src/compiler/dmd/trace.d

   1
   2 /* Trace dynamic profiler.
   3  * For use with the Digital Mars DMD compiler.
   4  * Copyright (C) 1995-2006 by Digital Mars
   5  * All Rights Reserved
   6  * Written by Walter Bright
   7  * www.digitalmars.com
   8  */
   9
  10 /*
  11  *  Modified by Sean Kelly for use with the D Runtime Project
  12  */
  13
  14 module rt.trace;
  15
  16 private
  17 {
  18     import util.string;
  19     import core.stdc.ctype;
  20     import core.stdc.stdio;
  21     import core.stdc.string;
  22     import core.stdc.stdlib;
  23 }
  24
  25 extern (C):
  26
  27 char* unmangle_ident(char*);    // from DMC++ runtime library
  28
  29 alias long timer_t;
  30
  31 /////////////////////////////////////
  32 //
  33
  34 struct SymPair
  35 {
  36     SymPair* next;
  37     Symbol* sym;        // function that is called
  38     uint count;         // number of times sym is called
  39 }
  40
  41 /////////////////////////////////////
  42 // A Symbol for each function name.
  43
  44 struct Symbol
  45 {
  46         Symbol* Sl, Sr;         // left, right children
  47         SymPair* Sfanin;        // list of calling functions
  48         SymPair* Sfanout;       // list of called functions
  49         timer_t totaltime;      // aggregate time
  50         timer_t functime;       // time excluding subfunction calls
  51         ubyte Sflags;
  52         char[] Sident;          // name of symbol
  53 }
  54
  55 const ubyte SFvisited = 1;      // visited
  56
  57 static Symbol* root;            // root of symbol table
  58
  59 //////////////////////////////////
  60 // Build a linked list of these.
  61
  62 struct Stack
  63 {
  64     Stack* prev;
  65     Symbol* sym;
  66     timer_t starttime;          // time when function was entered
  67     timer_t ohd;                // overhead of all the bookkeeping code
  68     timer_t subtime;            // time used by all subfunctions
  69 }
  70
  71 static Stack* stack_freelist;
  72 static Stack* trace_tos;                // top of stack
  73 static int trace_inited;                // !=0 if initialized
  74 static timer_t trace_ohd;
  75
  76 static Symbol** psymbols;
  77 static uint nsymbols;           // number of symbols
  78
  79 static string trace_logfilename = "trace.log";
  80 static FILE* fplog;
  81
  82 static string trace_deffilename = "trace.def";
  83 static FILE* fpdef;
  84
  85
  86 ////////////////////////////////////////
  87 // Set file name for output.
  88 // A file name of "" means write results to stdout.
  89 // Returns:
  90 //      0       success
  91 //      !=0     failure
  92
  93 int trace_setlogfilename(string name)
  94 {
  95     trace_logfilename = name;
  96     return 0;
  97 }
  98
  99 ////////////////////////////////////////
 100 // Set file name for output.
 101 // A file name of "" means write results to stdout.
 102 // Returns:
 103 //      0       success
 104 //      !=0     failure
 105
 106 int trace_setdeffilename(string name)
 107 {
 108     trace_deffilename = name;
 109     return 0;
 110 }
 111
 112 ////////////////////////////////////////
 113 // Output optimal function link order.
 114
 115 static void trace_order(Symbol *s)
 116 {
 117     while (s)
 118     {
 119         trace_place(s,0);
 120         if (s.Sl)
 121             trace_order(s.Sl);
 122         s = s.Sr;
 123     }
 124 }
 125
 126 //////////////////////////////////////////////
 127 //
 128
 129 static Stack* stack_malloc()
 130 {   Stack *s;
 131
 132     if (stack_freelist)
 133     {   s = stack_freelist;
 134         stack_freelist = s.prev;
 135     }
 136     else
 137         s = cast(Stack *)trace_malloc(Stack.sizeof);
 138     return s;
 139 }
 140
 141 //////////////////////////////////////////////
 142 //
 143
 144 static void stack_free(Stack *s)
 145 {
 146     s.prev = stack_freelist;
 147     stack_freelist = s;
 148 }
 149
 150 //////////////////////////////////////
 151 // Qsort() comparison routine for array of pointers to SymPair's.
