3. Definitions

Question 1

Arithmetic Logic Unit (ALU)

Answer 1

Hardware that performs addition, subtraction, and usually logical operations such as AND and OR.

Question 2

dividend

Answer 2

A number being divided.

Question 3

divisor

Answer 3

A number that the dividend is divided by.

Question 4

quotient

Answer 4

The primary result of a division; a number that when multiplied by the divisor and added to the remainder produces the dividend.

Question 5

remainder

Answer 5

The secondary result of a division; a number that when added to the product of the quotient and the divisor produces the dividend.

Question 6

scientific notation

Answer 6

A notation that renders numbers with a single digit to the left of the decimal point.

Question 7

normalized

Answer 7

A number in floating-point notation that has no leading 0s.

Question 8

floating point

Answer 8

Computer arithmetic that represents numbers in which the binary point is not fixed.

Question 9

fraction

Answer 9

The value, generally between 0 and 1, placed in the fraction field. The fraction is also called the mantissa.

Question 10

exponent

Answer 10

In the numerical representation system of floating-point arithmetic, the value that is placed in the exponent field.

Question 11

overflow (floating-point)

Answer 11

A situation in which a positive exponent becomes too large to fit in the exponent field.

Question 12

underflow (floating-point)

Answer 12

A situation in which a negative exponent becomes too large to fit in the exponent field.

Question 13

double precision

Answer 13

A floating-point value represented in a 64-bit doubleword.

Question 14

single precision

Answer 14

A floating-point value represented in a 32-bit word.

Question 15

exception. Also called interrupt.

Answer 15

An unscheduled event that disrupts program execution; used to detect overflow.

Question 16

interrupt

Answer 16

An exception that comes from outside of the processor. (Some architectures use the term interrupt for all exceptions.)

Question 17

guard

Answer 17

The first of two extra bits kept on the right during intermediate calculations of floating-point numbers; used to improve rounding accuracy

Question 18

round

Answer 18

Method to make the intermediate floating-point result fit the floating-point format; the goal is typically to find the nearest number that can be represented in the format. It is also the name of the second of two extra bits kept on the right during intermediate floating-point calculations, which improves rounding accuracy.

Question 19

units in the last place (ulp)

Answer 19

The number of bits in error in the least significant bits of the significand between the actual number and the number that can be represented.

Question 20

sticky bit

Answer 20

A bit used in rounding in addition to guard and round that is set whenever there are nonzero bits to the right of the round bit.

Question 21

fused multiply add

Answer 21

A floating-point instruction that performs both a multiply and an add, but rounds only once after the add.