VS2005浮点编译开关
C++对浮点数有几个重要的编译开关，在开发浮点计算相关的程序时候，值得注意使用：
- /fp (Specify Floating-Point Behavior)
http://msdn2.microsoft.com/en-us/library/e7s85ffb.aspx
- /arch用于控制SSE相关指令的产生。 /arch is only available when compiling for the x86 platform. This compiler option is not available when compiling for x64 or Itanium. The SSE instructions exist in various Pentium and AMD Athlon processors. The SSE2 instructions only exist on the Pentium 4 processor. /arch:SSE allows the compiler to use the SSE instructions, and /arch:SSE2 allows the compiler to use the SSE2 instructions.
