Promoting i386 version over x86_64?

[drago01]

On Tue, Dec 8, 2009 at 5:27 PM, Rallias UberNerd
<robinstar1574 at gmail.com> wrote:
> On Thu, 19 Nov 2009 17:39:16 -0600, Kevin Kofler <kevin.kofler at chello.at>
> wrote:
>
>> Bill McGonigle wrote:
>>>
>>> "Are you installing Fedora on the computer you're using now?" [YES]  [NO]
>>>  YES -> is any sort of check even possible if the user is running
>>> 32-bit on 64-bit?
>>
>> Yes, if the CPU has the lm (long mode) flag, it's a 64-bit-capable CPU and
>> using the 32-bit version is suboptimal.
>>
>>        Kevin Kofler
>>
> But wouldn't it be better to use 32 bit when less then 4 GB of ram is
> present?

no, using x86_64 means more registers, sse2 as default floating point
instruction set, better calling convention (register passing vs.
stack) or in other words in most cases faster code.