In these cases, the 'addr' is an u64, so is it necessary to perform this modification? I will do a critical analysis of the remaining code in the driver for any values that are, or have a risk of being on some platforms, a 32 bit entity and undergo this kind of shift action. Sincerely -- Mark Salyzyn -----Original Message----- From: Arjan van de Ven [mailto:arjan@xxxxxxxxxxxxx] Sent: Thursday, August 04, 2005 4:17 AM To: Mark Haverkamp Cc: Salyzyn, Mark; linux-scsi; James Bottomley Subject: Re: [PATCH 7/7] aacraid: sgraw command support On Wed, 2005-08-03 at 15:39 -0700, Mark Haverkamp wrote: > + psg->sg[0].addr[1] = cpu_to_le32((u32)(addr>>32)); this is very risky code; if addr is a 32 bit entity, then this is undefined behavior (which due to the vagities of x86 asm might get optimized out entirely). It is a lot safer to do (addr>>16)>>16 gcc will optimize that just fine, the difference is that it's still defined C behavior regardless of the type of addr. - : send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
