More on Delphi x64 by twitter kylix_rd (Allen Bauer)
Posted by jpluimers on 2010/11/09
As a continuation of the previous assembly, the new twitter kylix_rd messages on Delphi x64 (and some reactions by Danny Thorpe):
To save people from browsing Twitter history:
Interesting x64 fun fact: RIP relative addressing. Some instructions that use a 32bit offset, are interpreted as [RIP+offs].
7 nov@danny_thorpe Add x64 and it happens even more.
7 novBecause of the way the Intel instructions are encoded, it is possible to encode the same effective instruction in different ways.
7 novYou know what would have made the x64 “REX” prefix moniker even better? They could have called it T-REX.
7 novAs much as people like to deride the aging x86 architecture, I gotta admit that AMD did a fine job of stretching it into 64bit land.
7 nov@davidheff Undetermined. There are plenty of reasons to deliver them separately. Either way will have no impact on the results.
2 NovBe ready for 64 bit: In Delphi XE, this “Component.Tag := NativeInt(Self);” will just recompile in 64 bit.
2 Nov@davidheff Oh don’t worry… there will be plenty who will find that “limiting”, if only in concept and not in the real world :-)
2 Novx64 Fun Fact: JMP opcodes/offsets are identical to 32bit. Can only xfer control to an address +/- 2GB away. Thus the PE image size limit.
2 Nov
@kylix_rd I remember digging through the x64 specs. Fun times til mgmt shut it down. Still have my Amd x64 laptop circa 2003 or so.
8 nov@kylix_rd You just noticed? :P
8 nov
@kylix_rd is it still on course to be a cross-compiler as announced by Nick – single 32 bit compiler that can create 32 and 64 bit images
from Stavanger, Rogaland
2 Nov Favorite Retweet Reply@kylix_rd Actually, I wonder whether the compiler wouldn’t give out first at such a monstrous demand
from Stavanger, Rogaland
2 Nov@kylix_rd Think most of us should be able to avoid creating 2GB images!!!!
from Stavanger, Rogaland
2 Nov
–jeroen
via Allen Bauer (kylix_rd) on Twitter
Danny Thorpe (danny_thorpe) on Twitter
David Heffernan (davidheff) on Twitter
The Wiert Corner - irregular stream of stuff 
New years resolution: CHASM64 – More on Delphi x64 by twitter kylix_rd (Allen Bauer) « The Wiert Corner – irregular stream of Wiert stuff said
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LDS said
“Fact: JMP opcodes/offsets are identical to 32bit. Can only xfer control to an address +/- 2GB away”
“gotta admit that AMD did a fine job of stretching it into 64bit land”
They really look contradictory statements. I believe AMD made a very bad job, they had in mind just a 64 bit extension for code that most of the time would have been 32 bit compatible working on 32 bit data. IMHO the whole AMD 64 bit implementation is clumsy and lame – and shows why AMD is always a second choice.
Of course I can’t see executable sizes to become that large and needing that offsets anytime soon… but why put this restriction in place? Is this a technical need due to hardware implementation, or designers were simply shortsighted?
John said
Twitter is decidedly an impractical communication channel…
jpluimers said
“decidedly”: thanks for teaching me a new word today.
I agree completely :-)
–jeroen
Dorin Duminica said
Nice but this still doesn’t mean that the next Delphi release will be able to create 64 bit executables — IF by any chance it will be able, it will be VERY buggy I bet € 20 on the table.