Deck 10: Computer Arithmetic

Question 1

Booth's algorithm performs more additions and subtractions than a straightforward algorithm.

Answer 1

False

Question 2

For each 1 on the multiplier,an add and a shift operation are required; but for each 0 only a shift is required.

Answer 2

True

Question 3

Addition and subtraction can be performed on numbers in twos complement notation by treating them as unsigned integers.

Answer 3

True

Question 4

Both sign-magnitude representation and twos complement representation use the most significant bit as a sign bit.

Question 5

The numbers represented in floating-point notation are not spaced evenly along the number line,as are fixed-point numbers.

Question 6

__________ representation is almost universally used as the processor representation for integers.

A)Biased
B)Twos compliment
C)Sign-magnitude
D)Decimal

Question 7

Moving the sign bit to the new leftmost position and filling in with copies of the sign bit is called _________.

A)sign extension
B)range extension
C)bit extension
D)partial extension

Question 8

One of the trade-offs of floating-point math is that many calculations produce results that are not exact and have to be rounded to the nearest value that the notation can represent.

Question 9

Overflow is a less serious problem because the result can generally be satisfactorily approximated by 0.

Question 10

With a fixed-point notation it is possible to represent a range of positive and negative integers centered on or near 0.

Question 11

The most common scheme in implementing the integer portion of the ALU is:

A)sign-magnitude representation
B)biased representation
C)twos complement representation
D)ones complement representation

Question 12

One drawback of sign-magnitude representation is that there are two representations of 0.

Question 13

For base 2 representation,a normal number is one in which the most significant bit of the significand is zero.

Question 14

It is not necessary for the ALU to signal when overflow occurs.

Question 15

Overflow can only occur if there is a carry.

Question 16

Compared with addition and subtraction,multiplication is a complex operation,whether performed in hardware of software.

Question 17

An advantage of biased representation is that nonnegative floating-point numbers can be treated as integers for comparison purposes.

Question 18

Actual floating-point representations include a special bit pattern to designate zero.

Question 19

In ________ representation the rule for forming the negation of an integer is to invert the sign bit.

A)ones complement
B)twos complement
C)biased
D)sign-magnitude

Question 20

________ is when the result may be larger than can be held in the word size being used.

A)Overflow
B)Arithmetic shift
C)Underflow
D)Partial product

Question 21

Negative numbers greater than 2-127 are called _________.

A)negative overflow
B)negative underflow
C)positive overflow
D)positive underflow

Question 22

_________ representation is when the radix point is fixed and assumed to be to the right of the rightmost digit.

Question 23

The _________ is that part of the computer that actually performs arithmetic and logical operations on data.

Question 24

Negative numbers less than -(2 - 2-23)x 2 128 are called _________.

A)positive underflow
B)positive overflow
C)negative underflow
D)negative overflow

Question 25

__________ format is a fully specified,fixed-length binary encoding that allows data interchange between different platforms and that can be used for storage.

Question 26

Although considered obsolete,the term _________ is sometimes used instead of significand.

A)minuend
B)mantissa
C)base
D)subtrahend

Question 27

_________ are included in IEEE 754 to handle cases of exponent underflow.

A)Subnormal numbers
B)Guard bits
C)Normal numbers
D)Radix points

Question 28

A __________ is one in which the most significant digit of the significand is nonzero.

Question 29

The most important floating-point representation is defined in IEEE Standard _________,adopted in 1985 and revised in 2008.

Question 30

Positive numbers greater than (2 - 2-23)x 2-128 are called _________.

A)negative underflow
B)positive overflow
C)positive underflow
D)negative overflow

Question 31

_________ occurs when an arithmetic operation results in an absolute value greater than can be expressed with an exponent of 128.

Question 32

If two numbers are added,and they are both positive or both negative,then _________ occurs if and only if the result has the opposite sign.

Question 33

When the divisor is able to divide the number,a 1 is placed in the quotient and the divisor is subtracted from the partial dividend; the result is referred to as a ________.

Question 34

"To subtract one number from another,take the twos complement of the subtrahend and add it to the minuend" is the _________ rule.

Question 35

__________ is when a positive exponent exceeds the maximum possible exponent value.

A)Significand underflow
B)Significand overflow
C)Exponent overflow
D)Exponent underflow

Question 36

__________ involves the generation of partial products,one for each digit in the multiplier,which are then summed to produce the final product.

A)Addition
B)Subtraction
C)Multiplication
D)Division

Question 37

_________ formats extend a supported basic format by providing additional bits in the exponent and in the significand.

A)Arithmetic
B)Basic
C)Extended precision
D)Interchange

Question 38

__________ means that the number is too small to be represented and it may be reported as 0.

A)Negative underflow
B)Exponent underflow
C)Positive underflow
D)Significand underflow

Question 39

Positive numbers less than 2-127 are called ________.

A)positive underflow
B)positive overflow
C)negative underflow
D)negative overflow

Question 40

Extending the range of numbers that can be expressed by increasing the bit length is referred to as __________.

Question 41

The register contains additional bits,called __________,which are used to pad out the right end of the significand with 0s.

Question 42

__________ is when the result is put back into the floating-point format and the extra bits must be eliminated in such a way as to produce a result that is close to the exact result.

Question 43

_________ format covers five floating-point representations,three binary and two decimal,whose encodings are specified by the standard,and which can be used for arithmetic.

Question 44

The use of subnormal numbers is referred to as _________ underflow.

Question 45

IEEE 754-2008 defines an __________ format as a format with a precision and range that are defined under user control.