Measuring assembly instruction byte size (code length)

Trond · **Posted:** Fri May 11, 2018 10:09 am

Code:

; Measure the code size in bytes of assembly instructions
!@@:
; Instructions here
!mov [v_size], $-@b
Debug size

Example:

Code:

!@@:
!mov rax, 0
!mov [v_size], $-@b
Debug size

!@@:
!xor rax, rax
!mov [v_size], $-@b
Debug size

!@@:
!push 0
!pop  rax
!mov [v_size], $-@b
Debug size

Olliv · **Joined:** Tue Sep 22, 2009 10:41 pm **Posts:** 434

Good stuff. Bypasses Disassembly lib which is more complex to code, and less light than this.

Mijikai · **Joined:** Sun Sep 11, 2016 2:17 pm **Posts:** 512

Olliv wrote:

Good stuff. Bypasses Disassembly lib which is more complex to code, and less light than this.

Don't u need to know the size already since u need to know where to put this... ?

Olliv · **Joined:** Tue Sep 22, 2009 10:41 pm **Posts:** 434

https://www.purebasic.com/documentation/onerror/examineassembly.html

Mijikai wrote:

Don't u need to know the size already since u need to know where to put this... ?

I have no time to need to know where to put this : I was stolen this before. But I stamped a QRCode on this. No problem anymore.

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Measuring assembly instruction byte size (code length)

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