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## CrackNum: Decode/Encode IEE754 Numbers
[](http://hackage.haskell.org/package/crackNum)
[](http://travis-ci.org/LeventErkok/crackNum)
### Command line options:
crackNum v1.5, (c) Levent Erkok. Released with a BSD3 license.
Usage: crackNum precision bit/hex-pattern
--hp 16 bit half precision
--sp 32 bit single precision
--dp 64 bit double precision
--sb 8 bit signed byte
--sw 16 bit signed word
--sd 32 bit signed double
--sq 64 bit signed quad
--ub 8 bit unsigned byte
--uw 16 bit unsigned word
--ud 32 bit unsigned double
--uq 64 bit unsigned quad
--toIEEE=n Convert from decimal to IEEE SP/DP formats.
-l n --lanes=n number of lanes
-h, -? --help print help, with examples
-v --version print version info
Examples:
crackNum --hp fc00
crackNum --sp fc00 abcd
crackNum --dp fc00 abc1 2345 6789
crackNum --sp 01111111110000000000000000000000
crackNum -l2 --hp 01111111110000000000000000000000
crackNum --sb 7f
crackNum --sp --toIEEE=-2.3e6
crackNum --dp --toIEEE=max
crackNum --dp --toIEEE=ulp
Notes:
- You can use hexadecimal or binary as input.
- You can use _,- or space as a digit to improve readability.
- You can give input for multiple lanes, we will guess the #of lanes for you.
Or, you can specify number of lanes with the -l option.
- For "toIEEE" option (case doesn't matter):
- You can enter a number in decimal notation (like 2.3)
- OR, enter one of the following:
* infinity, -infinity: Positive/Negative infinities
* nan, snan, qnan: Not-A-Number; signaling/quiet
* 0, -0: Both kinds of zeros
* max : The maximum finite positive value
* -max: The minimum finite negative value
* min : The minimum normal positive value
* -min: The maximum normal negative value
* epsilon: The smallest possible value x s.t. 1+x /= 1.
* ulp: The minimum subnormal value
### Example: Decoding single-precision numbers on two lanes
$ crackNum --sp fc00 abc1 7F80 0001
== Lane: 1 ==========================================
3 2 1 0
1 09876543 21098765432109876543210
S ---E8--- ----------F23----------
Binary: 1 11111000 00000001010101111000001
Hex: FC00 ABC1
Precision: SP
Sign: Negative
Exponent: 121 (Stored: 248, Bias: 127)
Value: -2.6723903e36 (NORMAL)
== Lane: 0 ==========================================
3 2 1 0
1 09876543 21098765432109876543210
S ---E8--- ----------F23----------
Binary: 0 11111111 00000000000000000000001
Hex: 7F80 0001
Precision: SP
Sign: Positive
Exponent: 128 (Stored: 255, Bias: 127)
Value: NaN (Signaling)
Note: Representation for NaN's is not unique.
### Example: Encoding a float as a IEEE754 single-precision bit-pattern
$ crackNum --sp --toIEEE=-2.3e6
3 2 1 0
1 09876543 21098765432109876543210
S ---E8--- ----------F23----------
Binary: 1 10010100 00011000110000110000000
Hex: CA0C 6180
Precision: SP
Sign: Negative
Exponent: 21 (Stored: 148, Bias: 127)
Value: -2300000.0 (NORMAL)
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