On 10/14/07, Darryl L. Miles <[EMAIL PROTECTED]> wrote: > > Hello, > > On SPARC there is an ABI that is V8+ which allows the linking (and > mixing) of V8 ABI but makes uses of features of 64bit UltraSparc CPUs > (that were not available in the older 32bit only CPUs). Admittedly > looking at the way this works it could be said that Sun had a certain > about of forward thinking when they developed their 32bit ABI (this is > not true of the 32bit Intel IA32 ABIs that exist).
Sun didn't have much forward thinking with their 32-bit ABI. It's just that their 32-bit ISA was relatively amenable to 64-bit extension with 32-bit ABI compatibility, which can not be said for IA32. > Are there any plans for a plan a new Intel IA32 ABI that is designed > solely to run on 64bit capable Intel IA32 CPUs (that support EMT64) ? > Userspace would have 32bit memory addressing, but access to more > registers, better function call conventions, etc... > > This would be aimed to replace the existing i386/i686 ABIs on the > desktop and would not be looking to maintain backward compatibility > directly. > > My own anecdotal evidence is that I've been using a x86_64 distribution > (with dual 64bit and 32bit runtime support) for a few years now and have > found performance to be lacking in my two largest footprint applications > (my browser and my development IDE totaling 5Gb of footprint between > them). I recently converted both these applications from their 64bit > versions to 32bit (they are the only 32bit applications running) and the > overall interactive performance has improved considerably possibly due > to the reduced memory footprint alone, a 4.5 Gb footprint 64bit > application is equivalent to a 2 Gb footprint 32bit application in these > application domains. > > Maybe someone knows of a white paper published to find out if the > implications and benefit a movement in this direction would mean. Maybe > just using the existing 64bit ABI with 32bit void pointers (and long's) > is as good a specification as any. > > RFCs, > > Darryl More appropriate comparison is probably against MIPS, with their two 32-bit ABIs (O32 and N32 ABI). Essentially you're asking for N32 equivalent. My bet is that most people simply don't care enough about the performance differential. -- #pragma ident "Seongbae Park, compiler, http://seongbae.blogspot.com";
