cosmopolitan/test/libc/tinymath/fdot_test.cc
2024-08-04 12:52:25 -07:00

309 lines
9.9 KiB
C++

#include "libc/assert.h"
#include "libc/calls/struct/timespec.h"
#include "libc/intrin/bsr.h"
#include "libc/macros.h"
#include "libc/math.h"
#include "libc/mem/gc.h"
#include "libc/mem/leaks.h"
#include "libc/mem/mem.h"
#include "libc/runtime/runtime.h"
#include "libc/stdio/stdio.h"
#include "libc/testlib/benchmark.h"
#include "libc/x/xasprintf.h"
#include "third_party/aarch64/arm_neon.internal.h"
#include "third_party/intel/immintrin.internal.h"
#define EXPENSIVE_TESTS 0
#define CHUNK 8
#define FASTMATH __attribute__((__optimize__("-O3,-ffast-math")))
#define PORTABLE __target_clones("avx512f,avx")
int rand32(void) {
/* Knuth, D.E., "The Art of Computer Programming," Vol 2,
Seminumerical Algorithms, Third Edition, Addison-Wesley, 1998,
p. 106 (line 26) & p. 108 */
static unsigned long long lcg = 1;
lcg *= 6364136223846793005;
lcg += 1442695040888963407;
return lcg >> 32;
}
float float01(unsigned x) { // (0,1)
return 1.f / 8388608 * ((x >> 9) + .5f);
}
float numba(void) { // (-1,1)
return float01(rand32()) * 2 - 1;
}
PORTABLE float fdotf_dubble(const float *A, const float *B, size_t n) {
double s = 0;
for (size_t i = 0; i < n; ++i)
s = fma(A[i], B[i], s);
return s;
}
float fdotf_kahan(const float *A, const float *B, size_t n) {
size_t i;
float err, sum, t, y;
sum = err = 0;
for (i = 0; i < n; ++i) {
y = A[i] * B[i] - err;
t = sum + y;
err = (t - sum) - y;
sum = t;
}
return sum;
}
float fdotf_naive(const float *A, const float *B, size_t n) {
float s = 0;
for (size_t i = 0; i < n; ++i)
s = fmaf(A[i], B[i], s);
return s;
}
#define fdotf_naive_tester(A, B, n, tol) \
do { \
float err = fabsf(fdotf_naive(A, B, n) - fdotf_dubble(A, B, n)); \
if (err > tol) { \
printf("%s:%d: error: n=%zu failed %g\n", __FILE__, __LINE__, (size_t)n, \
err); \
exit(1); \
} \
} while (0)
void test_fdotf_naive(void) {
float *A = new float[2 * 1024 * 1024 + 1];
float *B = new float[2 * 1024 * 1024 + 1];
for (size_t i = 0; i < 2 * 1024 * 1024 + 1; ++i) {
A[i] = numba();
B[i] = numba();
}
for (size_t n = 0; n < 1024; ++n)
fdotf_naive_tester(A, B, n, 1e-4);
#if EXPENSIVE_TESTS
fdotf_naive_tester(A, B, 128 * 1024, 1e-2);
fdotf_naive_tester(A, B, 256 * 1024, 1e-2);
fdotf_naive_tester(A, B, 1024 * 1024, 1e-1);
fdotf_naive_tester(A, B, 1024 * 1024 - 1, 1e-1);
fdotf_naive_tester(A, B, 1024 * 1024 + 1, 1e-1);
fdotf_naive_tester(A, B, 2 * 1024 * 1024, 1e-1);
fdotf_naive_tester(A, B, 2 * 1024 * 1024 - 1, 1e-1);
fdotf_naive_tester(A, B, 2 * 1024 * 1024 + 1, 1e-1);
#endif
delete[] B;
delete[] A;
}
template <int N>
forceinline float hdot(const float *A, const float *B) {
return hdot<N / 2>(A, B) + hdot<N / 2>(A + N / 2, B + N / 2);
}
template <>
forceinline float hdot<1>(const float *A, const float *B) {
