[Help me With Instruction logic]

On 6/26/2019 at 3:02 AM, Un_Known said:

Can anybody explain logic here 

It's ARM instruction set:

Here dword_36BD38 is uninitialized variable in .bss section

LDR       R3, =(dword_36BD38 - 0x19D86C) 

ADD      R3, PC, R3  ; dword_36BD38

CMP      R0, #0

STR       R0, [R3]

MOVLT   R2, #0x7FFFFFFF

STRLT     R2, [R3]

I have a little idea what's happening here but couldn't understand whole logic!

What is that for?