1 - 110 1111 1111 - 0010 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0010 1111 64 Bit Double Precision IEEE 754 Binary Floating Point Representation Standard Converted to Decimal
1 - 110 1111 1111 - 0010 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0010 1111: 64 bit double precision IEEE 754 binary floating point representation standard converted to decimal
What are the steps to convert
1 - 110 1111 1111 - 0010 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0010 1111, 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:
110 1111 1111
The last 52 bits contain the mantissa:
0010 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0010 1111
2. Convert the exponent from binary (from base 2) to decimal (in base 10).
The exponent is allways a positive integer.
110 1111 1111(2) =
1 × 210 + 1 × 29 + 0 × 28 + 1 × 27 + 1 × 26 + 1 × 25 + 1 × 24 + 1 × 23 + 1 × 22 + 1 × 21 + 1 × 20 =
1,024 + 512 + 0 + 128 + 64 + 32 + 16 + 8 + 4 + 2 + 1 =
1,024 + 512 + 128 + 64 + 32 + 16 + 8 + 4 + 2 + 1 =
1,791(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 = 1,791 - 1023 = 768
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).
0010 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0010 1111(2) =
0 × 2-1 + 0 × 2-2 + 1 × 2-3 + 0 × 2-4 + 0 × 2-5 + 0 × 2-6 + 0 × 2-7 + 0 × 2-8 + 0 × 2-9 + 0 × 2-10 + 0 × 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 + 1 × 2-47 + 0 × 2-48 + 1 × 2-49 + 1 × 2-50 + 1 × 2-51 + 1 × 2-52 =
0 + 0 + 0.125 + 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 + 0 + 0 + 0 + 0 + 0 + 0.000 000 000 000 007 105 427 357 601 001 858 711 242 675 781 25 + 0 + 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 + 0.000 000 000 000 000 444 089 209 850 062 616 169 452 667 236 328 125 + 0.000 000 000 000 000 222 044 604 925 031 308 084 726 333 618 164 062 5 =
0.125 + 0.000 000 000 000 007 105 427 357 601 001 858 711 242 675 781 25 + 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 + 0.000 000 000 000 000 444 089 209 850 062 616 169 452 667 236 328 125 + 0.000 000 000 000 000 222 044 604 925 031 308 084 726 333 618 164 062 5 =
0.125 000 000 000 010 436 096 431 476 471 479 982 137 680 053 710 937 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 + 0.125 000 000 000 010 436 096 431 476 471 479 982 137 680 053 710 937 5) × 2768 =
-1.125 000 000 000 010 436 096 431 476 471 479 982 137 680 053 710 937 5 × 2768 = ...
= -1 746 582 853 838 313 754 271 124 786 608 005 390 303 106 097 565 558 286 363 691 480 296 843 957 501 025 382 206 470 018 566 198 915 633 054 406 971 999 219 100 067 834 598 925 940 091 125 884 742 572 517 556 995 045 891 781 635 129 024 358 466 801 572 043 605 594 599 320 690 184 644 058 103 250 451 169 280
1 - 110 1111 1111 - 0010 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0010 1111, a 64 bit double precision IEEE 754 binary floating point representation standard to a decimal number, written in base ten (double) = -1 746 582 853 838 313 754 271 124 786 608 005 390 303 106 097 565 558 286 363 691 480 296 843 957 501 025 382 206 470 018 566 198 915 633 054 406 971 999 219 100 067 834 598 925 940 091 125 884 742 572 517 556 995 045 891 781 635 129 024 358 466 801 572 043 605 594 599 320 690 184 644 058 103 250 451 169 280(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.