!"#$%$&'(!"#$!%&!'#$(%)+,-./0123/,-/4/561-7.89:-75:* %.0 ;72-1.7<!=>?,1?.9$=!=*

Size: px

Start display at page:

Download "!"#$%$&'(!"#$!%&!'#$(%)*+,-./0123/,*-/*4/561-7.*89:-75:* %.0 *;72-1.7<*!=*>?,1?.9*$=!=*"

Edward Watson
6 years ago
Views:

1 !"#$%$&'(!"#$!%&!'#$(%)*+,-./0123/,*-/*4/561-7.*89:-75:* %.0 -)#+./0(! -1$23#'(#+(423/4&(#5$(/)#+./0('6'#$2(! 7&/89:(+0'*$"49$'(

2 B/'#(C42$,(D4#'(E(D6#$'(! D4#':(D6#$':(F+&?'(! G$*42/.:(04"/&6:(5$H/?$*42/.(&$3&$'$"#/9+"(! I4&#)/.(2$2+&6('3/*$:(/??&$''4"%:(06#$(+&?$&4"%(! D++.$/"(/.%$0&/(! D4#(J$&')'(.+%4*/.(+3$&/9+"'(4"(<( C+?/6,(!"#$%$&'(! K$3&$'$"#/9+",()"'4%"$?(/"?('4%"$?(! <+"J$&'4+":(*/'9"%(! LH3/"?4"%:(#&)"*/9"%(! -??49+":("$%/9+":(2).93.4*/9+":('54M4"%(! N)22/&6(

3 L"*+?4"%(!"#$%$&'( P"'4%"$?( CQ+R'(<+23.$2$"#( short int x = 15213; short int y = ;! <(short(o(06#$'(.+"%( N4%"( D4#(! N4%"(D4#(! G/.*$H:*2/56B757,-<*5/:-*:AE,AI2?,-*JA-*A,0A2?-7:*:AE,*! =*K/.*,/,,7E?3L7*!!*K/.*,7E?3L7* L"*+?4"%(LH/23.$(><+"#SA( x = 15213: y = :

4 T)2$&4*(K/"%$'(! P"'4%"$?(I/.)$'(!!"#$ *M *=* ===N=*!!"%&* *M **$ ' *O*!*!!!N!*!(CQ+R'(<+23.$2$"#(I/.)$'(! ("#$ *M **O$ 'O!*!==N=*! ("%&* *M **$ 'O! *O*!* =!!N!*!(U#5$&(I/.)$'(! PA,1:*!*!!!N!* I/.)$'(=+&(!(V(WX( I/.)$'(=+&(G4Y$&$"#(F+&?(N4Z$'(! U0'$&J/9+"'(! Q("#$)Q* *M* *("%&*R*!*! S:9557-.A2*.?,E7*!!"%& *M *$*T*("%&*R*!**! <([&+%&/224"%(! UA,2B107*VBA5A-:WXY*! Z72B?.7:*2/,:-?,-:<*7WEW<*! [;\CD]PS^*! ;\CD]PS^*! ;\CD]P+C*! _?B17:*6B?`/.5*:672AI2 **

5 P"'4%"$?(E(N4%"$?(T)2$&4*(I/.)$'( *) DOP>#A( DOC>#A( ====* =* =* ===!*!*!* ==!=* $* $* ==!!* %* %* =!==* (* (* =!=!* "* "* =!!=* h* h* =!!!* i* i*!===* '* O'*!==!* j* Oi*!=!=*!=* Oh*!=!!*!!* O"*!!==*!$* O(*!!=!*!%* O%*!!!=*!(* O$*!!!!*!"* O!*! 8?57*7,2/0A,E:*K/.*,/,,7E?3L7* L?B17:*! al7.9*ja-*6?b7.,*.76.7:7,-:* 1,Ac17*A,-7E7.*L?B17*! a?2x*.76.7:7,-?jb7*a,-7e7.*x?:* 1,Ac17*JA-*7,2/0A,E*!!(</"(!"J$&#(\/334"%'(! #! A,-7E7.*! #! A,-7E7.* C+?/6,(!"#$%$&'(! K$3&$'$"#/9+",()"'4%"$?(/"?('4%"$?(! <+"J$&'4+":(*/'9"%(! LH3/"?4"%:(#&)"*/9"%(! -??49+":("$%/9+":(2).93.4*/9+":('54M4"%(! N)22/&6(

