up:
Chapter 17 -- 80386 Instruction Set
prev: LEA Load Effective Address
next: LGDT/LIDT Load Global/Interrupt Descriptor Table Register
LEAVE -- High Level Procedure Exit
Opcode Instruction Clocks Description
C9 LEAVE 4 Set SP to BP, then pop BP
C9 LEAVE 4 Set ESP to EBP, then pop EBP
Operation
IF StackAddrSize = 16
THEN
SP := BP;
ELSE (* StackAddrSize = 32 *)
ESP := EBP;
FI;
IF OperandSize = 16
THEN
BP := Pop();
ELSE (* OperandSize = 32 *)
EBP := Pop();
FI;
Description
LEAVE reverses the actions of the
ENTER instruction. By copying the
frame pointer to the stack pointer, LEAVE releases the stack space used
by a procedure for its local variables. The old frame pointer is popped
into BP or EBP, restoring the caller's frame. A subsequent
RET
instruction removes any arguments pushed onto the stack of the exiting
procedure.
Flags Affected
None
Protected Mode Exceptions
#SS(0) if BP does not point to a location within the limits of the current
stack segment
Real Address Mode Exceptions
Interrupt 13 if any part of the operand would lie outside of the effective
address space from 0 to 0FFFFH
Virtual 8086 Mode Exceptions
Same exceptions as in Real Address Mode
up:
Chapter 17 -- 80386 Instruction Set
prev: LEA Load Effective Address
next: LGDT/LIDT Load Global/Interrupt Descriptor Table Register