 152
 153 static int sympair_cmp(in void* e1, in void* e2)
 154 {   SymPair** psp1;
 155     SymPair** psp2;
 156
 157     psp1 = cast(SymPair**)e1;
 158     psp2 = cast(SymPair**)e2;
 159
 160     return (*psp2).count - (*psp1).count;
 161 }
 162
 163 //////////////////////////////////////
 164 // Place symbol s, and then place any fan ins or fan outs with
 165 // counts greater than count.
 166
 167 static void trace_place(Symbol *s, uint count)
 168 {   SymPair* sp;
 169     SymPair** base;
 170
 171     if (!(s.Sflags & SFvisited))
 172     {   size_t num;
 173         uint u;
 174
 175         //printf("\t%.*s\t%u\n", s.Sident, count);
 176         fprintf(fpdef,"\t%.*s\n", s.Sident);
 177         s.Sflags |= SFvisited;
 178
 179         // Compute number of items in array
 180         num = 0;
 181         for (sp = s.Sfanin; sp; sp = sp.next)
 182             num++;
 183         for (sp = s.Sfanout; sp; sp = sp.next)
 184             num++;
 185         if (!num)
 186             return;
 187
 188         // Allocate and fill array
 189         base = cast(SymPair**)trace_malloc(SymPair.sizeof * num);
 190         u = 0;
 191         for (sp = s.Sfanin; sp; sp = sp.next)
 192             base[u++] = sp;
 193         for (sp = s.Sfanout; sp; sp = sp.next)
 194             base[u++] = sp;
 195
 196         // Sort array
 197         qsort(base, num, (SymPair *).sizeof, &sympair_cmp);
 198
 199         //for (u = 0; u < num; u++)
 200             //printf("\t\t%.*s\t%u\n", base[u].sym.Sident, base[u].count);
 201
 202         // Place symbols
 203         for (u = 0; u < num; u++)
 204         {
 205             if (base[u].count >= count)
 206             {   uint u2;
 207                 uint c2;
 208
 209                 u2 = (u + 1 < num) ? u + 1 : u;
 210                 c2 = base[u2].count;
 211                 if (c2 < count)
 212                     c2 = count;
 213                 trace_place(base[u].sym,c2);
 214             }
 215             else
 216                 break;
 217         }
 218
 219         // Clean up
 220         trace_free(base);
 221     }
 222 }
 223
 224 /////////////////////////////////////
 225 // Initialize and terminate.
 226
 227 static this()
 228 {
 229     trace_init();
 230 }
 231
 232 static ~this()
 233 {
 234     trace_term();
 235 }
 236
 237 ///////////////////////////////////
 238 // Report results.
 239 // Also compute nsymbols.
 240
 241 static void trace_report(Symbol* s)
 242 {   SymPair* sp;
 243     uint count;
 244
 245     //printf("trace_report()\n");
 246     while (s)
 247     {   nsymbols++;
 248         if (s.Sl)
 249             trace_report(s.Sl);
 250         fprintf(fplog,"------------------\n");
 251         count = 0;
 252         for (sp = s.Sfanin; sp; sp = sp.next)
 253         {
 254             fprintf(fplog,"\t%5d\t%.*s\n", sp.count, sp.sym.Sident);
 255             count += sp.count;
 256         }
 257         fprintf(fplog,"%.*s\t%u\t%lld\t%lld\n",s.Sident,count,s.totaltime,s.functime);
 258         for (sp = s.Sfanout; sp; sp = sp.next)
 259         {
 260             fprintf(fplog,"\t%5d\t%.*s\n",sp.count,sp.sym.Sident);
 261         }
 262         s = s.Sr;
 263     }
 264 }
 265
 266 ////////////////////////////////////
 267 // Allocate and fill array of symbols.
 268
 269 static void trace_array(Symbol *s)
 270 {   static uint u;
 271
 272     if (!psymbols)
 273     {   u = 0;
 274         psymbols = cast(Symbol **)trace_malloc((Symbol *).sizeof * nsymbols);
 275     }
 276     while (s)
 277     {
 278         psymbols[u++] = s;
 279         trace_array(s.Sl);
 280         s = s.Sr;
 281     }
 282 }
 283
 284
 285 //////////////////////////////////////
 286 // Qsort() comparison routine for array of pointers to Symbol's.