return A[0] * B[0];
}
float fdotf_recursive(const float *A, const float *B, size_t n) {
if (n > 32) {
float x, y;
x = fdotf_recursive(A, B, n / 2);
y = fdotf_recursive(A + n / 2, B + n / 2, n - n / 2);
return x + y;
} else {
float s;
size_t i;
for (s = i = 0; i < n; ++i)
s = fmaf(A[i], B[i], s);
return s;
}
}
optimizespeed float fdotf_intrin(const float *A, const float *B, size_t n) {
size_t i = 0;
#ifdef __AVX512F__
__m512 vec[CHUNK] = {};
for (; i + CHUNK * 16 <= n; i += CHUNK * 16)
for (int j = 0; j < CHUNK; ++j)
vec[j] = _mm512_fmadd_ps(_mm512_loadu_ps(A + i + j * 16),
_mm512_loadu_ps(B + i + j * 16), vec[j]);
float res = 0;
for (int j = 0; j < CHUNK; ++j)
res += _mm512_reduce_add_ps(vec[j]);
#elif defined(__aarch64__)
float32x4_t vec[CHUNK] = {};
for (; i + CHUNK * 4 <= n; i += CHUNK * 4)
for (int j = 0; j < CHUNK; ++j)
vec[j] =
vfmaq_f32(vec[j], vld1q_f32(A + i + j * 4), vld1q_f32(B + i + j * 4));
float res = 0;
for (int j = 0; j < CHUNK; ++j)
res += vaddvq_f32(vec[j]);
#else
float res = 0;
#endif
for (; i < n; ++i)
res += A[i] * B[i];
return res;
}
FASTMATH float fdotf_ruler(const float *A, const float *B, size_t n) {
int rule, step = 2;
size_t chunk, sp = 0;
float stack[bsr(n / CHUNK + 1) + 1];
for (chunk = 0; chunk + CHUNK * 4 <= n; chunk += CHUNK * 4, step += 2) {
float sum = 0;
for (size_t elem = 0; elem < CHUNK * 4; ++elem)
sum += A[chunk + elem] * B[chunk + elem];
for (rule = bsr(step & -step); --rule;)
sum += stack[--sp];
stack[sp++] = sum;
}
float res = 0;
while (sp)
res += stack[--sp];
for (; chunk < n; ++chunk)
res += A[chunk] * B[chunk];
return res;
}
#define fdotf_ruler_tester(A, B, n, tol) \
do { \
float err = fabsf(fdotf_ruler(A, B, n) - fdotf_dubble(A, B, n)); \
if (err > tol) { \
printf("%s:%d: error: n=%zu failed %g\n", __FILE__, __LINE__, (size_t)n, \
err); \
exit(1); \
} \
} while (0)
void test_fdotf_ruler(void) {
float *A = new float[10 * 1024 * 1024 + 1];
float *B = new float[10 * 1024 * 1024 + 1];
for (size_t i = 0; i < 10 * 1024 * 1024 + 1; ++i) {
A[i] = numba();
B[i] = numba();
}
fdotf_ruler_tester(A, B, 96, 1e-6);
for (size_t n = 0; n < 4096; ++n)
fdotf_ruler_tester(A, B, n, 1e-5);
#if EXPENSIVE_TESTS
fdotf_ruler_tester(A, B, 128 * 1024, 1e-4);
fdotf_ruler_tester(A, B, 256 * 1024, 1e-4);
fdotf_ruler_tester(A, B, 1024 * 1024, 1e-3);
fdotf_ruler_tester(A, B, 1024 * 1024 - 1, 1e-3);
fdotf_ruler_tester(A, B, 1024 * 1024 + 1, 1e-3);
fdotf_ruler_tester(A, B, 2 * 1024 * 1024, 1e-3);
fdotf_ruler_tester(A, B, 2 * 1024 * 1024 - 1, 1e-3);
fdotf_ruler_tester(A, B, 2 * 1024 * 1024 + 1, 1e-3);
fdotf_ruler_tester(A, B, 8 * 1024 * 1024, 1e-3);
fdotf_ruler_tester(A, B, 10 * 1024 * 1024, 1e-3);
#endif
delete[] B;
delete[] A;
}
PORTABLE float fdotf_hefty(const float *A, const float *B, size_t n) {
