Macro wasmtime_environ::__core::simd::simd_swizzle
source · [−]pub macro simd_swizzle {
($vector:expr, $index:expr $(,)?) => { ... },
($first:expr, $second:expr, $index:expr $(,)?) => { ... },
}
🔬 This is a nightly-only experimental API. (
portable_simd
)Expand description
Constructs a new vector by selecting values from the lanes of the source vector or vectors to use.
When swizzling one vector, the indices of the result vector are indicated by a const
array
of usize
, like Swizzle
.
When swizzling two vectors, the indices are indicated by a const
array of Which
, like
Swizzle2
.
Examples
One source vector
let v = Simd::<f32, 4>::from_array([0., 1., 2., 3.]);
// Keeping the same size
let r = simd_swizzle!(v, [3, 0, 1, 2]);
assert_eq!(r.to_array(), [3., 0., 1., 2.]);
// Changing the number of lanes
let r = simd_swizzle!(v, [3, 1]);
assert_eq!(r.to_array(), [3., 1.]);
Two source vectors
use Which::*;
let a = Simd::<f32, 4>::from_array([0., 1., 2., 3.]);
let b = Simd::<f32, 4>::from_array([4., 5., 6., 7.]);
// Keeping the same size
let r = simd_swizzle!(a, b, [First(0), First(1), Second(2), Second(3)]);
assert_eq!(r.to_array(), [0., 1., 6., 7.]);
// Changing the number of lanes
let r = simd_swizzle!(a, b, [First(0), Second(0)]);
assert_eq!(r.to_array(), [0., 4.]);