1 - 111 1000 0000 - 1111 1111 1110 0000 0000 0000 0000 0000 0000 0000 0000 0000 1000 64 Bit Double Precision IEEE 754 Binary Floating Point Representation Standard Converted to Decimal
1 - 111 1000 0000 - 1111 1111 1110 0000 0000 0000 0000 0000 0000 0000 0000 0000 1000: 64 bit double precision IEEE 754 binary floating point representation standard converted to decimal
What are the steps to convert
1 - 111 1000 0000 - 1111 1111 1110 0000 0000 0000 0000 0000 0000 0000 0000 0000 1000, a 64 bit double precision IEEE 754 binary floating point representation standard to decimal?
1. Identify the elements that make up the binary representation of the number:
The first bit (the leftmost) indicates the sign,
1 = negative, 0 = positive.
1
The next 11 bits contain the exponent:
111 1000 0000
The last 52 bits contain the mantissa:
1111 1111 1110 0000 0000 0000 0000 0000 0000 0000 0000 0000 1000
2. Convert the exponent from binary (from base 2) to decimal (in base 10).
The exponent is allways a positive integer.
111 1000 0000(2) =
1 × 210 + 1 × 29 + 1 × 28 + 1 × 27 + 0 × 26 + 0 × 25 + 0 × 24 + 0 × 23 + 0 × 22 + 0 × 21 + 0 × 20 =
1,024 + 512 + 256 + 128 + 0 + 0 + 0 + 0 + 0 + 0 + 0 =
1,024 + 512 + 256 + 128 =
1,920(10)
3. Adjust the exponent.
Subtract the excess bits: 2(11 - 1) - 1 = 1023,
that is due to the 11 bit excess/bias notation.
The exponent, adjusted = 1,920 - 1023 = 897
4. Convert the mantissa from binary (from base 2) to decimal (in base 10).
The mantissa represents the fractional part of the number (what comes after the whole part of the number, separated from it by a comma).
1111 1111 1110 0000 0000 0000 0000 0000 0000 0000 0000 0000 1000(2) =
1 × 2-1 + 1 × 2-2 + 1 × 2-3 + 1 × 2-4 + 1 × 2-5 + 1 × 2-6 + 1 × 2-7 + 1 × 2-8 + 1 × 2-9 + 1 × 2-10 + 1 × 2-11 + 0 × 2-12 + 0 × 2-13 + 0 × 2-14 + 0 × 2-15 + 0 × 2-16 + 0 × 2-17 + 0 × 2-18 + 0 × 2-19 + 0 × 2-20 + 0 × 2-21 + 0 × 2-22 + 0 × 2-23 + 0 × 2-24 + 0 × 2-25 + 0 × 2-26 + 0 × 2-27 + 0 × 2-28 + 0 × 2-29 + 0 × 2-30 + 0 × 2-31 + 0 × 2-32 + 0 × 2-33 + 0 × 2-34 + 0 × 2-35 + 0 × 2-36 + 0 × 2-37 + 0 × 2-38 + 0 × 2-39 + 0 × 2-40 + 0 × 2-41 + 0 × 2-42 + 0 × 2-43 + 0 × 2-44 + 0 × 2-45 + 0 × 2-46 + 0 × 2-47 + 0 × 2-48 + 1 × 2-49 + 0 × 2-50 + 0 × 2-51 + 0 × 2-52 =
0.5 + 0.25 + 0.125 + 0.062 5 + 0.031 25 + 0.015 625 + 0.007 812 5 + 0.003 906 25 + 0.001 953 125 + 0.000 976 562 5 + 0.000 488 281 25 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0 + 0.000 000 000 000 001 776 356 839 400 250 464 677 810 668 945 312 5 + 0 + 0 + 0 =
0.5 + 0.25 + 0.125 + 0.062 5 + 0.031 25 + 0.015 625 + 0.007 812 5 + 0.003 906 25 + 0.001 953 125 + 0.000 976 562 5 + 0.000 488 281 25 + 0.000 000 000 000 001 776 356 839 400 250 464 677 810 668 945 312 5 =
0.999 511 718 750 001 776 356 839 400 250 464 677 810 668 945 312 5(10)
5. Put all the numbers into expression to calculate the double precision floating point decimal value:
(-1)Sign × (1 + Mantissa) × 2(Adjusted exponent) =
(-1)1 × (1 + 0.999 511 718 750 001 776 356 839 400 250 464 677 810 668 945 312 5) × 2897 =
-1.999 511 718 750 001 776 356 839 400 250 464 677 810 668 945 312 5 × 2897 = ...
= -2 112 662 211 914 600 689 196 425 384 019 916 383 116 259 619 616 869 266 527 788 136 852 670 918 468 781 576 934 979 192 757 102 948 208 693 832 092 013 124 189 308 715 371 837 820 103 329 851 259 941 418 533 568 198 799 601 217 568 204 148 191 558 619 213 172 843 559 941 748 408 622 858 166 837 783 145 340 927 764 394 250 973 538 052 554 318 469 960 564 736
1 - 111 1000 0000 - 1111 1111 1110 0000 0000 0000 0000 0000 0000 0000 0000 0000 1000, a 64 bit double precision IEEE 754 binary floating point representation standard to a decimal number, written in base ten (double) = -2 112 662 211 914 600 689 196 425 384 019 916 383 116 259 619 616 869 266 527 788 136 852 670 918 468 781 576 934 979 192 757 102 948 208 693 832 092 013 124 189 308 715 371 837 820 103 329 851 259 941 418 533 568 198 799 601 217 568 204 148 191 558 619 213 172 843 559 941 748 408 622 858 166 837 783 145 340 927 764 394 250 973 538 052 554 318 469 960 564 736(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.