core/portable-simd/crates/core_simd/src/
select.rs

1use crate::simd::{LaneCount, Mask, MaskElement, Simd, SimdElement, SupportedLaneCount};
2
3impl<T, const N: usize> Mask<T, N>
4where
5    T: MaskElement,
6    LaneCount<N>: SupportedLaneCount,
7{
8    /// Choose elements from two vectors.
9    ///
10    /// For each element in the mask, choose the corresponding element from `true_values` if
11    /// that element mask is true, and `false_values` if that element mask is false.
12    ///
13    /// # Examples
14    /// ```
15    /// # #![feature(portable_simd)]
16    /// # use core::simd::{Simd, Mask};
17    /// let a = Simd::from_array([0, 1, 2, 3]);
18    /// let b = Simd::from_array([4, 5, 6, 7]);
19    /// let mask = Mask::from_array([true, false, false, true]);
20    /// let c = mask.select(a, b);
21    /// assert_eq!(c.to_array(), [0, 5, 6, 3]);
22    /// ```
23    #[inline]
24    #[must_use = "method returns a new vector and does not mutate the original inputs"]
25    pub fn select<U>(self, true_values: Simd<U, N>, false_values: Simd<U, N>) -> Simd<U, N>
26    where
27        U: SimdElement<Mask = T>,
28    {
29        // Safety: The mask has been cast to a vector of integers,
30        // and the operands to select between are vectors of the same type and length.
31        unsafe { core::intrinsics::simd::simd_select(self.to_int(), true_values, false_values) }
32    }
33
34    /// Choose elements from two masks.
35    ///
36    /// For each element in the mask, choose the corresponding element from `true_values` if
37    /// that element mask is true, and `false_values` if that element mask is false.
38    ///
39    /// # Examples
40    /// ```
41    /// # #![feature(portable_simd)]
42    /// # use core::simd::Mask;
43    /// let a = Mask::<i32, 4>::from_array([true, true, false, false]);
44    /// let b = Mask::<i32, 4>::from_array([false, false, true, true]);
45    /// let mask = Mask::<i32, 4>::from_array([true, false, false, true]);
46    /// let c = mask.select_mask(a, b);
47    /// assert_eq!(c.to_array(), [true, false, true, false]);
48    /// ```
49    #[inline]
50    #[must_use = "method returns a new mask and does not mutate the original inputs"]
51    pub fn select_mask(self, true_values: Self, false_values: Self) -> Self {
52        self & true_values | !self & false_values
53    }
54}
core/portable-simd/crates/core_simd/src/select.rs

core/portable-simd/crates/core_simd/src/
select.rs
