mdw@git.distorted.org.uk Git - mLib/blob - test/tvec-bench.c

   1 /* -*-c-*-
   2  *
   3  * Benchmarking in the test-vector framework
   4  *
   5  * (c) 2023 Straylight/Edgeware
   6  */
   7
   8 /*----- Licensing notice --------------------------------------------------*
   9  *
  10  * This file is part of the mLib utilities library.
  11  *
  12  * mLib is free software: you can redistribute it and/or modify it under
  13  * the terms of the GNU Library General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or (at
  15  * your option) any later version.
  16  *
  17  * mLib is distributed in the hope that it will be useful, but WITHOUT
  18  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  19  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public
  20  * License for more details.
  21  *
  22  * You should have received a copy of the GNU Library General Public
  23  * License along with mLib.  If not, write to the Free Software
  24  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  25  * USA.
  26  */
  27
  28 /*----- Header files ------------------------------------------------------*/
  29
  30 #include "bench.h"
  31 #include "tvec.h"
  32
  33 /*----- Data structures ---------------------------------------------------*/
  34
  35 struct benchrun {
  36   struct tvec_state *tv;                /* test vector state */
  37   const struct tvec_env *env;           /* subordinate environment */
  38   void *ctx;                            /* subordinate env's context */
  39   unsigned long *n;                     /* iteration count address */
  40   const struct tvec_reg *in; struct tvec_reg *out; /* register vectors */
  41   tvec_testfn *fn;                      /* test function to run */
  42 };
  43
  44 /*----- Global variables --------------------------------------------------*/
  45
  46 struct bench_state *tvec_benchstate;    /* common benchmarking state */
  47
  48 /*----- Utilities ---------------------------------------------------------*/
  49
  50 /* --- @normalize@ --- *
  51  *
  52  * Arguments:   @double *x_inout@ = address of a value to normalize
  53  *              @const char **unit_out@ = address to store unit prefix
  54  *              @double scale@ = scale factor for unit steps
  55  *
  56  * Returns:     ---
  57  *
  58  * Use:         Adjust @*x_inout@ by a power of @scale@, and set @*unit_out@
  59  *              so that printing the two reflects the original value with an
  60  *              appropriate SI unit scaling.  The @scale@ should be 1024 for
  61  *              binary quantities, most notably memory sizes, or 1000 for
  62  *              other quantities.
  63  */
  64
  65 static void normalize(double *x_inout, const char **unit_out, double scale)
  66 {
  67   static const char
  68     *const nothing = "",
  69     *const big[] = { "k", "M", "G", "T", "P", "E", 0 },
  70     *const little[] = { "m", "µ", "n", "p", "f", "a", 0 };
  71   const char *const *u;
  72   double x = *x_inout;
  73
  74   if (x < 1)
  75     for (u = little, x *= scale; x < 1 && u[1]; u++, x *= scale);
  76   else if (x >= scale)
  77     for (u = big, x /= scale; x >= scale && u[1]; u++, x /= scale);
  78   else
  79     u = &nothing;
  80
  81   *x_inout = x; *unit_out = *u;
  82 }
  83
  84 /* --- @benchloop_...@ --- *
  85  *
  86  * Arguments:   @unsigned long n@ = iteration count
  87  *              @void *ctx@ = benchmark running context
  88  *
  89  * Returns:     ---
  90  *
  91  * Use:         Run various kinds of benchmarking loops.
  92  *
  93  *                * The @..._outer_...@ functions call the underlying
  94  *                  function @n@ times in a loop; by contrast, the
  95  *                  @..._inner_...@ functions set a register value to the
  96  *                  chosen iteration count and expect the underlying function
  97  *                  to perform the loop itself.
  98  *
  99  *                * The @..._direct@ functions just call the underlying test
 100  *                  function directly (though still through an `indirect
 101  *                  jump' instruction); by contrast, the @..._indirect@
 102  *                  functions invoke a subsidiary environment's @run@
 103  *                  function, which adds additional overhead.
