1 - 110 1111 1111 - 0010 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0010 1110 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 1110: 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 1110, 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 1110
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 1110(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 + 0 × 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 =
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 =
0.125 000 000 000 010 214 051 826 551 440 171 897 411 346 435 546 875(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 + 0.125 000 000 000 010 214 051 826 551 440 171 897 411 346 435 546 875) × 2768 =
-1.125 000 000 000 010 214 051 826 551 440 171 897 411 346 435 546 875 × 2768 = ...
= -1 746 582 853 838 313 409 542 858 342 733 799 219 757 593 133 133 446 060 856 622 162 477 321 901 421 688 118 694 039 554 552 710 157 591 804 285 483 962 479 488 511 987 640 430 264 050 684 372 794 526 747 583 050 577 082 339 971 746 358 819 955 727 826 856 516 718 562 613 716 585 552 583 557 494 282 911 744
1 - 110 1111 1111 - 0010 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0010 1110, a 64 bit double precision IEEE 754 binary floating point representation standard to a decimal number, written in base ten (double) = -1 746 582 853 838 313 409 542 858 342 733 799 219 757 593 133 133 446 060 856 622 162 477 321 901 421 688 118 694 039 554 552 710 157 591 804 285 483 962 479 488 511 987 640 430 264 050 684 372 794 526 747 583 050 577 082 339 971 746 358 819 955 727 826 856 516 718 562 613 716 585 552 583 557 494 282 911 744(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.