Instruction Scheduling

Transcription

1 Instrution Sulin Not y Bris Aktmur: Our slis r pt from Coopr n Torzon s slis tt ty prpr for COMP 412 t Ri. Copyrit 20, Kit D. Coopr & Lin Torzon, ll rits rsrv. Stunts nroll in Comp 412 t Ri Univrsity v xpliit prmission to mk opis of ts mtrils for tir prsonl us. Fulty from otr utionl institutions my us ts mtrils for nonprofit utionl purposs, provi tis opyrit noti is prsrv. Wt Mks Co Run Fst? Mny oprtions v non-zro ltnis Morn mins n issu svrl oprtions pr yl Exution tim is orr-pnnt (n s n sin t 60 s) Oprtion Cyls lo 3 stor 3 loi 1 1 mult 2 f 1 fmult 2 sift 1 rn 0 to Los & stors my or my not lok on issu > Non-lokin fill tos issu slots Brn osts vry wit pt tkn Brns typilly v ly slots > Fill slots wit unrlt oprtions > Prolts rn upwr Sulr soul i t ltnis Assum ltnis for xmpl on nxt sli. Comp 412, Fll

2 Exmpl * 2 * * * Simpl sul Sul los rly Rorrin oprtions for sp is ll instrution sulin Comp 412, Fll 20 2 ALU Crtris.s Tis t is surprisinly r to msur urtly Vlu-pnnt vior Intl E5530 opr/on ltnis Contxt-pnnt vior Instru/on Cost Compilr vior 64 it intr sutrt 1 Hv sn unrllot & 64 it intr mul.ply 3 inflt opr.on osts wit 64 it intr ivi 41 mmory rfrns (spills) Doul prision 3 Hv sn ommril ompilr Doul prision sutrt 3 nrt 3 xtr ops pr ivi risin ff.v ost y 3 Doul prision mul.ply 5 Diffiult to ronil msur Doul prision ivi 22 rlity wit t t in t Sinl prision 3 Mnuls (.. intr ivi Sinl prision sutrt 3 on Nlm) Sinl prision mul.ply 4 Sinl prision ivi 14 Comp 412, Fll 20 Xon E5530 uss t Nlm mirorittur, s os I7 3 2

3 Instrution Sulin (Eninr s Viw) T Prolm Givn o frmnt for som trt min n t ltnis for iniviul oprtion, rorr t oprtions to minimiz xution tim T Conpt Min sription slow Sulr o fst o T Tsk Prou orrt o Minimiz wst yls Avoi spillin ristrs Oprt ffiintly Comp 412, Fll 20 4 Instrution Sulin (T Astrt Viw) To ptur proprtis of t o, uil prn rp G Nos n G r oprtions wit typ(n) n ly(n) An = (n 1,n 2 ) G if & only if n 2 uss t rsult of n 1 f i T Co T Prn Grp Comp 412, Fll

4 Instrution Sulin (Dfinitions) A orrt sul S mps n N into non-ntiv intr rprsntin its yl numr, n 1. S(n) 0, for ll n N, oviously 2. If (n 1,n 2 ) E, S(n 1 ) + ly(n 1 ) S(n 2 ) 3. For typ t, tr r no mor oprtions of typ t in ny yl tn t trt min n issu T lnt of sul S, not L(S), is L(S) = mx n N (S(n) + ly(n)) T ol is to fin t sortst possil orrt sul. S is tim-optiml if L(S) L(S 1 ), for ll otr suls S 1 A sul mit lso optiml in trms of ristrs, powr, or sp. Comp 412, Fll 20 6 Instrution Sulin (Wt s so iffiult?) Critil Points All oprns must vill Multipl oprtions n ry Movin oprtions n lntn ristr liftims Plin uss nr finitions n sortn ristr liftims Oprns n v multipl prssors Totr, ts issus mk sulin r (NP-Complt) Lol sulin is t simpl s Rstrit to strit-lin o Consistnt n pritl ltnis Comp 412, Fll

