pow的SSE类型 [英] pow for SSE types

问题描述

我使用SSE类型进行一些明确的向量化计算，例如 __ m128 （在 xmmintrin.h 等中定义） ，但现在我需要将向量的所有元素提升到一些（相同的）权力，即理想情况下，我会想要像 __ m128 _mm_pow_ps（__ m128，float），不幸的是

I do some explicitly vectorised computations using SSE types, such as __m128 (defined in xmmintrin.h etc), but now I need to raise all elements of the vector to some (same) power, i.e. ideally I would want something like __m128 _mm_pow_ps(__m128, float), which unfortunately doesn't exist.

这是最好的方法是什么？我可以存储向量，调用 std :: pow 在每个元素，然后重新加载它。这是我能做的最好的吗？当自动向量化代码否则是很好的向量化的时，编译器如何实现对 std :: pow 的调用？是否有任何库提供了有用的功能？

What is the best way around this? I could store the vector, call std::pow on each element, and then reload it. Is this the best I can do? How do compilers implement a call to std::pow when auto-vectorising code that otherwise is well vectorisable? Are there any libraries that provide something useful?

（请注意

(note that this question is related by not a duplicate and certainly doesn't have a useful answer.)

推荐答案

对 pow（x，y） exp（y * log（x）） c>和具有exp和log的SSE实现的库。

Use the formula exp(y*log(x)) for pow(x, y) and a library with SSE implementations of exp and log.

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