Ollydbg : sign extending with Movsx

时间:2015-11-12 11:25:34

标签: assembly x86 ollydbg sign-extension

Movsx sign-extends a register with 1 right?

So why in Ollydbg i got this :

  • Before: before
  • After: after

I should have FFFFFF65 instead of 00000065 in ECX no?

Thank you !

1 个答案:

答案 0 :(得分:3)

The byte at the memory location has the value 65h. This is a positive number and thus the extension will fill the 3 highest bytes of ECX with zero giving 00000065h .