sfmt 0.4.0

Rust implementation of SIMD-oriented Fast Mersenne Twister (SFMT)
Documentation 
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//! packed_simd-like wrapper layer

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

#[allow(non_camel_case_types)]
pub(crate) type i32x4 = __m128i;

pub(crate) fn new(e0: i32, e1: i32, e2: i32, e3: i32) -> i32x4 {
    unsafe { _mm_set_epi32(e3, e2, e1, e0) }
}

pub(crate) fn zero() -> i32x4 {
    unsafe { _mm_setzero_si128() }
}

pub(crate) fn extract(vals: i32x4, imm: usize) -> u32 {
    unsafe {
        match imm {
            0 => _mm_extract_epi32(vals, 0) as u32,
            1 => _mm_extract_epi32(vals, 1) as u32,
            2 => _mm_extract_epi32(vals, 2) as u32,
            3 => _mm_extract_epi32(vals, 3) as u32,
            _ => unreachable!(),
        }
    }
}

pub(crate) fn insert(vals: &mut i32x4, val: i32, imm: usize) {
    let updated = unsafe {
        match imm {
            0 => _mm_insert_epi32(*vals, val, 0),
            1 => _mm_insert_epi32(*vals, val, 1),
            2 => _mm_insert_epi32(*vals, val, 2),
            3 => _mm_insert_epi32(*vals, val, 3),
            _ => unreachable!(),
        }
    };
    ::std::mem::replace(vals, updated);
}