From: Matthew Wilcox <matthew@wil.cx>
To: Grant Grundler <grundler@google.com>
Cc: "Salyzyn, Mark" <Mark_Salyzyn@adaptec.com>,
"linux-scsi@vger.kernel.org" <linux-scsi@vger.kernel.org>
Subject: Re: [PATCH 1/1] aacraid: big endian issues
Date: Tue, 8 Jan 2008 14:39:29 -0700 [thread overview]
Message-ID: <20080108213928.GL16309@parisc-linux.org> (raw)
In-Reply-To: <da824cf30801081317q68516370x4a46f9eb80583d28@mail.gmail.com>
On Tue, Jan 08, 2008 at 01:17:15PM -0800, Grant Grundler wrote:
> Why apply le32_to_cpu() to the constant instead of the variable?
> On systems were le32_to_cpu() is doing something, can gcc or
> preprocessor optimize the constant?
> I've always assumed it could not but that might be wrong.
$ grep constant_p include/linux/byteorder/*
include/linux/byteorder/swabb.h:(__builtin_constant_p((__u32)(x)) ? \
include/linux/byteorder/swabb.h:(__builtin_constant_p((__u32)(x)) ? \
include/linux/byteorder/swab.h:(__builtin_constant_p((__u16)(x)) ? \
include/linux/byteorder/swab.h:(__builtin_constant_p((__u32)(x)) ? \
include/linux/byteorder/swab.h:(__builtin_constant_p((__u64)(x)) ? \
--
Intel are signing my paycheques ... these opinions are still mine
"Bill, look, we understand that you're interested in selling us this
operating system, but compare it to ours. We can't possibly take such
a retrograde step."
next prev parent reply other threads:[~2008-01-08 21:39 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-10-31 4:02 [PATCH] aacraid: don't assign cpu_to_le32(constant) to u8 Stephen Rothwell
2007-10-31 13:53 ` Salyzyn, Mark
2007-11-01 6:32 ` [PATCHv2] " Stephen Rothwell
2007-11-01 13:11 ` Salyzyn, Mark
2007-11-01 13:31 ` Andreas Schwab
2007-11-07 15:58 ` [PATCH 1/1] aacraid: don't assign cpu_to_le32(int) " Salyzyn, Mark
2007-11-07 17:33 ` Christoph Hellwig
2007-11-07 18:51 ` Salyzyn, Mark
2007-11-08 17:27 ` Christoph Hellwig
2007-11-08 18:09 ` Salyzyn, Mark
2008-01-08 20:01 ` [PATCH 1/1] aacraid: add aacraid.cache parameter to driver to control FUA and SYNCHRONIZE_CACHE policy Salyzyn, Mark
[not found] ` <532ABFBDAAC3A34EB12EBA6CEC2838F40FE734@ADPE2K703.adaptec.com>
2008-01-08 20:09 ` [PATCH 1/1] aacraid: add call to flush_kernel_dcache_page for architectures that require it Salyzyn, Mark
2008-01-11 16:41 ` James Bottomley
2008-01-11 19:46 ` [PATCH 1/1] aacraid: add call to flush_kernel_dcache_page for architectures that require it (take 2) Salyzyn, Mark
2008-01-11 19:56 ` James Bottomley
[not found] ` <532ABFBDAAC3A34EB12EBA6CEC2838F40FE735@ADPE2K703.adaptec.com>
2008-01-08 20:23 ` [PATCH 1/1] aacraid: add sysfs report of RAID level Salyzyn, Mark
[not found] ` <532ABFBDAAC3A34EB12EBA6CEC2838F40FE736@ADPE2K703.adaptec.com>
2008-01-08 20:32 ` [PATCH 1/1] aacraid: variable redefinition hides earlier warning Salyzyn, Mark
2008-01-08 20:48 ` [PATCH 1/1] aacraid: big endian issues Salyzyn, Mark
2008-01-08 21:17 ` Grant Grundler
2008-01-08 21:37 ` Salyzyn, Mark
2008-01-09 3:57 ` Grant Grundler
2008-01-08 21:39 ` Matthew Wilcox [this message]
[not found] ` <532ABFBDAAC3A34EB12EBA6CEC2838F40FE738@ADPE2K703.adaptec.com>
2008-01-08 20:57 ` [PATCH 1/1] aacraid: multiple definition of automatic variable warning Salyzyn, Mark
2008-01-08 21:08 ` Salyzyn, Mark
2008-01-08 21:26 ` [PATCH 1/1] aacraid: OS panic after Adapter panic (hardening) Salyzyn, Mark
[not found] ` <532ABFBDAAC3A34EB12EBA6CEC2838F40FE739@ADPE2K703.adaptec.com>
2008-01-08 22:07 ` [PATCH 1/1] aacraid: improve queue balancing Salyzyn, Mark
2008-01-24 15:40 ` [PATCH 1/1] aacraid: fib context lock for management ioctls Salyzyn, Mark
2008-01-28 20:16 ` [PATCH 1/1] aacraid: fib context lock for management ioctls (take 2) Salyzyn, Mark
[not found] ` <532ABFBDAAC3A34EB12EBA6CEC2838F40FE73E@ADPE2K703.adaptec.com>
2008-01-11 16:15 ` [PATCH 1/1] aacraid: respond to enclosure service events Salyzyn, Mark
[not found] ` <532ABFBDAAC3A34EB12EBA6CEC2838F437E96989@ADPE2K703.adaptec.com>
2008-01-11 16:41 ` [RFC] aacraid: driver feature flags? Salyzyn, Mark
2008-01-11 19:56 ` [PATCH 1/1] aacraid: respond to enclosure service events (take 2) Salyzyn, Mark
2008-01-11 21:46 ` [PATCH 1/1] aacraid: SMC vendor identification Salyzyn, Mark
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