 287
 288 static int symbol_cmp(in void* e1, in void* e2)
 289 {   Symbol** ps1;
 290     Symbol** ps2;
 291     timer_t diff;
 292
 293     ps1 = cast(Symbol **)e1;
 294     ps2 = cast(Symbol **)e2;
 295
 296     diff = (*ps2).functime - (*ps1).functime;
 297     return (diff == 0) ? 0 : ((diff > 0) ? 1 : -1);
 298 }
 299
 300
 301 ///////////////////////////////////
 302 // Report function timings
 303
 304 static void trace_times(Symbol* root)
 305 {   uint u;
 306     timer_t freq;
 307
 308     // Sort array
 309     qsort(psymbols, nsymbols, (Symbol *).sizeof, &symbol_cmp);
 310
 311     // Print array
 312     QueryPerformanceFrequency(&freq);
 313     fprintf(fplog,"\n======== Timer Is %lld Ticks/Sec, Times are in Microsecs ========\n\n",freq);
 314     fprintf(fplog,"  Num          Tree        Func        Per\n");
 315     fprintf(fplog,"  Calls        Time        Time        Call\n\n");
 316     for (u = 0; u < nsymbols; u++)
 317     {   Symbol* s = psymbols[u];
 318         timer_t tl,tr;
 319         timer_t fl,fr;
 320         timer_t pl,pr;
 321         timer_t percall;
 322         SymPair* sp;
 323         uint calls;
 324         char[] id;
 325
 326         version (Windows)
 327         {
 328             char* p = (s.Sident ~ '\0').ptr;
 329             p = unmangle_ident(p);
 330             if (p)
 331                 id = p[0 .. strlen(p)];
 332         }
 333         if (!id)
 334             id = s.Sident;
 335         calls = 0;
 336         for (sp = s.Sfanin; sp; sp = sp.next)
 337             calls += sp.count;
 338         if (calls == 0)
 339             calls = 1;
 340
 341 version (all)
 342 {
 343         tl = (s.totaltime * 1000000) / freq;
 344         fl = (s.functime  * 1000000) / freq;
 345         percall = s.functime / calls;
 346         pl = (s.functime * 1000000) / calls / freq;
 347
 348         fprintf(fplog,"%7d%12lld%12lld%12lld     %.*s\n",
 349             calls,tl,fl,pl,id);
 350 }
 351 else
 352 {
 353         tl = s.totaltime / freq;
 354         tr = ((s.totaltime - tl * freq) * 10000000) / freq;
 355
 356         fl = s.functime  / freq;
 357         fr = ((s.functime  - fl * freq) * 10000000) / freq;
 358
 359         percall = s.functime / calls;
 360         pl = percall  / freq;
 361         pr = ((percall  - pl * freq) * 10000000) / freq;
 362
 363         fprintf(fplog,"%7d\t%3lld.%07lld\t%3lld.%07lld\t%3lld.%07lld\t%.*s\n",
 364             calls,tl,tr,fl,fr,pl,pr,id);
 365 }
 366         if (id !is s.Sident)
 367             free(id.ptr);
 368     }
 369 }
 370
 371
 372 ///////////////////////////////////
 373 // Initialize.
 374
 375 static void trace_init()
 376 {
 377     if (!trace_inited)
 378     {
 379         trace_inited = 1;
 380
 381         {   // See if we can determine the overhead.
 382             uint u;
 383             timer_t starttime;
 384             timer_t endtime;
 385             Stack *st;
 386
 387             st = trace_tos;
 388             trace_tos = null;
 389             QueryPerformanceCounter(&starttime);
 390             for (u = 0; u < 100; u++)
 391             {
 392                 asm
 393                 {
 394                     call _trace_pro_n   ;
 395                     db   0              ;
 396                     call _trace_epi_n   ;
 397                 }
 398             }
 399             QueryPerformanceCounter(&endtime);
 400             trace_ohd = (endtime - starttime) / u;
 401             //printf("trace_ohd = %lld\n",trace_ohd);
 402             if (trace_ohd > 0)
 403                 trace_ohd--;            // round down
 404             trace_tos = st;
 405         }
 406     }
 407 }
 408
 409 /////////////////////////////////
 410 // Terminate.
