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assemblyx86att

What does the minus sign mean in a `movl` instruction?

I have this assembly code:

movl -4(%ebp),%eax

What does the -4 before the (%ebp) mean?

Solution

  • The -4 is a constant offset to the pointer held by the register. This code reads the long value at ebp - 4 and stores it in eax. This is AT&T syntax; the Intel syntax for the same instruction would be mov eax, dword ptr [ebp-4].