MIPSProject4:

06 Aug MIPSProject4:

PostfixExpressionCalculatorinHex

AssignedOn:Apr5 th ,2017

DueOn:April26 th ,endoftheday(11:59pm)

–NOLATEDELIVERYACCEPTEDTHISTIME–

 

WehavediscussedinclassthedetailsofINFIXandbrieflyPOSTFIX.InthisfinalProject,youneedtoimplementa

postfixexpressioncalculator,wherenumbersareinhex,andwitha >>STACK<< ofyourown(ofsize5).With

yourownstack,youareresponsibleofdesigning(coding)theregularstackoperations(suchaspush/pop),aswell

ascheckforoverflow/underflowatappropriateplaces.

Yourprogramwilltaketheuser’sinputasapostfixexpressionwithhexnumbers,useyourownstacktoevaluate

it, and display the result in both hex and decimal forms. The numbers and operations in the expression are

assumedtobeseparatedby(oneormore)spaces.Youcanassumethatnonegativenumberswillbepresentedin

theinputexpression,butintermediateandfinalresultsmightbenegative.

 

Youhavethreedifferentlevelsofcompletion:picktheONEwithwhichyouaremostconfident:

SilverLevel[80/100POINTS]

Calculateasingle-digitvalidpostfixexpression.Forexample:

 

9 A – 4 8 + * B / = -1 (dec), -1 (hex)

E 0 A B + 7 / – – = 17 (dec), 11 (hex)

GoldLevel[100/100POINTS]

Samephilosophyofthepreviouslevel,butnowallowingmulti-digitnumbers,detectingillegalpostfixexpressions,

aswellasreportingoverflowforyourstack.Forexample:

 

3 64 69 – + 1B1 * = -866 (dec), -362 (hex)

F 10E0 10 – + * 4A33 is invalid

F GH 5 – + 4A33 * is invalid

3 F E0 150 52 4EE * – + * overflows my stack of 5

PlatinumLevel[120/100POINTS]

WiththerespecttotheGoldLevel,yourprogrammustsupportrealnumbersininput,suchas10F.DE3.Output

onlyneedstobeindecimalthistime.

 

ExamplealgorithmofpostfixcalculationforsingledigitnumbersinHex:

a)

Fromlefttoright,gothrougheverycharacteroftheexpression,dothefollowing:

i. ifthecharacterisavaliddigitinHex(0–9,A-F):

converttheASCIIbytetointegerandpushthatnumberontostack

ii. ifthecharacterisanoperation(+-*/):

1. popfromthestackanumber->x

2. popfromthestackanumber->y

3. calculateyopx(for/,usequotientasresultandignoretheremainder).

4. pushtheresultnumberbackontostack

b) Popoutfromstack->finalresult

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Whattosubmit

Ina*.ZIParchive(mandatory),containing:

1. Yourassemblycodeas*.asmfile;

2. APDFfilecontainingaDETAILEDreportofyourworkdiscussingthephilosophyyoufollowedinsolvingthe

problem,youralgorithmicimplementation+FIVEmeaningfulscreenshotsoftheI/Ooutputwindowfrom

MARS(eventuallyaddafewcommentstodescribethem).

 

Wheretosubmit

TurninyourworkonBlackboardasAssignment,withintheProgrammingProjectssectionintheCourseMaterial,as

a*.zipfile,containingcodesourcefileinassemblyandreportinPDF.

 

 

Gradingcriteriaforthislab

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Programfunctionalityandcorrectness(40%);

Labreport(50%)judgedbythewrite-upqualityandinsightfulness;

Codequalityandstyle(10%).