Assembler:Commands:IDIV
command idiv operand
Performs an unsigned division of two operands.
Divides (signed) the value in accumulator registers (dividend) by the source operand (divisor) and stores the result in the AX (AH:AL), DX:AX, or EDX:EAX registers. The source operand can be a general-purpose register or a memory location. The action of this instruction depends on the operand size (dividend/divisor).
The CF, OF, SF, ZF, AF, and PF flags are undefined.
| Dividend | Divisor | Quotient | Remainder | Maximum Quotient |
|---|---|---|---|---|
| Word/Byte | AX | r/m8 | AL | AH |
| Doubleword/Word | DX:AX | r/m16 | AX | DX |
| Quadword/Doubleword | EDX:EAX | r/m32 | EAX | EDX |
| Octoword/Quadword | RDX:RAX | r/m64 | RAX | RDX |
AL (r=AH) = AH:AL/operand : byte AX (r=DX) = DX:AX/operand : WORD EAX (r=EDX) = EDX:EAX/operand : DWORD RAX (r=RDX) = RDX:RAX/operand : QWORD
Divides (signed) the value in the AX, DX:AX, or EDX:EAX registers (dividend) by the source operand (divisor) and stores the result in the AX (AH:AL), DX:AX, or EDX:EAX registers. The source operand can be a general-purpose register or a memory location. The action of this instruction depends on the operand size (dividend/divisor).
Command Parameters
| Parameter | Description |
|---|---|
| operand | The divisor operand |
Examples
idiv ecx
mov eax,6 mov edx,0 mov ecx,2 idiv ecx // eax (r=edx) = edx:eax / ecx // eax = 3, edx = 0
mov eax,9 mov edx,0 mov esi,2 idiv esi // eax (r=edx) = edx:eax / esi // eax = 4, edx = 1
mov eax,0 mov edx,1 mov esi,0x10 idiv esi // eax (r=edx) = edx:eax / esi // eax = 0x10000000, edx = 0
mov eax,6 mov edx,0 mov [00123ABC],2 idiv [00123ABC] // eax (r=edx) = edx:eax / [00123ABC] // eax = 6, edx = 0
mov eax,6 mov edx,0 mov [SomeSymbol],2 idiv [SomeSymbol] // eax (r=edx) = edx:eax / [SomeSymbol] // eax = 6, edx = 0
