diff options
Diffstat (limited to 'tests/fp/fp-bench.c')
| -rw-r--r-- | tests/fp/fp-bench.c | 630 |
1 files changed, 630 insertions, 0 deletions
diff --git a/tests/fp/fp-bench.c b/tests/fp/fp-bench.c new file mode 100644 index 0000000000..f5bc5edebf --- /dev/null +++ b/tests/fp/fp-bench.c @@ -0,0 +1,630 @@ +/* + * fp-bench.c - A collection of simple floating point microbenchmarks. + * + * Copyright (C) 2018, Emilio G. Cota <cota@braap.org> + * + * License: GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + */ +#ifndef HW_POISON_H +#error Must define HW_POISON_H to work around TARGET_* poisoning +#endif + +#include "qemu/osdep.h" +#include <math.h> +#include <fenv.h> +#include "qemu/timer.h" +#include "fpu/softfloat.h" + +/* amortize the computation of random inputs */ +#define OPS_PER_ITER 50000 + +#define MAX_OPERANDS 3 + +#define SEED_A 0xdeadfacedeadface +#define SEED_B 0xbadc0feebadc0fee +#define SEED_C 0xbeefdeadbeefdead + +enum op { + OP_ADD, + OP_SUB, + OP_MUL, + OP_DIV, + OP_FMA, + OP_SQRT, + OP_CMP, + OP_MAX_NR, +}; + +static const char * const op_names[] = { + [OP_ADD] = "add", + [OP_SUB] = "sub", + [OP_MUL] = "mul", + [OP_DIV] = "div", + [OP_FMA] = "mulAdd", + [OP_SQRT] = "sqrt", + [OP_CMP] = "cmp", + [OP_MAX_NR] = NULL, +}; + +enum precision { + PREC_SINGLE, + PREC_DOUBLE, + PREC_FLOAT32, + PREC_FLOAT64, + PREC_MAX_NR, +}; + +enum rounding { + ROUND_EVEN, + ROUND_ZERO, + ROUND_DOWN, + ROUND_UP, + ROUND_TIEAWAY, + N_ROUND_MODES, +}; + +static const char * const round_names[] = { + [ROUND_EVEN] = "even", + [ROUND_ZERO] = "zero", + [ROUND_DOWN] = "down", + [ROUND_UP] = "up", + [ROUND_TIEAWAY] = "tieaway", +}; + +enum tester { + TESTER_SOFT, + TESTER_HOST, + TESTER_MAX_NR, +}; + +static const char * const tester_names[] = { + [TESTER_SOFT] = "soft", + [TESTER_HOST] = "host", + [TESTER_MAX_NR] = NULL, +}; + +union fp { + float f; + double d; + float32 f32; + float64 f64; + uint64_t u64; +}; + +struct op_state; + +typedef float (*float_func_t)(const struct op_state *s); +typedef double (*double_func_t)(const struct op_state *s); + +union fp_func { + float_func_t float_func; + double_func_t double_func; +}; + +typedef void (*bench_func_t)(void); + +struct op_desc { + const char * const name; +}; + +#define DEFAULT_DURATION_SECS 1 + +static uint64_t random_ops[MAX_OPERANDS] = { + SEED_A, SEED_B, SEED_C, +}; +static float_status soft_status; +static enum precision precision; +static enum op operation; +static enum tester tester; +static uint64_t n_completed_ops; +static unsigned int duration = DEFAULT_DURATION_SECS; +static int64_t ns_elapsed; +/* disable optimizations with volatile */ +static volatile union fp res; + +/* + * From: https://en.wikipedia.org/wiki/Xorshift + * This is faster than rand_r(), and gives us a wider range (RAND_MAX is only + * guaranteed to be >= INT_MAX). + */ +static uint64_t xorshift64star(uint64_t x) +{ + x ^= x >> 12; /* a */ + x ^= x << 25; /* b */ + x ^= x >> 27; /* c */ + return x * UINT64_C(2685821657736338717); +} + +static void update_random_ops(int n_ops, enum precision prec) +{ + int i; + + for (i = 0; i < n_ops; i++) { + uint64_t r = random_ops[i]; + + if (prec == PREC_SINGLE || PREC_FLOAT32) { + do { + r = xorshift64star(r); + } while (!float32_is_normal(r)); + } else if (prec == PREC_DOUBLE || PREC_FLOAT64) { + do { + r = xorshift64star(r); + } while (!float64_is_normal(r)); + } else { + g_assert_not_reached(); + } + random_ops[i] = r; + } +} + +static void fill_random(union fp *ops, int n_ops, enum precision prec, + bool no_neg) +{ + int i; + + for (i = 0; i < n_ops; i++) { + switch (prec) { + case PREC_SINGLE: + case PREC_FLOAT32: + ops[i].f32 = make_float32(random_ops[i]); + if (no_neg && float32_is_neg(ops[i].f32)) { + ops[i].f32 = float32_chs(ops[i].f32); + } + /* raise the exponent to limit the frequency of denormal results */ + ops[i].f32 |= 0x40000000; + break; + case PREC_DOUBLE: + case PREC_FLOAT64: + ops[i].f64 = make_float64(random_ops[i]); + if (no_neg && float64_is_neg(ops[i].f64)) { + ops[i].f64 = float64_chs(ops[i].f64); + } + /* raise the exponent to limit the frequency of denormal results */ + ops[i].f64 |= LIT64(0x4000000000000000); + break; + default: + g_assert_not_reached(); + } + } +} + +/* + * The main benchmark function. Instead of (ab)using macros, we rely + * on the compiler to unfold this at compile-time. + */ +static void bench(enum precision prec, enum op op, int n_ops, bool no_neg) +{ + int64_t tf = get_clock() + duration * 1000000000LL; + + while (get_clock() < tf) { + union fp ops[MAX_OPERANDS]; + int64_t t0; + int i; + + update_random_ops(n_ops, prec); + switch (prec) { + case PREC_SINGLE: + fill_random(ops, n_ops, prec, no_neg); + t0 = get_clock(); + for (i = 0; i < OPS_PER_ITER; i++) { + float a = ops[0].f; + float b = ops[1].f; + float c = ops[2].f; + + switch (op) { + case OP_ADD: + res.f = a + b; + break; + case OP_SUB: + res.f = a - b; + break; + case OP_MUL: + res.f = a * b; + break; + case OP_DIV: + res.f = a / b; + break; + case OP_FMA: + res.f = fmaf(a, b, c); + break; + case OP_SQRT: + res.f = sqrtf(a); + break; + case OP_CMP: + res.u64 = isgreater(a, b); + break; + default: + g_assert_not_reached(); + } + } + break; + case PREC_DOUBLE: + fill_random(ops, n_ops, prec, no_neg); + t0 = get_clock(); + for (i = 0; i < OPS_PER_ITER; i++) { + double a = ops[0].d; + double b = ops[1].d; + double c = ops[2].d; + + switch (op) { + case OP_ADD: + res.d = a + b; + break; + case OP_SUB: + res.d = a - b; + break; + case OP_MUL: + res.d = a * b; + break; + case OP_DIV: + res.d = a / b; + break; + case OP_FMA: + res.d = fma(a, b, c); + break; + case OP_SQRT: + res.d = sqrt(a); + break; + case OP_CMP: + res.u64 = isgreater(a, b); + break; + default: + g_assert_not_reached(); + } + } + break; + case PREC_FLOAT32: + fill_random(ops, n_ops, prec, no_neg); + t0 = get_clock(); + for (i = 0; i < OPS_PER_ITER; i++) { + float32 a = ops[0].f32; + float32 b = ops[1].f32; + float32 c = ops[2].f32; + + switch (op) { + case OP_ADD: + res.f32 = float32_add(a, b, &soft_status); + break; + case OP_SUB: + res.f32 = float32_sub(a, b, &soft_status); + break; + case OP_MUL: + res.f = float32_mul(a, b, &soft_status); + break; + case OP_DIV: + res.f32 = float32_div(a, b, &soft_status); + break; + case OP_FMA: + res.f32 = float32_muladd(a, b, c, 0, &soft_status); + break; + case OP_SQRT: + res.f32 = float32_sqrt(a, &soft_status); + break; + case OP_CMP: + res.u64 = float32_compare_quiet(a, b, &soft_status); + break; + default: + g_assert_not_reached(); + } + } + break; + case PREC_FLOAT64: + fill_random(ops, n_ops, prec, no_neg); + t0 = get_clock(); + for (i = 0; i < OPS_PER_ITER; i++) { + float64 a = ops[0].f64; + float64 b = ops[1].f64; + float64 c = ops[2].f64; + + switch (op) { + case OP_ADD: + res.f64 = float64_add(a, b, &soft_status); + break; + case OP_SUB: + res.f64 = float64_sub(a, b, &soft_status); + break; + case OP_MUL: + res.f = float64_mul(a, b, &soft_status); + break; + case