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 /*----- Benchmark environment scaffolding ---------------------------------*/
  85
  86 /* --- @tvec_benchsetup@ --- *
  87  *
  88  * Arguments:   @struct tvec_state *tv@ = test vector state
  89  *              @const struct tvec_env *env@ = environment description
  90  *              @void *pctx@ = parent context (ignored)
  91  *              @void *ctx@ = context pointer to initialize
  92  *
  93  * Returns:     ---
  94  *
  95  * Use:         Initialize a benchmarking environment context.
  96  *
  97  *              The environment description must really be a @struct
  98  *              tvec_benchenv@.  If the @bst@ slot is null, then a temporary
  99  *              benchmark state is allocated for the current test group and
 100  *              released at the end.  Otherwise, it must be the address of a
 101  *              pointer to a benchmark state: if the pointer is null, then a
 102  *              fresh state is allocated and initialized and the pointer is
 103  *              updated; otherwise, the pointer is assumed to refer to an
 104  *              existing valid benchmark state.
 105  */
 106
 107 void tvec_benchsetup(struct tvec_state *tv, const struct tvec_env *env,
 108                      void *pctx, void *ctx)
 109 {
 110   struct tvec_benchctx *bc = ctx;
 111   const struct tvec_benchenv *be = (const struct tvec_benchenv *)env;
 112   const struct tvec_env *subenv = be->env;
 113   struct bench_timer *bt;
 114
 115   /* Basic initialization. */
 116   bc->be = be; bc->bst = 0; bc->subctx = 0;
 117
 118   /* Set up the benchmarking state if it hasn't been done before. */
 119   if (!be->bst || !*be->bst) {
 120     bt = bench_createtimer(); if (!bt) goto fail_timer;
 121     bc->bst = xmalloc(sizeof(*bc->bst)); bench_init(bc->bst, bt);
 122     if (be->bst) *be->bst = bc->bst;
 123   } else if (!(*be->bst)->tm)
 124     goto fail_timer;
 125   else
 126     bc->bst = *be->bst;
 127
 128   /* Set the default target time. */
 129   bc->dflt_target = bc->bst->target_s;
 130
 131   /* Initialize the subordinate environment. */
 132   if (subenv && subenv->ctxsz) bc->subctx = xmalloc(subenv->ctxsz);
 133   if (subenv && subenv->setup) subenv->setup(tv, subenv, bc, bc->subctx);
 134
 135   /* All done. */
 136 end:
 137   return;
 138 fail_timer:
 139   tvec_skipgroup(tv, "failed to create timer"); goto end;
 140 }
 141
 142 /* --- @tvec_benchset@ --- *
 143  *
 144  * Arguments:   @struct tvec_state *tv@ = test vector state
 145  *              @const char *var@ = variable name to set
 146  *              @const struct tvec_env *env@ = environment description
 147  *              @void *ctx@ = context pointer
 148  *
 149  * Returns:     Zero on success, @-1@ on failure.
 150  *
 151  * Use:         Set a special variable.  The following special variables are
 152  *              supported.
 153  *
 154  *                * %|@target|% is the (approximate) number of seconds to run
 155  *                  the benchmark.
 156  *
 157  *              Unrecognized variables are passed to the subordinate
 158  *              environment, if there is one.
 159  */
 160
 161 int tvec_benchset(struct tvec_state *tv, const char *var,
 162                   const struct tvec_env *env, void *ctx)
 163 {
 164   struct tvec_benchctx *bc = ctx;
 165   const struct tvec_benchenv *be = (const struct tvec_benchenv *)env;
 166   const struct tvec_env *subenv = be->env;
 167   union tvec_regval rv;
 168   static const struct tvec_floatinfo fi = { TVFF_NOMAX, 0.0, 0.0, 0.0 };
 169   static const struct tvec_regdef rd =
 170     { "@target", -1, &tvty_float, 0, { &fi } };
 171
 172   if (STRCMP(var, ==, "@target")) {
 173     if (tvty_float.parse(&rv, &rd, tv)) return (-1);
 174     if (bc) bc->bst->target_s = rv.f;
 175     return (1);
 176   } else if (subenv && subenv->set)
 177     return (subenv->set(tv, var, subenv, bc->subctx));
 178   else
 179     return (0);
 180 }
 181
 182 /* --- @tvec_benchbefore@ --- *
 183  *
 184  * Arguments:   @struct tvec_state *tv@ = test vector state
 185  *              @void *ctx@ = context pointer
 186  *
 187  * Returns:     ---
 188  *
 189  * Use:         Invoke the subordinate environment's @before@ function to
 190  *              prepare for the benchmark.
