source code
/* The Computer Language Benchmarks Game
* https://salsa.debian.org/benchmarksgame-team/benchmarksgame/
*
* Contributed by Bogdan Sharkov
* Optimized memory access (AVX intrinsics), compile with -march=native -fopenmp for best results
*
* Contributed by Mr Ledrug
* Algorithm lifted from Intel Fortran #2 code by Steve Decker et al.
*/
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <malloc.h>
#include <x86intrin.h>
double dot(double * v, double * u, int n) {
int i;
double sum = 0;
for (i = 0; i < n; i++)
sum += *v++ * *u++;
return sum;
}
void mult_Av(double * v, double * out, const int n) {
__m256i ONE = _mm256_set1_epi32(1);
__m256i EIGHT = _mm256_set1_epi32(8);
unsigned int i, j;
#pragma omp parallel for schedule(static)
for (i = 1; i <= n; i++) {
j = i-1;
int k = n+j;
__m256i m = _mm256_set1_epi32(i);
__m256d mysum =_mm256_setzero_pd();
__m256i x = _mm256_setr_epi32(j, j + 1, j + 2, j + 3, j + 4, j + 5, j + 6, j + 7);
for (double* pv = v; j < k; j+=8, pv+=4) {
__m256i y = _mm256_add_epi32(x, ONE);
__m256i a = _mm256_mullo_epi32(x, y);
x = _mm256_add_epi32(x, EIGHT);
a = _mm256_srli_epi32(a, 1);
a = _mm256_add_epi32(a, m);
__m128i a1 = _mm256_castsi256_si128(a);
__m256d mul = _mm256_cvtepi32_pd(a1);
__m256d src = _mm256_load_pd(pv);
pv+=4;
__m256d res = _mm256_div_pd(src, mul);
mysum = _mm256_add_pd(mysum, res);
a1 = _mm256_extracti128_si256(a, 1);
mul = _mm256_cvtepi32_pd(a1);
src = _mm256_load_pd(pv);
res = _mm256_div_pd(src, mul);
mysum = _mm256_add_pd(mysum, res);
}
out[i-1] = ((double*)&mysum)[0] + ((double*)&mysum)[1] + ((double*)&mysum)[2] + ((double*)&mysum)[3];
}
for(i=n;i<n+7;i++) out[i] =0.0;
}
void mult_Atv(double * v, double * out, const int n) {
__m256i ONE = _mm256_set1_epi32(1);
__m256i EIGHT = _mm256_set1_epi32(8);
int i;
#pragma omp parallel for schedule(static)
for (i = 0; i < n; i++) {
double* pv = v;
__m256d mysum =_mm256_setzero_pd();
__m256i x = _mm256_setr_epi32(i, i + 1, i + 2, i + 3, i + 4, i + 5, i + 6, i + 7);
__m256i aj = _mm256_setr_epi32(1, 2, 3, 4, 5, 6, 7, 8);
for (int j=0; j < n;j+=8, pv+=4){
__m256i y = _mm256_add_epi32(x, ONE);
__m256i a = _mm256_mullo_epi32(x, y);
x = _mm256_add_epi32(x, EIGHT);
a = _mm256_srli_epi32(a, 1);
a = _mm256_add_epi32(a, aj);
aj = _mm256_add_epi32(aj, EIGHT);
__m128i a1 = _mm256_castsi256_si128(a);
__m256d mul = _mm256_cvtepi32_pd(a1);
__m256d src = _mm256_load_pd(pv);
pv+=4;
__m256d res = _mm256_div_pd(src, mul);
mysum = _mm256_add_pd(mysum, res);
a1 = _mm256_extracti128_si256(a, 1);
mul = _mm256_cvtepi32_pd(a1);
src = _mm256_load_pd(pv);
res = _mm256_div_pd(src, mul);
mysum = _mm256_add_pd(mysum, res);
}
out[i] = ((double*)&mysum)[0] + ((double*)&mysum)[1] + ((double*)&mysum)[2] + ((double*)&mysum)[3];
}
for(i=n;i<n+7;i++) out[i]=0.0;
}
double *tmp;
void mult_AtAv(double *v, double *out, const int n) {
mult_Av(v, tmp, n);
mult_Atv(tmp, out, n);
}
int main(int argc, char**argv) {
int n = 2000;
if (argc >= 2) n = atoi(argv[1]);
double *u, *v;
u = _mm_malloc((n+7) * sizeof(double),sizeof(__m256d));
v = _mm_malloc((n+7) * sizeof(double),sizeof(__m256d));
tmp = _mm_malloc((n+7) * sizeof(double),sizeof(__m256d));
int i;
for (i = 0; i < n; i++) u[i] = 1;
for(i=n;i<n+7;i++) u[i]=0.0;
for (i = 0; i < 10; i++) {
mult_AtAv(u, v, n);
mult_AtAv(v, u, n);
}
printf("%.9f\n", sqrt(dot(u,v, n) / dot(v,v,n)));
_mm_free(u);
_mm_free(v);
_mm_free(tmp);
