blocks|key|3465281|text|摘自J.Richter的"CLR+via+C#“第三版：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3465282|3465283|一个128位的高精度浮点值，通常用于不能容忍舍入误差的财务计算。在128位中，1位表示值的符号，96位表示值本身，8位表示除以96位值的10的幂(可以是从0到28的任意位置)。剩余的位未使用。|blockquote|3465284|3465285|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|J|8|@]|9|@]|A|$]]|$1|C|3|D|5|E|7|K|8|@]|9|@]|A|$]]|$1|F|3|-4|5|6|7|L|8|@]|9|@]|A|$]]|$1|G|3|-4|5|6|7|M|8|@]|9|@]|A|$]]]|H|$]]

From "CLR via C#" 3rd Edition by J.Richter:

<blockquote>
 A 128-bit high-precision
 floating-point value commonly used for
 financial calculations in which
 rounding errors can’t be tolerated. Of
 the 128 bits, 1 bit represents the
 sign of the value, 96 bits represent
 the value itself, and 8 bits represent
 the power of 10 to divide the 96-bit
 value by (can be anywhere from 0 to
 28). The remaining bits are unused.
</blockquote>

blocks|key|3252119|text|如http://msdn.microsoft.com/en-us/library/system.decimal(VS.80).aspx上MSDN十进制结构页面所述|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|3252120|3252121|十进制值的二进制表示形式由一个1位符号、一个96位整数和一个比例因子组成，该比例因子用于将96位整数相除并指定它的哪个部分是小数。比例因子隐含地是数字10，其指数从0到28。因此，十进制值的二进制表示形式为(-296到296)+/+10(0到28))，其中-296-1等于MinValue，296-1等于MaxValue。|blockquote|3252122|3252123|缩放因子还会保留十进制数中的所有尾随零。在算术或比较运算中，尾随零不影响Decimal数字的值。但是，如果应用了适当的格式字符串，则ToString方法可以显示尾随零。|3252124|entityMap|0|LINK|mutability|MUTABLE|url|http://msdn.microsoft.com/en-us/library/system.decimal(VS.80).aspx)^0|1|1U|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@$A|T|B|U|1|V]]|C|$]]|$1|D|3|-4|5|6|7|W|8|@]|9|@]|C|$]]|$1|E|3|F|5|G|7|X|8|@]|9|@]|C|$]]|$1|H|3|-4|5|6|7|Y|8|@]|9|@]|C|$]]|$1|I|3|J|5|6|7|Z|8|@]|9|@]|C|$]]|$1|K|3|-4|5|6|7|10|8|@]|9|@]|C|$]]]|L|$M|$5|N|O|P|C|$Q|R]]]]

As described on MSDN's Decimal Structure page at <a href="http://msdn.microsoft.com/en-us/library/system.decimal(VS.80).aspx" rel="nofollow noreferrer">http://msdn.microsoft.com/en-us/library/system.decimal(VS.80).aspx</a>:

<blockquote>
 The binary representation of a Decimal
 value consists of a 1-bit sign, a
 96-bit integer number, and a scaling
 factor used to divide the 96-bit
 integer and specify what portion of it
 is a decimal fraction. The scaling
 factor is implicitly the number 10,
 raised to an exponent ranging from 0
 to 28. Therefore, the binary
 representation of a Decimal value is
 of the form, ((-296 to 296) / 10(0 to
 28)), where -296-1 is equal to
 MinValue, and 296-1 is equal to
 MaxValue.
 
 The scaling factor also preserves any
 trailing zeroes in a Decimal number.
 Trailing zeroes do not affect the
 value of a Decimal number in
 arithmetic or comparison operations.
 However, trailing zeroes can be
 revealed by the ToString method if an
 appropriate format string is applied.
</blockquote>

blocks|key|409412|text|type|unstyled|depth|inlineStyleRanges|entityRanges|data|409413|关键字decimal表示128位数据类型。|blockquote|409414|409415|409416|Source|offset|length|409417|409418|十进制值的二进制表示形式由一个1位符号、一个96位整数和一个比例因子组成，该比例因子用于将96位整数相除并指定它的哪个部分是小数。比例因子隐含地是数字10，其指数从0到28。因此，十进制值的二进制表示形式为(-296到296)+/+10(0到28))，其中-296-1等于MinValue，296-1等于MaxValue。|409419|409420|409421|409422|entityMap|0|LINK|mutability|MUTABLE|url|http://msdn.microsoft.com/en-us/library/364x0z75(VS.71).aspx|1|http://msdn.microsoft.com/en-us/library/system.decimal.aspx^0|0|0|0|0|0|6|0|0|0|0|0|0|0|6|1|0^^$0|@$1|2|3|-4|4|5|6|Z|7|@]|8|@]|9|$]]|$1|A|3|B|4|C|6|10|7|@]|8|@]|9|$]]|$1|D|3|-4|4|5|6|11|7|@]|8|@]|9|$]]|$1|E|3|-4|4|5|6|12|7|@]|8|@]|9|$]]|$1|F|3|G|4|5|6|13|7|@]|8|@$H|14|I|15|1|16]]|9|$]]|$1|J|3|-4|4|5|6|17|7|@]|8|@]|9|$]]|$1|K|3|L|4|C|6|18|7|@]|8|@]|9|$]]|$1|M|3|-4|4|5|6|19|7|@]|8|@]|9|$]]|$1|N|3|-4|4|5|6|1A|7|@]|8|@]|9|$]]|$1|O|3|G|4|5|6|1B|7|@]|8|@$H|1C|I|1D|1|1E]]|9|$]]|$1|P|3|-4|4|5|6|1F|7|@]|8|@]|9|$]]]|Q|$R|$4|S|T|U|9|$V|W]]|X|$4|S|T|U|9|$V|Y]]]]