6 CQ+R'(<+23.$2$"#( P"'4%"$?( x! ux! X! \/334"%(D$#Q$$"(N4%"$?(E(P"'4%"$?( CQ+R'(<+23.$2$"#( P"'4%"$?( ux! x! X!! \/334"%'(0$$"()"'4%"$?(/"?(#Q+R'(*+23.$2$"#(")20$&',( (]$$3(04#(&$3&$'$"#/9+"'(/"?(&$4"#$&3&$#( \/334"%(N4%"$?("(P"'4%"$?( POC( COP(

7 \/334"%(N4%"$?("(P"'4%"$?( V( ^WX( K$./9+"(0$#Q$$"(N4%"$?(E(P"'4%"$?( CQ+R'(<+23.$2$"#( w 1! 0! ux! x! f$[* x! ux! X! P?A,-?A,*8?57*@A-*k?b7.,* P"'4%"$?( B/&%$("$%/9J$(Q$4%5#( +,-./,0) B/&%$(3+'49J$(Q$4%5#(

8 <+"J$&'4+"(I4')/.4Z$?(! OR'(<+23S(#(P"'4%"$?(! \.07.A,E*+,L7.:A/,*! ("%&) ("%&))R*!) ("%&) [,:AE,70* l?,e7* $H:*4/56B757,- *l?,e7* =* O!* O$* =* ("#$) N4%"$?(J'S(P"'4%"$?(4"(<(! [,:AE,70*AK*X?L7*m[n*?:*:1op* 0U, U! </'9"%(! ap6ba2a-*2?:3,e*j7-g77,*:ae,70*q*1,:ae,70*:?57*?:*[$f*?,0*f$[* int tx, ty; unsigned ux, uy; tx = (int) ux; uy = (unsigned) ty;! +56BA2A-*2?:3,E*?B:/*/221.:*LA?*?::AE,57,-:*?,0*6./2701.7*2?BB:* tx = ux; uy = ty;

9 </'9"%(N)&3&4'$'( *= 0 *=[ 0U ** == )"'4%"$? *#! -1 *= 0 ** < '4%"$? *#! -1 *=[ 0U ** > )"'4%"$? *$!(i('%h(i *#$!(i('%h(i#!* ** > '4%"$?( *$!(i('%h(i[ U *#$!(i('%h(i#!* ** < )"'4%"$? *#! -1 *#$* -2 ** > '4%"$? *d1,:ae,70e#! (unsigned) -1 *#$* -2 ** > )"'4%"$? **$!(i('%h(i* *$!(i('%h('[* U < ** )"'4%"$? **$!(i('%h(i* *da,-e*$!(i('%h('[* (int) U > '4%"$?! LH3&$''4+"(LJ/.)/9+"(! +K*-X7.7*A:*?*5Ap*/K*1,:AE,70*?,0*:AE,70*A,*:A,EB7*7p6.7::A/,<** $%&'()"*+,-($"%./,%0%1,2"0+$1"13"-'$%&'()"! +,2B10A,E*2/56?.A:/,*/67.?3/,:*<:(>:(==:(<=:(>=! ap?56b7:*k/.*1*m*%$)****c\!t(v(_o:w`a:`bc:x`b(:(((((c\-d(v(o:w`a:`bc:x`a(! <+"'#/"# W (<+"'#/"# O (K$./9+" (LJ/.)/9+"( <+?$(N$*)&4#6(LH/23.$( /* Kernel memory region holding user-accessible data */ #define KSIZE 1024 char kbuf[ksize]; /* Copy at most maxlen bytes from kernel region to user buffer */ int copy_from_kernel(void *user_dest, int maxlen) { /* Byte count len is minimum of buffer size and maxlen */ int len = KSIZE < maxlen? KSIZE : maxlen; memcpy(user_dest, kbuf, len); return len; }! N424./&(#+(*+?$(=+)"?(4"(e&$$DNGR'(423.$2$"#/9+"(+=( %$#3$$&"/2$(! C5$&$(/&$(.$%4+"'(+=('2/&#(3$+3.$(#&64"%(#+(f"?( J)."$&/04.49$'(4"(3&+%&/2'(