 104  */
 105
 106 static void benchloop_outer_direct(unsigned long n, void *ctx)
 107 {
 108   struct benchrun *r = ctx;
 109   tvec_testfn *fn = r->fn; void *tctx = r->ctx;
 110   const struct tvec_reg *in = r->in; struct tvec_reg *out = r->out;
 111
 112   while (n--) fn(in, out, tctx);
 113 }
 114
 115 static void benchloop_inner_direct(unsigned long n, void *ctx)
 116   { struct benchrun *r = ctx; *r->n = n; r->fn(r->in, r->out, r->ctx); }
 117
 118 static void benchloop_outer_indirect(unsigned long n, void *ctx)
 119 {
 120   struct benchrun *r = ctx;
 121   struct tvec_state *tv = r->tv;
 122   void (*run)(struct tvec_state *, tvec_testfn, void *) = r->env->run;
 123   tvec_testfn *fn = r->fn; void *tctx = r->ctx;
 124
 125   while (n--) run(tv, fn, tctx);
 126 }
 127
 128 static void benchloop_inner_indirect(unsigned long n, void *ctx)
 129   { struct benchrun *r = ctx; *r->n = n; r->env->run(r->tv, r->fn, r->ctx); }
 130
 131 /*----- Output utilities --------------------------------------------------*/
 132
 133 /* --- @tvec_benchreport@ --- *
 134  *
 135  * Arguments:   @const struct gprintf_ops *gops@ = print operations
 136  *              @void *go@ = print destination
 137  *              @unsigned unit@ = the unit being measured (~TVBU_...@)
 138  *              @const struct bench_timing *tm@ = the benchmark result
 139  *
 140  * Returns:     ---
 141  *
 142  * Use:         Formats a report about the benchmark performance.  This
 143  *              function is intended to be called on by an output
 144  *              @ebench@ function.
 145  */
 146
 147 void tvec_benchreport(const struct gprintf_ops *gops, void *go,
 148                       unsigned unit, const struct bench_timing *tm)
 149 {
 150   double scale, x, n = tm->n;
 151   const char *u, *what, *whats;
 152
 153   if (!tm) { gprintf(gops, go, "benchmark FAILED"); return; }
 154
 155   assert(tm->f&BTF_TIMEOK);
 156
 157   switch (unit) {
 158     case TVBU_OP:
 159       gprintf(gops, go, "%.0f iterations ", n);
 160       what = "op"; whats = "ops"; scale = 1000;
 161       break;
 162     case TVBU_BYTE:
 163       x = n; normalize(&x, &u, 1024); gprintf(gops, go, "%.3f %sB ", x, u);
 164       what = whats = "B"; scale = 1024;
 165       break;
 166     default:
 167       abort();
 168   }
 169
 170   x = tm->t; normalize(&x, &u, 1000);
 171   gprintf(gops, go, "in %.3f %ss", x, u);
 172   if (tm->f&BTF_CYOK) {
 173     x = tm->cy; normalize(&x, &u, 1000);
 174     gprintf(gops, go, " (%.3f %scy)", x, u);
 175   }
 176   gprintf(gops, go, ": ");
 177
 178   x = n/tm->t; normalize(&x, &u, scale);
 179   gprintf(gops, go, "%.3f %s%s/s", x, u, whats);
 180   x = tm->t/n; normalize(&x, &u, 1000);
 181   gprintf(gops, go, ", %.3f %ss/%s", x, u, what);
 182   if (tm->f&BTF_CYOK) {
 183     x = tm->cy/n; normalize(&x, &u, 1000);
 184     gprintf(gops, go, " (%.3f %scy/%s)", x, u, what);
 185   }
 186 }
 187
 188 /*----- Benchmark environment scaffolding ---------------------------------*/
 189
 190 /* --- @tvec_benchsetup@ --- *
 191  *
 192  * Arguments:   @struct tvec_state *tv@ = test vector state
 193  *              @const struct tvec_env *env@ = environment description
 194  *              @void *pctx@ = parent context (ignored)
 195  *              @void *ctx@ = context pointer to initialize
 196  *
 197  * Returns:     ---
 198  *
 199  * Use:         Initialize a benchmarking environment context.
 200  *
 201  *              The environment description must really be a @struct
 202  *              tvec_benchenv@.  If the @bst@ slot is null, then a temporary
 203  *              benchmark state is allocated for the current test group and
 204  *              released at the end.  Otherwise, it must be the address of a
 205  *              pointer to a benchmark state: if the pointer is null, then a
 206  *              fresh state is allocated and initialized and the pointer is
 207  *              updated; otherwise, the pointer is assumed to refer to an
 208  *              existing valid benchmark state.