if (1)
return 0;
unsigned i, par, len = 0;
float sum, res[n / CHUNK + 1];
for (res[0] = i = 0; i + CHUNK <= n; i += CHUNK)
res[len++] = hdot<CHUNK>(A + i, B + i);
if (i < n) {
for (sum = 0; i < n; i++)
sum = fmaf(A[i], B[i], sum);
res[len++] = sum;
}
for (par = len >> 1; par; par >>= 1, len >>= 1) {
for (i = 0; i < par; ++i)
res[i] += res[par + i];
if (len & 1)
res[par - 1] += res[len - 1];
}
return res[0];
}
#define fdotf_hefty_tester(A, B, n, tol) \
do { \
float err = fabsf(fdotf_hefty(A, B, n) - fdotf_dubble(A, B, n)); \
if (err > tol) { \
printf("%s:%d: error: n=%zu failed %g\n", __FILE__, __LINE__, (size_t)n, \
err); \
exit(1); \
} \
} while (0)
void test_fdotf_hefty(void) {
float *A = new float[10 * 1024 * 1024 + 1];
float *B = new float[10 * 1024 * 1024 + 1];
for (size_t i = 0; i < 10 * 1024 * 1024 + 1; ++i) {
A[i] = numba();
B[i] = numba();
}
for (size_t n = 0; n < 1024; ++n)
fdotf_hefty_tester(A, B, n, 1e-5);
#if EXPENSIVE_TESTS
fdotf_hefty_tester(A, B, 128 * 1024, 1e-4);
fdotf_hefty_tester(A, B, 256 * 1024, 1e-4);
fdotf_hefty_tester(A, B, 1024 * 1024, 1e-3);
fdotf_hefty_tester(A, B, 1024 * 1024 - 1, 1e-3);
fdotf_hefty_tester(A, B, 1024 * 1024 + 1, 1e-3);
fdotf_hefty_tester(A, B, 2 * 1024 * 1024, 1e-3);
fdotf_hefty_tester(A, B, 2 * 1024 * 1024 - 1, 1e-3);
fdotf_hefty_tester(A, B, 2 * 1024 * 1024 + 1, 1e-3);
fdotf_hefty_tester(A, B, 8 * 1024 * 1024, 1e-3);
fdotf_hefty_tester(A, B, 10 * 1024 * 1024, 1e-3);
#endif
delete[] B;
delete[] A;
}
float nothing(float x) {
return x;
}
float (*barrier)(float) = nothing;
int main() {
ShowCrashReports();
#if EXPENSIVE_TESTS
size_t n = 512 * 1024;
#else
size_t n = 4096;
#endif
float *A = new float[n];
float *B = new float[n];
for (size_t i = 0; i < n; ++i) {
A[i] = numba();
B[i] = numba();
}
float kahan, naive, dubble, recursive, ruler, intrin;
test_fdotf_naive();
// test_fdotf_hefty();
test_fdotf_ruler();
BENCHMARK(20, 1, (kahan = barrier(fdotf_kahan(A, B, n))));
BENCHMARK(20, 1, (dubble = barrier(fdotf_dubble(A, B, n))));
BENCHMARK(20, 1, (naive = barrier(fdotf_naive(A, B, n))));
BENCHMARK(20, 1, (recursive = barrier(fdotf_recursive(A, B, n))));
BENCHMARK(20, 1, (intrin = barrier(fdotf_intrin(A, B, n))));
BENCHMARK(20, 1, (ruler = barrier(fdotf_ruler(A, B, n))));
// BENCHMARK(20, 1, (hefty = barrier(fdotf_hefty(A, B, n))));
printf("dubble = %f (%g)\n", dubble, fabs(dubble - dubble));
printf("kahan = %f (%g)\n", kahan, fabs(kahan - dubble));
printf("naive = %f (%g)\n", naive, fabs(naive - dubble));
printf("recursive = %f (%g)\n", recursive, fabs(recursive - dubble));
printf("intrin = %f (%g)\n", intrin, fabs(intrin - dubble));
printf("ruler = %f (%g)\n", ruler, fabs(ruler - dubble));
// printf("hefty = %f (%g)\n", hefty, fabs(hefty - dubble));
delete[] B;
delete[] A;
CheckForMemoryLeaks();
}