05 machine basics

8/9/2019 05 Machine Basics

1/51

Carnegie Mellon

1

Machine-Level ProgrammingI: Basics

15-213/18-213: Introduction to Computer Systems5thLecture, Jan 28, 201

Instructors:

Seth Copen !o"dstein, #nthony $o%e, !re& 'esden


2/51

Carnegie Mellon

2

Today: MachineProgramming I: Basics

History of Intel processors andarchitectures

C, assemly, machine code !ssemly Basics: "egisters, operands,

move Intro to #$%-%&


3/51

Carnegie Mellon

3

Intel #$% Processors

Totally dominate laptop'des(top'servermar(et

)volutionary design

(ac)%ards compati*"e up unti" 808+, introduced in18

#dded more .eatures as time &oes on

Comple# instruction set computer *CI+C any dierent instructions %ith many dierent.ormats

(ut, on"y sma"" su*set encountered %ith Linupro&rams

ard to match per.ormance o. $educed InstructionSet Computers $ISC4


4/51

Carnegie Mellon

4

Intel #$% )volution: Milestones

Name Date Transistors MHz$$% ./0$ 1/2 3-.

irst 1+-*it Inte" processor7 (asis .or I( 9C ;


5/51

Carnegie Mellon

5

Moore6s La7

Goodness

Time


6/51

Carnegie Mellon

6

Moore6s La7

Goodness

Time


7/51

Carnegie Mellon

7

Moore6s La7

Goodness

Time


8/51

Carnegie Mellon

8

Moore6s La7

Goodness

Time

Happy

Bday

Happ yB Day

Happy

BDay

?


9/51

Carnegie Mellon

9

More on Moore6s La7You can uy !"is #o$ %6 !oday&

Compare to./$4


10/51

Carnegie Mellon

1'

More on Moore6s La7You can uy !"is #o$ %6 !oday&

(o$e !"an 39)8'')'''*

imp$o+emen! in %,cc3

-n 1983 do..a$s) !"e e/ui+a.en! cos! 0%125)'''&'' i! in 01)25' o*es

C i M ll


11/51

Carnegie Mellon

11

Intel #$% Processors, cont8Machine )volution

38+ 185 073 9entium 13 371

9entium/A 1 75

9entium9ro 15 +75

9entium III 1 872

9entium 2001 2 Core 2 ;uo 200+ 21

Core i 2008 31

!dded 5eatures

Instructions to support mu"timedia operations Instructions to ena*"e more eBcient conditiona"

operations

ransition .rom 32 *its to + *its

ore cores

C i M ll


12/51

Carnegie Mellon

12

#$% Clones: !dvanced Micro9evices *!M9

Historically#; has .o""o%ed ust *ehind Inte"

# "itt"e *it s"o%er, a "ot cheaper

Then

$ecruited top circuit desi&ners .rom ;i&ita" DEuipmentCorp7 and other do%n%ard trendin& companies

(ui"t


13/51

Carnegie Mellon

13

Intel6s %&-Bit Intel !ttempted "adical +hift from I!41 to

I!%& ota""y dierent architecture Itanium4

Decutes I#32 code on"y as "e&acy

9er.ormance disappointin&

!M9 +tepped in 7ith )volutionary+olution 8+-+ no% ca""ed =#;+?4

Intel 5elt ligated to 5ocus on I!%&

ard to admit mista)e or that #; is *etter 1&: Intel !nnounces )M%&T e#tension to

I!41 Dtended emory +-*it echno"o&y

#"most identica" to 8+-+6

!ll ut lo7-end #$% rocessors su ort

C i M ll


14/51

Carnegie Mellon

14

ur Coverage

I!41 he traditiona" 8+

shark> gcc m32 hello.c

#$%-%&

he emer&in& standard shark> gcc hello.c

shark> gcc m64 hello.c

Presentation (oo) presents I#32 in Sections 371G3712

CoFers 8+-+ in 3713

He %i"" coFer *oth simu"taneous"y

Some "a*s %i"" *e *ased on 8+-+, others on I#32

Carnegie Mellon


15/51

Carnegie Mellon

15





Carnegie Mellon


16/51

Carnegie Mellon

16

9e;nitions

!rchitecture:*also I+!: instruction setarchitecture The parts of a processordesign that one needs to understand to7rite assemly code8 Damp"es: instruction set specication, re&isters7

Microarchitecture:Implementation of thearchitecture8 Damp"es: cache sies and core .reEuency7

)#ample I+!s *Intel: #$%, I!

