This will allow us to measure the performance impact of FP
emulation optimizations.
Signed-off-by: Emilio G. Cota <c...@braap.org>
---
tests/fp-bench.c | 290 +++++++++++++++++++++++++++++++++++++++++++++++++
tests/.gitignore | 1 +
tests/Makefile.include | 3 +-
3 files changed, 293 insertions(+), 1 deletion(-)
create mode 100644 tests/fp-bench.c
diff --git a/tests/fp-bench.c b/tests/fp-bench.c
new file mode 100644
index 0000000..a782093
--- /dev/null
+++ b/tests/fp-bench.c
@@ -0,0 +1,290 @@
+/*
+ * fp-bench.c - A collection of simple floating point microbenchmarks.
+ *
+ * Copyright (C) 2018, Emilio G. Cota <c...@braap.org>
+ *
+ * License: GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+#include "qemu/osdep.h"
+#include "qemu/atomic.h"
+
+#include <math.h>
+
+#include <sys/time.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <time.h>
+
+/* amortize the computation of random inputs */
+#define OPS_PER_ITER (1000ULL)
+
+#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,
+};
+
+static const char * const op_names[] = {
+ [OP_ADD] = "add",
+ [OP_SUB] = "sub",
+ [OP_MUL] = "mul",
+ [OP_DIV] = "div",
+ [OP_FMA] = "fma",
+ [OP_SQRT] = "sqrt",
+};
+
+static uint64_t n_ops = 10000000;
+static enum op op;
+static const char *precision = "float";
+
+static const char commands_string[] =
+ " -n = number of floating point operations\n"
+ " -o = floating point operation (add, sub, mul, div, fma, sqrt). Default:
add\n"
+ " -p = precision (float|single, double). Default: float";
+
+static void usage_complete(int argc, char *argv[])
+{
+ fprintf(stderr, "Usage: %s [options]\n", argv[0]);
+ fprintf(stderr, "options:\n%s\n", commands_string);
+ exit(-1);
+}
+
+static void set_op(const char *name)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(op_names); i++) {
+ if (strcmp(name, op_names[i]) == 0) {
+ op = i;
+ return;
+ }
+ }
+ fprintf(stderr, "Unsupported op '%s'\n", name);
+ exit(EXIT_FAILURE);
+}
+
+static inline int64_t get_clock_realtime(void)
+{
+ struct timeval tv;
+
+ gettimeofday(&tv, NULL);
+ return tv.tv_sec * 1000000000LL + (tv.tv_usec * 1000);
+}
+
+/*
+ * 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 inline bool u32_is_normal(uint32_t x)
+{
+ return ((x + 0x00800000) & 0x7fffffff) >= 0x01000000;
+}
+
+static inline bool u64_is_normal(uint64_t x)
+{
+ return ((x + (1ULL << 52)) & -1ULL >> 1) >= 1ULL << 53;
+}
+
+static inline float get_random_float(uint64_t *x)
+{
+ uint64_t r = *x;
+ uint32_t r32;
+
+ do {
+ r = xorshift64star(r);
+ } while (!u32_is_normal(r));
+ *x = r;
+ r32 = r;
+ return *(float *)&r32;
+}
+
+static inline double get_random_double(uint64_t *x)
+{
+ uint64_t r = *x;
+
+ do {
+ r = xorshift64star(r);
+ } while (!u64_is_normal(r));
+ *x = r;
+ return *(double *)&r;
+}
+
+/*
+ * Disable optimizations (e.g. "a OP b" outside of the inner loop) with
+ * volatile.
+ */
+#define GEN_BENCH_1OPF(NAME, FUNC, PRECISION) \
+ static void NAME(volatile PRECISION *res) \
+ { \
+ uint64_t ra = SEED_A; \
+ uint64_t i, j; \
+ \
+ for (i = 0; i < n_ops; i += OPS_PER_ITER) { \
+ volatile PRECISION a = glue(get_random_, PRECISION)(&ra); \
+ \
+ for (j = 0; j < OPS_PER_ITER; j++) { \
+ *res = FUNC(a); \
+ } \
+ } \
+ }
+
+GEN_BENCH_1OPF(bench_float_sqrt, sqrtf, float)
+GEN_BENCH_1OPF(bench_double_sqrt, sqrt, double)
+#undef GEN_BENCH_1OPF
+
+#define GEN_BENCH_2OP(NAME, OP, PRECISION) \
+ static void NAME(volatile PRECISION *res) \
+ { \
+ uint64_t ra = SEED_A; \
+ uint64_t rb = SEED_B; \
+ uint64_t i, j; \
+ \
+ for (i = 0; i < n_ops; i += OPS_PER_ITER) { \
+ volatile PRECISION a = glue(get_random_, PRECISION)(&ra); \
+ volatile PRECISION b = glue(get_random_, PRECISION)(&rb); \
+ \
+ for (j = 0; j < OPS_PER_ITER; j++) { \
+ *res = a OP b; \
+ } \
+ } \
+ }
+
+GEN_BENCH_2OP(bench_float_add, +, float)
+GEN_BENCH_2OP(bench_float_sub, -, float)
+GEN_BENCH_2OP(bench_float_mul, *, float)
+GEN_BENCH_2OP(bench_float_div, /, float)