10 C634*/.(P'/%$( /* Kernel memory region holding user-accessible data */ #define KSIZE 1024 char kbuf[ksize]; /* Copy at most maxlen bytes from kernel region to user buffer */ int copy_from_kernel(void *user_dest, int maxlen) { /* Byte count len is minimum of buffer size and maxlen */ int len = KSIZE < maxlen? KSIZE : maxlen; memcpy(user_dest, kbuf, len); return len; } #define MSIZE 528 void getstuff() { char mybuf[msize]; copy_from_kernel(mybuf, MSIZE); printf( %s\n, mybuf); } \/.4*4+)'(P'/%$( /* Declaration of library function memcpy */ void *memcpy(void *dest, void *src, size_t n); /* Kernel memory region holding user-accessible data */ #define KSIZE 1024 char kbuf[ksize]; /* Copy at most maxlen bytes from kernel region to user buffer */ int copy_from_kernel(void *user_dest, int maxlen) { /* Byte count len is minimum of buffer size and maxlen */ int len = KSIZE < maxlen? KSIZE : maxlen; memcpy(user_dest, kbuf, len); return len; } #define MSIZE 528 void getstuff() { char mybuf[msize]; copy_from_kernel(mybuf, -MSIZE);... }

11 N)22/&6( </'9"%(N4%"$?(g(P"'4%"$?,(D/'4*(K).$'(! D4#(3/1$&"(4'(2/4"#/4"$?(! D)#(&$4"#$&3&$#$?(! </"(5/J$()"$H3$*#$?($Y$*#',(/??4"%(+&(')0#&/*9"%(O Q(! LH3&$''4+"(*+"#/4"4"%('4%"$?(/"?()"'4%"$?(4"#(! A,-*A:*2?:-*-/*1,:AE,70rr* C+?/6,(!"#$%$&'(! K$3&$'$"#/9+",()"'4%"$?(/"?('4%"$?(! <+"J$&'4+":(*/'9"%(! LH3/"?4"%:(#&)"*/9"%(! -??49+":("$%/9+":(2).93.4*/9+":('54M4"%(! N)22/&6(

12 N4%"(LH#$"'4+"(! C/'],(! DAL7,*'#JA-*:AE,70*A,-7E7.*&*! 4/,L7.-*A-*-/*'R2#JA-*A,-7E7.*gA-X*:?57*L?B17*! K).$,(! P?s7*2*2/6A7:*/K*:AE,*JA-)*! **$*M**& 'O!* <N<*& 'O!* <*& 'O!* <*& 'O$* <N<*& =* 4(*+34$'(+=(\ND( X % ') X $% 2) ') N4%"(LH#$"'4+"(LH/23.$( short int x = 15213; int ix = (int) x; short int y = ; int iy = (int) y; Decimal Hex Binary x B 6D ix B 6D y C iy FF FF C ! <+"J$&9"%(=&+2('2/..$&(#+(./&%$&(4"#$%$&(?/#/(#63$(! <(/)#+2/9*/..6(3$&=+&2'('4%"($H#$"'4+"(