Carnegie Mellon


17/51

Carnegie Mellon

17

CPect program *p1.op2.o

)#ecutale program *p

+taticliraries *.a

Turning C into >ectCode Code in "esp1.c p2.c

Compi"e %ith command: gcc O1 p1.c p2.c -o p @se *asic optimiations -O14 9ut resu"tin& *inary in "ep

Carnegie Mellon


19/51

Carnegie Mellon

19

Compiling Into !ssemly

C Code

int sum(int x, int y){ int t = x+y; rturn t;!

?enerated I!41

!ssemlysum" pus#l $%p mo&l $sp,$%p mo&l 12($%p),$ax addl '($%p),$ax

popl $%p rt

tain 7ith commandusrlocal%ingcc O1 -S cod.c

Produces ;le cod.s

Carnegie Mellon


20/51

Carnegie Mellon

2'

!ssemly Characteristics: 9ataTypes

@IntegerA data of ., 1, or & ytes ;ata Fa"ues #ddresses untyped pointers4

5loating point data of &, $, or . ytes

o aggregate types such as arrays orstructures Just conti&uous"y a""ocated *ytes in memory

Carnegie Mellon


21/51

Carnegie Mellon

21

!ssemly Characteristics:perations

Perform arithmetic function on register ormemory data

Transfer data et7een memory and register

Load data .rom memory into re&ister Store re&ister data into memory

Transfer control

@nconditiona" umps to/.rom procedures Conditiona" *ranches

Carnegie Mellon


22/51

Carnegie Mellon

22

Code for sum

x*1* sum"

x x' x x'%

x* xc x/ x* x' xd xc/

>ect Code

!ssemler

rans"ates .sinto .o

(inary encodin& o. each instruction

Kear"y-comp"ete ima&e o. eecuta*"ecode

issin& "in)a&es *et%een code indierent "es

Lin(er $eso"Fes re.erences *et%een "es

Com*ines %ith static run-time "i*raries

D7&7, code .ormalloc,print0

Some "i*raries are dynamically linked

Lin)in& occurs %hen pro&ram *e&inseecution

Total of ..ytes

)achinstruction., 1, or 4

ytes +tarts at

Carnegie Mellon

M hi I i


23/51

g

23

Machine Instruction)#ample C Code

#dd t%o si&ned inte&ers

!ssemly #dd t%o -*yte inte&ers

=Lon&? %ords in !CCpar"ance

Same instruction %hethersi&ned or unsi&ned


24/51

g

24

9isassemled

9isassemling >ectCode

9isassemler

o%4dump -d p @se.u" too" .or eaminin& o*ect code

#na"yes *it pattern o. series o. instructions

9roduces approimate rendition o. assem*"y code

Can *e run on either a.outcomp"ete eecuta*"e4 or .o

"e

'*'/c* sum"'*'/c*" pus# $%p'*'/c" ' mo& $sp,$%p'*'/c5" '% * c mo& xc($%p),$ax'*'/ca" / * ' add x'($%p),$ax

'*'/cd" d pop $%p'*'/c" c/ rt

Carnegie Mellon


25/51

g

25

9isassemled

6ump o0 assm%lr cod 0or 0unction sum"x'*'/c* sum+" pus# $%px'*'/c sum+1" mo& $sp,$%px'*'/c5 sum+/" mo& xc($%p),$axx'*'/ca sum+7" add x'($%p),$ax

x'*'/cd sum+" pop $%px'*'/c sum+1" rt

!lternate 9isassemly

Dithin gd 9eugger

gd% pdisassm%l sum

;isassem*"e procedure

x11x% sum

Damine the 11 *ytes startin& at sum

>ect

x*1*"x

x' x x'% x* xc x/ x* x' xd

xc/


26/51


27/51

Carnegie Mellon


28/51

28

Integer "egisters *I!41

$ax

$cx

$dx

$%x

$si

$di

$sp

$%p

$ax

$cx

$dx

$%x

$si

$di

$sp

$%p

$a#

$c#

$d#

$%#

$al

$cl

$dl

$%l

.%-it virtual registers*ac(7ards compatiility

genera

lpurpose

accumulate

counter

data

base

source

index

destination

index

stackpointer

base

pointer

rigin*mostly osolet

Carnegie Mellon


29/51

29

Moving 9ata: I!41 Moving 9ata

mo&lSource, Dest:

perand Types Immediate:Constant inte&er data

Damp"e: ?x*, ?-// Li)e C constant, *ut preed %ith @?A Dncoded %ith 1, 2, or *ytes

