fp-bench.c (19958B)
1 /* 2 * fp-bench.c - A collection of simple floating point microbenchmarks. 3 * 4 * Copyright (C) 2018, Emilio G. Cota <cota@braap.org> 5 * 6 * License: GNU GPL, version 2 or later. 7 * See the COPYING file in the top-level directory. 8 */ 9 #ifndef HW_POISON_H 10 #error Must define HW_POISON_H to work around TARGET_* poisoning 11 #endif 12 13 #include "qemu/osdep.h" 14 #include <math.h> 15 #include <fenv.h> 16 #include "qemu/timer.h" 17 #include "qemu/int128.h" 18 #include "fpu/softfloat.h" 19 20 /* amortize the computation of random inputs */ 21 #define OPS_PER_ITER 50000 22 23 #define MAX_OPERANDS 3 24 25 #define SEED_A 0xdeadfacedeadface 26 #define SEED_B 0xbadc0feebadc0fee 27 #define SEED_C 0xbeefdeadbeefdead 28 29 enum op { 30 OP_ADD, 31 OP_SUB, 32 OP_MUL, 33 OP_DIV, 34 OP_FMA, 35 OP_SQRT, 36 OP_CMP, 37 OP_MAX_NR, 38 }; 39 40 static const char * const op_names[] = { 41 [OP_ADD] = "add", 42 [OP_SUB] = "sub", 43 [OP_MUL] = "mul", 44 [OP_DIV] = "div", 45 [OP_FMA] = "mulAdd", 46 [OP_SQRT] = "sqrt", 47 [OP_CMP] = "cmp", 48 [OP_MAX_NR] = NULL, 49 }; 50 51 enum precision { 52 PREC_SINGLE, 53 PREC_DOUBLE, 54 PREC_QUAD, 55 PREC_FLOAT32, 56 PREC_FLOAT64, 57 PREC_FLOAT128, 58 PREC_MAX_NR, 59 }; 60 61 enum rounding { 62 ROUND_EVEN, 63 ROUND_ZERO, 64 ROUND_DOWN, 65 ROUND_UP, 66 ROUND_TIEAWAY, 67 N_ROUND_MODES, 68 }; 69 70 static const char * const round_names[] = { 71 [ROUND_EVEN] = "even", 72 [ROUND_ZERO] = "zero", 73 [ROUND_DOWN] = "down", 74 [ROUND_UP] = "up", 75 [ROUND_TIEAWAY] = "tieaway", 76 }; 77 78 enum tester { 79 TESTER_SOFT, 80 TESTER_HOST, 81 TESTER_MAX_NR, 82 }; 83 84 static const char * const tester_names[] = { 85 [TESTER_SOFT] = "soft", 86 [TESTER_HOST] = "host", 87 [TESTER_MAX_NR] = NULL, 88 }; 89 90 union fp { 91 float f; 92 double d; 93 float32 f32; 94 float64 f64; 95 float128 f128; 96 uint64_t u64; 97 }; 98 99 struct op_state; 100 101 typedef float (*float_func_t)(const struct op_state *s); 102 typedef double (*double_func_t)(const struct op_state *s); 103 104 union fp_func { 105 float_func_t float_func; 106 double_func_t double_func; 107 }; 108 109 typedef void (*bench_func_t)(void); 110 111 struct op_desc { 112 const char * const name; 113 }; 114 115 #define DEFAULT_DURATION_SECS 1 116 117 static uint64_t random_ops[MAX_OPERANDS] = { 118 SEED_A, SEED_B, SEED_C, 119 }; 120 121 static float128 random_quad_ops[MAX_OPERANDS] = { 122 {SEED_A, SEED_B}, {SEED_B, SEED_C}, {SEED_C, SEED_A}, 123 }; 124 static float_status soft_status; 125 static enum precision precision; 126 static enum op operation; 127 static enum tester tester; 128 static uint64_t n_completed_ops; 129 static unsigned int duration = DEFAULT_DURATION_SECS; 130 static int64_t ns_elapsed; 131 /* disable optimizations with volatile */ 132 static volatile union fp res; 133 134 /* 135 * From: https://en.wikipedia.org/wiki/Xorshift 136 * This is faster than rand_r(), and gives us a wider range (RAND_MAX is only 137 * guaranteed to be >= INT_MAX). 