<blockquote>
 The decimal keyword denotes a 128-bit data type.
</blockquote>

<a href="http://msdn.microsoft.com/en-us/library/364x0z75(VS.71).aspx" rel="nofollow noreferrer">Source</a>

<blockquote>
 The binary representation of a Decimal value consists of a 1-bit sign, a 96-bit integer number, and a scaling factor used to divide the 96-bit integer and specify what portion of it is a decimal fraction. The scaling factor is implicitly the number 10, raised to an exponent ranging from 0 to 28. Therefore, the binary representation of a Decimal value is of the form, ((-296 to 296) / 10(0 to 28)), where -296-1 is equal to MinValue, and 296-1 is equal to MaxValue.
</blockquote>

<a href="http://msdn.microsoft.com/en-us/library/system.decimal.aspx" rel="nofollow noreferrer">Source</a>

blocks|key|409424|text|维基百科上的Decimal+Floating+Point文章，以及这篇关于System.Decimal的文章的特定链接。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|409425|409426|十进制是以128位存储的，即使只有102位是严格需要的。可以方便地将小数看作三个表示尾数的32位整数，然后是一个表示符号和指数的整数。最后一个整数的最高位是符号位(正常情况下，对于负数，该位被设置为(1)+)，位16-23+(高位16位字的低位)包含指数。其他位必须全部清零(0)。这种表示是由decimal.GetBits(十进制)给出的，它返回一个由4个整数组成的数组。|blockquote|409427|409428|entityMap|0|LINK|mutability|MUTABLE|url|http://en.wikipedia.org/wiki/Decimal_floating_point|1|http://csharpindepth.com/Articles/General/Decimal.aspx^0|11|E|6|M|0|11|E|1|0|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@$9|V|A|W|B|C]]|D|@$9|X|A|Y|1|Z]|$9|10|A|11|1|12]]|E|$]]|$1|F|3|-4|5|6|7|13|8|@]|D|@]|E|$]]|$1|G|3|H|5|I|7|14|8|@]|D|@]|E|$]]|$1|J|3|-4|5|6|7|15|8|@]|D|@]|E|$]]|$1|K|3|-4|5|6|7|16|8|@]|D|@]|E|$]]]|L|$M|$5|N|O|P|E|$Q|R]]|S|$5|N|O|P|E|$Q|T]]]]

<a href="http://en.wikipedia.org/wiki/Decimal_floating_point" rel="noreferrer">Decimal Floating Point</a> article on Wikipedia with specific link to this article about <a href="http://csharpindepth.com/Articles/General/Decimal.aspx" rel="noreferrer"><code>System.Decimal</code></a>.

<blockquote>
 A decimal is stored in 128 bits, even though only 102 are strictly necessary. It is convenient to consider the decimal as three 32-bit integers representing the mantissa, and then one integer representing the sign and exponent. The top bit of the last integer is the sign bit (in the normal way, with the bit being set (1) for negative numbers) and bits 16-23 (the low bits of the high 16-bit word) contain the exponent. The other bits must all be clear (0). This representation is the one given by decimal.GetBits(decimal) which returns an array of 4 ints. 
</blockquote>

blocks|key|409430|text|type|unstyled|depth|inlineStyleRanges|entityRanges|data|409431|+decimal类型只是浮点数的另一种形式-但与float和double不同，它使用的基数是10。|blockquote|409432|409433|409434|这里有一个简单的解释，http://csharpindepth.com/Articles/General/Decimal.aspx|offset|length|409435|entityMap|0|LINK|mutability|MUTABLE|url|http://csharpindepth.com/Articles/General/Decimal.aspx^0|0|0|0|0|B|1I|0|0^^$0|@$1|2|3|-4|4|5|6|R|7|@]|8|@]|9|$]]|$1|A|3|B|4|C|6|S|7|@]|8|@]|9|$]]|$1|D|3|-4|4|5|6|T|7|@]|8|@]|9|$]]|$1|E|3|-4|4|5|6|U|7|@]|8|@]|9|$]]|$1|F|3|G|4|5|6|V|7|@]|8|@$H|W|I|X|1|Y]]|9|$]]|$1|J|3|-4|4|5|6|Z|7|@]|8|@]|9|$]]]|K|$L|$4|M|N|O|9|$P|Q]]]]

<blockquote>
 The decimal type is just another form
 of floating point number - but unlike
 float and double, the base used is 10.
</blockquote>

A simple explanation is here <a href="http://csharpindepth.com/Articles/General/Decimal.aspx" rel="nofollow noreferrer">http://csharpindepth.com/Articles/General/Decimal.aspx</a>

How is the <code>decimal</code> type implemented?

Update

<ul>
<li>It's a 128-bit value type (16 bytes)</li>
<li>1 sign bit</li>
<li>96 bits (12 bytes) for the mantissa</li>
<li>8 bits for the exponent</li>
<li>remaining bits (23 of them!) set to 0</li>
</ul>

Thanks! I'm gonna stick with using a 64-bit long with my own implied scale.

Behind the scenes, what's happening with decimal value type in C#/.NET?

decimal类型是如何实现的？更新它是一个128位的值类型(16字节)1符号位96位(12字节)用于尾数8位用于尾数位(其中23位！)设置为0谢谢!我将坚持使用64位的长度和我自己的隐含小数。

问在幕后，十进制值类型在C#/.NET中发生了什么？
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