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bird2 ver 2.0.7

    1: /*
    2:  *	BIRD Library -- Generic Bit Operations Tests
    3:  *
    4:  *	(c) 2015 CZ.NIC z.s.p.o.
    5:  *
    6:  *	Can be freely distributed and used under the terms of the GNU GPL.
    7:  */
    8: 
    9: #include "test/birdtest.h"
   10: #include "test/bt-utils.h" /* naive_pow() */
   11: 
   12: #include "lib/bitops.h"
   13: 
   14: #define MAX_NUM 1000
   15: #define CHECK_BIT(var,pos) ((var) & (u32)(1<<(pos)))
   16: 
   17: static int
   18: t_mkmask(void)
   19: {
   20:   int i;
   21:   u32 compute, expect;
   22: 
   23:   bt_assert(u32_mkmask(0) == 0x00000000);
   24:   for (i = 1; i <= 32; i++)
   25:   {
   26:     compute = u32_mkmask(i);
   27:     expect  = (u32) (0xffffffff << (32-i));
   28:     bt_assert_msg(compute == expect, "u32_mkmask(%d) = 0x%08X, expected 0x%08X", i, compute, expect);
   29:   }
   30: 
   31:   return 1;
   32: }
   33: 
   34: static int
   35: u32_masklen_expected(u32 mask)
   36: {
   37:   int j, expect = 0;
   38: 
   39:   int valid = 0;
   40:   for (j = 0; j <= 32; j++)
   41:     if (mask == (j ? (0xffffffff << (32-j)) : 0)) /* Shifting 32-bit value by 32 bits is undefined behavior */
   42: 	valid = 1;
   43: 
   44:   if (!valid && mask != 0)
   45:     expect = 255;
   46:   else
   47:     for (j = 0; j <= 31; j++)
   48:       if (CHECK_BIT(mask, (31-j)))
   49: 	expect = j+1;
   50:       else
   51: 	break;
   52:   return expect;
   53: }
   54: 
   55: static void
   56: check_mask(u32 mask)
   57: {
   58:   int expected, masklen;
   59: 
   60:   expected = u32_masklen_expected(mask);
   61:   masklen = u32_masklen(mask);
   62:   int ok = (expected == masklen);
   63:   bt_debug("u32_masklen(Ox%08x) = %d, expected %d  %s\n", mask, masklen, expected, ok ? "OK" : "FAIL!");
   64:   bt_assert(ok);
   65: }
   66: 
   67: static int
   68: t_masklen(void)
   69: {
   70:   u32 i;
   71: 
   72:   check_mask(0x82828282);
   73:   check_mask(0x00000000);
   74: 
   75:   for (i = 0; i <= 32; i++)
   76:     check_mask(((u32) (i ? (0xffffffff << (32-i)) : 0)) & 0xffffffff); /* Shifting 32-bit value by 32 bits is undefined behavior */
   77: 
   78:   for (i = 0; i <= MAX_NUM; i++)
   79:     check_mask(bt_random());
   80: 
   81:   return 1;
   82: }
   83: 
   84: static void
   85: check_log2(u32 n)
   86: {
   87:   u32 log  = u32_log2(n);
   88:   u32 low  = bt_naive_pow(2, log);
   89:   u32 high = bt_naive_pow(2, log+1);
   90: 
   91:   bt_assert_msg(n >= low && n < high,
   92: 		"u32_log2(%u) = %u, %u should be in the range <%u, %u)",
   93: 		n, log, n, low, high);
   94: }
   95: 
   96: static int
   97: t_log2(void)
   98: {
   99:   u32 i;
  100: 
  101:   for (i = 0; i < 31; i++)
  102:     bt_assert(u32_log2(bt_naive_pow(2, i+1)) == i+1);
  103: 
  104:   for (i = 1; i < MAX_NUM; i++)
  105:     check_log2(i);
  106: 
  107:   for (i = 1; i < MAX_NUM; i++)
  108:     check_log2(((u32) bt_random()) % 0x0fffffff);
  109: 
  110:   return 1;
  111: }
  112: 
  113: int
  114: main(int argc, char *argv[])
  115: {
  116:   bt_init(argc, argv);
  117: 
  118:   bt_test_suite(t_mkmask, "u32_mkmask()");
  119:   bt_test_suite(t_masklen, "u32_masklen()");
  120:   bt_test_suite(t_log2, "u32_log2()");
  121: 
  122:   return bt_exit_value();
  123: }