138 */ 139 static uint64_t xorshift64star(uint64_t x) 140 { 141 x ^= x >> 12; /* a */ 142 x ^= x << 25; /* b */ 143 x ^= x >> 27; /* c */ 144 return x * UINT64_C(2685821657736338717); 145 } 146 147 static void update_random_ops(int n_ops, enum precision prec) 148 { 149 int i; 150 151 for (i = 0; i < n_ops; i++) { 152 153 switch (prec) { 154 case PREC_SINGLE: 155 case PREC_FLOAT32: 156 { 157 uint64_t r = random_ops[i]; 158 do { 159 r = xorshift64star(r); 160 } while (!float32_is_normal(r)); 161 random_ops[i] = r; 162 break; 163 } 164 case PREC_DOUBLE: 165 case PREC_FLOAT64: 166 { 167 uint64_t r = random_ops[i]; 168 do { 169 r = xorshift64star(r); 170 } while (!float64_is_normal(r)); 171 random_ops[i] = r; 172 break; 173 } 174 case PREC_QUAD: 175 case PREC_FLOAT128: 176 { 177 float128 r = random_quad_ops[i]; 178 uint64_t hi = r.high; 179 uint64_t lo = r.low; 180 do { 181 hi = xorshift64star(hi); 182 lo = xorshift64star(lo); 183 r = make_float128(hi, lo); 184 } while (!float128_is_normal(r)); 185 random_quad_ops[i] = r; 186 break; 187 } 188 default: 189 g_assert_not_reached(); 190 } 191 } 192 } 193 194 static void fill_random(union fp *ops, int n_ops, enum precision prec, 195 bool no_neg) 196 { 197 int i; 198 199 for (i = 0; i < n_ops; i++) { 200 switch (prec) { 201 case PREC_SINGLE: 202 case PREC_FLOAT32: 203 ops[i].f32 = make_float32(random_ops[i]); 204 if (no_neg && float32_is_neg(ops[i].f32)) { 205 ops[i].f32 = float32_chs(ops[i].f32); 206 } 207 break; 208 case PREC_DOUBLE: 209 case PREC_FLOAT64: 210 ops[i].f64 = make_float64(random_ops[i]); 211 if (no_neg && float64_is_neg(ops[i].f64)) { 212 ops[i].f64 = float64_chs(ops[i].f64); 213 } 214 break; 215 case PREC_QUAD: 216 case PREC_FLOAT128: 217 ops[i].f128 = random_quad_ops[i]; 218 if (no_neg && float128_is_neg(ops[i].f128)) { 219 ops[i].f128 = float128_chs(ops[i].f128); 220 } 221 break; 222 default: 223 g_assert_not_reached(); 224 } 225 } 226 } 227 228 /* 229 * The main benchmark function. Instead of (ab)using macros, we rely 230 * on the compiler to unfold this at compile-time. 231 */ 232 static void bench(enum precision prec, enum op op, int n_ops, bool no_neg) 233 { 234 int64_t tf = get_clock() + duration * 1000000000LL; 235 236 while (get_clock() < tf) { 237 union fp ops[MAX_OPERANDS]; 238 int64_t t0; 239 int i; 240 241 update_random_ops(n_ops, prec); 242 switch (prec) { 243 case PREC_SINGLE: 244 fill_random(ops, n_ops, prec, no_neg); 245 t0 = get_clock(); 246 for (i = 0; i < OPS_PER_ITER; i++) { 247 float a = ops[0].f; 248 float b = ops[1].f; 249 float c = ops[2].f; 250 251 switch (op) { 252 case OP_ADD: 253 res.f = a + b; 254 break; 255 case OP_SUB: 256 res.f = a - b; 257 break; 258 case OP_MUL: 259 res.f = a * b; 260 break; 261 case OP_DIV: 262 res.f = a / b; 263 break; 264 case OP_FMA: 265 res.f = fmaf(a, b, c); 266 break; 267 case OP_SQRT: 268 res.f = sqrtf(a); 269 break; 270 case OP_CMP: 271 res.u64 = isgreater(a, b); 272 break; 273 default: 274 g_assert_not_reached(); 275 } 276 } 277 break; 278 case PREC_DOUBLE: 279 fill_random(ops, n_ops, prec, no_neg); 280 t0 = get_clock(); 281 for (i = 0; i < OPS_PER_ITER; i++) { 282 double a = ops[0].d; 283 double b = ops[1].d; 284 double c = ops[2].d; 285 286 switch (op) { 287 case OP_ADD: 288 res.d = a + b; 289 break; 290 case OP_SUB: 291 res.d = a - b; 292 break; 293 case OP_MUL: 294 res.d = a * b; 295 break; 296 case OP_DIV: 297 res.d = a / b; 298 break; 299 case OP_FMA: 300 res.d = fma(a, b, c); 301 break; 302 case OP_SQRT: 303 res.d = sqrt(a); 304 break; 305 case OP_CMP: 306 res.u64 = isgreater(a, b); 307 break; 308 default: 309 g_assert_not_reached(); 310 } 311 } 312 break; 313 case PREC_FLOAT32: 314 fill_random(ops, n_ops, prec, no_neg); 315 t0 = get_clock(); 316 for (i = 0; i < OPS_PER_ITER; i++) { 317 float32 a = ops[0].f32; 318 float32 b = ops[1].f32; 319 float32 c = ops[2].f32; 320 321 switch (op) { 322 case OP_ADD: 323 res.f32 = float32_add(a, b, &soft_status); 324 break; 325 case OP_SUB: 326 res.f32 = float32_sub(a, b, &soft_status); 327 break; 328 case OP_MUL: 329 res.f = float32_mul(a, b, &soft_status); 330 break; 331 case OP_DIV: 332 res.f32 = float32_div(a, b, &soft_status); 333 break; 334 case OP_FMA: 335 res.f32 = float32_muladd(a, b, c, 0, &soft_status); 336 break; 337 case OP_SQRT: 338 res.f32 = float32_sqrt(a, &soft_status); 339 break; 340 case OP_CMP: 341 res.u64 = float32_compare_quiet(a, b, &soft_status); 342 break; 343 default: 344 g_assert_not_reached(); 345 } 346 } 347 break; 348 case PREC_FLOAT64: 349 fill_random(ops, n_ops, prec, no_neg); 350 t0 = get_clock(); 351 for (i = 0; i < OPS_PER_ITER; i++) { 352 float64 a = ops[0].f64; 353 float64 b = ops[1].f64; 354 float64 c = ops[2].f64; 355 356 switch (op) { 357 case OP_ADD: 358 res.f64 = float64_add(a, b, &soft_status); 359 break; 360 case OP_SUB: 361 res.f64 = float64_sub(a, b, &soft_status); 362 break; 363 case OP_MUL: 364 res.f = float64_mul(a, b, &soft_status); 365 break; 366 case OP_DIV: 367 res.f64 = float64_div(a, b, &soft_status); 368 break; 369 case OP_FMA: 370 res.f64 = float64_muladd(a, b, c, 0, &soft_status); 371 break; 372 case OP_SQRT: 373 res.f64 = float64_sqrt(a, &soft_status); 374 break; 375 case OP_CMP: 376 res.u64 = float64_compare_quiet(a, b, &soft_status); 377 break; 378 default: 379 g_assert_not_reached(); 380 } 381 } 382 break; 383 case PREC_FLOAT128: 384 fill_random(ops, n_ops, prec, no_neg); 385 t0 = get_clock(); 