13 N)22/&6,( LH3/"?4"%:(C&)"*/9"%,(D/'4*(K).$'(! LH3/"?4"%(>$S%S:('5+&#(4"#(#+(4"#A(! [,:AE,70)*t7./:*?0070*! C&)"*/9"%(>$S%S:()"'4%"$?(#+()"'4%"$?('5+&#A(! [,:AE,70&:AE,70)*JA-:*?.7*-.1,2?-70*! l7:1b-*.7a, *! [,:AE,70)*5/0*/67.?3/,*! 8AE,70)*:A5AB?.*-/*5/0*! G/.*:5?BB*,15J7.:*9A7B0:*7p672-70*J7X?LA/1.* C+?/6,(!"#$%$&'(! K$3&$'$"#/9+",()"'4%"$?(/"?('4%"$?(! <+"J$&'4+":(*/'9"%(! LH3/"?4"%:(#&)"*/9"%(! -??49+":("$%/9+":(2).93.4*/9+":('54M4"%(! N)22/&6(

14 T$%/9+",(<+23.$2$"#(E(!"*&$2$"#(! <./42,(e+..+Q4"%(h+.?'(=+&(OR'(<+23.$2$"#( ~x + 1 == -x! <+23.$2$"#(! \J:7.L?3/,)*~x + x == == -1 R* *p* up* #!*!*=*=*!*!*!*=*!* =*!*!* =*=* =*!*=*!*!*!*!*!*!*!*!*! <+23.$#$([&++=i <+23.$2$"#(E(!"*&$2$"#(LH/23.$'( H(V(WjOWc( H(V(k(

15 P"'4%"$?(-??49+"( \67.?,0:)*'*JA-:* f.17*815)*'r!*ja-:* ZA:2?.0*4?..9)*'*JA-:* u! +! v! u + v! UAdd w (u, v)!! N#/"?/&?(-??49+"(e)"*9+"(! +E,/.7:*2?..9*/1-61-*!!23.$2$"#'(\+?)./&(-&4#52$9*( 0 * *M **[S00 ' d3*<*4e *M* 3*R*4**5/0*$ ') I4')/.4Z4"%(>\/#5$2/9*/.A(!"#$%$&(-??49+"(!!"#$%$&(-??49+"(! (#JA-*A,-7E7.:*3<*4*! 4/561-7*-.17*:15* S00 ( d3*<*4e*! _?B17:*A,2.7?:7*BA,7?.B9* ga-x*3*?,0*4)! G/.5:*6B?,?.*:1.K?27* -??`>-(:(*A( *" -"

16 I4')/.4Z4"%(P"'4%"$?(-??49+"(! F&/3'(-&+)"?(! +K*-.17*:15*v*$ ' *! S-*5/:-*/,27* UJ$&l+Q( P-??`>-(:(*A( C&)$(N)2( $ 'R!* \L7.w/g* $ ') =* \+?)./&(N)2( -" *" \/#5$2/9*/.([&+3$&9$'(! \+?)./&(-??49+"(e+&2'(/"(56(,%+'"783-/(! <.+'$?*1,07.*?00A3/,* =**&*[S00 ' d3*<*4e***&**$ ' *O!*! <+22)#/9J$( [S00 ' d3*<*4e**m***[s00 ' d4*<*3e*! -''+*4/9J$( [S00 ' d5<*[s00 ' d3*<*4ee**m***[s00 ' d[s00 ' d5<*3*e<*4e*! k*a:*?00a3l7*a07,3-9* [S00 ' d3*<*=e**m**3*! al7.9*7b757,-*x?:*?00a3l7*4"j$&'$(! ;7-* *[4/56 ') d3*e**m*$ ' *O*3* [S00 ' d3*<*[4/56 ') d3*ee**m**=*

17 CQ+R'(<+23.$2$"#(-??49+"( \67.?,0:)*'*JA-:* f.17*815)*'r!*ja-:* ZA:2?.0*4?..9)*'*JA-:* u! + v! u + v! TAdd w (u, v)!! C-??(/"?(P-??(5/J$(!?$"9*/.(D4#_B$J$.(D$5/J4+&(! 8AE,70*L:W*1,:AE,70*?00A3/,*A,*4)* int s, t, u, v; s = (int) ((unsigned) u + (unsigned) v); t = u + v! xabb*eal7 s == t C-??(UJ$&l+Q(! e)"*9+"/.4#6(! f.17*:15*.7c1a.7:*'r!* JA-:*! Z./6*/y*P8@*! f.7?-*.75?a,a,e*ja-:*?:* $H:*2/56W*A,-7E7.* k*!!!n!* k*!==n=* k*===n=* C&)$(N)2( $ ' O!* $ ')O!* =* k/:\l7.* C-??(K$').#( =!!N!* ===N=* W*=!!N!* O$ ')O! O!*!==N=* W*===N=* O$ ') C7E\L7.*

