magnitute

#include <stdint.h>

int mag (uint64_t i) {
  int r;
  static void *jumptable[] = {
    &&lz0, &&lz1, &&lz2, &&lz3, &&lz4, &&lz5, &&lz6, &&lz7,
    &&lz8, &&lz9, &&lz10, &&lz11, &&lz12, &&lz13, &&lz14, &&lz15,
    &&lz16, &&lz17, &&lz18, &&lz19, &&lz20, &&lz21, &&lz22, &&lz23,
    &&lz24, &&lz25, &&lz26, &&lz27, &&lz28, &&lz29, &&lz30, &&lz31,
    &&lz32, &&lz33, &&lz34, &&lz35, &&lz36, &&lz37, &&lz38, &&lz39,
    &&lz40, &&lz41, &&lz42, &&lz43, &&lz44, &&lz45, &&lz46, &&lz47,
    &&lz48, &&lz49, &&lz50, &&lz51, &&lz52, &&lz53, &&lz54, &&lz55,
    &&lz56, &&lz57, &&lz58, &&lz59, &&lz60, &&lz61, &&lz62, &&lz63,
  };

  goto *jumptable[__builtin_clzll(i)];

 lz64:
 lz63:
 lz62:
 lz61:
  r = 0;
  goto end;
 lz60:
  r = (i < 10 ? 0 : 1);
  goto end;
 lz59:
 lz58:
  r = 1;
  goto end;
 lz57:
  r = (i < 100 ? 1 : 2);
  goto end;
 lz56:
 lz55:
  r = 2;
  goto end;
 lz54:
  r = (i < 1000 ? 2 : 3);
  goto end;
 lz53:
 lz52:
 lz51:
  r = 3;
  goto end;
 lz50:
  r = (i < 10000 ? 3 : 4);
  goto end;
 lz49:
 lz48:
  r = 4;
  goto end;
 lz47:
  r = (i < 100000 ? 4 : 5);
  goto end;
 lz46:
 lz45:
  r = 5;
  goto end;
 lz44:
  r = (i < 1000000 ? 5 : 6);
  goto end;
 lz43:
 lz42:
 lz41:
  r = 6;
  goto end;
 lz40:
  r = (i < 10000000 ? 6 : 7);
  goto end;
 lz39:
 lz38:
  r = 7;
  goto end;
 lz37:
  r = (i < 100000000 ? 7 : 8);
  goto end;
 lz36:
 lz35:
  r = 8;
  goto end;
 lz34:
  r = (i < 1000000000 ? 8 : 9);
  goto end;
 lz33:
 lz32:
 lz31:
  r = 9;
  goto end;
 lz30:
  r = (i < 10000000000 ? 9 : 10);
  goto end;
 lz29:
 lz28:
  r = 10;
  goto end;
 lz27:
  r = (i < 100000000000 ? 10 : 11);
  goto end;
 lz26:
 lz25:
  r = 11;
  goto end;
 lz24:
  r = (i < 1000000000000 ? 11 : 12);
  goto end;
 lz23:
 lz22:
 lz21:
  r = 12;
  goto end;
 lz20:
  r = (i < 10000000000000 ? 12 : 13);
  goto end;
 lz19:
 lz18:
  r = 13;
  goto end;
 lz17:
  r = (i < 100000000000000 ? 13 : 14);
  goto end;
 lz16:
 lz15:
  r = 14;
  goto end;
 lz14:
  r = (i < 1000000000000000 ? 14 : 15);
  goto end;
 lz13:
 lz12:
 lz11:
  r = 15;
  goto end;
 lz10:
  r = (i < 10000000000000000 ? 15 : 16);
  goto end;
 lz9:
 lz8:
  r = 16;
  goto end;
 lz7:
  r = (i < 100000000000000000 ? 16 : 17);
  goto end;
 lz6:
 lz5:
  r = 17;
  goto end;
 lz4:
  r = (i < 1000000000000000000 ? 17 : 18);
  goto end;
 lz3:
 lz2:
 lz1:
  r = 18;
  goto end;
 lz0:
  r = (i < 10000000000000000000ULL ? 18 : 19);
  goto end;


 end:

  return r;
}