On 4/27/2013 9:22 AM, Vyacheslav Egorov wrote: > > And therein lies the problem: x86-64 instruction set isn't > compatible with IA64 instruction set > > That is exactly what we are talking about: it's instruction set that > is the issue, not the amount of bits (32 vs. 64).
So, to move the discussion along: the code is 64bit clean, but there is no IA64 machine code. There is a Mips instruction set simulator. It's probably going to be the case that it will have to be a starting point. Or, is the mismatch between the RISC and VLIW too great to use that as a starting point? Jeff Chimene > > Vyacheslav Egorov > > > On Sat, Apr 27, 2013 at 6:18 PM, Jeffrey Chimene <[email protected] > <mailto:[email protected]>> wrote: > > On 4/27/2013 9:14 AM, Rodolph Perfetta wrote: >> In 2009 v8 didn't have a 64bits port, now as mentioned by >> Vyacheslav, it has (for intel x86-64). So the amount of bits is >> not a problem. > > And therein lies the problem: x86-64 instruction set isn't > compatible with IA64 instruction set > > >> >> On 27 April 2013 16:29, Jeffrey Chimene <[email protected] >> <mailto:[email protected]>> wrote: >> >> On 4/27/2013 8:17 AM, Vyacheslav Egorov wrote: >>> Amount of bits is not an issue here at all, for example V8 >>> already runs on x86-64 just fine. >> I should have been clearer. I'm referring to a thread from 2009 >> >> https://groups.google.com/forum/#!searchin/v8-dev/ia64/v8-dev/GuP1ZlPVIpE/uUUNjmXCJ-wJ >> >> <https://groups.google.com/forum/#%21searchin/v8-dev/ia64/v8-dev/GuP1ZlPVIpE/uUUNjmXCJ-wJ> >>> Making V8 work on 64-bits is much much bigger than changing >>> some types >>> around and changing the scons. It probably deserves some >>> fairly big >>> design discussions, and I would guess it would take at least >>> a few >>> months, and it will be hard not to fracture the code a >>> bunch, with >>> separate code for 32/64 bit (GC, object layout, etc). >> >> and in reply >> >> I'm certainly not expecting that type changes will magically >> make this code 64-bit clean. If that were true, it would've >> been done already. >> >> If it would be better, I can do these changes out of tree and >> come back with things when I have them working. My question >> from the previous email is whether or not generic changes >> would be accepted into the tree or not - if the answer is no, >> that's fine. >> >>> >>> Despite confusingly similar names ia32 and IA64 (Itanium) >>> are *very* different architectures. >> Agreed. The mode on the IA64 that executes 32 bit >> instructions isn't available on VMS >> >> >>> >>> I'd say generating efficient code for IA64 is much harder >>> because compiler has to carefully schedule instructions in >>> instruction bundles (IA64 is VLIW) to saturate execution >>> units and avoid dreadful stalls. >> Agreed. That may be why IA64 hasn't been produced. OTOH. it >> may be that the V8 code isn't 64-bit clean. >>> >>> [though I heard that newest >>> Itanium micro-architecture actually is more forgiving to >>> poor scheduling and is capable of a good built-in >>> out-of-order execution, but I am not closely following this >>> things so I might be wrong] >>> >>> >>> >>> >>> >>> Vyacheslav Egorov >>> >>> >>> On Sat, Apr 27, 2013 at 4:50 AM, <[email protected] >>> <mailto:[email protected]>> wrote: >>> >>> Hi Folks, >>> >>> I'd like to spearhead a port to IA64 on OpenVMS, which >>> does not support IA32 subset. Am I correct that this is >>> a deal breaker in that true 64 bit is a major initiative? >>> -- >>> -- >>> v8-dev mailing list >>> [email protected] <mailto:[email protected]> >>> http://groups.google.com/group/v8-dev >>> --- >>> You received this message because you are subscribed to >>> the Google Groups "v8-dev" group. >>> To unsubscribe from this group and stop receiving emails >>> from it, send an email to >>> [email protected] >>> <mailto:v8-dev%[email protected]>. >>> For more options, visit >>> https://groups.google.com/groups/opt_out. >>> >>> >>> >>> >>> -- >>> -- >>> v8-dev mailing list >>> [email protected] <mailto:[email protected]> >>> http://groups.google.com/group/v8-dev >>> --- >>> You received this message because you are subscribed to a >>> topic in the Google Groups "v8-dev" group. >>> To unsubscribe from this topic, visit >>> >>> https://groups.google.com/d/topic/v8-dev/HnPDu-HygB4/unsubscribe?hl=en. >>> To unsubscribe from this group and all its topics, send an >>> email to [email protected] >>> <mailto:[email protected]>. >>> >>> For more options, visit >>> https://groups.google.com/groups/opt_out. >>> >>> >> >> -- >> -- >> v8-dev mailing list >> [email protected] <mailto:[email protected]> >> http://groups.google.com/group/v8-dev >> --- >> You received this message because you are subscribed to the >> Google Groups "v8-dev" group. >> To unsubscribe from this group and stop receiving emails from >> it, send an email to [email protected] >> <mailto:v8-dev%[email protected]>. >> For more options, visit https://groups.google.com/groups/opt_out. >> >> >> >> >> -- >> -- >> v8-dev mailing list >> [email protected] <mailto:[email protected]> >> http://groups.google.com/group/v8-dev >> --- >> You received this message because you are subscribed to a topic >> in the Google Groups "v8-dev" group. >> To unsubscribe from this topic, visit >> https://groups.google.com/d/topic/v8-dev/HnPDu-HygB4/unsubscribe?hl=en. >> To unsubscribe from this group and all its topics, send an email >> to [email protected] >> <mailto:[email protected]>. >> For more options, visit https://groups.google.com/groups/opt_out. >> >> > > -- > -- > v8-dev mailing list > [email protected] <mailto:[email protected]> > http://groups.google.com/group/v8-dev > --- > You received this message because you are subscribed to the Google > Groups "v8-dev" group. > To unsubscribe from this group and stop receiving emails from it, > send an email to [email protected] > <mailto:v8-dev%[email protected]>. > For more options, visit https://groups.google.com/groups/opt_out. > > > > > -- > -- > v8-dev mailing list > [email protected] > http://groups.google.com/group/v8-dev > --- > You received this message because you are subscribed to a topic in the > Google Groups "v8-dev" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/v8-dev/HnPDu-HygB4/unsubscribe?hl=en. > To unsubscribe from this group and all its topics, send an email to > [email protected]. > For more options, visit https://groups.google.com/groups/opt_out. > > -- -- v8-dev mailing list [email protected] http://groups.google.com/group/v8-dev --- You received this message because you are subscribed to the Google Groups "v8-dev" group. 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