6 /// Supporting trait for vector `select` function
7 pub trait Select<Mask>: Sealed {
9 fn select(mask: Mask, true_values: Self, false_values: Self) -> Self;
12 macro_rules! impl_select {
14 $mask:ident ($bits_ty:ident): $($type:ident),*
17 impl<const LANES: usize> Sealed for crate::$type<LANES> where Self: crate::LanesAtMost32 {}
18 impl<const LANES: usize> Select<crate::$mask<LANES>> for crate::$type<LANES>
20 crate::$mask<LANES>: crate::Mask,
21 crate::$bits_ty<LANES>: crate::LanesAtMost32,
22 Self: crate::LanesAtMost32,
26 fn select(mask: crate::$mask<LANES>, true_values: Self, false_values: Self) -> Self {
27 unsafe { crate::intrinsics::simd_select(mask.to_int(), true_values, false_values) }
32 impl<const LANES: usize> Sealed for crate::$mask<LANES>
35 crate::$bits_ty<LANES>: crate::LanesAtMost32,
37 impl<const LANES: usize> Select<Self> for crate::$mask<LANES>
40 crate::$bits_ty<LANES>: crate::LanesAtMost32,
44 fn select(mask: Self, true_values: Self, false_values: Self) -> Self {
45 mask & true_values | !mask & false_values
49 impl<const LANES: usize> crate::$mask<LANES>
52 crate::$bits_ty<LANES>: crate::LanesAtMost32,
54 /// Choose lanes from two vectors.
56 /// For each lane in the mask, choose the corresponding lane from `true_values` if
57 /// that lane mask is true, and `false_values` if that lane mask is false.
60 /// # use core_simd::{Mask32, SimdI32};
61 /// let a = SimdI32::from_array([0, 1, 2, 3]);
62 /// let b = SimdI32::from_array([4, 5, 6, 7]);
63 /// let mask = Mask32::from_array([true, false, false, true]);
64 /// let c = mask.select(a, b);
65 /// assert_eq!(c.to_array(), [0, 5, 6, 3]);
68 /// `select` can also be used with masks:
70 /// # use core_simd::{Mask32};
71 /// let a = Mask32::from_array([true, true, false, false]);
72 /// let b = Mask32::from_array([false, false, true, true]);
73 /// let mask = Mask32::from_array([true, false, false, true]);
74 /// let c = mask.select(a, b);
75 /// assert_eq!(c.to_array(), [true, false, true, false]);
78 pub fn select<S: Select<Self>>(self, true_values: S, false_values: S) -> S {
79 S::select(self, true_values, false_values)
85 impl_select! { Mask8 (SimdI8): SimdU8, SimdI8 }
86 impl_select! { Mask16 (SimdI16): SimdU16, SimdI16 }
87 impl_select! { Mask32 (SimdI32): SimdU32, SimdI32, SimdF32}
88 impl_select! { Mask64 (SimdI64): SimdU64, SimdI64, SimdF64}
89 impl_select! { MaskSize (SimdIsize): SimdUsize, SimdIsize }