## _mm_roundscale_sd

# Function _mm_roundscale_sd

1.89.0 · Source

    pub fn _mm_roundscale_sd(a: __m128d, b: __m128d, const IMM8: i32) -> __m128d

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`

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