diff options
Diffstat (limited to 'library/portable-simd/crates/core_simd/src/select.rs')
-rw-r--r-- | library/portable-simd/crates/core_simd/src/select.rs | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/library/portable-simd/crates/core_simd/src/select.rs b/library/portable-simd/crates/core_simd/src/select.rs new file mode 100644 index 000000000..065c5987d --- /dev/null +++ b/library/portable-simd/crates/core_simd/src/select.rs @@ -0,0 +1,59 @@ +use crate::simd::intrinsics; +use crate::simd::{LaneCount, Mask, MaskElement, Simd, SimdElement, SupportedLaneCount}; + +impl<T, const LANES: usize> Mask<T, LANES> +where + T: MaskElement, + LaneCount<LANES>: SupportedLaneCount, +{ + /// Choose lanes from two vectors. + /// + /// For each lane in the mask, choose the corresponding lane from `true_values` if + /// that lane mask is true, and `false_values` if that lane mask is false. + /// + /// # Examples + /// ``` + /// # #![feature(portable_simd)] + /// # use core::simd::{Simd, Mask}; + /// let a = Simd::from_array([0, 1, 2, 3]); + /// let b = Simd::from_array([4, 5, 6, 7]); + /// let mask = Mask::from_array([true, false, false, true]); + /// let c = mask.select(a, b); + /// assert_eq!(c.to_array(), [0, 5, 6, 3]); + /// ``` + #[inline] + #[must_use = "method returns a new vector and does not mutate the original inputs"] + pub fn select<U>( + self, + true_values: Simd<U, LANES>, + false_values: Simd<U, LANES>, + ) -> Simd<U, LANES> + where + U: SimdElement<Mask = T>, + { + // Safety: The mask has been cast to a vector of integers, + // and the operands to select between are vectors of the same type and length. + unsafe { intrinsics::simd_select(self.to_int(), true_values, false_values) } + } + + /// Choose lanes from two masks. + /// + /// For each lane in the mask, choose the corresponding lane from `true_values` if + /// that lane mask is true, and `false_values` if that lane mask is false. + /// + /// # Examples + /// ``` + /// # #![feature(portable_simd)] + /// # use core::simd::Mask; + /// let a = Mask::<i32, 4>::from_array([true, true, false, false]); + /// let b = Mask::<i32, 4>::from_array([false, false, true, true]); + /// let mask = Mask::<i32, 4>::from_array([true, false, false, true]); + /// let c = mask.select_mask(a, b); + /// assert_eq!(c.to_array(), [true, false, true, false]); + /// ``` + #[inline] + #[must_use = "method returns a new mask and does not mutate the original inputs"] + pub fn select_mask(self, true_values: Self, false_values: Self) -> Self { + self & true_values | !self & false_values + } +} |