tests/ui/simd/shuffle.rs

//@ run-pass
//@ revisions: opt noopt
//@[noopt] compile-flags: -Copt-level=0
//@[opt] compile-flags: -O
#![feature(repr_simd, core_intrinsics)]
#![allow(incomplete_features)]
#![feature(adt_const_params)]

use std::marker::ConstParamTy;

use std::intrinsics::simd::simd_shuffle;

// not using `minisimd` because of the `ConstParamTy`
#[derive(Copy, Clone, ConstParamTy, PartialEq, Eq)]
#[repr(simd)]
struct Simd<T, const N: usize>([T; N]);

fn into_array<T, const N: usize>(v: Simd<T, N>) -> [T; N] {
    const { assert!(size_of::<Simd<T, N>>() == size_of::<[T; N]>()) }
    unsafe { std::intrinsics::transmute_unchecked(v) }
}

unsafe fn __shuffle_vector16<const IDX: Simd<u32, 16>, T, U>(x: T, y: T) -> U {
    simd_shuffle(x, y, IDX)
}

fn main() {
    const I1: Simd<u32, 4> = Simd([0, 2, 4, 6]);
    const I2: Simd<u32, 2> = Simd([1, 5]);
    let a = Simd::<u8, 4>([0, 1, 2, 3]);
    let b = Simd::<u8, 4>([4, 5, 6, 7]);
    unsafe {
        let x: Simd<u8, 4> = simd_shuffle(a, b, I1);
        assert_eq!(into_array(x), [0, 2, 4, 6]);

        let y: Simd<u8, 2> = simd_shuffle(a, b, I2);
        assert_eq!(into_array(y), [1, 5]);
    }

    // Test that an indirection (via an unnamed constant)
    // through a const generic parameter also works.
    // See https://github.com/rust-lang/rust/issues/113500 for details.
    let a = Simd::<u8, 16>([0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]);
    let b = Simd::<u8, 16>([16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31]);
    unsafe {
        __shuffle_vector16::<
            { Simd([1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16]) },
            Simd<u8, 16>,
            Simd<u8, 16>,
        >(a, b);
    }
}