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## _mm_fnmsub_round_sh

# Function _mm_fnmsub_round_sh

1.94.0 · Source

    pub fn _mm_fnmsub_round_sh(
        a: __m128h,
        b: __m128h,
        c: __m128h,
        const ROUNDING: i32,
    ) -> __m128h

Available on x86-64 and target feature `avx512fp16` only.
Expand description

Multiply the lower half-precision (16-bit) floating-point elements in a and b, and subtract the intermediate result from the lower element in c. Store the result in the lower element of dst, and copy the upper 7 packed elements from a to the upper elements of dst.

Rounding is done according to the rounding 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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