Opcode Instruction Clocks Description 8D /r LEA r16,m 2 Store effective address for m in register r16 8D /r LEA r32,m 2 Store effective address for m in register r32 8D /r LEA r16,m 2 Store effective address for m in register r16 8D /r LEA r32,m 2 Store effective address for m in register r32
IF OperandSize = 16 AND AddressSize = 16 THEN r16 := Addr(m); ELSE IF OperandSize = 16 AND AddressSize = 32 THEN r16 := Truncate_to_16bits(Addr(m)); (* 32-bit address *) ELSE IF OperandSize = 32 AND AddressSize = 16 THEN r32 := Truncate_to_16bits(Addr(m)); ELSE IF OperandSize = 32 AND AddressSize = 32 THEN r32 := Addr(m); FI; FI; FI; FI;
Operand Size Address 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.
up:
Chapter 17 -- 80386 Instruction Set
prev: LAR Load Access Rights Byte
next: LEAVE High Level Procedure Exit