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## _mm_round_ss

# Function _mm_round_ss

1.27.0 · Source

    pub fn _mm_round_ss(a: __m128, b: __m128, const ROUNDING: i32) -> __m128

Available on x86-64 and target feature `sse4.1` only.
Expand description

Round the lower single-precision (32-bit) floating-point element in `b` using the `ROUNDING` parameter, store the result as a single-precision floating-point element in the lower element of the intrinsic result, and copies the upper 3 packed elements from `a` to the upper elements of the intrinsic result. 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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