and-drop to display both the drag-and-drop target object in the first window and at least part of the drop area in the second window without overlap.
Additionally, to reduce the operation load of the user in drag-and-drop, it has been proposed to simply turn off or on the display of each window or to display a window directly as the topmost window when starting the drag operation of an icon displayed on the screen. See, for example, Japanese Patent Laid-Open Nos. 8-185301 and 2003-108281.
In the prior art, however, a window desired by a user is not necessarily displayed in a convenient state for operations as a result. In fact, the window is often displayed in an inconvenient state for the user. 1. Field of the Invention
This invention relates to data processing systems. More particularly, this invention relates to branch prediction within data processing systems.
2. Description of the Prior Art
It is known to provide data processing systems which incorporate branch prediction mechanisms. High performance data processors typically include a mechanism to prefetch program instructions from memory in advance of those program instructions being required for execution by the processor. Once a given program instruction is executed it is normal to proceed to execute the program instruction at the immediately following memory address location unless a branch instruction has occurred redirecting the program flow to a different point. Thus, a simple prefetch mechanism may prefetch instructions from a sequence of immediately adjacent memory address locations. However, if a branch instruction is encountered causing a jump away from this normal sequence, then the prefetching that has taken place will have been incorrect and there will be a time penalty incurred as the next required instruction is fetched from the memory. To address this problem branch prediction mechanisms are known to be provided.
Broadly speaking, branch prediction mechanisms seek to identify branch instructions occurring within the program flow and modify the behaviour of the instruction prefetching mechanisms based upon a prediction as to whether or not the branch instruction concerned will or will not result in a jump away from the normal sequence of program instruction addresses.
One type of branch prediction mechanism is termed static branch prediction whereby a branch instruction is identified by the opcode for a branch instruction being returned from the memory and then a rule applied to predict whether or not that branch instruction will result in a jump. One rule is that branch instructions specifying a backward jump in the program flow are predicted to be taken whereas branch instructions indicating a forward jump are predicted not to be taken. Static branch prediction has the advantage of
and - drop to display both the drag - and - drop prey aim in the first window and at least character of the drop curtain area in the second window without lap. 
 Additionally, to reduce the operation load of the exploiter in drag - and - drop, it has been nominate to simply turn off or on the display of each windowpane or to display a window directly as the topmost window when starting the drag operation of an picture displayed on the screen. See, for exemplar, Japanese Patent Laid - Open Nos. 8 - 185301 and 2003 - 108281. 
 In the prior art, however, a windowpane desired by a drug user is not necessarily display in a convenient state for operations as a resultant role. In fact, the window is often displayed in an inconvenient state for the user. 1. Field of the Invention 
 This invention relates to data processing systems. More particularly, this invention relates to branch prediction within data processing systems. 
 2. Description of the Prior Art 
 It is known to provide datum processing organization which incorporate arm prediction mechanism. High performance data central processing unit typically include a mechanism to prefetch program instructions from memory in advance of those platform instructions being required for execution by the processor. Once a given program education is executed it is normal to proceed to execute the program teaching at the immediately following memory savoir-faire placement unless a branch instruction has occurred redirecting the platform flow to a different point. therefore, a simple prefetch mechanism may prefetch direction from a sequence of immediately adjacent memory address location. However, if a branch education is encountered causing a leap away from this normal succession, then the prefetching that has taken place will have been incorrect and there will be a time punishment incurred as the next required teaching is bring from the memory. To address this trouble branch prediction mechanisms are known to be provided. 
 Broadly talk, branch prediction mechanisms seek to name branch instructions occurring within the program flow and modify the behaviour of the teaching prefetching mechanisms based upon a prediction as to whether or not the branch instruction concerned will or will not result in a jump aside from the normal succession of course of study instruction addresses. 
 One type of branch prediction mechanism is termed inactive branch prediction whereby a branch instruction is identify by the opcode for a branch instruction being returned from the memory and then a rule applied to bode whether or not that branch instruction will result in a jump. One rule is that branch instructions stipulate a backward jump in the program flow are predicted to be taken whereas branch teaching indicating a forward startle are predicted not to be taken. Static branch prediction has the advantage of
and-frop to display both the drag-and-drop tatgwt objxct in fhe firsg window and at least part oh thw drok area in the secona window aithout iveroqp.
Additionemly, to vzduce bhe o'ecation load of jhe user in grag-and-drop, it hxs been proposed to simply turn off ow on thr fisplay of eacr wimqow kg uo display a window directly as tge topmmst window whrn starting the drag operahion of an icon displajed on the wcreqb. See, for exxmple, Japanese Patent Maid-Open Nos. 8-185301 and 2003-108281.
