static const char f32_5[] =
{0x90, /* nop */
0x8d,0x74,0x26,0x00}; /* leal 0(%esi,1),%esi */
static const char f32_6[] =
{0x8d,0xb6,0x00,0x00,0x00,0x00}; /* leal 0L(%esi),%esi */
static const char f32_7[] =
{0x8d,0xb4,0x26,0x00,0x00,0x00,0x00}; /* leal 0L(%esi,1),%esi */
static const char f32_8[] =
{0x90, /* nop */
0x8d,0xb4,0x26,0x00,0x00,0x00,0x00}; /* leal 0L(%esi,1),%esi */
static const char f32_9[] =
{0x89,0xf6, /* movl %esi,%esi */
0x8d,0xbc,0x27,0x00,0x00,0x00,0x00}; /* leal 0L(%edi,1),%edi */
static const char f32_10[] =
{0x8d,0x76,0x00, /* leal 0(%esi),%esi */
0x8d,0xbc,0x27,0x00,0x00,0x00,0x00}; /* leal 0L(%edi,1),%edi */
static const char f32_11[] =
{0x8d,0x74,0x26,0x00, /* leal 0(%esi,1),%esi */
0x8d,0xbc,0x27,0x00,0x00,0x00,0x00}; /* leal 0L(%edi,1),%edi */
static const char f32_12[] =
{0x8d,0xb6,0x00,0x00,0x00,0x00, /* leal 0L(%esi),%esi */
0x8d,0xbf,0x00,0x00,0x00,0x00}; /* leal 0L(%edi),%edi */
static const char f32_13[] =
{0x8d,0xb6,0x00,0x00,0x00,0x00, /* leal 0L(%esi),%esi */
0x8d,0xbc,0x27,0x00,0x00,0x00,0x00}; /* leal 0L(%edi,1),%edi */
static const char f32_14[] =
{0x8d,0xb4,0x26,0x00,0x00,0x00,0x00, /* leal 0L(%esi,1),%esi */
0x8d,0xbc,0x27,0x00,0x00,0x00,0x00}; /* leal 0L(%edi,1),%edi */
static const char f32_15[] =
{0xeb,0x0d,0x90,0x90,0x90,0x90,0x90, /* jmp .+15; lotsa nops */
0x90,0x90,0x90,0x90,0x90,0x90,0x90,0x90};
- --
- --------------. ,-. 444 Castro Street
Ulrich Drepper \ ,-----------------' \ Mountain View, CA 94041 USA
Red Hat `--' drepper at redhat.com `---------------------------
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next prev parent reply other threads:[~2003-04-21 21:32 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-04-21 19:27 [PATCH] Runtime memory barrier patching Andi Kleen
2003-04-21 19:59 ` Linus Torvalds
2003-04-21 20:53 ` Andi Kleen
2003-04-21 21:04 ` Linus Torvalds
2003-04-21 21:43 ` Ulrich Drepper [this message]
2003-04-21 22:05 ` Linus Torvalds
2003-04-21 22:45 ` Andi Kleen
2003-04-21 22:11 ` Andi Kleen
2003-04-21 22:23 ` Linus Torvalds
2003-04-21 22:59 ` Andi Kleen
2003-04-21 23:35 ` Jamie Lokier
2003-04-21 23:46 ` Andi Kleen
2003-04-21 23:56 ` [PATCH] Runtime memory barrier patching II Andi Kleen
2003-04-21 23:57 ` [PATCH] Runtime memory barrier patching Jamie Lokier
2003-04-22 0:06 ` Linus Torvalds
2003-04-22 0:13 ` Jamie Lokier
-- strict thread matches above, loose matches on Subject: below --
2003-04-21 23:41 Chuck Ebbert
2003-04-22 0:04 ` Jamie Lokier
[not found] <200304220111.h3M1BEp5004047@hera.kernel.org>
2003-04-22 8:43 ` Arjan van de Ven
2003-04-22 11:18 ` Andi Kleen
2003-04-22 16:11 ` Dave Jones
2003-04-22 10:12 Chuck Ebbert
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