5 Instrution Sulin: T Bi Pitur 1. Buil prn rp, P 2. Comput priority funtion ovr t nos in P 3. Us list sulin to onstrut sul, 1 yl t tim. Us quu of oprtions tt r ry. At yl I. Coos t ist priority ry oprtion & sul it II. Upt t ry quu Lol list sulin T ominnt loritm for tirty yrs A ry, uristi, lol tniqu Comp 412, Fll 20 * Lol List Sulin Cyl 1 Ry lvs of P Ativ Ø wil (Ry Ativ Ø) if (Ry Ø) tn rmov n op from Ry S(op) Cyl Ativ Ativ op Cyl Cyl + 1 for op Ativ if (S(op) + ly(op) Cyl) tn rmov op from Ativ for sussor s of op in P if (s is ry) tn Ry Ry s Rmovl in priority orr op s omplt xution If sussor s oprns r ry, it to Ry Comp 412, Fll

6 Sulin Exmpl 1. Buil t prn rp f i T Co T Prn Grp Comp 412, Fll 20 Oprtion Cyls lo 3 Sulin Exmpl stor 3 loi 1 1. Buil t prn rp 1 mult 2 2. Dtrmin prioritis: f lonst ltny-wit 1 pt fmult 2 sift 1 rn 0 to f 5 i 3 T Co T Prn Grp Comp 412, Fll

7 Sulin Exmpl 1. Buil t prn rp 2. Dtrmin prioritis: lonst ltny-wit pt 3. Prform list sulin Us nw ristr nm 1) : l o A I r r 1 2) : l o A I r x r 2 3) : l o A I r y r 3 4) : r 1, r 1 r 1 5) : m ul t r 1, r 2 r 1 6) : l o A I r r 2 7) f: m ul t r 1, r 3 r 1 9) : m ul t r 1, r 2 r 1 11) i: s t o r A I r 1 r T Co f 5 i 3 T Prn Grp Comp 412, Fll Mor List Sulin List sulin rks own into two istint lsss Forwr list sulin Strt wit vill oprtions Work forwr in tim Ry ll oprns vill Bkwr list sulin Strt wit no sussors Work kwr in tim Ry ltny ovrs uss Vritions on list sulin Prioritiz ritil pt(s) Sul lst us s soon s possil Dpt first in prn rp (minimiz ristrs) Brt first in prn rp (minimiz intrloks) Prfr oprtion wit most sussors Comp 412, Fll

8 Lol Sulin Forwr n kwr n prou iffrnt rsults loi 1 lsift loi 2 loi 3 loi 4 Ltny to t r I mp stor 1 stor 2 stor 3 stor 4 stor 5 1 r Blok from SPEC nmrk o Oprtion lo loi I stor mp Ltny Susript to intify Comp 412, Fll Lol Sulin F o r w r S u l Int Int Mm 1 loi 1 lsift 2 loi 2 loi 3 3 loi I stor 1 6 mp stor 2 7 stor 3 stor 4 9 stor r B k w r S u l Int Int Mm 1 loi 4 2 I lsift 3 4 loi loi 2 stor loi 1 stor stor 3 7 stor 2 stor mp 12 r Comp 412, Fll 20 Usin ltny to root s t priority funtion 15

9 Sulin Lrr Rions On stp yon lok is n Extn Bsi Blok (EBB) EBB is mximl st of loks s.t. St s sinl ntry, B i E lok B j otr tn B i s xtly on prssor Exmpl CFG s tr EBBs B 2 f B 1 B 3 B 4 i B 5 j k B 6 l Comp 412, Fll 20 CFG Control Flow Grp 16 Sulin Lrr Rions On stp yon lok is n Extn Bsi Blok (EBB) EBB is mximl st of loks su tt St s sinl ntry, B i E lok B j otr tn B i s xtly on prssor Exmpl s tr EBBs Bi EBB s two pts {B 1,B 2,B 4 } & {B 1,B 3 } Mny optimiztions oprt on EBBs (inluin sulin) B 4 i B 2 f B 1 B 5 j k B 3 B 6 l Comp 412, Fll

10 Sulin Lrr Rions Suprlol Sulin Sul ntir pts trou EBBs Exmpl s four EBB pts B 1 B 2 f B 3 B 4 i B 5 j k B 6 l Comp 412, Fll 20 1