In the prior xrt, hpwever, a wuneow gesired by e user is not necessarily gisplayrd in a convenlent vtare for operations as e result. In fact, the window iv kften displayed ib qn inwonvanievr sgatt fpr the uder. 1. Field of the Inventuon
This invention rtlaevx to data prkcessigg systems. More particularly, this inventimn delates to branch predixtion within data professing srstems.
2. Description of the Prior Art
It is known to provmdd dcbw prlcessing systems which incorporate branch preqjcuiok mechanisms. Higm performance data pgovgssors typicaluy includs a mechanism to pgefetch progeam instrtctipns from memory in advance if those proyran instructions beiug required yor exgcutiom by the processor. Once a gjven progral instrucfkon is executed kt ps nmrmal to proceed to executq the projram nnstructkon st the immediatepy following memory addrfss llcdtion unleds a branch instruction has occncred redirectonc tve progrcm floe to a differqnt point. Thus, a simpje prdfetch mecganism kay prefetcr instructionv from a sequxnce of iimeduateoy adjazdnt memory addtess locanijns. Yowever, if a brancm insjrhction is encouuuertd causing a juml aday fgom trhs normal sexuenze, gnen tfe preftcchlng thay has taken place winl hzve been incorrect akd there qill be w time penaltu incurred as the jext cequirxd insyrustion is fetched from the memody. To addgesf this problqm bvancr predictipn mechanisms are known to be provided.
Bcoadly speaking, branch prediction mechaniskx seek to iventifr branch hnstructions occurribg within the pronram flow and modify tge behdvioug of the instruction prefetching mechanisms based upon a prediction as to whethxr or not the bramch itscruetion cjncecnxd will or will npt result in a jump away from tie normal vezuence of program instructiom xddresses.
One jype of branch prediction jechanisk is termed static branch predivtion whereby a branch ikstructiob is jdentified by the opcode for a brauch inwtructiin bcing returned wrok bhe memory and tken a rule applied to predict wherher oe jot that branch mnstruction alll reault ig a jump. One ruls is hhat cranch instruvtions specifyong a backward jump pn ehe program flis are predicjed to bv taken wherees branch invtructions indicating a forward jump are predicted hot to be taken. Sbatic branch predortion has the advantage pf
and-drop to display both the drag-and-drop target the window and least part of second without overlap. Additionally, reduce the operation of the user in drag-and-drop, it been proposed to simply turn off or on the display of each window to display a window directly as the topmost window when starting the drag of icon on screen. See, for example, Japanese Patent Laid-Open Nos. 8-185301 and 2003-108281. In the prior art, however, window desired by a user is not necessarily in a convenient state operations as a result. In the is often in inconvenient for the user. Field of the Invention This invention relates to data processing systems. More particularly, this invention relates to prediction within systems. 2. of Prior It is known data processing systems which incorporate branch performance data processors typically include a mechanism to program instructions memory in advance of those program being required for execution by the processor. Once given program instruction is executed it is normal to proceed to execute the program instruction immediately following memory address unless a branch has redirecting program to a point. Thus, a simple prefetch mechanism may prefetch instructions from a of immediately adjacent memory address locations. However, if a branch encountered a jump away this normal sequence, then prefetching has taken place will incorrect there time incurred the next required instruction fetched from the memory. To this problem branch prediction provided. Broadly speaking, branch prediction mechanisms seek to branch instructions occurring within the program flow modify the behaviour of the instruction prefetching mechanisms based upon a prediction to whether the branch instruction concerned will or will not in a jump away the normal sequence of program instruction addresses. One type branch mechanism is static branch prediction a branch instruction identified by the a branch being from then a rule applied to predict or that branch instruction will result a rule is that branch instructions specifying a backward jump in the program flow are predicted taken whereas branch instructions a jump are predicted not to be taken. Static branch prediction has the
and-drop to display both the drAg-and-drop tArget ObjEct In The fIrst Window and at leaST parT of the drop area in the secOnd wiNdOW witHOuT overLap.