 209  */
 210
 211 void tvec_benchsetup(struct tvec_state *tv, const struct tvec_env *env,
 212                      void *pctx, void *ctx)
 213 {
 214   struct tvec_benchctx *bc = ctx;
 215   const struct tvec_benchenv *be = (const struct tvec_benchenv *)env;
 216   const struct tvec_env *subenv = be->env;
 217   struct bench_timer *bt;
 218   dstr d = DSTR_INIT;
 219
 220   /* Basic initialization. */
 221   bc->be = be; bc->bst = 0; bc->subctx = 0;
 222
 223   /* Set up the benchmarking state if it hasn't been done before. */
 224   if (be->bst && *be->bst)
 225     bc->bst = *be->bst;
 226   else {
 227     bt = bench_createtimer(0);
 228     if (!bt)
 229       { tvec_skipgroup(tv, "failed to create timer"); goto timer_failed; }
 230     bc->bst = xmalloc(sizeof(*bc->bst)); bench_init(bc->bst, bt);
 231     *be->bst = bc->bst;
 232   }
 233
 234   /* If the timer isn't calibrated yet then do that now. */
 235   if (!(bc->bst->f&BTF_CLB)) {
 236     bc->bst->tm->ops->describe(bc->bst->tm, &d);
 237     tvec_notice(tv, "calibrating timer `%s'...", d.buf);
 238     if (bench_calibrate(bc->bst))
 239       { tvec_skipgroup(tv, "failed to calibrate timer"); goto timer_failed; }
 240   } else if (!(bc->bst->f&BTF_ANY))
 241     { tvec_skipgroup(tv, "timer broken"); goto timer_failed; }
 242
 243   /* Save the default target time. */
 244   bc->dflt_target = bc->bst->target_s;
 245
 246   /* Initialize the subordinate environment. */
 247 end:
 248   if (subenv && subenv->ctxsz) bc->subctx = xmalloc(subenv->ctxsz);
 249   if (subenv && subenv->setup) subenv->setup(tv, subenv, bc, bc->subctx);
 250
 251   /* All done. */
 252   dstr_destroy(&d);
 253   return;
 254
 255 timer_failed:
 256   if (!getenv("MLIB_BENCH_DEBUG"))
 257     tvec_notice(tv, "set `MLIB_BENCH_DEBUG=t' in the environment "
 258                 "for more detail");
 259   goto end;
 260 }
 261
 262 /* --- @tvec_benchfindvar@, @setvar@ --- *
 263  *
 264  * Arguments:   @struct tvec_state *tv@ = test vector state
 265  *              @const char *var@ = variable name to set
 266  *              @const union tvec_regval *rv@ = register value
 267  *              @void **ctx_out@ = where to put the @setvar@ context
 268  *              @void *ctx@ = context pointer
 269  *
 270  * Returns:     @tvec_benchfindvar@ returns a pointer to the variable
 271  *              definition, or null; @setvar@ returns zero on success or
 272  *              %$-1$% on error.
 273  *
 274  * Use:         Find a definition for a special variable.  The following
 275  *              special variables are supported.
 276  *
 277  *                * %|@target|% is the (approximate) duration to run
 278  *                  the benchmark.
 279  *
 280  *              Unrecognized variables are passed to the subordinate
 281  *              environment, if there is one.
 282  */
 283
 284 static int setvar(struct tvec_state *tv, const char *var,
 285                   const union tvec_regval *rv, void *ctx)
 286 {
 287   struct tvec_benchctx *bc = ctx;
 288
 289   if (STRCMP(var, ==, "@target")) {
 290     if (bc->f&TVBF_SETTRG) return (tvec_dupreg(tv, var));
 291     bc->bst->target_s = rv->f; bc->f |= TVBF_SETTRG;
 292   } else assert("unknown var");
 293   return (0);
 294 }
 295
 296 static const struct tvec_vardef target_var =
 297   { sizeof(struct tvec_reg), setvar, { "@target", -1, &tvty_duration, 0 } };
 298
 299 const struct tvec_vardef *tvec_benchfindvar
 300   (struct tvec_state *tv, const char *var, void **ctx_out, void *ctx)
 301 {
 302   struct tvec_benchctx *bc = ctx;
 303   const struct tvec_benchenv *be = bc->be;
 304   const struct tvec_env *subenv = be->env;
 305
 306   if (STRCMP(var, ==, "@target")) { *ctx_out = bc; return (&target_var); }
 307   else if (subenv && subenv->findvar)
 308     return (subenv->findvar(tv, var, ctx_out, bc->subctx));
 309   else return (0);
 310 }
 311
 312 /* --- @tvec_benchbefore@ --- *
 313  *
 314  * Arguments:   @struct tvec_state *tv@ = test vector state
 315  *              @void *ctx@ = context pointer
 316  *
 317  * Returns:     ---
 318  *
 319  * Use:         Invoke the subordinate environment's @before@ function to
 320  *              prepare for the benchmark.
 321  */
 322
 323 void tvec_benchbefore(struct tvec_state *tv, void *ctx)
 324 {
 325   struct tvec_benchctx *bc = ctx;
 326   const struct tvec_benchenv *be = bc->be;
 327   const struct tvec_env *subenv = be->env;
 328
 329   if (subenv && subenv->before) subenv->before(tv, bc->subctx);
 330 }
 331
 332 /* --- @tvec_benchrun@ --- *
 333  *
 334  * Arguments:   @struct tvec_state *tv@ = test vector state
 335  *              @tvec_testfn *fn@ = test function to run
 336  *              @void *ctx@ = context pointer for the test function
 337  *
 338  * Returns:     ---
 339  *
 340  * Use:         Measures and reports the performance of a test function.
