# Function _mm_mask_roundscale_ss

Source

    pub fn _mm_mask_roundscale_ss(
        src: __m128,
        k: __mmask8,
        a: __m128,
        b: __m128,
        const IMM8: i32,
    ) -> __m128

🔬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 single-precision (32-bit) floating-point element in b to the number of fraction bits specified by imm8, store the result in the lower element of dst using writemask k (the element is copied from src when mask bit 0 is not set), and copy the upper 3 packed elements from a to the upper elements 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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