 191  */
 192
 193 void tvec_benchbefore(struct tvec_state *tv, void *ctx)
 194 {
 195   struct tvec_benchctx *bc = ctx;
 196   const struct tvec_benchenv *be = bc->be;
 197   const struct tvec_env *subenv = be->env;
 198
 199   /* Just call the subsidiary environment. */
 200   if (subenv && subenv->before) subenv->before(tv, bc->subctx);
 201 }
 202
 203 /* --- @tvec_benchafter@ --- *
 204  *
 205  * Arguments:   @struct tvec_state *tv@ = test vector state
 206  *              @void *ctx@ = context pointer
 207  *
 208  * Returns:     ---
 209  *
 210  * Use:         Invoke the subordinate environment's @after@ function to
 211  *              clean up after the benchmark.
 212  */
 213
 214 void tvec_benchafter(struct tvec_state *tv, void *ctx)
 215 {
 216   struct tvec_benchctx *bc = ctx;
 217   const struct tvec_benchenv *be = bc->be;
 218   const struct tvec_env *subenv = be->env;
 219
 220   /* Restore the benchmark state's old target. */
 221   bc->bst->target_s = bc->dflt_target;
 222
 223   /* Pass the call on to the subsidiary environment. */
 224   if (subenv && subenv->after) subenv->after(tv, bc->subctx);
 225 }
 226
 227 /* --- @tvec_benchteardown@ --- *
 228  *
 229  * Arguments:   @struct tvec_state *tv@ = test vector state
 230  *              @void *ctx@ = context pointer
 231  *
 232  * Returns:     ---
 233  *
 234  * Use:         Tear down the benchmark environment.
 235  */
 236
 237 void tvec_benchteardown(struct tvec_state *tv, void *ctx)
 238 {
 239   struct tvec_benchctx *bc = ctx;
 240   const struct tvec_benchenv *be;
 241   const struct tvec_env *subenv;
 242
 243   if (!bc) return;
 244   be = bc->be; subenv = be->env;
 245
 246   /* Tear down any subsidiary environment. */
 247   if (subenv && subenv->teardown && bc->subctx)
 248     subenv->teardown(tv, bc->subctx);
 249
 250   /* If the benchmark state was temporary, then dispose of it. */
 251   if (bc->bst) {
 252     if (be->bst) bc->bst->target_s = bc->dflt_target;
 253     else { bench_destroy(bc->bst); xfree(bc->bst); }
 254   }
 255 }
 256
 257 /*----- Measurement machinery ---------------------------------------------*/
 258
 259 /* --- @benchloop_...@ --- *
 260  *
 261  * Arguments:   @unsigned long n@ = iteration count
 262  *              @void *ctx@ = benchmark running context
 263  *
 264  * Returns:     ---
 265  *
 266  * Use:         Run various kinds of benchmarking loops.
 267  *
 268  *                * The @..._outer_...@ functions call the underlying
 269  *                  function @n@ times in a loop; by contrast, the
 270  *                  @..._inner_...@ functions set a register value to the
 271  *                  chosen iteration count and expect the underlying function
 272  *                  to perform the loop itself.
 273  *
 274  *                * The @..._direct@ functions just call the underlying test
 275  *                  function directly (though still through an `indirect
 276  *                  jump' instruction); by contrast, the @..._indirect@
 277  *                  functions invoke a subsidiary environment's @run@
 278  *                  function, which adds additional overhead.
 279  */
 280
 281 static void benchloop_outer_direct(unsigned long n, void *ctx)
 282 {
 283   struct benchrun *r = ctx;
 284   tvec_testfn *fn = r->fn; void *tctx = r->ctx;
 285   const struct tvec_reg *in = r->in; struct tvec_reg *out = r->out;
 286
 287   while (n--) fn(in, out, tctx);
 288 }
 289
 290 static void benchloop_inner_direct(unsigned long n, void *ctx)
 291   { struct benchrun *r = ctx; *r->n = n; r->fn(r->in, r->out, r->ctx); }
 292
 293 static void benchloop_outer_indirect(unsigned long n, void *ctx)
 294 {
 295   struct benchrun *r = ctx;
 296   struct tvec_state *tv = r->tv;
 297   void (*run)(struct tvec_state *, tvec_testfn, void *) = r->env->run;
 298   tvec_testfn *fn = r->fn; void *tctx = r->ctx;
 299
 300   while (n--) run(tv, fn, tctx);
 301 }
 302
 303 static void benchloop_inner_indirect(unsigned long n, void *ctx)
 304   { struct benchrun *r = ctx; *r->n = n; r->env->run(r->tv, r->fn, r->ctx); }
 305
 306 /* --- @tvec_benchrun@ --- *
 307  *
 308  * Arguments:   @struct tvec_state *tv@ = test vector state
 309  *              @tvec_testfn *fn@ = test function to run
 310  *              @void *ctx@ = context pointer for the test function
 311  *
 312  * Returns:     ---
 313  *
 314  * Use:         Measures and reports the performance of a test function.
