x86 lea

lea dest, src Used to store pointers to addresses in memory. Moves the address of src into dest.

Can also be used to compute values quickly, as it abuses [] feature to allow for computations rather than x86 Variable Dereferencing.

Example (Address)

lea rax, [rip+0x20040]

• Will compute the address within the square brackets (Its not x86 Variable Dereferencing)
• rax will then be that address
• Equivalent to saying mov rax, rip+0x20040 (but this instr is invalid)

Example (Computation)

lea rax, [rbx * 5 + 5]

• With rbx storing a number instead of address
• lea is used for computations rather than address arithmetic
• More efficient for compiler