Difference in SSE/AVX vector types

Question

What is the difference between _m256i and _m256d and _m256 ? and
What is the difference between _m128i and _m128d and _m128 ?

Answer 1

经验法则： i后缀用于所有整数矢量类型， d用于双精度浮点矢量类型，而当没有后缀时，则用于单精度浮点矢量类型。

Answer 2

The documentation states :

The __m256 data type is used to represent the contents of the extended SSE register - the YMM register, used by the Intel® AVX intrinsics. The __m256 data type can hold eight 32-bit floating-point values.

The __m256d data type can hold four 64-bit double precision floating-point values.

The __m256i data type can hold thirty-two 8-bit, sixteen 16-bit, eight 32-bit, or four 64-bit integer values.