 341  */
 342
 343 void tvec_benchrun(struct tvec_state *tv, tvec_testfn *fn, void *ctx)
 344 {
 345   struct tvec_benchctx *bc = ctx;
 346   const struct tvec_benchenv *be = bc->be;
 347   const struct tvec_env *subenv = be->env;
 348   const struct tvec_regdef *rd;
 349   struct tvec_output *o = tv->output;
 350   struct bench_timing tm;
 351   struct benchrun r;
 352   bench_fn *loopfn;
 353   unsigned unit;
 354   dstr d = DSTR_INIT;
 355   double base;
 356   unsigned f = 0;
 357 #define f_any 1u
 358
 359   /* Fill in the easy parts of the run context. */
 360   r.tv = tv; r.env = subenv; r.ctx = bc->subctx;
 361   r.in = tv->in; r.out = tv->out; r.fn = fn;
 362
 363   /* Decide on the run function to select. */
 364   if (be->riter >= 0) {
 365     r.n = &TVEC_REG(tv, in, be->riter)->v.u;
 366     loopfn = subenv && subenv->run ?
 367       benchloop_inner_indirect : benchloop_inner_direct;
 368   } else {
 369     r.n = 0;
 370     loopfn = subenv && subenv->run ?
 371       benchloop_outer_indirect : benchloop_outer_direct;
 372   }
 373
 374   /* Decide on the kind of unit and the base count. */
 375   base = be->niter;
 376   if (be->rbuf < 0) unit = TVBU_OP;
 377   else { unit = TVBU_BYTE; base *= TVEC_REG(tv, in, be->rbuf)->v.bytes.sz; }
 378
 379   /* Construct a description of the test using the identifier registers. */
 380   for (rd = tv->test->regs; rd->name; rd++)
 381     if (rd->f&TVRF_ID) {
 382       if (f&f_any) dstr_puts(&d, ", ");
 383       else f |= f_any;
 384       dstr_putf(&d, "%s = ", rd->name);
 385       rd->ty->dump(&TVEC_REG(tv, in, rd->i)->v, rd,
 386                    TVSF_COMPACT, &dstr_printops, &d);
 387     }
 388
 389   /* Run the benchmark. */
 390   o->ops->bbench(o, d.buf, unit);
 391   if (bench_measure(bc->bst, &tm, base, loopfn, &r))
 392     o->ops->ebench(o, d.buf, unit, 0);
 393   else
 394     o->ops->ebench(o, d.buf, unit, &tm);
 395
 396   dstr_destroy(&d);
 397
 398 #undef f_any
 399 }
 400
 401 /* --- @tvec_benchafter@ --- *
 402  *
 403  * Arguments:   @struct tvec_state *tv@ = test vector state
 404  *              @void *ctx@ = context pointer
 405  *
 406  * Returns:     ---
 407  *
 408  * Use:         Invoke the subordinate environment's @after@ function to
 409  *              clean up after the benchmark.
 410  */
 411
 412 void tvec_benchafter(struct tvec_state *tv, void *ctx)
 413 {
 414   struct tvec_benchctx *bc = ctx;
 415   const struct tvec_benchenv *be = bc->be;
 416   const struct tvec_env *subenv = be->env;
 417
 418   /* Restore the benchmark state's old target. */
 419   if (bc->bst) bc->bst->target_s = bc->dflt_target;
 420   bc->f &= ~TVBF_SETTRG;
 421
 422   /* Pass the call on to the subsidiary environment. */
 423   if (subenv && subenv->after) subenv->after(tv, bc->subctx);
 424 }
 425
 426 /* --- @tvec_benchteardown@ --- *
 427  *
 428  * Arguments:   @struct tvec_state *tv@ = test vector state
 429  *              @void *ctx@ = context pointer
 430  *
 431  * Returns:     ---
 432  *
 433  * Use:         Tear down the benchmark environment.
 434  */
 435
 436 void tvec_benchteardown(struct tvec_state *tv, void *ctx)
 437 {
 438   struct tvec_benchctx *bc = ctx;
 439   const struct tvec_benchenv *be;
 440   const struct tvec_env *subenv;
 441
 442   be = bc->be; subenv = be->env;
 443
 444   /* Tear down any subsidiary environment. */
 445   if (subenv && subenv->teardown)
 446     subenv->teardown(tv, bc->subctx);
 447
 448   /* If the benchmark state was temporary, then dispose of it. */
 449   if (bc->bst) {
 450     if (be->bst) bc->bst->target_s = bc->dflt_target;
 451     else { bench_destroy(bc->bst); xfree(bc->bst); }
 452   }
 453 }
 454
 455 /*----- That's all, folks -------------------------------------------------*/