performance measurements
Each table row shows performance measurements for this C GNU gcc program with a particular command-line input value N.
| N | CPU secs | Elapsed secs | Memory KB | Code B | ≈ CPU Load |
|---|---|---|---|---|---|
| 10 | 0.47 | 392 | 628 | ||
| 11 | 5.87 | 392 | 628 | ||
| 9 | 0.05 | 392 | 628 |
Read the ↓ make, command line, and program output logs to see how this program was run.
Read fannkuch benchmark to see what this program should do.
fannkuch C GNU gcc program source code
/* * The Computer Lannguage Shootout * http://shootout.alioth.debian.org/ * Contributed by Heiner Marxen * * "fannkuch" for C gcc * * $Id: fannkuch.1.gcc.code,v 1.1 2008-08-06 18:32:49 igouy-guest Exp $ */ #include <stdio.h> #include <stdlib.h> #define Int int #define Aint int static long fannkuch( int n ) { Aint* perm; Aint* perm1; Aint* count; long flips; long flipsMax; Int r; Int i; Int k; Int didpr; const Int n1 = n - 1; if( n < 1 ) return 0; perm = calloc(n, sizeof(*perm )); perm1 = calloc(n, sizeof(*perm1)); count = calloc(n, sizeof(*count)); for( i=0 ; i<n ; ++i ) perm1[i] = i; /* initial (trivial) permu */ r = n; didpr = 0; flipsMax = 0; for(;;) { if( didpr < 30 ) { for( i=0 ; i<n ; ++i ) printf("%d", (int)(1+perm1[i])); printf("\n"); ++didpr; } for( ; r!=1 ; --r ) { count[r-1] = r; } #define XCH(x,y) { Aint t_mp; t_mp=(x); (x)=(y); (y)=t_mp; } if( ! (perm1[0]==0 || perm1[n1]==n1) ) { flips = 0; for( i=1 ; i<n ; ++i ) { /* perm = perm1 */ perm[i] = perm1[i]; } k = perm1[0]; /* cache perm[0] in k */ do { /* k!=0 ==> k>0 */ Int j; for( i=1, j=k-1 ; i<j ; ++i, --j ) { XCH(perm[i], perm[j]) } ++flips; /* * Now exchange k (caching perm[0]) and perm[k]... with care! * XCH(k, perm[k]) does NOT work! */ j=perm[k]; perm[k]=k ; k=j; }while( k ); if( flipsMax < flips ) { flipsMax = flips; } } for(;;) { if( r == n ) { return flipsMax; } /* rotate down perm[0..r] by one */ { Int perm0 = perm1[0]; i = 0; while( i < r ) { k = i+1; perm1[i] = perm1[k]; i = k; } perm1[r] = perm0; } if( (count[r] -= 1) > 0 ) { break; } ++r; } } } int main( int argc, char* argv[] ) { int n = (argc>1) ? atoi(argv[1]) : 0; printf("Pfannkuchen(%d) = %ld\n", n, fannkuch(n)); return 0; }
notes
make, command-line, and program output logs
BUILD COMMANDS FOR: fannkuch.gcc Tue Apr 29 16:02:12 PDT 2008 /usr/bin/gcc -pipe -Wall -O3 -fomit-frame-pointer -march=pentium4 fannkuch.c -o fannkuch.gcc_run ================================================================= COMMAND LINE (%A is single numeric argument): fannkuch.gcc_run %A PROGRAM OUTPUT ============== 1234567891011 2134567891011 2314567891011 3214567891011 3124567891011 1324567891011 2341567891011 3241567891011 3421567891011 4321567891011 4231567891011 2431567891011 3412567891011 4312567891011 4132567891011 1432567891011 1342567891011 3142567891011 4123567891011 1423567891011 1243567891011 2143567891011 2413567891011 4213567891011 2345167891011 3245167891011 3425167891011 4325167891011 4235167891011 2435167891011 Pfannkuchen(11) = 51