third_party/nanopb/examples/using_double_on_avr/test_conversions.c

#include "double_conversion.h"
#include <math.h>
#include <stdio.h>

static const double testvalues[] = {
           0.0,        -0.0,         0.1,         -0.1,
          M_PI,       -M_PI,  123456.789,  -123456.789,
      INFINITY,   -INFINITY,         NAN, INFINITY - INFINITY,
          1e38,       -1e38,        1e39,        -1e39,
         1e-38,      -1e-38,       1e-39,       -1e-39,
   3.14159e-37,-3.14159e-37, 3.14159e-43, -3.14159e-43,
         1e-60,      -1e-60,       1e-45,       -1e-45,
    0.99999999999999, -0.99999999999999, 127.999999999999, -127.999999999999
};

#define TESTVALUES_COUNT (sizeof(testvalues)/sizeof(testvalues[0]))

int main()
{
    int status = 0;
    int i;
    for (i = 0; i < TESTVALUES_COUNT; i++)
    {
        double orig = testvalues[i];
        float expected_float = (float)orig;
        double expected_double = (double)expected_float;
        
        float got_float = double_to_float(*(uint64_t*)&orig);
        uint64_t got_double = float_to_double(got_float);
        
        uint32_t e1 = *(uint32_t*)&expected_float;
        uint32_t g1 = *(uint32_t*)&got_float;
        uint64_t e2 = *(uint64_t*)&expected_double;
        uint64_t g2 = got_double;
        
        if (g1 != e1)
        {
            printf("%3d double_to_float fail: %08x != %08x\n", i, g1, e1);
            status = 1;
        }
        
        if (g2 != e2)
        {
            printf("%3d float_to_double fail: %016llx != %016llx\n", i,
                (unsigned long long)g2,
                (unsigned long long)e2);
            status = 1;
        }
    }

    return status;
}