CS61C Introduction to Pipelining. Lecture 25. April 28, 1999 Dave Patterson (http.cs.berkeley.edu/~patterson)

Transcription

1 S61 Ioucio o Pipliig Lcu 25 pil 28, 1999 v Po (hp.c.bly.u/~po) www-i.c.bly.u/~c61c/chul.hml uli Rviw Pm Pig o Sc Pipliig logy Pipliig Iucio Excuio miiivi, Wh hi Suff fo? Hz o Pipliig Soluio o Hz vc Pipliig ocp by logy ocluio c 61 L25 pipli.1 c 61 L25 pipli.2 Rviw 1/1 Evy mchi h covio fo how gum p. I MIPS, wh o h gum go if you pig mo h 4 wo? Sc! I i omim uful o hv vibl umb of gum. h covio i o u... *fm i u o mi h umb of vibl hi yp. c 61 L25 pipli.3 Pipliig i Nul! Luy Exmpl, i, hy, v ch hv o lo of cloh o wh, y, fol, pu wy Wh 30 miu y 30 miu Fol 30 miu Sh 30 miu o pu cloh io w c 61 L25 pipli.4

2 Squil Luy M im Squil luy 8 hou fo 4 lo Pipli Luy: S wo SP 12 2 M im Pipli luy 3.5 hou fo 4 lo! c 61 L25 pipli.5 c 61 L25 pipli.6 Pipliig Lo Pipliig Lo 6 PM im Pipliig o hlp lcy of igl, i hlp houghpu of i wolo Mulipl opig imulouly uig iff ouc Poil pup = Numb pip g im o fill pipli im o i i uc pup: 2.3X v. 4X i hi xmpl 6 PM im Suppo w Wh 20 miu, w Sh 20 miu. How much f i pipli? Pipli limi by low pipli g Ublc lgh of pip g lo uc pup c 61 L25 pipli.7 c 61 L25 pipli.8

3 Rviw: Sp i Excuig MIPS (Lc. 20) 1) Ifch: Fch Iucio, Icm P 2) co Iucio, R Rgi 3) Excu: Mm-f: lcul ih-log: Pfom pio ch: omp if op == 4) Mmoy: Lo: So: ch: R fom Mmoy Wi o Mmoy if op ==, hg P 5) Wi c: Wi o Rgi Pipli Excuio Rpio im IFch c IFch c Pogm Flow Exc Mm W IFch c Exc Mm W IFch c Exc Mm W IFch c Exc Mm W IFch c Exc Mm W Exc Mm W Evy iucio m umb of p, lo cll pipli g c 61 L25 pipli.9 c 61 L25 pipli.10 Rviw: ph fo MIPS (Lc. 20) Sg 5 Iucio P Rgi ch ch Sg 1 Sg 2 Sg 3 (Sg 4) U ph figu o p pipli IFch c Exc Mm W I. Gphicl Pipli Rpio Lo So Sub im (cloc cycl) Rg $ Rg (igh hlf highligh m, lf hlf wi) c 61 L25 pipli.11 c 61 L25 pipli.12

4 Exmpl Suppo 2 fo mmoy cc, 2 fo opio, 1 fo gi fil o wi Nopipli Excuio: lw : IF + R Rg + + Mmoy + Wi Rg = = 8 : IF + R Rg + + Wi Rg = = 6 Pipli Excuio: Mx(IF,R Rg,, Mmoy,Wi Rg) = 2 miiivi Pojc 6 (l): u oy Nx Rig: h homwo (l): u Fiy 4/30 7PM Exci 2.6, 2.13, 6.1, 6.3, 6.4 c 61 L25 pipli.13 c 61 L25 pipli.14 miiivi: R of 61 F 4/30 Rviw: ch/l/vm; Scio 7.5 M 5/3 c 61 L25 pipli.15 li o coc you g co W 5/5 Rviw: Iup / Pollig;.7 F 5/7 61 Summy / You l hig / HKN ou Evluio (u: Fil 61 Suvy i lb; Ru) Su 5/9 Fil Rviw ig 2PM (1 Pimil) W 5/12 Fil (5PM 1 Pimil) N liv Fil? oc m@coy Wh hi Suff (Poilly) Fo? Liig Eim o Violc 100 of ui i c c hv vl ic colio bw xpou o mi violc--icluig vio gm-- ic ggio. "W chig h g of iizio which h iflicig of pi uffig h bcom ouc of im; viciou plu h h vulio. W lig o ill, w lig o li i." Li h obcco iuy, h vic i h." h 14-y-ol boy who op fi o py goup i Ky. chool foy i 1997 w vio-gm xp. H h v fi piol bfo, bu i h uig ml, h fi 8 ho, hi 8 popl, ill 3. h vg lw focm offic i h Ui S, ic of 7 y, hi fw h 1 i 5 ho. cu of fom of pch i vlu h w o' w o compomi, i lly com ow o h popl cig h gm. h' wh h poibiliy li." N.Y. im, 4/26/99 c 61 L25 pipli.16

