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> Macroinstructions > Macro to generate x64 opcodes |
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Tomasz Grysztar 04 Jan 2006, 08:02
Theoretically it would be possible, but you actually don't need macros for this. Just do it like:
Code: use64
mov rax,rbx
use32 to make any x64 instructions in your Win32 program. |
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04 Jan 2006, 08:02 |
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alorent 04 Jan 2006, 08:10
Thanks a lot. It's amazing how powerful FASM is
 Didn't know you could switch between use32 and use64 in a single application 
Anyway, I have been trying to make this macro for a long time but "manually" (without the use64 directive) and my curiosity is killing me
Any hint on how that could be done? An example for the _MOV instruction will be great so I could extend it to the other instructions 
Thanks a lot! |
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04 Jan 2006, 08:10 |
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Borsuc 04 Jan 2006, 12:39
It's quite difficult.. You'll have to do A LOT of ifs, match and other to write instructions manually with db directive. Of course, you must also know the x86-64 encoding scheme to do it.
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04 Jan 2006, 12:39 |
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alorent 04 Jan 2006, 12:53
Hello,
Yes, you might be right. Too much work that can be easily done by "use64"
Thanks. |
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04 Jan 2006, 12:53 |
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Borsuc 04 Jan 2006, 12:55
And also too much overhead, for every mov instruction you use. It's best to let assembler 'assemble' it with it's fast internal core
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04 Jan 2006, 12:55 |
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Reverend 04 Jan 2006, 16:37
I wrote some macro that should enable (at least partially) the functionality you want:
Code: ; first define which instructions to overload ; you can give whatever you wish overload64 mov, add, sub ; normal code mov eax, 100 add eax, 200 ; now let's put 64bit code _mov <rax, rdx> _add <rcx, rax> 2. Macro creates other macros with '_' in the beginning like _mov, _add, etc. 3. Operands must be in < > And here's the macro: Code: macro overload64 [instr] { local __macro_name __macro_name equ _ # instr match name, __macro_name \{ macro name operand \\{ use64 instr operand use32 \\} \} } BTW. Can anyone plz tell me how to create lists in macro? I want to have them in some 'equ' variable just as they were passed to macro. Like this: someone wrote 'imul edx, ecx, 16', and my macro gets one by one: 'edx', 'ecx', '16'. How to put it together again to 'edx, ecx, 16'? I know it's possible (I've seen it somewhere), but none of my match tries, neither forward/reverse, nor EQUs worked |
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04 Jan 2006, 16:37 |
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Borsuc 04 Jan 2006, 16:55
Have you tried the # operator? irp might also prove useful.
Do you need a variable-length list or a fixed-length list? something like this (dunno if it works, though): Code: params equ p1#,#p2#,#p3 ; p1, p2 and p3 are eax edx 16 I don't know how to do it for variable-length lists, maybe rept, irp or irps will help there. |
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04 Jan 2006, 16:55 |
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Borsuc 04 Jan 2006, 17:56
Or, if you have something like:
Code: macro xxx [p] { common params equ forward ; do some stuff for each param... params equ params,p common ; now you want to use the params to imul imul params } But I think you can get away with a simple imul p without needing params constant. EDIT: Apparently, it seems the list will begin with a comma. Try this at the end: Code: match =,any, params \{ \forward restore params \common restore params ; the empty value define params any \} then use imul params. Does this help? |
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04 Jan 2006, 17:56 |
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Reverend 04 Jan 2006, 18:23
Lists are not of fixed length. Some instructions don't have any operands, some have even three. I remember it was possible with heavy usage of match - but the version as I remember it just didn't work for me. And AFAIK it is posssible without rept, irp or irps
AFTER A LONG WHILE CODING I got this finally As usual - the simplest is the correct one. Code: macro _64 [instr] { local _name _name equ _#instr match any, _name \{ macro any [operand] \\{ \\common local _args _args equ operand use64 instr _args use32 \\} \} } _64 mov, sub, shl _mov rax, rdx _sub rcx, rax _shl rax, 1 Thanks The_Grey_Beast for help. But the soultion is just to 'equ' in 'common'. BTW. Which keywords have to be reserved? I had problems because I didn;t know that common must have \. What are the other words? |
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04 Jan 2006, 18:23 |
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Tomasz Grysztar 04 Jan 2006, 18:32
You should escape any operations that otherwise would get processed by the outer macro. So these are all the symbols that are processed by macro processor: "forward", "reverse", "common", "local", "#", "`"; in case of nested "struct" macros you might need to escape the symbol starting with dot, too.
I tried to explain it simply but completely in the manual. If you've got suggestions what more samples would I put there, write them to me. Last edited by Tomasz Grysztar on 04 Jan 2006, 18:33; edited 1 time in total |
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04 Jan 2006, 18:32 |
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Borsuc 04 Jan 2006, 18:33
Glad you got it working. And sorry about fixed-length lists confusion.
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04 Jan 2006, 18:33 |
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