Register:


30/51

3'

Moving 9ata: I!41 Moving 9ata

mo&lSource, Dest:

perand Types Immediate:Constant inte&er data

Damp"e: ?x*, ?-// Li)e C constant, *ut preed %ith @?A Dncoded %ith 1, 2, or *ytes

Register:


31/51

31

mo&lperandCominations

Cannot do memory-memory transfer wit a

sing!e instruction

mo&l

Imm

Reg

Mem

Reg

Mem

Reg

Mem

Reg

+ource 9est C !nalog

mo&l ?x*,$ax tmp = x*;

mo&l ?-1*5,($ax) p = -1*5;

mo&l $ax,$dx tmp2 = tmp1;

mo&l $ax,($dx) p = tmp;

mo&l ($ax),$dx tmp = p;

+rc,9est


32/51

Carnegie Mellon


33/51

33


34/51

34


35/51

35


36/51

36


37/51

37


38/51

38


39/51

39

*7


40/51

4'


41/51

41

*7

*7


42/51

42


43/51

43

Complete Memory !ddressingModes

Most ?eneral 5orm

9*","i,+Mem"eg"FG+K"eg"iFG 9F ;: Constant =disp"acement? 1, 2, or *ytes

$*: (ase re&ister: #ny o. 8 inte&er re&isters

$i: Inde re&ister: #ny, ecept .or $sp

@n"i)e"y youMd use $%p, either S: Sca"e: 1, 2, , or 8 why these numbers?4

+pecial Cases

*","i Mem"eg"FG"eg"iFF

9*","i Mem"eg"FG"eg"iFG9F

*","i,+ Mem"eg"FG+K"eg"iFF

Carnegie Mellon


44/51

44





Carnegie Mellon


45/51

45

9ata "epresentations: I!41G #$%-%&

+ies of C >ects *in Bytes C ;ata ype !eneric 32-*itInte" I#32 8+-+

unsi&ned

int

"on& int

8

char 1 11

short 2 22

>oat

dou*"e 8 88

Carnegie Mellon


46/51

46

rsp

#$%-%& Integer "egisters

Dtend eistin& re&isters7 #dd 8 ne% ones7

a)e Oe*p/Or*p &enera" purpose

ea#

e#

ec#

ed#

esi

edi

esp

ep

r$d

r/d

r.d

r..d

r.1d

r.4d

r.&d

r.3d

r$

r/

r.

r..

r.1

r.4

r.&

r.3

ra#

r#

rc#

rd#

rsi

rdi

rp

Carnegie Mellon


47/51

47

Instructions

Long 7ord l *& Bytes Nuad 7ord O *$Bytes

e7 instructions:

moF" P moFE add" P addE

sa"" P sa"E

etc7

41-it instructions that generate 41-itresults Set hi&her order *its o. destination re&ister to 0

Damp"e: add"

Carnegie Mellon


48/51

48

41-it code for s7ap

&oid sBap(int xp, int yp){ int t = xp; int t1 = yp; xp = t1; yp = t;!

Body

+et


49/51

49

%&-it code for s7ap

perands passed in registers *7hyusefulE

irst p4 in Ordi, second yp4 in Orsi

+-*it pointers

o stac( operations reOuired 41-it data

;ata he"d in re&isters Oea and Oed

&oid sBap(int xp, int yp){ int t = xp; int t1 = yp; xp = t1; yp = t;!

Body

+et


50/51

5'

%&-it code for long ints7ap

%&-it data ;ata he"d in re&isters Ora and Ord

moFE operation

=E? stands .or Euad-%ord

&oid sBap(long xp, long yp){ long t = xp; long t1 = yp; xp = t1; yp = t;!

Body

+et


51/51

Machine Programming I:+ummary

History of Intel processors andarchitectures DFo"utionary desi&n "eads to many Euir)s and arti.acts

C, assemly, machine code Compi"er must trans.orm statements, epressions,

procedures into "o%-"eFe" instruction seEuences

!ssemly Basics: "egisters, operands,move he 8+ moFe instructions coFer %ide ran&e o. data

moFement .orms Intro to #$%-%&

# maor departure .rom the sty"e o. code seen in I#32

05 machine basics

Documents