# 1.27.0[−][src]Function core::arch::x86::_mm_round_ss

    pub unsafe fn _mm_round_ss(a: __m128, b: __m128, rounding: i32) -> __m128

This is supported on x86 and target feature `sse4.1` only.

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 instrinsic result. Rounding is done according to the rounding parameter, which can be one of:

    #[cfg(target_arch = "x86")]
    use std::arch::x86::*;
    #[cfg(target_arch = "x86_64")]
    use std::arch::x86_64::*;

    // round to nearest, and suppress exceptions:
    _MM_FROUND_TO_NEAREST_INT | _MM_FROUND_NO_EXC;
    // round down, and suppress exceptions:
    _MM_FROUND_TO_NEG_INF | _MM_FROUND_NO_EXC;
    // round up, and suppress exceptions:
    _MM_FROUND_TO_POS_INF | _MM_FROUND_NO_EXC;
    // truncate, and suppress exceptions:
    _MM_FROUND_TO_ZERO | _MM_FROUND_NO_EXC;
    // use MXCSR.RC; see `_MM_SET_ROUNDING_MODE`:
    _MM_FROUND_CUR_DIRECTION;

Run

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