Vol. 2A 3-455
INSTRUCTION SET REFERENCE, A-M
IDIV—Signed Divide
THEN
#DE; (* Divide error *)
ELSE
EAX ← temp;
EDX ← EDXE:AX SignedModulus SRC;
FI;
FI;
ELSE IF OperandSize = 64 (* Doublequadword/quadword operation *)
temp ← RDX:RAX / SRC; (* Signed division *)
IF (temp > 7FFFFFFFFFFFH) or (temp < 8000000000000000H)
(* If a positive result is greater than 7FFFFFFFFFFFH
or a negative result is less than 8000000000000000H *)
THEN
#DE; (* Divide error *)
ELSE
RAX ← temp;
RDX ← RDE:RAX SignedModulus SRC;
FI;
FI;
FI;
Flags Affected
The CF, OF, SF, ZF, AF, and PF flags are undefined.
Protected Mode Exceptions
#DE If the source operand (divisor) is 0.
The signed result (quotient) is too large for the destination.
#GP(0) If a memory operand effective address is outside the CS, DS,
ES, FS, or GS segment limit.
If the DS, ES, FS, or GS register is used to access memory and it
contains a NULL segment selector.
#SS(0) If a memory operand effective address is outside the SS
segment limit.
#PF(fault-code) If a page fault occurs.
#AC(0) If alignment checking is enabled and an unaligned memory
reference is made while the current privilege level is 3.
#UD If the LOCK prefix is used.
Real-Address Mode Exceptions
#DE If the source operand (divisor) is 0.
The signed result (quotient) is too large for the destination.
