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      1 #include <stdio.h>
      2 #include <stdlib.h>
      3 
      4 double drand48(void);
      5 
      6 static int fails = 0;
      7 
      8 static int
      9 double_eq(double a, double b)
     10 {
     11     /* Compare two double values, and return 1 if they are "close" enough */
     12     double diff = a -b;
     13     if (diff < 0) diff = -diff;
     14     if (a < 0) {
     15         if (b >= 0)
     16             return 0;
     17         a = -a;
     18         b = -b;
     19     } else if (b < 0) {
     20         return 0;
     21     }
     22     if (a >= b)
     23         a = b;
     24 
     25     return diff < a*1e-8;
     26 }
     27 
     28 #define EXPECT_LONG(value,expected) \
     29     do { \
     30         long _val = (value); \
     31         long _expected = (expected); \
     32         printf( "%s: ", #value); \
     33         if (_val != _expected) { \
     34             printf("KO: %ld (%ld expected)\n", _val, _expected); \
     35             fails += 1; \
     36         } else { \
     37             printf("%ld (ok)\n", _expected); \
     38         } \
     39     } while (0)
     40 
     41 #define EXPECT_DOUBLE(value,expected) \
     42     do { \
     43         double _val = (value); \
     44         double _expected = (expected); \
     45         printf( "%s: ", #value); \
     46         if (!double_eq(_val,_expected)) { \
     47             printf("KO: %.12g (%.12g expected)\n", _val, _expected); \
     48             fails += 1; \
     49         } else { \
     50             printf("%.12g (ok)\n", _expected); \
     51         } \
     52     } while (0)
     53 
     54 int
     55 main(void)
     56 {
     57     long int l = -345678L;
     58     float  f = 123.456e14;
     59     double d = -87.65432e45;
     60 
     61     // Verify display of hard-coded float and double values.
     62     // This is done to confirm the correct printf format specifiers
     63     // are being used.
     64     puts("Hard-coded values");
     65     printf("  l: %li\n", l);
     66     printf("  f: %g\n", (double) f);
     67     printf("  d: %g\n", d);
     68 
     69     // lrand48
     70     puts("lrand48");
     71     puts("  srand48(100)");
     72     srand48(100);
     73     EXPECT_LONG(lrand48(),539144888);
     74     EXPECT_LONG(lrand48(),448713282);
     75     EXPECT_LONG(lrand48(),2020627300);
     76 
     77     // Try again, with same seed.  Should get the same values
     78     puts("  srand48(100)");
     79     srand48(100);
     80     EXPECT_LONG(lrand48(),539144888);
     81     EXPECT_LONG(lrand48(),448713282);
     82     EXPECT_LONG(lrand48(),2020627300);
     83 
     84     // Try again, but with a different seed
     85     puts("  srand48(101)");
     86     srand48(101);
     87     EXPECT_LONG(lrand48(),261694958);
     88     EXPECT_LONG(lrand48(),1961809783);
     89     EXPECT_LONG(lrand48(),1458943423);
     90 
     91     // drand48
     92     puts("drand48");
     93     puts("  srand48(100)");
     94     srand48(100);
     95     EXPECT_DOUBLE(drand48(),0.251058902665);
     96     EXPECT_DOUBLE(drand48(),0.208948404851);
     97     EXPECT_DOUBLE(drand48(),0.940927909958);
     98 
     99     // Try again, with same seed.  Should get the same values
    100     puts("  srand48(100)");
    101     srand48(100);
    102     EXPECT_DOUBLE(drand48(),0.251058902665);
    103     EXPECT_DOUBLE(drand48(),0.208948404851);
    104     EXPECT_DOUBLE(drand48(),0.940927909958);
    105 
    106     // Try again, but with a different seed
    107     puts("  srand48(101)");
    108     srand48(101);
    109     EXPECT_DOUBLE(drand48(),0.121861211331);
    110     EXPECT_DOUBLE(drand48(),0.913538869095);
    111     EXPECT_DOUBLE(drand48(),0.679373472502);
    112 
    113     return (fails > 0) ? 1 : 0;
    114 }
    115