 411
 412 void trace_term()
 413 {
 414     //printf("trace_term()\n");
 415     if (trace_inited == 1)
 416     {   Stack *n;
 417
 418         trace_inited = 2;
 419
 420         // Free remainder of the stack
 421         while (trace_tos)
 422         {
 423             n = trace_tos.prev;
 424             stack_free(trace_tos);
 425             trace_tos = n;
 426         }
 427
 428         while (stack_freelist)
 429         {
 430             n = stack_freelist.prev;
 431             stack_free(stack_freelist);
 432             stack_freelist = n;
 433         }
 434
 435         // Merge in data from any existing file
 436         trace_merge();
 437
 438         // Report results
 439         fplog = fopen(trace_logfilename.ptr, "w");
 440         if (fplog)
 441         {   nsymbols = 0;
 442             trace_report(root);
 443             trace_array(root);
 444             trace_times(root);
 445             fclose(fplog);
 446         }
 447
 448         // Output function link order
 449         fpdef = fopen(trace_deffilename.ptr,"w");
 450         if (fpdef)
 451         {   fprintf(fpdef,"\nFUNCTIONS\n");
 452             trace_order(root);
 453             fclose(fpdef);
 454         }
 455
 456         trace_free(psymbols);
 457         psymbols = null;
 458     }
 459 }
 460
 461 /////////////////////////////////
 462 // Our storage allocator.
 463
 464 static void *trace_malloc(size_t nbytes)
 465 {   void *p;
 466
 467     p = malloc(nbytes);
 468     if (!p)
 469         exit(EXIT_FAILURE);
 470     return p;
 471 }
 472
 473 static void trace_free(void *p)
 474 {
 475     free(p);
 476 }
 477
 478 //////////////////////////////////////////////
 479 //
 480
 481 static Symbol* trace_addsym(char[] id)
 482 {
 483     Symbol** parent;
 484     Symbol* rover;
 485     Symbol* s;
 486     int cmp;
 487     char c;
 488
 489     //printf("trace_addsym('%s',%d)\n",p,len);
 490     parent = &root;
 491     rover = *parent;
 492     while (rover !is null)               // while we haven't run out of tree
 493     {
 494         cmp = dstrcmp(id, rover.Sident);
 495         if (cmp == 0)
 496         {
 497             return rover;
 498         }
 499         parent = (cmp < 0) ?            /* if we go down left side      */
 500             &(rover.Sl) :               /* then get left child          */
 501             &(rover.Sr);                /* else get right child         */
 502         rover = *parent;                /* get child                    */
 503     }
 504     /* not in table, so insert into table       */
 505     s = cast(Symbol *)trace_malloc(Symbol.sizeof);
 506     memset(s,0,Symbol.sizeof);
 507     s.Sident = id;
 508     *parent = s;                        // link new symbol into tree
 509     return s;
 510 }
 511
 512 /***********************************
 513  * Add symbol s with count to SymPair list.
 514  */
 515
 516 static void trace_sympair_add(SymPair** psp, Symbol* s, uint count)
 517 {   SymPair* sp;
 518
 519     for (; 1; psp = &sp.next)
 520     {
 521         sp = *psp;
 522         if (!sp)
 523         {
 524             sp = cast(SymPair *)trace_malloc(SymPair.sizeof);
 525             sp.sym = s;
 526             sp.count = 0;
 527             sp.next = null;
 528             *psp = sp;
 529             break;
 530         }
 531         else if (sp.sym == s)
 532         {
 533             break;
 534         }
 535     }
 536     sp.count += count;
 537 }
 538
 539 //////////////////////////////////////////////
 540 //
 541
 542 static void trace_pro(char[] id)
 543 {
 544     Stack* n;
 545     Symbol* s;
 546     timer_t starttime;
 547     timer_t t;
 548
 549     QueryPerformanceCounter(&starttime);
 550     if (id.length == 0)
 551         return;
 552     if (!trace_inited)
 553         trace_init();                   // initialize package
 554     n = stack_malloc();
 555     n.prev = trace_tos;
 556     trace_tos = n;
 557     s = trace_addsym(id);
 558     trace_tos.sym = s;
 559     if (trace_tos.prev)
 560     {
 561         Symbol* prev;
 562         int i;
 563
 564         // Accumulate Sfanout and Sfanin
 565         prev = trace_tos.prev.sym;
 566         trace_sympair_add(&prev.Sfanout,s,1);
 567         trace_sympair_add(&s.Sfanin,prev,1);
 568     }
 569     QueryPerformanceCounter(&t);
 570     trace_tos.starttime = starttime;
 571     trace_tos.ohd = trace_ohd + t - starttime;
 572     trace_tos.subtime = 0;
 573     //printf("trace_tos.ohd=%lld, trace_ohd=%lld + t=%lld - starttime=%lld\n",
 574     //  trace_tos.ohd,trace_ohd,t,starttime);
 575 }
 576
 577 /////////////////////////////////////////
 578 //
 579
 580 static void trace_epi()
 581 {   Stack* n;
 582     timer_t endtime;
 583     timer_t t;
 584     timer_t ohd;
 585
 586     //printf("trace_epi()\n");
 587     if (trace_tos)
 588     {
 589         timer_t starttime;
 590         timer_t totaltime;
 591
 592         QueryPerformanceCounter(&endtime);
 593         starttime = trace_tos.starttime;
 594         totaltime = endtime - starttime - trace_tos.ohd;
 595         if (totaltime < 0)
 596         {   //printf("endtime=%lld - starttime=%lld - trace_tos.ohd=%lld < 0\n",
 597             //  endtime,starttime,trace_tos.ohd);
 598             totaltime = 0;              // round off error, just make it 0
 599         }
 600
 601         // totaltime is time spent in this function + all time spent in
 602         // subfunctions - bookkeeping overhead.
