1 - 101 1011 1011 - 0100 1000 1000 0100 0000 0000 0000 0000 0000 0000 0000 0011 1100 64 Bit Double Precision IEEE 754 Binary Floating Point Representation Standard Converted to Decimal
1 - 101 1011 1011 - 0100 1000 1000 0100 0000 0000 0000 0000 0000 0000 0000 0011 1100: 64 bit double precision IEEE 754 binary floating point representation standard converted to decimal
What are the steps to convert
1 - 101 1011 1011 - 0100 1000 1000 0100 0000 0000 0000 0000 0000 0000 0000 0011 1100, 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:
101 1011 1011
The last 52 bits contain the mantissa:
0100 1000 1000 0100 0000 0000 0000 0000 0000 0000 0000 0011 1100
2. Convert the exponent from binary (from base 2) to decimal (in base 10).
The exponent is allways a positive integer.
101 1011 1011(2) =
1 × 210 + 0 × 29 + 1 × 28 + 1 × 27 + 0 × 26 + 1 × 25 + 1 × 24 + 1 × 23 + 0 × 22 + 1 × 21 + 1 × 20 =
1,024 + 0 + 256 + 128 + 0 + 32 + 16 + 8 + 0 + 2 + 1 =
1,024 + 256 + 128 + 32 + 16 + 8 + 2 + 1 =
1,467(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 = 1,467 - 1023 = 444
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).
0100 1000 1000 0100 0000 0000 0000 0000 0000 0000 0000 0011 1100(2) =
0 × 2-1 + 1 × 2-2 + 0 × 2-3 + 0 × 2-4 + 1 × 2-5 + 0 × 2-6 + 0 × 2-7 + 0 × 2-8 + 1 × 2-9 + 0 × 2-10 + 0 × 2-11 + 0 × 2-12 + 0 × 2-13 + 1 × 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 + 1 × 2-47 + 1 × 2-48 + 1 × 2-49 + 1 × 2-50 + 0 × 2-51 + 0 × 2-52 =
0 + 0.25 + 0 + 0 + 0.031 25 + 0 + 0 + 0 + 0.001 953 125 + 0 + 0 + 0 + 0 + 0.000 061 035 156 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 + 0.000 000 000 000 007 105 427 357 601 001 858 711 242 675 781 25 + 0.000 000 000 000 003 552 713 678 800 500 929 355 621 337 890 625 + 0.000 000 000 000 001 776 356 839 400 250 464 677 810 668 945 312 5 + 0.000 000 000 000 000 888 178 419 700 125 232 338 905 334 472 656 25 + 0 + 0 =
0.25 + 0.031 25 + 0.001 953 125 + 0.000 061 035 156 25 + 0.000 000 000 000 007 105 427 357 601 001 858 711 242 675 781 25 + 0.000 000 000 000 003 552 713 678 800 500 929 355 621 337 890 625 + 0.000 000 000 000 001 776 356 839 400 250 464 677 810 668 945 312 5 + 0.000 000 000 000 000 888 178 419 700 125 232 338 905 334 472 656 25 =
0.283 264 160 156 263 322 676 295 501 878 485 083 580 017 089 843 75(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 + 0.283 264 160 156 263 322 676 295 501 878 485 083 580 017 089 843 75) × 2444 =
-1.283 264 160 156 263 322 676 295 501 878 485 083 580 017 089 843 75 × 2444 = ...
= -58 295 380 318 890 737 637 451 334 840 809 035 470 807 027 715 684 589 517 754 527 531 683 232 682 399 967 938 701 872 085 494 525 952 627 325 242 767 752 887 510 112 780 943 360
1 - 101 1011 1011 - 0100 1000 1000 0100 0000 0000 0000 0000 0000 0000 0000 0011 1100, a 64 bit double precision IEEE 754 binary floating point representation standard to a decimal number, written in base ten (double) = -58 295 380 318 890 737 637 451 334 840 809 035 470 807 027 715 684 589 517 754 527 531 683 232 682 399 967 938 701 872 085 494 525 952 627 325 242 767 752 887 510 112 780 943 360(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.