18 I4')/.4Z4"%(OR'(<+23.$2$"#(-??49+"( T$%UJ$&(! I/.)$'(! (#JA-*-g/H:*2/56W*! l?,e7*k./5*#'*-/*ri*! F&/3'(-&+)"?(! +K*:15*'*$ 'O! S-*5/:-*/,27*! +K*:15*V*O$ 'O! S-*5/:-*/,27* -" C-??`>-(:(*A( *" [+'UJ$&( <5/&/*#$&4Z4"%(C-??(! e)"*9+"/.4#6(! f.17*:15*.7c1a.7:*'r!*ja-:*! f.7?-*.75?a,a,e*ja-:*?:*$h:* 2/56W*A,-7E7.* C-??>-(:(*A( Y*=* v V*=* C7E?3L7*\L7.w/g* V*=* u Y*=* k/:a3l7*\l7.w/g* 2 w >T$%UJ$&A( 2 w >[+'UJ$&A(

19 \/#5$2/9*/.([&+3$&9$'(+=(C-??(!!'+2+&354*(7&+)3(#+()"'4%"$?'(Q4#5(P-??(! fs00 ' d3*<*4e*m**[$fd[s00 ' df$[d3*e<*f$[d4eee*! 8A,27*J/-X*X?L7*A07,32?B*JA-*6?b7.,:*! CQ+R'(<+23.$2$"#(P"?$&(C-??(e+&2'(/(7&+)3(! 4B/:70<*4/551-?3L7<*S::/2A?3L7<*=*A:*?00A3L7*A07,3-9*! al7.9*7b757,-*x?:*?00a3l7*a,l7.:7* \).93.4*/9+"(! <+23)9"%(LH/*#([&+?)*#(+=('_04#(")20$&'(&:(6)! aa-x7.*:ae,70*/.*1,:ae,70*! K/"%$'"! [,:AE,70)*=*z*&*T*6*z*d$ ' *O*!e* $ **M**$ $' *O*$ 'R! *R*!*! [6*-/*$'*JA-:*! fg/h:*2/56b757,-*5a,)*&*t*6**v*do$ 'O! etd$ 'O! O!e**M**O$ $'O$* R*$ 'O!*! [6*-/*$'O!*JA-:*! fg/h:*2/56b757,-*5?p)*&*t*6*z*do$ 'O! e* $ **M**$ $'O$*! [6*-/*$'*JA-:<*J1-*/,B9*K/.*d("#$ ' e $*! \/4"#/4"4"%(LH/*#(K$').#'(! x/1b0*,770*-/*s776*7p6?,0a,e*g/.0*:at7*ga-x*7?2x*6./012-*2/561-70*! Z/,7*A,*:/{g?.7*J9*m?.JA-.?.9*6.72A:A/,n*?.A-X5732*6?2s?E7:*

20 P"'4%"$?(\).93.4*/9+"(4"(<( \67.?,0:)*'*JA-:* f.17*k./012-)*$t'**ja-:* ZA:2?.0*'*JA-:)*'*JA-:* u v! u! * v! UMult w (u, v)!! N#/"?/&?(\).93.4*/9+"(e)"*9+"(! +E,/.7:*XAEX*/.07.*'*JA-:*!!23.$2$"#'(\+?)./&(-&4#52$9*( [P1B- ' d3*<*4e *M *3*** *4**5/0*$ ') <+?$(N$*)&4#6(LH/23.$(mO(! NPT(dGK(.40&/&6(! xa07b9*1:70*baj.?.9*k/.*-.?,:k7..a,e*0?-?*j7-g77,*5?2xa,7:* void* copy_elements(void *ele_src[], int ele_cnt, size_t ele_size); ele_src 2/..+*>$.$n*"#(o($.$n'4Z$A(

