SSE2在Visual C ++的选项（64） [英] SSE2 option in Visual C++ (x64)

问题描述

我已经添加了64位配置，我的C ++项目编译64位版本的我的应用程序。一切看起来正常，但编译器提供了以下警告：

I've added x64 configuration to my C++ project to compile 64-bit version of my app. Everything looks fine, but compiler gives the following warning:

`cl : Command line warning D9002 : ignoring unknown option '/arch:SSE2'`

有SSE2优化真的不适用于64位的项目？

Is there SSE2 optimization really not available for 64-bit projects?

推荐答案

似乎是所有的64位处理器具有SSE2。由于编译器选项总是打开默认情况下，无需手动切换了。

Seems to be all 64-bit processors has SSE2. Since compiler option always switched on by default no need to switch it on manually.

从维基百科：

SSE指令：采用了Intel的SSE和SSE2为核心的指令原AMD64架构。 SSE3指令是在2005年4月加入SSE2替代的x87指令集的IEEE 80位precision与任何IEEE 32位或64位浮点数学的选择。这提供了许多其他现代CPU兼容的浮点运算。在SSE和SSE2指令也被扩展到八个新的XMM寄存器操作。 SSE和SSE2是在现代的x86处理器的32位模式下可用;但是，如果他们在32位程序时，这些程序将只与具有功能的处理器，工作系统。这不是一个问题，在64位程序，的所有的AMD64处理器都SSE和SSE2，因此，使用SSE和SSE2指令代替的x87指令不会降低套机在其x64程序可以运行的 SSE和SSE2一般都比较快，而且重复的大部分传统的x87指令的功能，MMX和3DNow！

SSE instructions: The original AMD64 architecture adopted Intel's SSE and SSE2 as core instructions. SSE3 instructions were added in April 2005. SSE2 replaces the x87 instruction set's IEEE 80-bit precision with the choice of either IEEE 32-bit or 64-bit floating-point mathematics. This provides floating-point operations compatible with many other modern CPUs. The SSE and SSE2 instructions have also been extended to operate on the eight new XMM registers. SSE and SSE2 are available in 32-bit mode in modern x86 processors; however, if they're used in 32-bit programs, those programs will only work on systems with processors that have the feature. This is not an issue in 64-bit programs, as all AMD64 processors have SSE and SSE2, so using SSE and SSE2 instructions instead of x87 instructions does not reduce the set of machines on which x64 programs can be run. SSE and SSE2 are generally faster than, and duplicate most of the features of the traditional x87 instructions, MMX, and 3DNow!.

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