Function _mm256_mask_cvt_roundps_ph 

pub fn _mm256_mask_cvt_roundps_ph<const IMM8: i32>(
    src: __m128i,
    k: u8,
    a: __m256,
) -> __m128i

Convert packed single-precision (32-bit) floating-point elements in a to packed half-precision (16-bit) floating-point elements, and store the results in dst using writemask k (elements are copied from src when the corresponding mask bit is not set).
Rounding is done according to the imm8[2:0] parameter, which can be one of:

• _MM_FROUND_TO_NEAREST_INT | _MM_FROUND_NO_EXC : round to nearest and suppress exceptions
• _MM_FROUND_TO_NEG_INF | _MM_FROUND_NO_EXC : round down and suppress exceptions
• _MM_FROUND_TO_POS_INF | _MM_FROUND_NO_EXC : round up and suppress exceptions
• _MM_FROUND_TO_ZERO | _MM_FROUND_NO_EXC : truncate and suppress exceptions
• _MM_FROUND_CUR_DIRECTION : use MXCSR.RC - see _MM_SET_ROUNDING_MODE

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