浮点精度 [英] floating point precision

问题描述

我有一个用C＃编写的程序，有些部分是用本地C / C ++编写的。
我使用双精度计算一些值，有时结果是错误的，因为太小的精度。经过一番调查，我发现有人将浮点精度设置为24位。我的代码工作正常，当我将精度重置为至少53位（使用_fpreset或_controlfp），但我仍然需要弄清楚谁负责将精度设置为24位在第一位。

解决方案

这是由默认的Direct3D设备初始化。您可以通过传递 <$ c $来告诉Direct3D不要错过FPU精度c> D3DCREATE_FPU_PRESERVE 标记为 CreateDevice 。还有一个与此标志等效的托管代码（ CreateFlags.FpuPreserve ）。

有关详情，请访问 Direct3D和FPU 。

I have a program written in C# and some parts are writing in native C/C++. I use doubles to calculate some values and sometimes the result is wrong because of too small precision. After some investigation i figured out that someone is setting the floating-point precision to 24-bits. My code works fine, when i reset the precision to at least 53-bits (using _fpreset or _controlfp), but i still need to figure out who is responsible for setting the precision to 24-bits in the first place.

Any ideas who i could achieve this?

解决方案

This is caused by the default Direct3D device initialisation. You can tell Direct3D not to mess with the FPU precision by passing the D3DCREATE_FPU_PRESERVE flag to CreateDevice. There is also a managed code equivalent to this flag (CreateFlags.FpuPreserve) if you need it.

More information can be found at Direct3D and the FPU.

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