+
+GEN_BENCH_2OP(bench_double_add, +, double)
+GEN_BENCH_2OP(bench_double_sub, -, double)
+GEN_BENCH_2OP(bench_double_mul, *, double)
+GEN_BENCH_2OP(bench_double_div, /, double)
+
+#define GEN_BENCH_3OPF(NAME, FUNC, PRECISION) \
+ static void NAME(volatile PRECISION *res) \
+ { \
+ uint64_t ra = SEED_A; \
+ uint64_t rb = SEED_B; \
+ uint64_t rc = SEED_C; \
+ uint64_t i, j; \
+ \
+ for (i = 0; i < n_ops; i += OPS_PER_ITER) { \
+ volatile PRECISION a = glue(get_random_, PRECISION)(&ra); \
+ volatile PRECISION b = glue(get_random_, PRECISION)(&rb); \
+ volatile PRECISION c = glue(get_random_, PRECISION)(&rc); \
+ \
+ for (j = 0; j < OPS_PER_ITER; j++) { \
+ *res = FUNC(a, b, c); \
+ } \
+ } \
+ }
+
+GEN_BENCH_3OPF(bench_float_fma, fmaf, float)
+GEN_BENCH_3OPF(bench_double_fma, fma, double)
+#undef GEN_BENCH_3OPF
+
+static void parse_args(int argc, char *argv[])
+{
+ int c;
+
+ for (;;) {
+ c = getopt(argc, argv, "n:ho:p:");
+ if (c < 0) {
+ break;
+ }
+ switch (c) {
+ case 'h':
+ usage_complete(argc, argv);
+ exit(0);
+ case 'n':
+ n_ops = atoll(optarg);
+ if (n_ops < OPS_PER_ITER) {
+ n_ops = OPS_PER_ITER;
+ }
+ n_ops -= n_ops % OPS_PER_ITER;
+ break;
+ case 'o':
+ set_op(optarg);
+ break;
+ case 'p':
+ precision = optarg;
+ if (strcmp(precision, "float") &&
+ strcmp(precision, "single") &&
+ strcmp(precision, "double")) {
+ fprintf(stderr, "Unsupported precision '%s'\n", precision);
+ exit(EXIT_FAILURE);
+ }
+ break;
+ }
+ }
+}
+
+#define CALL_BENCH(OP, PRECISION, RESP) \
+ do { \
+ switch (OP) { \
+ case OP_ADD: \
+ glue(glue(bench_, PRECISION), _add)(RESP); \
+ break; \
+ case OP_SUB: \
+ glue(glue(bench_, PRECISION), _sub)(RESP); \
+ break; \
+ case OP_MUL: \
+ glue(glue(bench_, PRECISION), _mul)(RESP); \
+ break; \
+ case OP_DIV: \
+ glue(glue(bench_, PRECISION), _div)(RESP); \
+ break; \
+ case OP_FMA: \
+ glue(glue(bench_, PRECISION), _fma)(RESP); \
+ break; \
+ case OP_SQRT: \
+ glue(glue(bench_, PRECISION), _sqrt)(RESP); \
+ break; \
+ default: \
+ g_assert_not_reached(); \
+ } \
+ } while (0)
+
+int main(int argc, char *argv[])
+{
+ int64_t t0, t1;
+ double resd;
+
+ parse_args(argc, argv);
+ if (!strcmp(precision, "float") || !strcmp(precision, "single")) {
+ float res;
+ t0 = get_clock_realtime();
+ CALL_BENCH(op, float, &res);
+ t1 = get_clock_realtime();
+ resd = res;
+ } else if (!strcmp(precision, "double")) {
+ t0 = get_clock_realtime();
+ CALL_BENCH(op, double, &resd);
+ t1 = get_clock_realtime();
+ } else {
+ g_assert_not_reached();
+ }
+ printf("%.2f MFlops\n", (double)n_ops / (t1 - t0) * 1e3);
+ if (resd) {
+ return 0;
+ }
+ return 0;
+}
diff --git a/tests/.gitignore b/tests/.gitignore
index 18e58b2..df69175 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -12,6 +12,7 @@ check-qobject
check-qstring
check-qom-interface
check-qom-proplist
+fp-bench
qht-bench
rcutorture
test-aio
diff --git a/tests/Makefile.include b/tests/Makefile.include
index ef9b88c..f6121ee 100644
--- a/tests/Makefile.include
+++ b/tests/Makefile.include
@@ -587,7 +587,7 @@ test-obj-y = tests/check-qnum.o tests/check-qstring.o
tests/check-qdict.o \
tests/rcutorture.o tests/test-rcu-list.o \
tests/test-qdist.o tests/test-shift128.o \
tests/test-qht.o tests/qht-bench.o tests/test-qht-par.o \
- tests/atomic_add-bench.o
+ tests/atomic_add-bench.o tests/fp-bench.o
$(test-obj-y): QEMU_INCLUDES += -Itests
QEMU_CFLAGS += -I$(SRC_PATH)/tests
@@ -639,6 +639,7 @@ tests/test-qht-par$(EXESUF): tests/test-qht-par.o
tests/qht-bench$(EXESUF) $(tes
tests/qht-bench$(EXESUF): tests/qht-bench.o $(test-util-obj-y)
tests/test-bufferiszero$(EXESUF): tests/test-bufferiszero.o $(test-util-obj-y)
tests/atomic_add-bench$(EXESUF): tests/atomic_add-bench.o $(test-util-obj-y)
+tests/fp-bench$(EXESUF): tests/fp-bench.o $(test-util-obj-y)
tests/test-qdev-global-props$(EXESUF): tests/test-qdev-global-props.o \
hw/core/qdev.o hw/core/qdev-properties.o hw/core/hotplug.o\
--
2.7.4
