CSCI 223 Quiz 4

Question 1

ISA

Answer 1

Instruction Set Architecture - interface between software and hardware

Question 2

ISA is considered (micro/macro)architecture

Answer 2

macroarchitecture

Question 3

microarchitecture

Answer 3

implementation of macroarchitecture; not visible to software; can vary as long as it satisfies the macroarchitecture

Question 4

system stack: software

Answer 4

problem, algorithm, program

Question 5

system stack: hardware

Answer 5

microarchitecture, circuits, transistors

Question 6

Moore’s Law

Answer 6

transistor counts double every 18-24 months on a single chip (means the performance will double)

Question 7

PC (program counter)

Answer 7

contains the address of the next instruction to execute; called “%eip” (IA32) or “%rip” (x86-64)

Question 8

register file

Answer 8

collection of registers; used to store heavily used program data

Question 9

condition codes

Answer 9

store status information about most recent arithmetic operation; used for conditional branching

Question 10

memory

Answer 10

byte addressable array; code, user data, some OS data; includes stack used to support procedures

Question 11

three basic operations of machine instructions

Answer 11

1. arithmetic and logic operation (ALU)
2. memory operation (AKA data movement)
3. control-flow operation

Question 12

x86 is a (CISC/RISC) type

Answer 12

CISC

Question 13

CISC

Answer 13

Complex Instruction Set Computers; large number of instructions, varying instruction length, various addressing formats, complex compiler and hardware, compact code size

Question 14

RISC

Answer 14

Reduced Instruction Set Computers; smaller number of instructions, fixed instruction length, only a few addressing formats, simpler compiler and hardware, larger code size

Question 15

assembly data types

Answer 15

integer data (including memory address), floating point data; no aggregate types such as arrays or structures, just continuously allocated bytes in memory

Question 16

assembly operations

Answer 16

perform arithmetic/logical function on register or memory data, transfer data b/w memory and register, transfer control

Question 17

disassembler

Answer 17

useful tool for examining object code; analyses bit pattern of series of instructions, produces approximate rendition of assembly code, can be run on either a.out (complete executable) or .o file

Question 18

x86-64 Integer registers

Answer 18

supposed to contain integer value or memory address; can reference low-order 4 bytes; controlled by compiler; 16 registers

Question 19

IA32 integer registers

Answer 19

8 integer registers (first 6 - general purpose, %esp: stack pointer, %ebp: base pointer); can reference low-order 1 byte, 2 bytes, and 4 bytes; 16-bit registers with backwards compatibility

Question 20

operand types

Answer 20

immediate, register, memory

Question 21

immediate operand type

Answer 21

constant integer data; like C constant, but prefixed w/ ‘$’; encoded with 1, 2, or 4 bytes

Question 22

register operand type

Answer 22

one of 16 integer registers; %rsp reserved for special use; others have special uses for particular instructions

Question 23

memory operand type

Answer 23

8 consecutive bytes of memory at address given by register; various other “address modes”