x86-64 on i386 (was Re: Promoting i386 version over x86_64?)

Tom Lane tgl at redhat.com
Sun Dec 13 18:53:05 UTC 2009


Paul Jakma <paul at dishone.st> writes:
> On Wed, 18 Nov 2009, Roland McGrath wrote:
>> x86 is unlike other architectures because 64-bit also has twice as 
>> many registers as 32-bit.  So you get to trade off the benefits of 
>> register allocation across more registers against the memory/cache 
>> footprint of 64-bit pointers.

> For what percentage of code is that an appreciable advantage?

Pretty much everything, actually.  The x86 ISA completely sucks.

			regards, tom lane




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