 315  */
 316
 317 void tvec_benchrun(struct tvec_state *tv, tvec_testfn *fn, void *ctx)
 318 {
 319   struct tvec_benchctx *bc = ctx;
 320   const struct tvec_benchenv *be = bc->be;
 321   const struct tvec_env *subenv = be->env;
 322   const struct tvec_regdef *rd;
 323   struct tvec_output *o = tv->output;
 324   struct bench_timing tm;
 325   struct benchrun r;
 326   bench_fn *loopfn;
 327   unsigned unit;
 328   dstr d = DSTR_INIT;
 329   double base;
 330   unsigned f = 0;
 331 #define f_any 1u
 332
 333   /* Fill in the easy parts of the run context. */
 334   r.tv = tv; r.env = subenv; r.ctx = bc->subctx;
 335   r.in = tv->in; r.out = tv->out; r.fn = fn;
 336
 337   /* Decide on the run function to select. */
 338   if (be->riter >= 0) {
 339     r.n = &TVEC_REG(tv, in, be->riter)->v.u;
 340     loopfn = subenv && subenv->run ?
 341       benchloop_inner_indirect : benchloop_inner_direct;
 342   } else {
 343     r.n = 0;
 344     loopfn = subenv && subenv->run ?
 345       benchloop_outer_indirect : benchloop_outer_direct;
 346   }
 347
 348   /* Decide on the kind of unit and the base count. */
 349   base = be->niter;
 350   if (be->rbuf < 0) unit = TVBU_OP;
 351   else { unit = TVBU_BYTE; base *= TVEC_REG(tv, in, be->rbuf)->v.bytes.sz; }
 352
 353   /* Construct a description of the test using the identifier registers. */
 354   for (rd = tv->test->regs; rd->name; rd++)
 355     if (rd->f&TVRF_ID) {
 356       if (f&f_any) dstr_puts(&d, ", ");
 357       else f |= f_any;
 358       dstr_putf(&d, "%s = ", rd->name);
 359       rd->ty->dump(&TVEC_REG(tv, in, rd->i)->v, rd,
 360                    TVSF_COMPACT, &dstr_printops, &d);
 361     }
 362
 363   /* Run the benchmark. */
 364   o->ops->bbench(o, d.buf, unit);
 365   if (bench_measure(&tm, bc->bst, base, loopfn, &r))
 366     o->ops->ebench(o, d.buf, unit, 0);
 367   else
 368     o->ops->ebench(o, d.buf, unit, &tm);
 369
 370   dstr_destroy(&d);
 371
 372 #undef f_any
 373 }
 374
 375 /*----- Output utilities --------------------------------------------------*/
 376
 377 /* --- @tvec_benchreport@ --- *
 378  *
 379  * Arguments:   @const struct gprintf_ops *gops@ = print operations
 380  *              @void *go@ = print destination
 381  *              @unsigned unit@ = the unit being measured (~TVBU_...@)
 382  *              @const struct bench_timing *tm@ = the benchmark result
 383  *
 384  * Returns:     ---
 385  *
 386  * Use:         Formats a report about the benchmark performance.  This
 387  *              function is intended to be called on by an output
 388  *              @ebench@ function.
 389  */
 390
 391 void tvec_benchreport(const struct gprintf_ops *gops, void *go,
 392                       unsigned unit, const struct bench_timing *tm)
 393 {
 394   double scale, x, n = tm->n;
 395   const char *u, *what, *whats;
 396
 397   if (!tm) { gprintf(gops, go, "benchmark FAILED"); return; }
 398
 399   assert(tm->f&BTF_TIMEOK);
 400
 401   switch (unit) {
 402     case TVBU_OP:
 403       gprintf(gops, go, "%.0f iterations ", n);
 404       what = "op"; whats = "ops"; scale = 1000;
 405       break;
 406     case TVBU_BYTE:
 407       x = n; normalize(&x, &u, 1024); gprintf(gops, go, "%.3f %sB ", x, u);
 408       what = whats = "B"; scale = 1024;
 409       break;
 410     default:
 411       abort();
 412   }
 413
 414   x = tm->t; normalize(&x, &u, 1000);
 415   gprintf(gops, go, "in %.3f %ss", x, u);
 416   if (tm->f&BTF_CYOK) {
 417     x = tm->cy; normalize(&x, &u, 1000);
 418     gprintf(gops, go, " (%.3f %scy)", x, u);
 419   }
 420   gprintf(gops, go, ": ");
 421
 422   x = n/tm->t; normalize(&x, &u, scale);
 423   gprintf(gops, go, "%.3f %s%s/s", x, u, whats);
 424   x = tm->t/n; normalize(&x, &u, 1000);
 425   gprintf(gops, go, ", %.3f %ss/%s", x, u, what);
 426   if (tm->f&BTF_CYOK) {
 427     x = tm->cy/n; normalize(&x, &u, 1000);
 428     gprintf(gops, go, " (%.3f %scy/%s)", x, u, what);
 429   }
 430 }
 431
 432 /*----- That's all, folks -------------------------------------------------*/