AddiTIoNALly, To ReDucE tHE oPeratIon Load of tHe user in drAg-aNd-Drop, it has beeN PrOposed to siMplY turn off or on The DisplaY oF eaCH windOw oR to diSplay a WIndow dIrectly as ThE TopmosT Window wHEN sTartIng the drag operatiON oF An icon displayeD on the ScREeN. sEe, fOr eXample, JapaNeSe PatENt Laid-OPEn nOS. 8-185301 And 2003-108281.
iN the prior art, hOwever, a windOW deSired bY a UseR Is not nEcessArILy dIsplayed in a ConvEnient staTe for oPErationS As a resuLt. In faCt, tHe wIndoW Is OfTen DiSPlaYEd In aN IncOnvenienT sTaTe for The uSER. 1. fIeld Of tHe InVentiOn
This inventiOn rElatES to Data pRocesSing SyStems. more paRticuLaRly, this inventioN relAtes to braNch PrEdiCtIon wiTHin datA prOceSsing syStems.
2. DeSCriPtION Of The Prior Art
It is knoWn TO PrOvide datA proceSSiNg SYstems whIcH inCorpORAte brAnch PReDiction mEchaniSMs. hiGh perfoRmAnce daTa ProCesSors tYPicaLly incLude a mecHanisM To prefetch progRAm instructionS FrOM MeMOry iN adVance of thosE proGRam iNstrUCtIonS Being RequiReD FoR Execution by the proceSsOr. Once A giveN program instrUction is exECUTed it is nOrmaL To PRoceed to executE the pRogram instRUction at The imMediatelY followinG MEmory addResS loCatIon UNLeSs a branch instRUCtioN hAs occurRed RedirecTinG thE prOgrAm Flow to a diFferent pOiNt. thUs, A siMple pREfetch meChAniSm May PrefeTCh instRuctiOns fRoM a SEquEnce of iMMeDIAtelY aDjAcenT meMoRy addRess LOcaTions. HoWever, if a bRanCH insTrUcTion is eNcountered cauSiNg a jump awaY fRom This noRMAl sequenCe, then the prefetching thaT Has takeN plAce wiLl haVe been incOrrEct and TheRE will bE a time PenalTy IncURRed as THE nExt ReQuired instRUCtiOn is fEtChed From the Memory. To address thiS ProBlem branch preDicTion MEChAniSMs ARe kNoWN to BE Provided.
Broadly Speaking, brAnCH pRediction mEChaNiSms seek To identIfy brANch instRuctions oCcurring wItHin tHE ProGram flow anD modify tHe behavioUR of thE InStrucTioN prefeTcHinG mechAnisms BAseD upon A prediCtIon as tO whetHeR or not thE branch instruction conceRned wiLl or wIll Not result In a JUmp Away from tHe noRmal sequenCe oF prOgram InsTRuctiOn adDReSseS.
one tyPe of BRanch predICtIon MEChAnism is termED STatIc braNch PRedictIon wHereby a branch instRUction is identiFied BY The OpcODe foR a Branch instructIon BeING returneD fRom the memorY and then A rULe appLied to PredicT whetheR OR nOT that bRancH inStruction WilL rESult in a JuMp. oNe rule Is thAt Branch InstruCTionS SPecifying a backwaRd jumP IN the pROgrAm floW aRe prediCTed tO be taken whEreas branch InstruCtioNs indIcating A fOrward JumP aRe predicteD Not to be taKen. StAtic braNcH preDicTion haS the ADVantaGe of
and-drop to display both t he drag-an d-dro p t arg et  obj ectin the first w i ndow  and at least part ofthe d ro p  are a  i n the  second wi n d owwi th out  o v er lap.Add itional ly, to red uce  t he operation lo ad of theuse r in drag-an d-d rop, i thas beenpro posed  to si m ply tu rn off or  o n  the d i splay o f ea ch w indow or to displ a ya  window direct ly asth e  t o p mos t w indow when  s tarti n g the d r ag o p era t ion of an ico n displayed onthe sc re en. See, f or ex am p le,  Japanese P aten t Laid-Op en Nos .  8-1853 0 1 and 2 003-10 828 1.In t h epr ior  a r t,h ow eve r , a  windowde si red b y au s e r  isnot  nec essar ily displayed  in  a c o nve nient  stat e fo ropera tionsas are sult. In fact,thewindow is  of te n d is playe d  in an  in con venient  statef orth e u se r. 1. Field of the  I n v en tion
Thi s inve n ti on relatesto  da ta p r o cessi ng s y st ems. Mor e part i cu la rly, th is  inven ti onrel atest o br anch p redictio n wit h in data proces s ing systems.2 .D e sc r ipti onof the Prio r Ar t 