5 Pipli Hz: Mchig oc i l lo 12 2 M E F bubbl im p o ; ll ic fol i up Poblm fo ompu Limi o pipliig: Hz pv x iucio fom xcuig uig i ig cloc cycl Sucul hz: HW co uppo hi combiio of iucio (igl po o fol pu cloh wy) ool hz: Pipliig of bch & oh iucio ll h pipli uil h hz bubbl i h pipli hz: Iucio p o ul of pio iucio ill i h pipli (miig oc) c 61 L25 pipli.17 c 61 L25 pipli.18 I. Sigl Mmoy i Sucul Hz Lo I 1 I 2 I 3 I 4 im (cloc cycl) Rg $ Rg R m mmoy wic i m cloc cycl Sucul Hz limi pfomc Exmpl: if 1.3 mmoy cc p iucio (30% of iucio xcu lo o) oly o mmoy cc p cycl h vg PI 1.3 hwi ouc i mo h 100% uiliz c 61 L25 pipli.19 c 61 L25 pipli.20

6 I. ool Hz Soluio Sll: wi uil ciio i cl Mov up ciio o 2 g by ig hw o chc gi big im (cloc cycl) q Lo Impc: 2 cloc cycl p bch iucio low c 61 L25 pipli.21 bub bl Rg $ Rg I. ool Hz Soluio Pic: gu o icio, h bc up if wog c 61 L25 pipli.22 Fo xmpl, Pic o im (cloc cycl) q Lo Impc: 1 cloc p bch iucio if igh, 2 if wog (igh 50% of im) Mo ymic chm: hioy of 1 bch ( 90%) Rg $ Rg I. ool Hz Soluio Rfi bch bhvio ( plc f x iucio) ly bch q Mic Impc: 1 cloc cycl p bch iucio if c fi iucio o pu i lo ( 50% of im) c 61 L25 pipli.23 im (cloc cycl) Lo Rg $ Rg Rg $ Rg Exmpl Noly v. ly ch Noly ch ly ch o $8, $9,$10 $1,$2,$3 $1,$2,$3 ub $4, $5,$6 ub $4, $5,$6 bq $1, $4, Exi bq $1, $4, Exi o $8, $9,$10 xo $10, $1,$11 xo $10, $1,$11 Exi: Exi: c 61 L25 pipli.24

7 Hz o Rgi $1 $1,$2,$3 ub $4, $1,$3 $6, $1,$7 o $8, $1,$9 xo $10, $1,$11 Hz o $1: pci bcw i im hz I. im (cloc cycl) $1,$2,$3 ub $4,$1,$3 $6,$1,$7 o $8,$1,$9 xo $10,1,$11 IF I/RF EX MEM W Rg $ Rg c 61 L25 pipli.25 c 61 L25 pipli.26 Hz Soluio: Fow ul fom o g o oh I im (cloc cycl) IF I/RF EX MEM W $1,$2,$3. ub $4,$1,$3 $6,$1,$7 o $8,$1,$9 xo $10,1,$11 o K if fi /wi poply c 61 L25 pipli.27 Rg $ Rg Fowig (o ypig): Wh bou Lo pci bcw i im hz lw $1,0($2) ub $4,$1,$3 olv wih fowig Mu ll iucio p o lo c 61 L25 pipli.28 IF I/RF EX MEM W

8 Hz Ev wih Fowig Mu i ll o bubbl i pipli c 61 L25 pipli.29 im (cloc cycl) lw $1, 0($2) ub $4,$1,$6 $6,$1,$7 o $8,$1,$9 IF I/RF EX MEM W bub bl bub Rg $ Rg bl bub bl Rg $ Sofw Schulig o voi Lo Hz y poucig f co fo = b + c; = Ð f;, b, c,,, f i mmoy Slow co: F co: lw $2,b lw $2,b lw $3,c lw $3,c $1,$2,$3 lw $5, w $1, $1,$2,$3 lw $5, lw $6,f c 61 L25 pipli.30 lw $6,f ub $4,$5,$6 w $4, w $1, ub $4,$5,$6 w $4, vc Pipliig ocp (if im) u-of-o Excuio Supcl xcuio S-of-h- Micopoco Pipli Hz: Sll 12 2 M E F bubbl im p o ; ll ic fol i up c 61 L25 pipli.31 c 61 L25 pipli.32

9 u-of- Luy: oõ Wi Supcl Luy: Plll p g p o ; coiu; mo ouc o llow ou-of-o c 61 L25 pipli M E F bubbl im 12 2 M E F im (ligh clohig) ( clohig) (vy iy clohig) (ligh clohig) ( clohig) (vy iy clohig) Mo ouc, HW o mch mix of c 61 L25 pipli.34 plll? Supcl Luy: Mimch Mix (ligh clohig) mix uuiliz x ouc c 61 L25 pipli M im (ligh clohig) (ligh clohig) ( clohig) S of h : lph Millio io 2 64K cch o chip; 16M L2 cch off chip loc cycl im <1.7 c, o loc R >600 MHz (F y Supcompu: c) 90 w p chip! Supcl: fch up o 6 iucio/cloc cycl, i up o 4 iucio/cloc cycl Excuio ou-of-o c 61 L25 pipli.36

10 Summy 1/2: Pipliig Ioucio Pipliig i fuml cocp Mulipl p uig iic ouc Exploiig plllim i iucio Wh m i y? (MIPS v. 80x86) ll iucio h m lgh impl iucio fch Ju fw iucio fom gi bfo co iucio Mmoy op oly i lo o fw pipli g lig 1 mmoy cc / lo, o c 61 L25 pipli.37 Summy 2/2: Pipliig Ioucio Wh m i h? Sucul hz: uppo w h oly o cch? N mo HW ouc ool hz: o woy bou bch iucio? ch picio, ly bch hz: iucio p o pviou iucio? fowig, compil chulig c 61 L25 pipli.38