pub unsafe fn _mm_roundscale_round_sd(
    a: __m128d,
    b: __m128d,
    const IMM8: i32,
    const SAE: i32
) -> __m128d
🔬This is a nightly-only experimental API. (stdarch_x86_avx512 #111137)
Available on (x86 or x86-64) and target feature avx512f and x86 only.
Expand description

Round the lower double-precision (64-bit) floating-point element in b to the number of fraction bits specified by imm8, store the result in the lower element of dst, and copy the upper element from a to the upper element of dst.
Rounding is done according to the imm8[2:0] parameter, which can be one of:
_MM_FROUND_TO_NEAREST_INT // round to nearest
_MM_FROUND_TO_NEG_INF // round down
_MM_FROUND_TO_POS_INF // round up
_MM_FROUND_TO_ZERO // truncate
_MM_FROUND_CUR_DIRECTION // use MXCSR.RC; see _MM_SET_ROUNDING_MODE

Exceptions can be suppressed by passing _MM_FROUND_NO_EXC in the sae parameter. Intel’s documentation