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#include <sys/time.h>
#include <algorithm>
#include <cassert>
#include <cstdint>
#include <cstdio>
#include <cstring>
#include <vector>
static inline int ascii_std(const uint8_t *data, int len) {
return !std::any_of(data, data + len, [](int8_t b) { return b < 0; });
}
static inline int ascii_u64(const uint8_t *data, int len) {
uint8_t orall = 0;
if (len >= 16) {
uint64_t or1 = 0, or2 = 0;
const uint8_t *data2 = data + 8;
do {
or1 |= *(const uint64_t *)data;
or2 |= *(const uint64_t *)data2;
data += 16;
data2 += 16;
len -= 16;
} while (len >= 16);
/*
* Idea from Benny Halevy <bhalevy@scylladb.com>
* - 7-th bit set ==> orall = !(non-zero) - 1 = 0 - 1 = 0xFF
* - 7-th bit clear ==> orall = !0 - 1 = 1 - 1 = 0x00
*/
orall = !((or1 | or2) & 0x8080808080808080ULL) - 1;
}
while (len--) orall |= *data++;
return orall < 0x80;
}
#if defined(__x86_64__)
#include <x86intrin.h>
static inline int ascii_simd(const uint8_t *data, int len) {
if (len >= 32) {
const uint8_t *data2 = data + 16;
__m128i or1 = _mm_set1_epi8(0), or2 = or1;
while (len >= 32) {
__m128i input1 = _mm_loadu_si128((const __m128i *)data);
__m128i input2 = _mm_loadu_si128((const __m128i *)data2);
or1 = _mm_or_si128(or1, input1);
or2 = _mm_or_si128(or2, input2);
data += 32;
data2 += 32;
len -= 32;
}
or1 = _mm_or_si128(or1, or2);
if (_mm_movemask_epi8(_mm_cmplt_epi8(or1, _mm_set1_epi8(0)))) return 0;
}
return ascii_u64(data, len);
}
#elif defined(__aarch64__)
#include <arm_neon.h>
static inline int ascii_simd(const uint8_t *data, int len) {
if (len >= 32) {
const uint8_t *data2 = data + 16;
uint8x16_t or1 = vdupq_n_u8(0), or2 = or1;
while (len >= 32) {
const uint8x16_t input1 = vld1q_u8(data);
const uint8x16_t input2 = vld1q_u8(data2);
or1 = vorrq_u8(or1, input1);
or2 = vorrq_u8(or2, input2);
data += 32;
data2 += 32;
len -= 32;
}
or1 = vorrq_u8(or1, or2);
if (vmaxvq_u8(or1) >= 0x80) return 0;
}
return ascii_u64(data, len);
}
#endif
struct ftab {
const char *name;
int (*func)(const uint8_t *data, int len);
};
static const std::vector<ftab> _f = {
{
.name = "std",
.func = ascii_std,
},
{
.name = "u64",
.func = ascii_u64,
},
{
.name = "simd",
.func = ascii_simd,
},
};
static void load_test_buf(uint8_t *data, int len) {
uint8_t v = 0;
for (int i = 0; i < len; ++i) {
data[i] = v++;
v &= 0x7F;
}
}
static void bench(const struct ftab &f, const uint8_t *data, int len) {
const int loops = 1024 * 1024 * 1024 / len;
int ret = 1;
double time_aligned, time_unaligned, size;
struct timeval tv1, tv2;
fprintf(stderr, "bench %s (%d bytes)... ", f.name, len);
/* aligned */
gettimeofday(&tv1, 0);
for (int i = 0; i < loops; ++i) ret &= f.func(data, len);
gettimeofday(&tv2, 0);
time_aligned = tv2.tv_usec - tv1.tv_usec;
time_aligned = time_aligned / 1000000 + tv2.tv_sec - tv1.tv_sec;
/* unaligned */
gettimeofday(&tv1, 0);
for (int i = 0; i < loops; ++i) ret &= f.func(data + 1, len);
gettimeofday(&tv2, 0);
time_unaligned = tv2.tv_usec - tv1.tv_usec;
time_unaligned = time_unaligned / 1000000 + tv2.tv_sec - tv1.tv_sec;
printf("%s ", ret ? "pass" : "FAIL");
size = ((double)len * loops) / (1024 * 1024);
printf("%.0f/%.0f MB/s\n", size / time_aligned, size / time_unaligned);
}
static void test(const struct ftab &f, uint8_t *data, int len) {
int error = 0;
fprintf(stderr, "test %s (%d bytes)... ", f.name, len);
/* positive */
error |= !f.func(data, len);
/* negative */
if (len < 100 * 1024) {
for (int i = 0; i < len; ++i) {
data[i] += 0x80;
error |= f.func(data, len);
data[i] -= 0x80;
}
}
printf("%s\n", error ? "FAIL" : "pass");
}
/* ./ascii [test|bench] [alg] */
int main(int argc, const char *argv[]) {
int do_test = 1, do_bench = 1;
const char *alg = NULL;
if (argc > 1) {
do_bench &= !!strcmp(argv[1], "test");
do_test &= !!strcmp(argv[1], "bench");
}
if (do_bench && argc > 2) alg = argv[2];
const std::vector<int> size = {
9, 16 + 1, 32 - 1, 128 + 1,
1024 + 15, 16 * 1024 + 1, 64 * 1024 + 15, 1024 * 1024};
int max_size = *std::max_element(size.begin(), size.end());
uint8_t *_data = new uint8_t[max_size + 1];
assert(((uintptr_t)_data & 7) == 0);
uint8_t *data = _data + 1; /* Unalign buffer address */
_data[0] = 0;
load_test_buf(data, max_size);
if (do_test) {
printf("==================== Test ====================\n");
for (int sz : size) {
for (auto &f : _f) {
test(f, data, sz);
}
}
}
if (do_bench) {
printf("==================== Bench ====================\n");
for (int sz : size) {
for (auto &f : _f) {
if (!alg || strcmp(alg, f.name) == 0) bench(f, _data, sz);
}
printf("-----------------------------------------------\n");
}
}
delete _data;
return 0;
}
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