0 - 111 1110 1000 - 1000 1011 1011 1110 1001 0000 0000 0000 0000 0000 0000 0000 0001 64 Bit Double Precision IEEE 754 Binary Floating Point Representation Standard Converted to Decimal
0 - 111 1110 1000 - 1000 1011 1011 1110 1001 0000 0000 0000 0000 0000 0000 0000 0001: 64 bit double precision IEEE 754 binary floating point representation standard converted to decimal
What are the steps to convert
0 - 111 1110 1000 - 1000 1011 1011 1110 1001 0000 0000 0000 0000 0000 0000 0000 0001, 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.
0
The next 11 bits contain the exponent:
111 1110 1000
The last 52 bits contain the mantissa:
1000 1011 1011 1110 1001 0000 0000 0000 0000 0000 0000 0000 0001
2. Convert the exponent from binary (from base 2) to decimal (in base 10).
The exponent is allways a positive integer.
111 1110 1000(2) =
1 × 210 + 1 × 29 + 1 × 28 + 1 × 27 + 1 × 26 + 1 × 25 + 0 × 24 + 1 × 23 + 0 × 22 + 0 × 21 + 0 × 20 =
1,024 + 512 + 256 + 128 + 64 + 32 + 0 + 8 + 0 + 0 + 0 =
1,024 + 512 + 256 + 128 + 64 + 32 + 8 =
2,024(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 = 2,024 - 1023 = 1001
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).
1000 1011 1011 1110 1001 0000 0000 0000 0000 0000 0000 0000 0001(2) =
1 × 2-1 + 0 × 2-2 + 0 × 2-3 + 0 × 2-4 + 1 × 2-5 + 0 × 2-6 + 1 × 2-7 + 1 × 2-8 + 1 × 2-9 + 0 × 2-10 + 1 × 2-11 + 1 × 2-12 + 1 × 2-13 + 1 × 2-14 + 1 × 2-15 + 0 × 2-16 + 1 × 2-17 + 0 × 2-18 + 0 × 2-19 + 1 × 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 + 0 × 2-49 + 0 × 2-50 + 0 × 2-51 + 1 × 2-52 =
0.5 + 0 + 0 + 0 + 0.031 25 + 0 + 0.007 812 5 + 0.003 906 25 + 0.001 953 125 + 0 + 0.000 488 281 25 + 0.000 244 140 625 + 0.000 122 070 312 5 + 0.000 061 035 156 25 + 0.000 030 517 578 125 + 0 + 0.000 007 629 394 531 25 + 0 + 0 + 0.000 000 953 674 316 406 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 + 0.000 000 000 000 000 222 044 604 925 031 308 084 726 333 618 164 062 5 =
0.5 + 0.031 25 + 0.007 812 5 + 0.003 906 25 + 0.001 953 125 + 0.000 488 281 25 + 0.000 244 140 625 + 0.000 122 070 312 5 + 0.000 061 035 156 25 + 0.000 030 517 578 125 + 0.000 007 629 394 531 25 + 0.000 000 953 674 316 406 25 + 0.000 000 000 000 000 222 044 604 925 031 308 084 726 333 618 164 062 5 =
0.545 876 502 990 722 878 294 604 925 031 308 084 726 333 618 164 062 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)0 × (1 + 0.545 876 502 990 722 878 294 604 925 031 308 084 726 333 618 164 062 5) × 21001 =
1.545 876 502 990 722 878 294 604 925 031 308 084 726 333 618 164 062 5 × 21001 = ...
= 33 128 399 572 031 341 599 473 691 848 558 779 371 461 847 797 972 256 938 093 112 520 570 607 391 535 604 213 584 208 803 768 309 070 071 691 435 698 620 663 144 734 139 073 663 522 710 657 062 947 604 465 532 920 380 110 603 970 100 811 205 044 461 140 316 774 210 583 008 147 372 864 451 916 569 097 718 267 681 277 286 179 688 847 806 250 273 312 136 564 009 652 859 648 084 550 199 961 609 830 400
0 - 111 1110 1000 - 1000 1011 1011 1110 1001 0000 0000 0000 0000 0000 0000 0000 0001, a 64 bit double precision IEEE 754 binary floating point representation standard to a decimal number, written in base ten (double) = 33 128 399 572 031 341 599 473 691 848 558 779 371 461 847 797 972 256 938 093 112 520 570 607 391 535 604 213 584 208 803 768 309 070 071 691 435 698 620 663 144 734 139 073 663 522 710 657 062 947 604 465 532 920 380 110 603 970 100 811 205 044 461 140 316 774 210 583 008 147 372 864 451 916 569 097 718 267 681 277 286 179 688 847 806 250 273 312 136 564 009 652 859 648 084 550 199 961 609 830 400(10)
Spaces were used to group digits: for binary, by 4, for decimal, by 3.