Unit 4 Flashcards
When adding operands with blank, overflow cannot occur.
different signs
There are similar restrictions to the occurrence of overflow during subtract, but it’s just the opposite principle: when the signs of the operands are the blank, overflow cannot occur.
same
Blank occurs in subtraction when we subtract a negative number from a positive number and get a negative result, or when we subtract a positive number from a negative number and get a positive result.
Overflow
Hardware that performs addition, subtraction, and usually logical operations such as AND and OR
Arithmetic Logic Unit (ALU)
Which LEGv8 load instructions should be generated for byte and halfword arithmetic operations?
LDURB, LDURH
Which LEGv8 arithmetic instructions should be generated for byte and halfword arithmetic operations?
ADD, SUB, MUL, DIV
Which LEGv8 store instructions should be generated for byte and halfword arithmetic operations?
STURB, STURH
In multiplication, the first operand is called the blank and the second the blank. The final result is called the blank.
multiplicand
multiplier
product
In fact, if we ignore the sign bits, the length of the multiplication of an n-bit multiplicand and an m-bit multiplier is a product that is blank long. That is, blank are required to represent all possible products.
n + m bits
To produce a properly signed or unsigned 128-bit product, LEGv8 has three instructions: blank, blank and blank
multiply (MUL)
signed multiply high (SMULH)
unsigned multiply high (UMULH)
Divide’s two operands, called the blank and blank, and the result, called the blank, are accompanied by a second result, called the blank.
dividend and divisor
quotient
remainder
A number being divided.
Dividend
A number that the dividend is divided by.
Divisor
The primary result of a division; a number that when multiplied by the divisor and added to the remainder produces the dividend.
Quotient
The secondary result of a division; a number that when added to the product of the quotient and the divisor produces the dividend.
Remainder
A notation that renders numbers with a single digit to the left of the decimal point.
Scientific notation
A number in floating-point notation that has no leading 0s.
Normalized
Computer arithmetic that represents numbers in which the binary point is not fixed.
Floating point
The value, generally between 0 and 1, placed in the fraction field. The fraction is also called the mantissa.
Fraction
In the numerical representation system of floating-point arithmetic, the value that is placed in the exponent field
Exponent
A situation in which a positive exponent becomes too large to fit in the exponent field.
Overflow (floating-point)
A situation in which a negative exponent becomes too large to fit in the exponent field.
Underflow (floating-point)
A floating-point value represented in a 64-bit doubleword.
Double precision
A floating-point value represented in a 32-bit word.
Single precision
Also called interrupt. An unscheduled event that disrupts program execution; used to detect overflow.
Exception
An exception that comes from outside of the processer. (Some architectures use the term interrupt for all exceptions.
Interrupt
This symbol is NaN, for blank. The purpose of NaNs is to allow programmers to postpone some tests and decisions to a later time in the program when they are convenient.
Not a Number
LEGv8 supports the IEEE 754 single-precision and double-precision formats with these instructions
Floating-point addition, single (FADDS) and addition, double (FADDD)
Floating-point subtraction, single (FSUBS) and subtraction, double (FSUBD)
Floating-point multiplication, single (FMULS) and multiplication, double (FMULD)
Floating-point division, single (FDIVS) and division, double (FDIVD)
Floating-point comparison, single (FCMPS) and comparison, double (FCMPD), with the condition codes given slightly different interpretations
The first of two extra bits kept on the right during intermediate calculations of floating-point numbers; used to improve rounding accuracy.
Guard
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.
Round
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.
Units in the last place (ulp)
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.
Sticky bit
Fused multiply add: A floating-point instruction that performs both a multiply and an add, but rounds only once after the add.
Fused multiply add
Given that the parallelism occurs within a wide word, the extensions are classified as blank. It is also classified under the more general name of data level parallelism. They are known as well as vector or SIMD, for single instruction, multiple data (see COD Section 6.6 (Introduction to graphics processing units)).
subword parallelism
ARMv8 added _____-bit registers to support subword parallelism.
128
The add instruction, ADD, includes support for 8-bit, 16-bit, 32-bit, 64-bit, and 128-bit numbers. Operands can be integers, but not blank
floating point numbers
Number of assembly-language integer arithmetic and floating-point instructions in ARMv8
63
Floating-point multiply instruction that produces a negative product
FNMUL
Number of ARMv8 arithmetic core instructions
15
Conditional compare that only compares if the initial condition is true
FCCMP
ARMv8 has _____ assembly-language SIMD instructions.
245
Which SIMD instruction version means the width of the elements in the destination register is twice the width of the elements in all source registers?
long
Each SIMD version is denoted by a _____.
suffix
The prefixes U, S, and F refer to _____
data types
Wide means the width of the elements in the destination register and the first source registers is twice the width of the elements in the second source register.
Wide
Blank means the width of the elements in the destination register is twice the width of the elements in all source registers.
Long
Blank means the width of the elements in the destination register is half the width of the elements in all source registers.
Narrow
IEEE 754 is a _____ for floating-point representation and computation.
standard
The field of _____ examines how to solve mathematical problems using imprecision and limited representation of data.
numerical analysis
A situation where an operation yields a number that is too small to represent with the fixed number of bits available is called _____.
underflow