OP_DIV: + res.f64 = float64_div(a, b, &soft_status); + break; + case OP_FMA: + res.f64 = float64_muladd(a, b, c, 0, &soft_status); + break; + case OP_SQRT: + res.f64 = float64_sqrt(a, &soft_status); + break; + case OP_CMP: + res.u64 = float64_compare_quiet(a, b, &soft_status); + break; + default: + g_assert_not_reached(); + } + } + break; + default: + g_assert_not_reached(); + } + ns_elapsed += get_clock() - t0; + n_completed_ops += OPS_PER_ITER; + } +} + +#define GEN_BENCH(name, type, prec, op, n_ops) \ + static void __attribute__((flatten)) name(void) \ + { \ + bench(prec, op, n_ops, false); \ + } + +#define GEN_BENCH_NO_NEG(name, type, prec, op, n_ops) \ + static void __attribute__((flatten)) name(void) \ + { \ + bench(prec, op, n_ops, true); \ + } + +#define GEN_BENCH_ALL_TYPES(opname, op, n_ops) \ + GEN_BENCH(bench_ ## opname ## _float, float, PREC_SINGLE, op, n_ops) \ + GEN_BENCH(bench_ ## opname ## _double, double, PREC_DOUBLE, op, n_ops) \ + GEN_BENCH(bench_ ## opname ## _float32, float32, PREC_FLOAT32, op, n_ops) \ + GEN_BENCH(bench_ ## opname ## _float64, float64, PREC_FLOAT64, op, n_ops) + +GEN_BENCH_ALL_TYPES(add, OP_ADD, 2) +GEN_BENCH_ALL_TYPES(sub, OP_SUB, 2) +GEN_BENCH_ALL_TYPES(mul, OP_MUL, 2) +GEN_BENCH_ALL_TYPES(div, OP_DIV, 2) +GEN_BENCH_ALL_TYPES(fma, OP_FMA, 3) +GEN_BENCH_ALL_TYPES(cmp, OP_CMP, 2) +#undef GEN_BENCH_ALL_TYPES + +#define GEN_BENCH_ALL_TYPES_NO_NEG(name, op, n) \ + GEN_BENCH_NO_NEG(bench_ ## name ## _float, float, PREC_SINGLE, op, n) \ + GEN_BENCH_NO_NEG(bench_ ## name ## _double, double, PREC_DOUBLE, op, n) \ + GEN_BENCH_NO_NEG(bench_ ## name ## _float32, float32, PREC_FLOAT32, op, n) \ + GEN_BENCH_NO_NEG(bench_ ## name ## _float64, float64, PREC_FLOAT64, op, n) + +GEN_BENCH_ALL_TYPES_NO_NEG(sqrt, OP_SQRT, 1) +#undef GEN_BENCH_ALL_TYPES_NO_NEG + +#undef GEN_BENCH_NO_NEG +#undef GEN_BENCH + +#define GEN_BENCH_FUNCS(opname, op) \ + [op] = { \ + [PREC_SINGLE] = bench_ ## opname ## _float, \ + [PREC_DOUBLE] = bench_ ## opname ## _double, \ + [PREC_FLOAT32] = bench_ ## opname ## _float32, \ + [PREC_FLOAT64] = bench_ ## opname ## _float64, \ + } + +static const bench_func_t bench_funcs[OP_MAX_NR][PREC_MAX_NR] = { + GEN_BENCH_FUNCS(add, OP_ADD), + GEN_BENCH_FUNCS(sub, OP_SUB), + GEN_BENCH_FUNCS(mul, OP_MUL), + GEN_BENCH_FUNCS(div, OP_DIV), + GEN_BENCH_FUNCS(fma, OP_FMA), + GEN_BENCH_FUNCS(sqrt, OP_SQRT), + GEN_BENCH_FUNCS(cmp, OP_CMP), +}; + +#undef GEN_BENCH_FUNCS + +static void run_bench(void) +{ + bench_func_t f; + + f = bench_funcs[operation][precision]; + g_assert(f); + f(); +} + +/* @arr must be NULL-terminated */ +static int find_name(const char * const *arr, const char *name) +{ + int i; + + for (i = 0; arr[i] != NULL; i++) { + if (strcmp(name, arr[i]) == 0) { + return i; + } + } + return -1; +} + +static void usage_complete(int argc, char *argv[]) +{ + gchar *op_list = g_strjoinv(", ", (gchar **)op_names); + gchar *tester_list = g_strjoinv(", ", (gchar **)tester_names); + + fprintf(stderr, "Usage: %s [options]\n", argv[0]); + fprintf(stderr, "options:\n"); + fprintf(stderr, " -d = duration, in seconds. Default: %d\n", + DEFAULT_DURATION_SECS); + fprintf(stderr, " -h = show this help message.