 603         trace_tos.sym.totaltime += totaltime;
 604
 605         //if (totaltime < trace_tos.subtime)
 606         //printf("totaltime=%lld < trace_tos.subtime=%lld\n",totaltime,trace_tos.subtime);
 607         trace_tos.sym.functime  += totaltime - trace_tos.subtime;
 608         ohd = trace_tos.ohd;
 609         n = trace_tos.prev;
 610         stack_free(trace_tos);
 611         trace_tos = n;
 612         if (n)
 613         {   QueryPerformanceCounter(&t);
 614             n.ohd += ohd + t - endtime;
 615             n.subtime += totaltime;
 616             //printf("n.ohd = %lld\n",n.ohd);
 617         }
 618     }
 619 }
 620
 621
 622 ////////////////////////// FILE INTERFACE /////////////////////////
 623
 624 /////////////////////////////////////
 625 // Read line from file fp.
 626 // Returns:
 627 //      trace_malloc'd line buffer
 628 //      null if end of file
 629
 630 static char* trace_readline(FILE* fp)
 631 {   int c;
 632     int dim;
 633     int i;
 634     char *buf;
 635
 636     //printf("trace_readline(%p)\n", fp);
 637     i = 0;
 638     dim = 0;
 639     buf = null;
 640     while (1)
 641     {
 642         if (i == dim)
 643         {   char *p;
 644
 645             dim += 80;
 646             p = cast(char *)trace_malloc(dim);
 647             memcpy(p,buf,i);
 648             trace_free(buf);
 649             buf = p;
 650         }
 651         c = fgetc(fp);
 652         switch (c)
 653         {
 654             case EOF:
 655                 if (i == 0)
 656                 {   trace_free(buf);
 657                     return null;
 658                 }
 659             case '\n':
 660                 goto L1;
 661             default:
 662                 break;
 663         }
 664         buf[i] = cast(char)c;
 665         i++;
 666     }
 667 L1:
 668     buf[i] = 0;
 669     //printf("line '%s'\n",buf);
 670     return buf;
 671 }
 672
 673 //////////////////////////////////////
 674 // Skip space
 675
 676 static char *skipspace(char *p)
 677 {
 678     while (isspace(*p))
 679         p++;
 680     return p;
 681 }
 682
 683 ////////////////////////////////////////////////////////
 684 // Merge in profiling data from existing file.
