Home/ Questions/Q 8043537
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-06-05T04:55:58+00:00

I was looking at strcpy.S file in android platform at path libc/arch-arm/bionic, in this

  • 0

I was looking at strcpy.S file in android platform at path libc/arch-arm/bionic, in this file there are many arm instructions which i am not able to understand, i am also referring ARM System Developers Guide.
Here except “tst” and “tstne” i am not able to find any refrence for others in any book or ARM refrence manual.

tst r2, #0xff00
iteet   ne
strneh  r2, [ip], #2
lsreq   r2, r2, #8
    r2, [ip]
tstne   r2, #0xff

Not only these instructions there are many others in different files also.

Does anyone have any idea what these instructions are ?

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    strneh is a store command with some conditional execution/size specifier suffixes. The ARM docs are a good place to start: http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.dui0068b/Chdehgih.html

    If you google “arm conditional execution”, you’ll find a number of blogs/articles that may also help: http://blogs.arm.com/software-enablement/258-condition-codes-2-conditional-execution/

    As for your *strneh” instruction:

    • str = store
    • ne = execute if not equal (Z flag clear)
    • h = perform a half-word operation
    • 0