Intel 64 and IA-32 Architectures Software Developers Manual Volume 2A, Instruction Set Reference, A-M

Vol. 2 3-475
INSTRUCTION SET REFERENCE, A-M
THEN
IF current stack does not have room for 16 bytes (error code pushed)
or 12 bytes (no error code pushed)
THEN #SS(0); FI;
ELSE IF 16-bit gate
IF current stack does not have room for 8 bytes (error code pushed)
or 6 bytes (no error code pushed)
THEN #SS(0); FI;
ELSE (* 64-bit gate*)
IF StackAddress is non-canonical
THEN #SS(0);
FI;
FI;
IF instruction pointer not within code segment limit
THEN #GP(0); FI;
IF 32-bit gate
THEN
Push (EFLAGS);
Push (far pointer to return instruction); (* 3 words padded to 4 *)
CS:EIP ← Gate(CS:EIP); (* Segment descriptor information also loaded *)
Push (ErrorCode); (* If any *)
ELSE
IF 16-bit gate
THEN
Push (FLAGS);
Push (far pointer to return location); (* 2 words *)
CS:IP ← Gate(CS:IP);
(* Segment descriptor information also loaded *)
Push (ErrorCode); (* If any *)
ELSE (* 64-bit gate*)
Push(far pointer to old stack);
(* Old SS and SP, each an 8-byte push *)
Push(RFLAGS); (* 8-byte push *)
Push(far pointer to return instruction);
(* Old CS and RIP, each an 8-byte push *)
Push(ErrorCode); (* If needed, 8 bytes *)
CS:RIP ← GATE(CS:RIP);
(* Segment descriptor information also loaded *)
FI;
FI;
CS(RPL) ← CPL;
IF interrupt gate
THEN IF ← 0; FI; (* Interrupt flag set to 0: disabled *)
TF ← 0;