 685
 686 static void trace_merge()
 687 {   FILE *fp;
 688     char *buf;
 689     char *p;
 690     uint count;
 691     Symbol *s;
 692     SymPair *sfanin;
 693     SymPair **psp;
 694
 695     if (trace_logfilename && (fp = fopen(trace_logfilename.ptr,"r")) !is null)
 696     {
 697         buf = null;
 698         sfanin = null;
 699         psp = &sfanin;
 700         while (1)
 701         {
 702             trace_free(buf);
 703             buf = trace_readline(fp);
 704             if (!buf)
 705                 break;
 706             switch (*buf)
 707             {
 708                 case '=':               // ignore rest of file
 709                     trace_free(buf);
 710                     goto L1;
 711                 case ' ':
 712                 case '\t':              // fan in or fan out line
 713                     count = strtoul(buf,&p,10);
 714                     if (p == buf)       // if invalid conversion
 715                         continue;
 716                     p = skipspace(p);
 717                     if (!*p)
 718                         continue;
 719                     s = trace_addsym(p[0 .. strlen(p)]);
 720                     trace_sympair_add(psp,s,count);
 721                     break;
 722                 default:
 723                     if (!isalpha(*buf))
 724                     {
 725                         if (!sfanin)
 726                             psp = &sfanin;
 727                         continue;       // regard unrecognized line as separator
 728                     }
 729                 case '?':
 730                 case '_':
 731                 case '$':
 732                 case '@':
 733                     p = buf;
 734                     while (isgraph(*p))
 735                         p++;
 736                     *p = 0;
 737                     //printf("trace_addsym('%s')\n",buf);
 738                     s = trace_addsym(buf[0 .. strlen(buf)]);
 739                     if (s.Sfanin)
 740                     {   SymPair *sp;
 741
 742                         for (; sfanin; sfanin = sp)
 743                         {
 744                             trace_sympair_add(&s.Sfanin,sfanin.sym,sfanin.count);
 745                             sp = sfanin.next;
 746                             trace_free(sfanin);
 747                         }
 748                     }
 749                     else
 750                     {   s.Sfanin = sfanin;
 751                     }
 752                     sfanin = null;
 753                     psp = &s.Sfanout;
 754
 755                     {   timer_t t;
 756
 757                         p++;
 758                         count = strtoul(p,&p,10);
 759                         t = cast(long)strtoull(p,&p,10);
 760                         s.totaltime += t;
 761                         t = cast(long)strtoull(p,&p,10);
 762                         s.functime += t;
 763                     }
 764                     break;
 765             }
 766         }
 767     L1:
 768         fclose(fp);
 769     }
 770 }
 771
 772 ////////////////////////// COMPILER INTERFACE /////////////////////
 773
 774 /////////////////////////////////////////////
 775 // Function called by trace code in function prolog.
 776
 777 void _trace_pro_n()
 778 {
 779     /* Length of string is either:
 780      *  db      length
 781      *  ascii   string
 782      * or:
 783      *  db      0x0FF
 784      *  db      0
 785      *  dw      length
 786      *  ascii   string
 787      */
 788
 789     asm
 790     {   naked                           ;
 791         pushad                          ;
 792         mov     ECX,8*4[ESP]            ;
 793         xor     EAX,EAX                 ;
 794         mov     AL,[ECX]                ;
 795         cmp     AL,0xFF                 ;
 796         jne     L1                      ;
 797         cmp     byte ptr 1[ECX],0       ;
 798         jne     L1                      ;
 799         mov     AX,2[ECX]               ;
 800         add     8*4[ESP],3              ;
 801         add     ECX,3                   ;
 802     L1: inc     EAX                     ;
 803         inc     ECX                     ;
 804         add     8*4[ESP],EAX            ;
 805         dec     EAX                     ;
 806         push    ECX                     ;
 807         push    EAX                     ;
 808         call    trace_pro               ;
 809         add     ESP,8                   ;
 810         popad                           ;
 811         ret                             ;
 812     }
 813 }
 814
 815 /////////////////////////////////////////////
 816 // Function called by trace code in function epilog.
 817
 818
 819 void _trace_epi_n()
 820 {
 821     asm
 822     {   naked   ;
 823         pushad  ;
 824     }
 825     trace_epi();
 826     asm
 827     {
 828         popad   ;
 829         ret     ;
 830     }
 831 }
 832
 833
 834 version (Windows)
 835 {
 836     extern (Windows)
 837     {
 838         export int QueryPerformanceCounter(timer_t *);
 839         export int QueryPerformanceFrequency(timer_t *);
 840     }
 841 }
 842 else version (X86)
 843 {
 844     extern (D)
 845     {
 846         void QueryPerformanceCounter(timer_t* ctr)
 847         {
 848             asm
 849             {   naked                   ;
 850                 mov       ECX,EAX       ;
 851                 rdtsc                   ;
 852                 mov   [ECX],EAX         ;
 853                 mov   4[ECX],EDX        ;
 854                 ret                     ;
 855             }
 856         }
 857
 858         void QueryPerformanceFrequency(timer_t* freq)
 859         {
 860             *freq = 3579545;
 861         }
 862     }
 863 }
 864 else
 865 {
 866     static assert(0);
 867 }