3-353
INSTRUCTION SET REFERENCE
LEALoad Effective Address
Description
This instruction computes the effective address of the second operand (the source operand) and
stores it in the first operand (destination operand). The source operand is a memory address
(offset part) specified with one of the processors addressing modes; the destination operand is a
general-purpose register. The address-size and operand-size attributes affect the action
performed by this instruction, as shown in the following table. The operand-size attribute of the
instruction is determined by the chosen register; the address-size attribute is determined by the
attribute of the code segment.
Different assemblers may use different algorithms based on the size attribute and symbolic
reference of the source operand.
Opcode
Instruction
Description
8D /r
LEA r16,m
Store effective address for m in register r16
8D /r
LEA r32,m
Store effective address for m in register r32
Operand SizeAddress Size
Action Performed
16
16
16-bit effective address is calculated and stored in requested
16-bit register destination.
16
32
32-bit effective address is calculated. The lower 16 bits of the
address are stored in the requested 16-bit register destination.
32
16
16-bit effective address is calculated. The 16-bit address is zero-
extended and stored in the requested 32-bit register destination.
32
32
32-bit effective address is calculated and stored in the requested
32-bit register destination.
