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Emya
Newbie cheater
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Joined: 28 Jul 2024
Posts: 14
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 Posted: Mon Aug 19, 2024 3:41 pm Post subject: Int to String (asm) |
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Hey... big guys... maybe what I'm doing is ridiculous...
But at 5 AM, I finally managed to create a pure assembly function that converts a string into a signed 4-byte integer and a single-precision float. This is a huge achievement for me.
But I'm not satisfied yet. I want to convert a 4-byte integer into a string. Is this too difficult for me?
If any of you have done something similar, could you share some ideas or thoughts? (I'm looking for a technical challenge)
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ParkourPenguin
I post too much
 Reputation: 152
Joined: 06 Jul 2014
Posts: 4703
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| Posted: Mon Aug 19, 2024 4:53 pm Post subject: |
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You're better off calling an API function. Using C:
| Code: | globalalloc(foo,4096)
label(num)
label(strval)
{$c}
#include <stdlib.h>
void int_to_str(int v, char *str) {
_itoa(v, str, 10);
}
{$asm}
foo:
{$ccode}
extern int num;
extern char strval[252];
int_to_str(num, strval);
{$asm}
ret
foo+800:
num:
resd 1
strval:
resb 252
createthread(foo) |
Assembly:
| Code: | globalalloc(foo,4096)
label(num)
label(strval)
foo:
push rbp
mov rbp,rsp
sub rsp,20
// char * _itoa( int value, char *buffer, int radix );
mov ecx,[num]
mov rdx,strval
mov r8d,#10
call _itoa
mov rsp,rbp
pop rbp
ret
foo+800:
num:
resd 1
strval:
resb 252
createthread(foo) |
If you don't want to use a function from some other API, search for "itoa implementation" to get examples. (compile C code to see assembly; might need to use `volatile` on inputs & outputs to force the compiler to actually generate code)
_________________
I don't know where I'm going, but I'll figure it out when I get there. |
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Emya
Newbie cheater
![]() Reputation: 0
Joined: 28 Jul 2024
Posts: 14
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| Posted: Tue Aug 20, 2024 9:56 am Post subject: Maybe I need a usable template |
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| ParkourPenguin wrote: | You're better off calling an API function. Using C:
| Code: | globalalloc(foo,4096)
label(num)
label(strval)
{$c}
#include <stdlib.h>
void int_to_str(int v, char *str) {
_itoa(v, str, 10);
}
{$asm}
foo:
{$ccode}
extern int num;
extern char strval[252];
int_to_str(num, strval);
{$asm}
ret
foo+800:
num:
resd 1
strval:
resb 252
createthread(foo) |
Assembly:
| Code: | globalalloc(foo,4096)
label(num)
label(strval)
foo:
push rbp
mov rbp,rsp
sub rsp,20
// char * _itoa( int value, char *buffer, int radix );
mov ecx,[num]
mov rdx,strval
mov r8d,#10
call _itoa
mov rsp,rbp
pop rbp
ret
foo+800:
num:
resd 1
strval:
resb 252
createthread(foo) |
If you don't want to use a function from some other API, search for "itoa implementation" to get examples. (compile C code to see assembly; might need to use `volatile` on inputs & outputs to force the compiler to actually generate code) |
Ah... it's just unbelievable. The output code seems to be somewhere, but I don't have any programming background. I want to refine it into a callable template like the one below, but I'm too dumb to understand what the senior provided...
Maybe I need a usable template. I'll do my best to learn things
| Code: |
alloc(code,$100)
createthread(code)
code:
push ebp
mov ebp,esp
pushad
push #114514
call Int_to_String
mov [String_output],eax
popad
mov esp,ebp
pop ebp
ret |
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ParkourPenguin
I post too much
Reputation: 152
Joined: 06 Jul 2014
Posts: 4703
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| Posted: Tue Aug 20, 2024 11:07 am Post subject: |
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Ok, here's a more complete example using 32-bit code:
| Code: | [ENABLE]
{$lua}
-- just makes a couple memory records if needed
if syntaxcheck then return end
assert(memrec, 'Assign script to table')
if memrec.Count == 0 then
createTimer(1,function()
local mrInput = AddressList.createMemoryRecord()
mrInput.Description = 'Input (number)'
mrInput.Address = 'input_number'
mrInput.Type = vtDword
mrInput.ShowAsSigned = true
mrInput.appendToEntry(memrec)
local mrOutput = AddressList.createMemoryRecord()
mrOutput.Description = 'Output (string)'
mrOutput.Address = 'output_string'
mrOutput.Type = vtString
mrOutput.String.Size = 252
mrOutput.appendToEntry(memrec)
end)
end
{$asm}
globalalloc(foo,4096)
label(input_number)
label(output_string)
foo:
push ebp
mov ebp,esp
push 10
push [input_number]
push output_string
call _itoa
mov esp,ebp
pop ebp
ret
foo+800:
input_number:
resd 1
output_string:
resb 252
registersymbol(input_number)
registersymbol(output_string)
createthread(foo)
[DISABLE] |
I can't quite test this right now, but it should be correct
_________________
I don't know where I'm going, but I'll figure it out when I get there. |
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Emya
Newbie cheater
![]() Reputation: 0
Joined: 28 Jul 2024
Posts: 14
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| Posted: Tue Aug 20, 2024 1:40 pm Post subject: dont use lua |
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I’m very sorry for making you write so much code. Lua's efficiency is too slow. I have a new idea. First, calculate the number of digits like this:
mov eax,[ebp+08]
mov eax,[eax]
mov esi,01
xor edi,edi // digit count
newmem:
inc edi
imul esi,esi,#10
cmp esi,eax
jb newmem
Then, move the address where the output string should be placed to esi, and start from the end:
mov esi,str
add esi,edi
Next, I’ll figure out how to execute eax/10, obtain the remainder (units digit) and result (other digits), and then add bl,'0'. This way, I can fill in the string one digit at a time and complete the conversion from an unsigned 4-byte integer to a string!
Maybe one day in the future, I’ll come back and understand the advanced language code you’ve written. Love you, bro!
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