Does Lea read memory?
The lea instruction (“load effective address”) takes the memory address of the first value and adds it to the second value – which may be multiplied. It then loads that memory address into a given register.
What is MOVQ?
movq (assuming you’re talking about x86) is a move of a quadword (64-bit value). This particular instruction: movq (%rsp), %rsp. looks very much like code that will walk up through stack frames.
What is effective address?
An effective address is any operand to an instruction which references memory. Effective addresses, in NASM, have a very simple syntax: they consist of an expression evaluating to the desired address, enclosed in square brackets.
What’s the purpose of the Lea instruction in ESI?
Instead of a MOV, the compiler can generate which will load the address in ESI. From the “Zen of Assembly” by Abrash: LEA, the only instruction that performs memory addressing calculations but doesn’t actually address memory.
What’s the purpose of the Lea instruction in the 8086?
The 8086 has a large family of instructions that accept a register operand and an effective address, perform some computations to compute the offset part of that effective address, and perform some operation involving the register and the memory referred to by the computed address.
What’s the purpose and when should I use Lea?
For me, it just seems like a funky MOV. What’s its purpose and when should I use it? As others have pointed out, LEA (load effective address) is often used as a “trick” to do certain computations, but that’s not its primary purpose.
What’s the purpose of the Lea instruction in Intel?
The LEA (Load Effective Address) instruction is a way of obtaining the address which arises from any of the Intel processor’s memory addressing modes. That is to say, if we have a data move like this: MOV EAX, . it moves the contents of the designated memory location into the target register.