return 0;
}
notes, command-line, and program output
NOTES:
64-bit Ubuntu quad core
13.2.0-4ubuntu3
Fri, 01 Mar 2024 00:28:16 GMT
MAKE:
/usr/bin/gcc -pipe -Wall -O3 -fomit-frame-pointer -march=ivybridge -fopenmp spectralnorm.gcc-8.c -o spectralnorm.gcc-8.gcc_run -lm
In file included from /usr/lib/gcc/x86_64-linux-gnu/13/include/immintrin.h:51,
from /usr/lib/gcc/x86_64-linux-gnu/13/include/x86intrin.h:32,
from spectralnorm.gcc-8.c:15:
/usr/lib/gcc/x86_64-linux-gnu/13/include/avx2intrin.h: In function ‘mult_Av._omp_fn.0’:
/usr/lib/gcc/x86_64-linux-gnu/13/include/avx2intrin.h:1096:1: error: inlining failed in call to ‘always_inline’ ‘_mm256_extracti128_si256’: target specific option mismatch
1096 | _mm256_extracti128_si256 (__m256i __X, const int __M)
| ^~~~~~~~~~~~~~~~~~~~~~~~
spectralnorm.gcc-8.c:52:33: note: called from here
52 | a1 = _mm256_extracti128_si256(a, 1);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/lib/gcc/x86_64-linux-gnu/13/include/avx2intrin.h:119:1: error: inlining failed in call to ‘always_inline’ ‘_mm256_add_epi32’: target specific option mismatch
119 | _mm256_add_epi32 (__m256i __A, __m256i __B)
| ^~~~~~~~~~~~~~~~
spectralnorm.gcc-8.c:43:29: note: called from here
43 | a = _mm256_add_epi32(a, m);
| ^~~~~~~~~~~~~~~~~~~~~~
/usr/lib/gcc/x86_64-linux-gnu/13/include/avx2intrin.h:773:1: error: inlining failed in call to ‘always_inline’ ‘_mm256_srli_epi32’: target specific option mismatch
773 | _mm256_srli_epi32 (__m256i __A, int __B)
| ^~~~~~~~~~~~~~~~~
spectralnorm.gcc-8.c:42:29: note: called from here
42 | a = _mm256_srli_epi32(a, 1);
| ^~~~~~~~~~~~~~~~~~~~~~~
/usr/lib/gcc/x86_64-linux-gnu/13/include/avx2intrin.h:119:1: error: inlining failed in call to ‘always_inline’ ‘_mm256_add_epi32’: target specific option mismatch
119 | _mm256_add_epi32 (__m256i __A, __m256i __B)
| ^~~~~~~~~~~~~~~~
spectralnorm.gcc-8.c:41:29: note: called from here
41 | x = _mm256_add_epi32(x, EIGHT);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/lib/gcc/x86_64-linux-gnu/13/include/avx2intrin.h:560:1: error: inlining failed in call to ‘always_inline’ ‘_mm256_mullo_epi32’: target specific option mismatch
560 | _mm256_mullo_epi32 (__m256i __A, __m256i __B)
| ^~~~~~~~~~~~~~~~~~
spectralnorm.gcc-8.c:40:37: note: called from here
40 | __m256i a = _mm256_mullo_epi32(x, y);
| ^~~~~~~~~~~~~~~~~~~~~~~~
/usr/lib/gcc/x86_64-linux-gnu/13/include/avx2intrin.h:119:1: error: inlining failed in call to ‘always_inline’ ‘_mm256_add_epi32’: target specific option mismatch
119 | _mm256_add_epi32 (__m256i __A, __m256i __B)
| ^~~~~~~~~~~~~~~~
spectralnorm.gcc-8.c:39:37: note: called from here
39 | __m256i y = _mm256_add_epi32(x, ONE);
| ^~~~~~~~~~~~~~~~~~~~~~~~
/usr/lib/gcc/x86_64-linux-gnu/13/include/avx2intrin.h:1096:1: error: inlining failed in call to ‘always_inline’ ‘_mm256_extracti128_si256’: target specific option mismatch
1096 | _mm256_extracti128_si256 (__m256i __X, const int __M)
| ^~~~~~~~~~~~~~~~~~~~~~~~
spectralnorm.gcc-8.c:52:33: note: called from here
52 | a1 = _mm256_extracti128_si256(a, 1);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
make: [/home/dunham/all-benchmarksgame/2000-benchmarksgame/nanobench/makefiles/u64q.programs.Makefile:43: spectralnorm.gcc-8.gcc_run] Error 1 (ignored)
rm spectralnorm.gcc-8.c
2.19s to complete and log all make actions
COMMAND LINE:
./spectralnorm.gcc-8.gcc_run 500
MAKE ERROR