What does lea 0xY(%esp), %esi do?

问题

I dont understand what this code will do

lea   0x13(%esp), %esi

%esp is a stack pointer, %esi is index register.

Is 0x13 offset?

回答1:

I'm used to the Intel syntax, so I believe this is what's happening:

lea esi, [esp+13h]

Say esp is 0x18000 - the result of this operation will be 0x18013, since you're not actually accessing any memory with lea.

Again, I only have experience with the Intel syntax, so my answer may be incorrect. Hopefully this has helped you!

来源：https://stackoverflow.com/questions/23869183/what-does-lea-0xyesp-esi-do