IBM SA14-2339-04 Manuel D’Utilisation

PPC405 Core User’s Manual

Divide Word Unsigned

divwu
Divide Word Unsigned

(RT)

←

(RA)

 ÷

 (RB)

The contents of register RA are divided by the contents of register RB. The quotient is placed into
register RT.

The dividend and the divisor are interpreted as unsigned integers. The quotient is the unique
unsigned integer that satisfies:

dividend = (quotient

×

divisor) + remainder

If an attempt is made to perform (

n

 ÷

 0), the contents of register RT are undefined; if the Rc also

contains 1, the contents of CR[CR0]

LT, GT, EQ

 are also undefined. The invalid division operation also

sets XER[OV, SO] to 1 if the OE field contains 1.

• RT

• CR[CR0]

LT, GT, EQ, SO

 if Rc contains 1

• XER[OV, SO] if OE contains 1

The 32-bit remainder can be calculated using the following sequence of instructions

divwu

RT,RA,RB

# RT = quotient

mullw

RT,RT,RB

# RT = quotient

×

divisor

subf

RT,RT,RA

# RT = remainder

This sequence does not calculate the correct result if the divisor is zero.

This instruction is part of the PowerPC User Instruction Set Architecture.

RT, RA, RB

OE=0, Rc=0

RT, RA, RB

OE=0, Rc=1

RT, RA, RB

OE=1, Rc=0

RT, RA, RB

OE=1, Rc=1

0

6

11

16

21 22

31