Floating Point Numbers
IEEE Standard 754 Floating Point Numbers
Comparing floating point numbers
a tool: IEEE-754 Analysis
| Sign | Exponent (e) | Fraction (f) | Value |
|---|---|---|---|
| 0 | 00..00 | 00..00 | +0 |
| 0 | 00..00 | 00..01 : 11..11 |
Positive Denormalized Real 0.f × 2(-b+1) |
| 0 | 00..01 : 11..10 |
XX..XX | Positive Normalized Real 1.f × 2(e-b) |
| 0 | 11..11 | 00..00 | +Infinity |
| 0 | 11..11 | 00..01 : 01..11 |
SNaN |
| 0 | 11..11 | 10..00 : 11..11 |
QNaN |
| 1 | 00..00 | 00..00 | -0 |
| 1 | 00..00 | 00..01 : 11..11 |
Negative Denormalized Real -0.f × 2(-b+1) |
| 1 | 00..01 : 11..10 |
XX..XX | Negative Normalized Real -1.f × 2(e-b) |
| 1 | 11..11 | 00..00 | -Infinity |
| 1 | 11..11 | 00..01 : 01..11 |
SNaN |
| 1 | 11..11 | 10..00 : 11.11 |
QNaN |
对于单精度而言，超过2^24 - 1的数的整数部分精度就开始降低为2^(n-24), n为bit位数。
