Java开发网 - [j2se]请问如何将Sun的浮点数变换成Intel的浮点数？

Topic: [j2se]请问如何将Sun的浮点数变换成Intel的浮点数？

1.[j2se]请问如何将Sun的浮点数变换成Intel的浮点数？	Copy to clipboard
Posted by: huqp Posted on: 2003-05-30 18:04

2.Re:请问如何将Sun的浮点数变换成Intel的浮点数？ [Re: huqp]

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Posted by: zhongyijie
Posted on: 2003-07-18 10:43

Description
In the Java 2 platform and later, floating point calculations can now be done using the IEEE 754 extended-precision formats. These formats permit the exponent portion of intermediate results to be wider than the 32- or 64-bit size of the end result of the operation. In the original Java virtual machine specification, floating point operations were required to truncate intermediate results of calculations, which is now called strict mode. The strictfp keyword, added in the Java 2 SDK, forces floating point calculations in methods to operate in strict mode. All the methods in a class declared with the strictfp keyword will operate in strict mode.

The default mode on Windows for methods that do not use the strictfp keyword is to use the wider exponent on the operand stack. The wider exponent improves the performance of floating point operations.
A wider exponent would not help performance on Solaris, so the default mode is the same as strict mode.

In most situations, default mode will give you the same result as strict mode. The result of a floating point operation in default mode will differ from the strict mode result only if the calculation overflows or underflows in strict mode in places it doesn't in default mode. Since most floating point calculations occur nowhere near underflow or overflow, default mode will most often yield the same result as strict mode.

Source: The Java Language Specification. Copyright (C) 1996 Sun Microsystems, Inc.

清楚了吗？

3.Re:请问如何将Sun的浮点数变换成Intel的浮点数？ [Re: huqp]

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Posted by: zhongyijie
Posted on: 2003-07-18 10:52

补充：
第二段指Windows平台，
第三段指Solaris平台。
从JDK1.2开始，Float和Double都符合IEEE 754 浮点数规范，允许中间结果不截断，而原来老的方式就叫strictfp，是Java的keyword，自己结果会截断。

java的浮点数只有一种格式，就是IEEE 754。不知你说的Sun的浮点数变换成Intel的浮点数是指什么？