21 dgk(<+?$( void* copy_elements(void *ele_src[], int ele_cnt, size_t ele_size) { /* * Allocate buffer for ele_cnt objects, each of ele_size bytes * and copy from locations designated by ele_src */ void *result = malloc(ele_cnt * ele_size); if (result == NULL) /* malloc failed */ return NULL; void *next = result; int i; for (i = 0; i < ele_cnt; i++) { /* Copy object i to destination */ memcpy(next, ele_src[i], ele_size); /* Move pointer to next memory region */ next += ele_size; } return result; } dgk(i)."$&/04.4#6( 2/..+*>$.$n*"#(o($.$n'4Z$A(! F5/#(4=,(! ele_cnt *M*$ $= *R*!*! ele_size* *M*(=jh* * *M*$!$*! SBB/2?3/, *M*}}*! h+q(*/"(!(2/]$(#54'(=)"*9+"('$*)&$i(

22 N4%"$?(\).93.4*/9+"(4"(<( \67.?,0:)*'*JA-:* f.17*k./012-)*$t'**ja-:* ZA:2?.0*'*JA-:)*'*JA-:* u v! u! * v! TMult w (u, v)!! N#/"?/&?(\).93.4*/9+"(e)"*9+"(! +E,/.7:*XAEX*/.07.*'*JA-:*! 8/57*/K*gXA2X*?.7*0Ay7.7,-*K/.*:AE,70* L:W*1,:AE,70*51B36BA2?3/,*! ;/g7.*ja-:*?.7*-x7*:?57* [+Q$&_+=_O(\).93.6(Q4#5(N54M(! U3$&/9+"(! u << k(eal7:*u * 9 \67.?,0:)*'*JA-:* f.17*k./012-)*'r2**ja-:* u 2 k!! LH/23.$'(! u << 3 == u * 8! u << 5 - u << 3 == u * 24! P/:-*5?2XA,7:*:XA{*?,0*?00*K?:-7.*-X?,*51B36B9*! 4/56AB7.*E7,7.?-7:*-XA:*2/07*?1-/5?32?BB9* * u! 2 k! ZA:2?.0*2)*JA-:)*'*JA-:* UMult w (u, 2 k )! TMult w (u, 2 k )! k!

23 <+234.$?(\).93.4*/9+"(<+?$( <(e)"*9+"( int mul12(int x) { return x*12; } <+234.$?(-&4#52$9*(U3$&/9+"'( leal (%eax,%eax,2), %eax sall $2, %eax LH3./"/9+"( t <- x+x*2 return t << 2;! <(*+234.$&(/)#+2/9*/..6(%$"$&/#$'('54Mp/??(*+?$(Q5$"( 2).93.64"%(06(*+"'#/"#( P"'4%"$?([+Q$&_+=_O(G4J4?$(Q4#5(N54M(! q)+9$"#(+=(p"'4%"$?(06([+q$&(+=(o(! u >> k(eal7:**((u / 9 4" ) "! [:7:*B/EA2?B*:XA{* k! u! \67.?,0:)* / 2 k! ZALA:A/,)** l7:1b-)* u / 2 k! ( u / 2 k )*

24 <+234.$?(P"'4%"$?(G4J4'4+"(<+?$( <(e)"*9+"( unsigned udiv8(unsigned x) { return x/8; } <+234.$?(-&4#52$9*(U3$&/9+"'( shrl $3, %eax LH3./"/9+"( # Logical shift return x >> 3;! P'$'(.+%4*/.('54M(=+&()"'4%"$?(! e+&(r/j/(p'$&'((! ;/EA2?B*:XA{*g.Ab7,*?:*>>> N4%"$?([+Q$&_+=_O(G4J4?$(Q4#5(N54M(! q)+9$"#(+=(n4%"$?(06([+q$&(+=(o(! x >> k(eal7:**((x / 9 4" ) "! [:7:*?.A-X5732*:XA{*! l/1,0:*g./,e*0a.723/,*gx7,*u < 0 \67.?,0:)* ZALA:A/,)** l7:1b-)* / x! 2 k! x / 2 k! RoundDown(x / 2 k )! 0 k!

