> -----Original Message----- > From: Jim Sibley [mailto:[EMAIL PROTECTED] > Sent: Monday, July 14, 2003 11:15 AM > To: [EMAIL PROTECTED] > Subject: Re: Probly a stoopid ?, but what's "better"...31-bit > or 64-bit? > > > If you don't have any 64 bit apps, then there is no point in > using 64 bit > (some of the 64 bit instructions are quite a bit "slower" > than their 31/32 > bit counterparts).
Is there any doc on which ones are slower? I'm especially interested in the ones which do arithmetic. From all that I can tell, you can do 64 bit arithmetic even in 31 bit addressing mode. From what I've read, there are only a few instructions which are "modal" in that their operation differs depending on the AMODE in effect at the time. All of which are "branching" type instructions. Is something like AG (Add Grande) slower than A (Add)? > <snip> > > Regards, Jim > Linux S/390-zSeries Support, SEEL, IBM Silicon Valley Labs > t/l 543-4021, 408-463-4021, [EMAIL PROTECTED] > *** Grace Happens *** > n -- John McKown Senior Systems Programmer UICI Insurance Center Applications & Solutions Team +1.817.255.3225 This message (including any attachments) contains confidential information intended for a specific individual and purpose, and its' content is protected by law. If you are not the intended recipient, you should delete this message and are hereby notified that any disclosure, copying, or distribution of this transmission, or taking any action based on it, is strictly prohibited.
