Created
July 7, 2020 22:35
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| #include <stdio.h> | |
| #include <stdlib.h> | |
| #include <string.h> | |
| void print_bits(int i) { | |
| // prints out the binary representation of a 32bit int | |
| int mask = (1 << 1) - 1; | |
| int bit = 0; | |
| printf("0x%08X is\n", i); | |
| // reverse loop pulling out one bit at a time | |
| for (int x = 31; x > -1; x--) { | |
| if (x == 30 || x == 22) { | |
| printf(" "); | |
| } | |
| bit = (i >> x) & mask; | |
| printf("%i", bit); | |
| } | |
| printf("\n"); | |
| // print out some nice lines | |
| for (int x = 0; x < 32; x++) { | |
| if (x == 1 || x == 9) { | |
| printf(" "); | |
| } | |
| printf("-"); | |
| } | |
| printf("\ns exp frac\n\n"); | |
| } | |
| void print_num(const char* bits) { | |
| int num = 0; | |
| int place = 0; | |
| char str[] = "0"; | |
| // forward loop over the string to print out the bits | |
| for (int x = 0; x < strlen(bits); x++) { | |
| if (bits[x] == ' ') continue; | |
| printf("%c", bits[x]); | |
| } | |
| // reverse loop over the bits, use OR op to set bits of num | |
| for (int x = strlen(bits) - 1; x < 31 - strlen(bits); x--) { | |
| if (bits[x] == ' ') continue; | |
| str[0] = bits[x]; | |
| num ^= (-atoi(str) ^ num) & (1UL << place); | |
| place++; | |
| } | |
| printf(" is \n0x%08X (or %i as decimal)\n\n", num, num); | |
| } | |
| int main() { | |
| print_bits(0x1); | |
| print_bits(0x2); | |
| print_bits(0x3); | |
| print_bits(0xC0400001); | |
| print_bits(0xdeadbeef); | |
| print_bits(0x7F7FFFFF); | |
| print_bits(0xffffffff); | |
| print_bits(0x3E800000); | |
| print_bits(0x41300000); | |
| print_bits(0x3FC00000); | |
| // bits will start on the right side | |
| // spaces are ignored | |
| print_num( "111"); | |
| print_num("0 00000000 00000000000000000000001"); | |
| print_num("1 00000000 00000000000000000000001"); | |
| print_num("1 00000000 00000000000000000000000"); | |
| print_num("1 10000000 10000000000000000000001"); | |
| print_num("1 11111111 00000000000000000000001"); | |
| print_num("1 11111111 10000000000000000000001"); | |
| print_num("1 11111111 11111111111111111111111"); | |
| return 0; | |
| } |
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