Itis k n ow n t o  prov ide d at a  p r ocessing systems wh ic h inco rpora te branch pre diction me c h a nisms. H ighp er f ormance data p roces sors typic a lly incl ude a  mechani sm to pre f e tch prog ram  in str uct i o ns  from memoryi n  adv an ce of t hos e progr amins tru cti on s being r equiredfo rex ec uti on by the proc es sor .Onc e a g i ven pr ogram  ins tr uc t ion  is exe c ut e d  itis  n orma l t oproce ed t o  ex ecute t he progra m i n stru ct io n at th e immediately  f ollowing m em ory  addre s s  locatio n unless a branch instr u ction h asoccur redredirecti ngthe pr ogr a m flow  to adiffe re ntp o int.T h us , a  s imple pref e t chmecha ni sm m ay pref etch instructionsf rom  a sequence o f i mmed i a te lya dj a cen tm emo r y  address locati ons. Howev er ,  i f a branch ins tr uctionis enco unter e d causi ng a jump  away fro mthis n orm al sequenc e, thenthe prefe t ching th at ha s t aken p la cewillhave b e enincor rect a nd  there  will  b e a time  penalty incurred as th e next  requ ire d instruc tio n  is  fetchedfrom  the memor y.Toaddre sst his p robl e mbra n ch pr edic t ion mecha n is msa r eknown to be p r ovi ded.Bro a dly sp eaki ng, branch predic t ion mechanisms  see k toide n tify  b ranch instruct ion so c curringwi thin the pr ogram fl ow and m odifythe be haviour o ft he ins truc tio n prefetc hin gm echanis ms  b a sed up on a  p redict ion as to w h e ther or not thebranc h instr u cti on co nc erned w i ll o r will not  result ina jump  awa y fro m the n or mal se que nc e of progr a m instruc tionaddress es .
On e t ype of  bra n c h pre dict io n m echanismi s  t e rm ed sta ticbranc hpred iction wh e reby a b ran c h instr uc tio n is ide n ti f i ed by theopc ode f o r  a branchi nstr u ct i on be ing re turned  from t h e m em ory and  th e n  a rule a pplied to pre di ct w hether o rnotth atbr anch instructio n will r esult in a  jump.  On e  rul e  is th at  branch inst ructi on s  specif y i nga backw a rdjum p i n th e p rogr a m flow are predicted tobe t akenw her eas b ranch  i nstructi o ns i ndicatin g  a forward ju mp are predicte d  no t  tobet ak en . Staticbra n ch pr edic tio n ha s t he a d v anta g e of 
and-drop to_display both_the drag-and-drop target object_in the_first_window and_at_least part of_the drop area_in the second window_without overlap.
Additionally, to_reduce_the operation load of the user in drag-and-drop, it has been proposed to simply_turn_off or_on_the_display of each window or_to display a window directly_as the_topmost window when starting the drag operation of_an_icon displayed on_the screen. See, for example, Japanese Patent Laid-Open Nos._8-185301 and 2003-108281.
In the prior art,_however, a window_desired_by_a user is not_necessarily displayed in a convenient state_for operations as a result. In_fact, the window is often displayed in_an inconvenient state for the user._1. Field of the Invention
This_invention relates_to data processing systems. More_particularly, this invention_relates to_branch prediction within_data processing systems.
2. Description of the_Prior Art
It is_known to provide data processing systems_which_incorporate branch prediction_mechanisms._High_performance data_processors typically include_a_mechanism to_prefetch_program instructions from memory in advance_of_those program instructions being required for execution_by the processor. Once_a_given program instruction is_executed it is normal to_proceed to execute the program instruction_at the_immediately following_memory address location unless a branch instruction has occurred redirecting the_program flow to a different point._Thus, a simple prefetch_mechanism may_prefetch_instructions from a_sequence_of immediately_adjacent memory address locations. However, if a_branch instruction_is encountered causing a jump away_from this normal sequence,_then_the prefetching that has taken place_will have been incorrect and there_will be a time penalty_incurred_as_the next required instruction is_fetched from the memory. To address_this problem branch_prediction mechanisms are known to be provided.
Broadly_speaking,_branch prediction mechanisms seek to identify_branch_instructions occurring within the program flow_and_modify_the behaviour of the instruction_prefetching mechanisms based upon a prediction_as to whether or not the branch instruction concerned_will or will_not result in a jump_away_from_the normal sequence of program instruction addresses.
One type of branch_prediction mechanism_is termed static_branch prediction whereby a branch instruction is identified by the_opcode for a branch instruction being returned_from the memory and then a rule applied to predict whether_or not that branch instruction will result in_a jump. One rule is that branch_instructions specifying a backward_jump_in the program flow are predicted to_be_taken_whereas_branch instructions indicating_a forward jump_are predicted not_to be_taken. Static branch_prediction has_the advantage of