How to get the sign, mantissa and exponent of a floating point number

by

I think it is better to use unions to do the casts, it is clearer.

#include <stdio.h>

typedef union {
  float f;
  struct {
    unsigned int mantisa : 23;
    unsigned int exponent : 8;
    unsigned int sign : 1;
  } parts;
} float_cast;

int main(void) {
  float_cast d1 = { .f = 0.15625 };
  printf("sign = %x\n", d1.parts.sign);
  printf("exponent = %x\n", d1.parts.exponent);
  printf("mantisa = %x\n", d1.parts.mantisa);
}

Example based on http://en.wikipedia.org/wiki/Single_precision

More Related Contents:

  1. error: incompatible types for a function that returns float in C
  2. How do I restrict a float value to only two places after the decimal point in C?
  3. Dividing 1/n always returns 0.0 [duplicate]
  4. How to represent FLOAT number in memory in C
  5. How to generate random float number in C
  6. What is the instruction that gives branchless FP min and max on x86?
  7. Is the behaviour of casting a negative double to unsigned int defined in the C standard? Different behaviour on ARM vs. x86
  8. Checking if float is an integer
  9. What happens to a float variable when %d is used in a printf?
  10. Why is printf round floating point numbers up?
  11. Why doesn’t C have unsigned floats?
  12. What is the fastest way to convert float to int on x86
  13. Casting float to int (bitwise) in C
  14. Why does adding a small float to a large float just drop the small one?
  15. How does printf and co differentiate between float and double
  16. pow() seems to be out by one here
  17. Can I make gcc tell me when a calculation results in NaN or inf at runtime?
  18. Status of __STDC_IEC_559__ with modern C compilers
  19. Is fmod() exact when y is an integer?
  20. Encoding int value as an IEEE-754 float (binary32)
  21. Trouble with float on C [duplicate]
  22. When does underflow occur?
  23. Serialize double and float with C
  24. C printf using %d and %f
  25. What’s the proper implementation for hardware emulation?
  26. Comparing float and double
  27. Why do you need an explicit `-lm` compiler option? [duplicate]
  28. pow() cast to integer, unexpected result
  29. C fundamentals: double variable not equal to double expression?
  30. C dynamically printf double, no loss of precision and no trailing zeroes

Leave a Comment