25 <+&&$*#([+Q$&_+=_O(G4J4?$(! q)+9$"#(+=(t$%/9j$(t)20$&(06([+q$&(+=(o(! x?,-***(x / O 4" +((((dl/1,0*f/g?.0*=e*! 4/561-7*?:**(((x+O 4-1)/ O 4" )(! +,*4)*(x + (1<<k)-1) >> </'$(W,(T+(&+)"?4"%( ZALA07,0)* u! +2 k 1! ZALA:/.)** / 2 k! * u / 2 k +! :%+$%'&";+$"'3"(<(01" k! <+&&$*#([+Q$&_+=_O(G4J4?$(><+"#SA( </'$(O,(K+)"?4"%( ZALA07,0)* k! 1 x! +2 k 1! ZALA:/.)** / 2 k! * x / 2 k +! +,2.757,-70*J9*!* :%+$%'&"+))$"="13">'+,"8($-,1" +,2.757,-70*J9*!*

26 <+234.$?(N4%"$?(G4J4'4+"(<+?$( <(e)"*9+"( int idiv8(int x) { return x/8; } <+234.$?(-&4#52$9*(U3$&/9+"'( testl %eax, %eax js L4 L3: sarl $3, %eax ret L4: addl $7, %eax jmp L3 LH3./"/9+"( if x < 0 x += 7; # Arithmetic shift return x >> 3;! P'$'(/&4#52$9*('54M(=+&(4"#(! e+&(r/j/(p'$&'((! S.A-XW*:XA{*g.Ab7,*?:*>> -&4#52$9*,(D/'4*(K).$'(! -??49+",(! [,:AE,70&:AE,70)*C/.5?B*?00A3/,*K/BB/g70*J9*-.1,2?-7<* :?57*/67.?3/,*/,*JA-*B7L7B*! [,:AE,70)*?00A3/,*5/0*$ g*! P?-X75?32?B*?00A3/,*R*6/::AJB7*:1J-.?23/,*/K*$g*! 8AE,70)*5/0AI70*?00A3/,*5/0*$ g* d.7:1b-*a,*6./67.*.?,e7e *! P?-X75?32?B*?00A3/,*R*6/::AJB7*?00A3/,*/.*:1J-.?23/,*/K*$g*! \).93.4*/9+",(! [,:AE,70&:AE,70)*C/.5?B*51B36BA2?3/,*K/BB/g70*J9*-.1,2?-7<* :?57*/67.?3/,*/,*JA-*B7L7B*! [,:AE,70)*51B36BA2?3/,*5/0*$ g*! 8AE,70)*5/0AI70*51B36BA2?3/,*5/0*$ g* d.7:1b-*a,*6./67.*.?,e7e *

27 -&4#52$9*,(D/'4*(K).$'(! P"'4%"$?(4"#':(OR'(*+23.$2$"#(4"#'(/&$(4'+2+&354*(&4"%',( 4'+2+&354'2(V(*/'9"%(! B$M('54M(! [,:AE,70&:AE,70)*51B36BA2?3/,*J9*$ s*! SBg?9:*B/EA2?B*:XA{*! K4%5#('54M(! [,:AE,70)*B/EA2?B*:XA{<*0AL*d0ALA:A/,*R*./1,0*-/*t7./e*J9*$ s*! 8AE,70)*?.A-X5732*:XA{*! k/:a3l7*,15j7.:)*0al*d0ala:a/,*r*./1,0*-/*t7./e*j9*$ s*! C7E?3L7*,15J7.:)*0AL*d0ALA:A/,*R*./1,0*?g?9*K./5*t7./e*J9*$ s* [:7*JA?:A,E*-/*Ip* C+?/6,(!"#$%$&'(! K$3&$'$"#/9+",()"'4%"$?(/"?('4%"$?(! <+"J$&'4+":(*/'9"%(! LH3/"?4"%:(#&)"*/9"%(! -??49+":("$%/9+":(2).93.4*/9+":('54M4"%(! N)22/&6(