\n"); + fprintf(stderr, " -o = floating point operation (%s). Default: %s\n", + op_list, op_names[0]); + fprintf(stderr, " -p = floating point precision (single, double). " + "Default: single\n"); + fprintf(stderr, " -r = rounding mode (even, zero, down, up, tieaway). " + "Default: even\n"); + fprintf(stderr, " -t = tester (%s). Default: %s\n", + tester_list, tester_names[0]); + fprintf(stderr, " -z = flush inputs to zero (soft tester only). " + "Default: disabled\n"); + fprintf(stderr, " -Z = flush output to zero (soft tester only). " + "Default: disabled\n"); + + g_free(tester_list); + g_free(op_list); +} + +static int round_name_to_mode(const char *name) +{ + int i; + + for (i = 0; i < N_ROUND_MODES; i++) { + if (!strcmp(round_names[i], name)) { + return i; + } + } + return -1; +} + +static void QEMU_NORETURN die_host_rounding(enum rounding rounding) +{ + fprintf(stderr, "fatal: '%s' rounding not supported on this host\n", + round_names[rounding]); + exit(EXIT_FAILURE); +} + +static void set_host_precision(enum rounding rounding) +{ + int rhost; + + switch (rounding) { + case ROUND_EVEN: + rhost = FE_TONEAREST; + break; + case ROUND_ZERO: + rhost = FE_TOWARDZERO; + break; + case ROUND_DOWN: + rhost = FE_DOWNWARD; + break; + case ROUND_UP: + rhost = FE_UPWARD; + break; + case ROUND_TIEAWAY: + die_host_rounding(rounding); + return; + default: + g_assert_not_reached(); + } + + if (fesetround(rhost)) { + die_host_rounding(rounding); + } +} + +static void set_soft_precision(enum rounding rounding) +{ + signed char mode; + + switch (rounding) { + case ROUND_EVEN: + mode = float_round_nearest_even; + break; + case ROUND_ZERO: + mode = float_round_to_zero; + break; + case ROUND_DOWN: + mode = float_round_down; + break; + case ROUND_UP: + mode = float_round_up; + break; + case ROUND_TIEAWAY: + mode = float_round_ties_away; + break; + default: + g_assert_not_reached(); + } + soft_status.float_rounding_mode = mode; +} + +static void parse_args(int argc, char *argv[]) +{ + int c; + int val; + int rounding = ROUND_EVEN; + + for (;;) { + c = getopt(argc, argv, "d:ho:p:r:t:zZ"); + if (c < 0) { + break; + } + switch (c) { + case 'd': + duration = atoi(optarg); + break; + case 'h': + usage_complete(argc, argv); + exit(EXIT_SUCCESS); + case 'o': + val = find_name(op_names, optarg); + if (val < 0) { + fprintf(stderr, "Unsupported op '%s'\n", optarg); + exit(EXIT_FAILURE); + } + operation = val; + break; + case 'p': + if (!strcmp(optarg, "single")) { + precision = PREC_SINGLE; + } else if (!strcmp(optarg, "double")) { + precision = PREC_DOUBLE; + } else { + fprintf(stderr, "Unsupported precision '%s'\n", optarg); + exit(EXIT_FAILURE); + } + break; + case 'r': + rounding = round_name_to_mode(optarg); + if (rounding < 0) { + fprintf(stderr, "fatal: invalid rounding mode '%s'\n", optarg); + exit(EXIT_FAILURE); + } + break; + case 't': + val = find_name(tester_names, optarg); + if (val < 0) { + fprintf(stderr, "Unsupported tester '%s'\n", optarg); + exit(EXIT_FAILURE); + } + tester = val; + break; + case 'z': + soft_status.flush_inputs_to_zero = 1; + break; + case 'Z': + soft_status.flush_to_zero = 1; + break; + } + } + + /* set precision and rounding mode based on the tester */ + switch (tester) { + case TESTER_HOST: + set_host_precision(rounding); + break; + case TESTER_SOFT: + set_soft_precision(rounding); + switch (precision) { + case PREC_SINGLE: + precision = PREC_FLOAT32; + break; + case PREC_DOUBLE: + precision = PREC_FLOAT64; + break; + default: + g_assert_not_reached(); + } + break; + default: + g_assert_not_reached(); + } +} + +static void pr_stats(void) +{ + printf("%.2f MFlops\n", (double)n_completed_ops / ns_elapsed * 1e3); +} + +int main(int argc, char *argv[]) +{ + parse_args(argc, argv); + run_bench(); + pr_stats(); + return 0; +} |