performance measurements
Each table row shows performance measurements for this C++ g++ program with a particular command-line input value N.
| N | CPU secs | Elapsed secs | Memory KB | Code B | ≈ CPU Load |
|---|---|---|---|---|---|
| 10 | 0.26 | 0.27 | 372 | 894 | 4% 4% 0% 100% |
| 11 | 3.14 | 3.15 | 372 | 894 | 0% 0% 1% 100% |
| 12 | 40.52 | 40.54 | 376 | 894 | 0% 0% 0% 100% |
Read the ↓ make, command line, and program output logs to see how this program was run.
Read fannkuch-redux benchmark to see what this program should do.
notes
gcc (Ubuntu/Linaro 4.7.3-1ubuntu1) 4.7.3
fannkuch-redux C++ g++ #6 program source code
/* The Computer Language Benchmarks Game http://benchmarksgame.alioth.debian.org/ contributed by Branimir Maksimovic */ #include <cstdlib> #include <cstdio> #include <cstring> #include <algorithm> #include <immintrin.h> int checksum; int maxflips; typedef unsigned char int_t; void reverse(int_t* p,int n) { static __attribute__((aligned(16))) unsigned long long w[11][2] = { {0x0706050403020001ll,0x0f0e0d0c0b0a0908ll}, {0x0706050403000102ll,0x0f0e0d0c0b0a0908ll}, {0x0706050400010203ll,0x0f0e0d0c0b0a0908ll}, {0x0706050001020304ll,0x0f0e0d0c0b0a0908ll}, {0x0706000102030405ll,0x0f0e0d0c0b0a0908ll}, {0x0700010203040506ll,0x0f0e0d0c0b0a0908ll}, {0x0001020304050607ll,0x0f0e0d0c0b0a0908ll}, {0x0102030405060708ll,0x0f0e0d0c0b0a0900ll}, {0x0203040506070809ll,0x0f0e0d0c0b0a0001ll}, {0x030405060708090all,0x0f0e0d0c0b000102ll}, {0x0405060708090a0bll,0x0f0e0d0c00010203ll}, }; __m128i a,b; b = _mm_load_si128((__m128i*)&w[n-2][0]); a = _mm_load_si128((__m128i*)p); a = _mm_shuffle_epi8(a,b); _mm_store_si128((__m128i*)p,a); } void rotate(int_t* p, int n) { static __attribute__((aligned(16))) unsigned long long w[11][2] = { {0x0706050403020001ll,0x0f0e0d0c0b0a0908ll}, {0x0706050403000201ll,0x0f0e0d0c0b0a0908ll}, {0x0706050400030201ll,0x0f0e0d0c0b0a0908ll}, {0x0706050004030201ll,0x0f0e0d0c0b0a0908ll}, {0x0706000504030201ll,0x0f0e0d0c0b0a0908ll}, {0x0700060504030201ll,0x0f0e0d0c0b0a0908ll}, {0x0007060504030201ll,0x0f0e0d0c0b0a0908ll}, {0x0807060504030201ll,0x0f0e0d0c0b0a0900ll}, {0x0807060504030201ll,0x0f0e0d0c0b0a0009ll}, {0x0807060504030201ll,0x0f0e0d0c0b000a09ll}, {0x0807060504030201ll,0x0f0e0d0c000b0a09ll}, }; __m128i a,b; b = _mm_load_si128((__m128i*)&w[n-1][0]); a = _mm_load_si128((__m128i*)p); a = _mm_shuffle_epi8(a,b); _mm_store_si128((__m128i*)p,a); } bool next_permutation(int_t* beg, int n, int_t* c) { int i = 1; while(i<n) { rotate(beg,i); if(c[i]>=i)c[i++]=0; else break; } if(i>=n)return false; ++c[i]; return true; } struct next{ next():n(0){} int_t operator ()(){ return ++n;} int_t n; }; void fannkuch(int n) { checksum = 0; maxflips = 0; __attribute__((aligned(16))) int_t perm[16]; __attribute__((aligned(16))) int_t tperm[16]; int permcount = 0; int_t count[16]={0}; std::generate(perm,perm+n,next()); do { std::copy(perm,perm+n,tperm); int flips = 0; while(tperm[0] != 1) { reverse(tperm,tperm[0]); ++flips; } checksum += (permcount%2 == 0)?flips:-flips; maxflips = std::max(maxflips,flips); }while(++permcount,next_permutation(perm,n,count)); } int main(int argc, char** argv) { int n = 7; if(argc > 1)n = atoi(argv[1]); if(n < 3 || n > 12) { printf("n should be between 3 and 12\n"); return 0; } fannkuch(n); printf("%d\nPfannkuchen(%d) = %d\n",checksum,n,maxflips); }
make, command-line, and program output logs
Mon, 29 Apr 2013 19:42:07 GMT
MAKE:
/usr/bin/g++ -c -pipe -O3 -fomit-frame-pointer -march=native -falign-labels=8 fannkuchredux.gpp-6.c++ -o fannkuchredux.gpp-6.c++.o && \
/usr/bin/g++ fannkuchredux.gpp-6.c++.o -o fannkuchredux.gpp-6.gpp_run
rm fannkuchredux.gpp-6.c++
0.23s to complete and log all make actions
COMMAND LINE:
./fannkuchredux.gpp-6.gpp_run 12
PROGRAM OUTPUT:
3968050
Pfannkuchen(12) = 65