assembly,x86-64 , x86_64 relative jmp operand

## Question:

Tag: assembly,x86-64

I can't understand how the operand `FE FC FF FF` results to 0x9e7080.

I tried some math sub/add to the current address, because it should be relative jump, but the result still not equal to 0x9e7080.

``````instruction address | bytes | text form

L_009E737D | E9 FE FC FF FF | jmp 0x9e7080
``````

There are three things to consider:

1. `FEFCFFFF` is given as little endian and represents a hex value of `0xFFFFFCFE`.
2. This hex value is sign extended and is thus negative with a decimal value of `-770`.
3. You also have to add the number of bytes the instruction takes.

This leads to `0x009E737D + 0xFFFFFCFE + 5 = 0x009e7080`, which equals `0x009E737D - 0x00000302 + 5 = 0x009e7080`.

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