From: "H. Peter Anvin" <hpa@zytor.com>
To: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
Andi Kleen <ak@muc.de>, Chuck Ebbert <cebbert@redhat.com>,
Christoph Hellwig <hch@infradead.org>,
Jeremy Fitzhardinge <jeremy@goop.org>
Subject: Re: [patch 5/8] Immediate Values - x86 Optimization (update)
Date: Tue, 13 Nov 2007 17:02:01 -0800 [thread overview]
Message-ID: <473A4909.1020609@zytor.com> (raw)
In-Reply-To: <20071114003409.GA18032@Krystal>
Mathieu Desnoyers wrote:
>
> Ok, so the most flexible solution that I see, that should fit for both
> i386 and x86_64 would be :
>
>
> 1 byte : "=Q" : Any register accessible as rh: a, b, c, and d.
> 2, 4 bytes : "=R" : Legacy register—the eight integer registers available
> on all i386 processors (a, b, c, d, si, di, bp, sp).
> 8 bytes : (only for x86_64)
> "=r" : A register operand is allowed provided that it is in a
> general register.
>
> That should make sure x86_64 won't try to use REX prefixed opcodes for
> 1, 2 and 4 bytes values.
>
> Does it make sense ?
>
That's probably the best bet.
-hpa
next prev parent reply other threads:[~2007-11-14 1:05 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-11-13 18:58 [patch 0/8] Immediate Values (now with merged x86 support) Mathieu Desnoyers
2007-11-13 18:58 ` [patch 1/8] Immediate Values - Architecture Independent Code Mathieu Desnoyers
2007-11-13 18:58 ` [patch 2/8] Immediate Values - Kconfig menu in EMBEDDED Mathieu Desnoyers
2007-11-13 18:58 ` [patch 3/8] Immediate Values - Move Kprobes x86 restore_interrupt to kdebug.h Mathieu Desnoyers
2007-11-13 18:58 ` [patch 4/8] Add asm-compat.h to x86 Mathieu Desnoyers
2007-11-13 19:05 ` H. Peter Anvin
2007-11-13 20:37 ` [patch 4/8] Add asm-compat.h to x86 -> use new asm.h instead Mathieu Desnoyers
2007-11-13 18:58 ` [patch 5/8] Immediate Values - x86 Optimization Mathieu Desnoyers
2007-11-13 19:07 ` H. Peter Anvin
2007-11-13 19:24 ` Mathieu Desnoyers
2007-11-13 19:36 ` H. Peter Anvin
2007-11-13 19:45 ` Mathieu Desnoyers
2007-11-13 19:56 ` H. Peter Anvin
2007-11-13 20:40 ` [patch 5/8] Immediate Values - x86 Optimization (update) Mathieu Desnoyers
2007-11-13 21:26 ` H. Peter Anvin
2007-11-13 22:02 ` Mathieu Desnoyers
2007-11-13 22:35 ` H. Peter Anvin
2007-11-14 0:34 ` Mathieu Desnoyers
2007-11-14 1:02 ` H. Peter Anvin [this message]
2007-11-14 1:44 ` [patch 5/8] Immediate Values - x86 Optimization (update 2) Mathieu Desnoyers
2007-11-14 2:58 ` H. Peter Anvin
2007-11-14 14:16 ` Mathieu Desnoyers
2007-11-14 18:52 ` [PATCH] Immediate Values x86 Optimization Declare Discarded Instruction Mathieu Desnoyers
2007-11-14 19:00 ` H. Peter Anvin
2007-11-14 19:16 ` [PATCH] Add __discard section to x86 Mathieu Desnoyers
2007-11-14 19:33 ` H. Peter Anvin
2007-11-15 3:08 ` [patch 5/8] Immediate Values - x86 Optimization Rusty Russell
2007-11-15 4:06 ` Mathieu Desnoyers
2007-11-15 4:45 ` Rusty Russell
2007-11-15 5:37 ` Mathieu Desnoyers
2007-11-15 11:06 ` Rusty Russell
2007-11-16 14:03 ` [patch 5/8] Immediate Values - x86 Optimization (simplified) Mathieu Desnoyers
2007-11-18 23:11 ` Rusty Russell
2007-11-19 14:28 ` Mathieu Desnoyers
2007-11-19 23:06 ` Rusty Russell
2007-11-20 17:02 ` Mathieu Desnoyers
2007-11-19 19:15 ` Mathieu Desnoyers
2007-11-13 18:58 ` [patch 6/8] Immediate Values - Powerpc Optimization Mathieu Desnoyers
2007-11-13 18:58 ` [patch 7/8] Immediate Values - Documentation Mathieu Desnoyers
2007-11-13 18:58 ` [patch 8/8] Scheduler Profiling - Use Immediate Values Mathieu Desnoyers
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