shifty-nifty games with data and endianness

// gcc -std=c11 -c -pipe -Wall -Wextra -pedantic -O2 -g0 -fPIC -o test.o test.c
// gcc -Wall -Wextra -pedantic -O2 -g0 -fPIC -o test test.o

#include <stdio.h>
#include <stddef.h>
#include <stdlib.h>
#include <stdint.h>

typedef union {
        uint32_t h;
        float f;

        struct {
                uint32_t m : 23, e : 8, f : 1;
        } ieee754_le;

        struct {
                uint32_t f : 1, e : 8, m : 23;
        } ieee754_be;

        uint8_t c[4];
} test;

void dump_bin(size_t val, size_t bits) {
        char * str = NULL;
        char * str_end = NULL;
        size_t temp = val;
        size_t i = 0;

        str = malloc(bits + 1);

        str_end = str + bits;
        *str_end = 0;

        for (i = 0, --str_end; i < bits; ++i, --str_end) {
                *str_end = '0' + (temp & 1);
                temp >>= 1;
        }

        printf("%s", str);

        free(str);
}

void dump(const test * val) {
        printf("float:   %f\n", val->f);
        printf("int:     %08x\n", val->h);

        printf("bytes:   ");
        for (size_t i = 0; i < sizeof(val->c); ++i) {
                printf("%02x", val->c[i]);
                putchar(' ');
        }; putchar('\n');

        putchar('\n');

        printf("LE-bits: ");
        {
                dump_bin(val->ieee754_le.f, 1);
                putchar(' ');
                dump_bin(val->ieee754_le.e, 8);
                putchar('\n');
                dump_bin(val->ieee754_le.m, 23);
                putchar('\n');
        }; putchar('\n');

        printf("BE-bits: ");
        {
                dump_bin(val->ieee754_be.f, 1);
                putchar(' ');
                dump_bin(val->ieee754_be.e, 8);
                putchar('\n');
                dump_bin(val->ieee754_be.m, 23);
                putchar('\n');
        }; putchar('\n');
}

int main(void) {
        test z;

        printf("// dump float 1234567.0");
        z.f = 1234567.0;
        dump(&z);

        printf("// dump int 1234567");
        z.h = 1234567;
        dump(&z);

        return 0;
}