fork download
copy 
  1. #include <stdio.h>
  2. const char digits[] = "0123456789abcdef";
  3.  
  4. union Float64 {
  5. 	double y;
  6. 	char bytes[8];
  7. };
  8.  
  9. struct Tdat {
  10. 	char *txt;
  11. 	double y;
  12. };
  13.  
  14. static void test(struct Tdat *tst, char *end) {
  15. 	union Float64 q;
  16. 	char a, b;
  17.  
  18. 	q.y = tst->y;  // set the double value for the test
  19.  
  20. 	for (int i = 7; i >= 0; i--) {
  21. 		a = digits[q.bytes[i] & 0x0f];         // lower nibble
  22. 		b = digits[(q.bytes[i] & 0xf0) >> 4];  // upper nibble
  23. 		printf("%c%c ", b, a);
  24. 	}
  25. 	printf("%s%c", tst->txt, end);
  26.  
  27. 	return;
  28. }
  29.  
  30. int main(void) {
  31. 	// tests only, pure and simple
  32.  
  33. 	printf("Initial cases:\n");
  34. 	test(&(struct Tdat){ .y = +1.0, .txt = "(+1.0)" }, '\n');
  35. 	test(&(struct Tdat){ .y = -1.0, .txt = "(-1.0)" }, '\n');
  36. 	test(&(struct Tdat){ .y = -0.0, .txt = "(-0.0)" }, '\n');
  37.  
  38. 	printf("Consecutive and ascending Numbers:\n");
  39. 	test(&(struct Tdat){ .y = +2.0, .txt = "(+2.0)" }, '\n');
  40. 	test(&(struct Tdat){ .y = +3.0, .txt = "(+3.0)" }, '\n');
  41. 	test(&(struct Tdat){ .y = +4.0, .txt = "(+4.0)" }, '\n');
  42. 	test(&(struct Tdat){ .y = +8.0, .txt = "(+8.0)" }, '\n');
  43. 	test(&(struct Tdat){ .y = +16.0, .txt = "(+16.0)" }, '\n');
  44.  
  45. 	printf("Numbers with fractions:\n");
  46. 	test(&(struct Tdat){ .y = +1.1, .txt = "(+1.1)" }, '\n');
  47. 	test(&(struct Tdat){ .y = +3.14159, .txt = "(+3.14159)" }, '\n');
  48.  
  49. 	printf("Fractions ending in 5\n");
  50. 	test(&(struct Tdat){ .y = +1.5, .txt = "(+1.5)" }, '\n');
  51. 	test(&(struct Tdat){ .y = +1.25, .txt = "(+1.25)" }, '\n');
  52. 	test(&(struct Tdat){ .y = +1.125, .txt = "(+1.125)" }, '\n');
  53. 	test(&(struct Tdat){ .y = +1.0625, .txt = "(+1.0625)" }, '\n');
  54. 	test(&(struct Tdat){ .y = +1.03125, .txt = "(+1.03125)" }, '\n');
  55.  
  56. 	printf("Special cases:\n");
  57. 	test(&(struct Tdat){ .y = +1.0 / +0.0, .txt = "(Inf)" }, '\n');
  58. 	test(&(struct Tdat){ .y = +0.0 / +0.0, .txt = "(NaN)" }, '\0');
  59.  
  60.  	return 0;
  61. }
Success #stdin #stdout 0s 5312KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
Initial cases:
3f f0 00 00 00 00 00 00 (+1.0)
bf f0 00 00 00 00 00 00 (-1.0)
80 00 00 00 00 00 00 00 (-0.0)
Consecutive and ascending Numbers:
40 00 00 00 00 00 00 00 (+2.0)
40 08 00 00 00 00 00 00 (+3.0)
40 10 00 00 00 00 00 00 (+4.0)
40 20 00 00 00 00 00 00 (+8.0)
40 30 00 00 00 00 00 00 (+16.0)
Numbers with fractions:
3f f1 99 99 99 99 99 9a (+1.1)
40 09 21 f9 f0 1b 86 6e (+3.14159)
Fractions ending in 5
3f f8 00 00 00 00 00 00 (+1.5)
3f f4 00 00 00 00 00 00 (+1.25)
3f f2 00 00 00 00 00 00 (+1.125)
3f f1 00 00 00 00 00 00 (+1.0625)
3f f0 80 00 00 00 00 00 (+1.03125)
Special cases:
7f f0 00 00 00 00 00 00 (Inf)
ff f8 00 00 00 00 00 00 (NaN)
https://ideone.com/SyQG9P
Tests only, pure and simple
language:
C (gcc 8.3)
created:
17 hours ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!