28 [&+3$&9$'(+=(P"'4%"$?(-&4#52$9*(! P"'4%"$?(\).93.4*/9+"(Q4#5(-??49+"(e+&2'( <+22)#/9J$(K4"%(! S00A3/,*A:*2/551-?3L7*E./16*! 4B/:70*1,07.*51B36BA2?3/,* =**&*[P1B- ' d3*<*4e**&**$ ' *O!*! P1B36BA2?3/,*4/551-?3L7* [P1B- ' d3*<*4e**m***[p1b- ' d4*<*3e*! P1B36BA2?3/,*A:*S::/2A?3L7* [P1B- ' d5<*[p1b- ' d3*<*4ee**m***[p1b- ' d[p1b- ' d5<*3*e<*4e*!!*a:*51b36ba2?3l7*a07,3-9* [P1B- ' d3*<*!e**m**3*! P1B36BA2?3/,*0A:-.AJ1-7:*/L7.*?003/,* [P1B- ' d5<*[s00 ' d3*<*4ee**m***[s00 ' d[p1b- ' d5<*3*e<*[p1b- ' d5<*4ee* [&+3$&9$'(+=(CQ+R'(<+23S(-&4#52$9*(!!'+2+&354*(-.%$0&/'(! [,:AE,70*51B36BA2?3/,*?,0*?00A3/,*! f.1,2?3,e*-/*'*ja-:*! fg/h:*2/56b757,-*51b36ba2?3/,*?,0*?00a3/,*! f.1,2?3,e*-/*'*ja-:*! D+#5(e+&2(K4"%'(! +:/5/.6XA2*-/*.A,E*/K*A,-7E7.:*5/0*$ ' *! +,-7E7.:*/J79*/.07.A,E*6./67.37:<*7WEW<* 3*Y*= *! *3*R*4*Y*4* 3*Y*=<*4*Y*= *! *3* *4*Y*=*! fx7:7*6./67.37:*?.7*,/-*/j7970*j9*-g/h:*2/56w*?.a-x5732* ("%& + 1 == ("#$ * == d!h#ja-*g/.0:e*

29 a?:9*-/*5?s7*5a:-?s7:* unsigned i; for (i = cnt-2; i >= 0; i--) a[i] += a[i+1];! 4?,*J7*L7.9*:1J-B7* #define DELTA sizeof(int) int i; for (i = CNT; i-delta >= 0; i-= DELTA)...!?3(P'$(F5$"([$&=+&24"%(\+?)./&(-&4#52$9*(! P1B36.72A:A/,*?.A-X5732*!?3(P'$(F5$"(P'4"%(D4#'(#+(K$3&$'$"#(N$#'(! ;/EA2?B*.AEX-*:XA{<*,/*:AE,*7p-7,:A/,*!"#$%$&(<([)ZZ.$'(!"49/.4Z/9+"( 4"#(H(V(=++>As( 4"#(6(V(0/&>As( )"'4%"$?()H(V(Hs( )"'4%"$?()6(V(6s( x < 0! ((x*2) < 0) ux >= 0 x & 7 == 7! (x<<30) < 0 ux > -1 x > y! -x < -y x * x >= 0 x > 0 && y > 0! x + y > 0 x >= 0! -x <= 0 x <= 0! -x >= 0 (x -x)>>31 == -1 ux >> 3 == ux/8 x >> 3 == x/8 x & (x-1)!= 0(

Systems Programming and Computer Architecture ( )

Systems Group Department of Computer Science ETH Zürich Systems Programming and Computer Architecture (252-0061-00) Timothy Roscoe Herbstsemester 2016 1 3: Integers in C Computer Architecture and Systems