From: rick.c.hodgin@nospicedham.gmail.com   
      
   On 07/18/2018 04:20 PM, Rod Pemberton wrote:   
   > Here's the corrected and bitmask extended C version of Rick's:   
   >   
   > #include    
   > #include    
   > #include    
   >   
   > void fizz(uint32_t num) {printf("Fizz\n");}   
   > void buzz(uint32_t num) {printf("Buzz\n");}   
   > void fizzbuzz(uint32_t num) {printf("FizzBuzz\n");}   
   > void other(uint32_t num) {printf("%d\n",num);}   
   >   
   > struct STargets {void (*func)(uint32_t num);};   
   > struct STargets funcs[4]={{other},{fizz},{buzz},{fizzbuzz}};   
   >   
   > uint64_t three_data[3]={0x4924924924924924,0x2492492492492492,   
   >                         0x9249249249249249};   
   > uint64_t five_data[5]={0x0842108421084210,0x1084210842108421,   
   >                        0x2108421084210842,0x4210842108421084,   
   >                        0x8421084210842108};   
   >   
   > int main(int argc, char* argv[])   
   > {   
   >   uint32_t lnI;   
   >   uint64_t saved_data;   
   >   
   > /* WARNING bitmasks start at value one */   
   > /* bitmasks must be shifted for lnI != 1 */   
   >   
   >   for(lnI=1;lnI<=1000000;++lnI)   
   >   {   
   >     funcs[(three_data[0]&0x1)+(2*(five_data[0]&0x1))].func(lnI);   
   >   
   >     saved_data=three_data[0];   
   >     three_data[0]=(three_data[0]>>1)|((three_data[1]&1)<<63);   
   >     three_data[1]=(three_data[1]>>1)|((three_data[2]&1)<<63);   
   >     three_data[2]=(three_data[2]>>1)|((saved_data&1)<<63);   
   >   
   >     saved_data=five_data[0];   
   >     five_data[0]=(five_data[0]>>1)|((five_data[1]&1)<<63);   
   >     five_data[1]=(five_data[1]>>1)|((five_data[2]&1)<<63);   
   >     five_data[2]=(five_data[2]>>1)|((five_data[3]&1)<<63);   
   >     five_data[3]=(five_data[3]>>1)|((five_data[4]&1)<<63);   
   >     five_data[4]=(five_data[4]>>1)|((saved_data&1)<<63);   
   >     }   
   >   
   > return(0);   
   > }   
      
   There's a simpler version that's been posted now on comp.lang.c.   
   It is written by Ben Bacarisse, altered slightly here by me.  I   
   have not tested it, but you can see it here and see if it's any   
   faster using less values, and less complexity:   
      
       #include    
      
       void fizz(void)         { printf("fizz\n");      }   
       void buzz(void)         { printf("buzz\n");      }   
       void fizzbuzz(void)     { printf("fizzbuzz\n");  }   
       void other(void)        { printf("%d\n", num);   }   
      
       void (*funcs[4])(int) = { other, fizz, buzz, fizzbuzz };   
      
       int num;   
      
       int main(void)   
       {   
            int threes = 1 << 2, fives = 1 << 4;   
      
            for (num = 1; num <= 100; ++num) {   
                 funcs[(threes & 1) + (2 * (fives & 1))]();   
      
                 threes = (threes >> 1) | ((threes & 1) << 2);   
                 fives  = (fives  >> 1) | ((fives  & 1) << 4);   
           }   
       }   
      
   --   
   Rick C. Hodgin   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)