386 for (i = 0; i < OPS_PER_ITER; i++) { 387 float128 a = ops[0].f128; 388 float128 b = ops[1].f128; 389 float128 c = ops[2].f128; 390 391 switch (op) { 392 case OP_ADD: 393 res.f128 = float128_add(a, b, &soft_status); 394 break; 395 case OP_SUB: 396 res.f128 = float128_sub(a, b, &soft_status); 397 break; 398 case OP_MUL: 399 res.f128 = float128_mul(a, b, &soft_status); 400 break; 401 case OP_DIV: 402 res.f128 = float128_div(a, b, &soft_status); 403 break; 404 case OP_FMA: 405 res.f128 = float128_muladd(a, b, c, 0, &soft_status); 406 break; 407 case OP_SQRT: 408 res.f128 = float128_sqrt(a, &soft_status); 409 break; 410 case OP_CMP: 411 res.u64 = float128_compare_quiet(a, b, &soft_status); 412 break; 413 default: 414 g_assert_not_reached(); 415 } 416 } 417 break; 418 default: 419 g_assert_not_reached(); 420 } 421 ns_elapsed += get_clock() - t0; 422 n_completed_ops += OPS_PER_ITER; 423 } 424 } 425 426 #define GEN_BENCH(name, type, prec, op, n_ops) \ 427 static void __attribute__((flatten)) name(void) \ 428 { \ 429 bench(prec, op, n_ops, false); \ 430 } 431 432 #define GEN_BENCH_NO_NEG(name, type, prec, op, n_ops) \ 433 static void __attribute__((flatten)) name(void) \ 434 { \ 435 bench(prec, op, n_ops, true); \ 436 } 437 438 #define GEN_BENCH_ALL_TYPES(opname, op, n_ops) \ 439 GEN_BENCH(bench_ ## opname ## _float, float, PREC_SINGLE, op, n_ops) \ 440 GEN_BENCH(bench_ ## opname ## _double, double, PREC_DOUBLE, op, n_ops) \ 441 GEN_BENCH(bench_ ## opname ## _float32, float32, PREC_FLOAT32, op, n_ops) \ 442 GEN_BENCH(bench_ ## opname ## _float64, float64, PREC_FLOAT64, op, n_ops) \ 443 GEN_BENCH(bench_ ## opname ## _float128, float128, PREC_FLOAT128, op, n_ops) 444 445 GEN_BENCH_ALL_TYPES(add, OP_ADD, 2) 446 GEN_BENCH_ALL_TYPES(sub, OP_SUB, 2) 447 GEN_BENCH_ALL_TYPES(mul, OP_MUL, 2) 448 GEN_BENCH_ALL_TYPES(div, OP_DIV, 2) 449 GEN_BENCH_ALL_TYPES(fma, OP_FMA, 3) 450 GEN_BENCH_ALL_TYPES(cmp, OP_CMP, 2) 451 #undef GEN_BENCH_ALL_TYPES 452 453 #define GEN_BENCH_ALL_TYPES_NO_NEG(name, op, n) \ 454 GEN_BENCH_NO_NEG(bench_ ## name ## _float, float, PREC_SINGLE, op, n) \ 455 GEN_BENCH_NO_NEG(bench_ ## name ## _double, double, PREC_DOUBLE, op, n) \ 456 GEN_BENCH_NO_NEG(bench_ ## name ## _float32, float32, PREC_FLOAT32, op, n) \ 457 GEN_BENCH_NO_NEG(bench_ ## name ## _float64, float64, PREC_FLOAT64, op, n) \ 458 GEN_BENCH_NO_NEG(bench_ ## name ## _float128, float128, PREC_FLOAT128, op, n) 459 460 GEN_BENCH_ALL_TYPES_NO_NEG(sqrt, OP_SQRT, 1) 461 #undef GEN_BENCH_ALL_TYPES_NO_NEG 462 463 #undef GEN_BENCH_NO_NEG 464 #undef GEN_BENCH 465 466 #define GEN_BENCH_FUNCS(opname, op) \ 467 [op] = { \ 468 [PREC_SINGLE] = bench_ ## opname ## _float, \ 469 [PREC_DOUBLE] = bench_ ## opname ## _double, \ 470 [PREC_FLOAT32] = bench_ ## opname ## _float32, \ 471 [PREC_FLOAT64] = bench_ ## opname ## _float64, \ 472 [PREC_FLOAT128] = bench_ ## opname ## _float128, \ 473 } 474 475 static const bench_func_t bench_funcs[OP_MAX_NR][PREC_MAX_NR] = { 476 GEN_BENCH_FUNCS(add, OP_ADD), 477 GEN_BENCH_FUNCS(sub, OP_SUB), 478 GEN_BENCH_FUNCS(mul, OP_MUL), 479 GEN_BENCH_FUNCS(div, OP_DIV), 480 GEN_BENCH_FUNCS(fma, OP_FMA), 481 GEN_BENCH_FUNCS(sqrt, OP_SQRT), 482 GEN_BENCH_FUNCS(cmp, OP_CMP), 483 }; 484 485 #undef GEN_BENCH_FUNCS 486 487 static void run_bench(void) 488 { 489 bench_func_t f; 490 491 f = bench_funcs[operation][precision]; 492 g_assert(f); 493 f(); 494 } 495 496 /* @arr must be NULL-terminated */ 497 static int find_name(const char * const *arr, const char *name) 498 { 499 int i; 500 501 for (i = 0; arr[i] != NULL; i++) { 502 if (strcmp(name, arr[i]) == 0) { 503 return i; 504 } 505 } 506 return -1; 507 } 508 509 static void usage_complete(int argc, char *argv[]) 510 { 511 gchar *op_list = g_strjoinv(", ", (gchar **)op_names); 512 gchar *tester_list = g_strjoinv(", ", (gchar **)tester_names); 513 514 fprintf(stderr, "Usage: %s [options]\n", argv[0]); 515 fprintf(stderr, "options:\n"); 516 fprintf(stderr, " -d = duration, in seconds. Default: %d\n", 517 DEFAULT_DURATION_SECS); 518 fprintf(stderr, " -h = show this help message.\n"); 519 fprintf(stderr, " -o = floating point operation (%s). Default: %s\n", 520 op_list, op_names[0]); 521 fprintf(stderr, " -p = floating point precision (single, double, quad[soft only]). " 522 "Default: single\n"); 523 fprintf(stderr, " -r = rounding mode (even, zero, down, up, tieaway). " 524 "Default: even\n"); 525 fprintf(stderr, " -t = tester (%s). Default: %s\n", 526 tester_list, tester_names[0]); 527 fprintf(stderr, " -z = flush inputs to zero (soft tester only). " 528 "Default: disabled\n"); 529 fprintf(stderr, " -Z = flush output to zero (soft tester only). " 530 "Default: disabled\n"); 531 532 g_free(tester_list); 533 g_free(op_list); 534 } 535 536 static int round_name_to_mode(const char *name) 537 { 538 int i; 539 540 for (i = 0; i < N_ROUND_MODES; i++) { 541 if (!strcmp(round_names[i], name)) { 542 return i; 543 } 544 } 545 return -1; 546 } 547 548 static G_NORETURN 549 void die_host_rounding(enum rounding rounding) 550 { 551 fprintf(stderr, "fatal: '%s' rounding not supported on this host\n", 552 round_names[rounding]); 553 exit(EXIT_FAILURE); 554 } 555 556 static void set_host_precision(enum rounding rounding) 557 { 558 int rhost; 559 560 switch (rounding) { 561 case ROUND_EVEN: 562 rhost = FE_TONEAREST; 563 break; 564 case ROUND_ZERO: 565 rhost = FE_TOWARDZERO; 566 break; 567 case ROUND_DOWN: 568 rhost = FE_DOWNWARD; 569 break; 570 case ROUND_UP: 571 rhost = FE_UPWARD; 572 break; 573 case ROUND_TIEAWAY: 574 die_host_rounding(rounding); 575 return; 576 default: 577 g_assert_not_reached(); 578 } 579 580 if (fesetround(rhost)) { 581 die_host_rounding(rounding); 582 } 583 } 584 585 static void set_soft_precision(enum rounding rounding) 586 { 587 signed char mode; 588 589 switch (rounding) { 590 case ROUND_EVEN: 591 mode = float_round_nearest_even; 592 break; 593 case ROUND_ZERO: 594 mode = float_round_to_zero; 595 break; 596 case ROUND_DOWN: 597 mode = float_round_down; 598 break; 599 case ROUND_UP: 600 mode = float_round_up; 601 break; 602 case ROUND_TIEAWAY: 603 mode = float_round_ties_away; 604 break; 605 default: 606 g_assert_not_reached(); 607 } 608 soft_status.float_rounding_mode = mode; 609 } 610 611 static void parse_args(int argc, char *argv[]) 612 { 613 int c; 614 int val; 615 int rounding = ROUND_EVEN; 616 617 for (;;) { 618 c = getopt(argc, argv, "d:ho:p:r:t:zZ"); 619 if (c < 0) { 620 break; 621 } 622 switch (c) { 623 case 'd': 624 duration = atoi(optarg); 625 break; 626 case 'h': 627 usage_complete(argc, argv); 628 exit(EXIT_SUCCESS); 629 case 'o': 630 val = find_name(op_names, optarg); 631 if (val < 0) { 632 fprintf(stderr, "Unsupported op '%s'\n", optarg); 633 exit(EXIT_FAILURE); 634 } 635 operation = val; 636 break; 637 case 'p': 638 if (!strcmp(optarg, "single")) { 639 precision = PREC_SINGLE; 640 } else if (!strcmp(optarg, "double")) { 641 precision = PREC_DOUBLE; 642 } else if (!strcmp(optarg, "quad")) { 643 precision = PREC_QUAD; 644 } else { 645 fprintf(stderr, "Unsupported precision '%s'\n", optarg); 646 exit(EXIT_FAILURE); 647 } 648 break; 649 case 'r': 650 rounding = round_name_to_mode(optarg); 651 if (rounding < 0) { 652 fprintf(stderr, "fatal: invalid rounding mode '%s'\n", optarg); 653 exit(EXIT_FAILURE); 654 } 655 break; 656 case 't': 657 val = find_name(tester_names, optarg); 658 if (val < 0) { 659 fprintf(stderr, "Unsupported tester '%s'\n", optarg); 660 exit(EXIT_FAILURE); 661 } 662 tester = val; 663 break; 664 case 'z': 665 soft_status.flush_inputs_to_zero = 1; 666 break; 667 case 'Z': 668 soft_status.flush_to_zero = 1; 669 break; 670 } 671 } 672 673 /* set precision and rounding mode based on the tester */ 674 switch (tester) { 675 case TESTER_HOST: 676 set_host_precision(rounding); 677 break; 678 case TESTER_SOFT: 679 set_soft_precision(rounding); 680 switch (precision) { 681 case PREC_SINGLE: 682 precision = PREC_FLOAT32; 683 break; 684 case PREC_DOUBLE: 685 precision = PREC_FLOAT64; 686 break; 687 case PREC_QUAD: 688 precision = PREC_FLOAT128; 689 break; 690 default: 691 g_assert_not_reached(); 692 } 693 break; 694 default: 695 g_assert_not_reached(); 696 } 697 } 698 699 static void pr_stats(void) 700 { 701 printf("%.2f MFlops\n", (double)n_completed_ops / ns_elapsed * 1e3); 702 } 703 704 int main(int argc, char *argv[]) 705 { 706 parse_args(argc, argv); 707 run_bench(); 708 pr_stats(); 709 return 0; 710 }