algea 0.2.0

Small fixed-size SIMD-oriented vectors and matrices
Documentation
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
// TODO(codegen-optimization): Compare balanced arithmetic trees on representative targets without
// FMA, and change the lowering only when codegen or benchmarks show a consistent improvement.
#[rustfmt::skip]
macro_rules! arith {
    // TODO(api-cleanup): fix macro parsing when higher-precedence operators appear on the right.
    ($a:tt + $b:tt * $c:tt) => { $crate::utils::ArithPrimitive::mul_add_($b, $c, $a) };
    ($a:tt - $b:tt * $c:tt) => { $crate::utils::ArithPrimitive::neg_mul_add_($b, $c, $a) };
    ($a:tt * $b:tt + $c:tt) => { $crate::utils::ArithPrimitive::mul_add_($a, $b, $c) };
    ($a:tt * $b:tt - $c:tt) => { $crate::utils::ArithPrimitive::mul_sub_($a, $b, $c) };
    ($a:tt * $b:tt + $($t:tt)+) => { arith!(($crate::utils::ArithPrimitive::mul_noexcept_($a, $b)) + $($t)+) };
    ($a:tt * $b:tt - $($t:tt)+) => { arith!(($crate::utils::ArithPrimitive::mul_noexcept_($a, $b)) - $($t)+) };
    ($a:tt + $b:tt * $c:tt + $($t:tt)+) => { arith!((arith!($a + $b * $c)) + $($t)+) };
    ($a:tt + $b:tt * $c:tt - $($t:tt)+) => { arith!((arith!($a + $b * $c)) - $($t)+) };
    ($a:tt - $b:tt * $c:tt + $($t:tt)+) => { arith!((arith!($a - $b * $c)) + $($t)+) };
    ($a:tt - $b:tt * $c:tt - $($t:tt)+) => { arith!((arith!($a - $b * $c)) - $($t)+) };
    // ($a:tt + $b:tt) => { $a + $b };
    // ($a:tt - $b:tt) => { $a - $b };
    // ($a:tt * $b:tt) => { $a * $b };
    // ($a:tt) => { $a };
}

macro_rules! if_ {
    (1 == 1 and 1 != 1 { $($then:tt)* }) => { };
    (1 == 1 and $_:tt != 1 { $($then:tt)* }) => { $($then)* };
    (2 == 2 and 1 == 1 { $($then:tt)* }) => { $($then)* };
    (3 == 3 and 1 == 1 { $($then:tt)* }) => { $($then)* };
    (4 == 4 and 1 == 1 { $($then:tt)* }) => { $($then)* };
    (1 == 1 and 1 == 1 { $($then:tt)* }) => { $($then)* };
    (2 == 2 and 2 == 2 { $($then:tt)* }) => { $($then)* };
    (3 == 3 and 3 == 3 { $($then:tt)* }) => { $($then)* };
    (4 == 4 and 4 == 4 { $($then:tt)* }) => { $($then)* };
    (1 == 1 { $($then:tt)* }) => { $($then)* };
    (1 == 1 { $($then:tt)* } else { $($else:tt)* }) => { $($then)* };
    (32 == 32 { $($then:tt)* }) => { $($then)* };
    ($_:tt == 1 { $($then:tt)* } else { $($else:tt)* }) => { $($else)* };
    (signed int == signed int { $($then:tt)* }) => { $($then)* };
    (unsigned int == unsigned int { $($then:tt)* }) => { $($then)* };
    (float == float { $($then:tt)* }) => { $($then)* };
    (not_float == not_float { $($then:tt)* }) => { $($then)* };
    (signed == signed { $($then:tt)* }) => { $($then)* };
    (unsigned == unsigned { $($then:tt)* }) => { $($then)* };
    (int == int { $($then:tt)* }) => { $($then)* };
    (matrix == matrix { $($then:tt)* }) => { $($then)* };
    ($($_:tt)*) => {};
}

pub(crate) use arith;
pub(crate) use if_;

// TODO(lane-count-generics): consider `ArithPrimitive<const N: usize>` and the same for
// `MaskPrimitive`, so `any`/`all`/`cast`/`to_bitmask` can tell 2, 3 and 4 lanes apart.
pub(crate) trait ArithPrimitive: Copy {
    type Scalar;
    type F32;
    type F64;
    type I32;
    type I64;
    type U32;
    type U64;
    type Mask: MaskPrimitive;
    const ZERO_: Self;
    const ONE_: Self;
    #[allow(dead_code)]
    fn filled_(a: Self::Scalar) -> Self;
    #[allow(dead_code)]
    fn as_array_(&self) -> &[Self::Scalar];
    #[allow(dead_code)]
    fn as_mut_array_(&mut self) -> &mut [Self::Scalar];
    fn cast_from_f32_<const N: usize>(_a: Self::F32) -> Self { unimplemented!() }
    fn cast_from_f64_<const N: usize>(_a: Self::F64) -> Self { unimplemented!() }
    fn cast_from_i32_<const N: usize>(_a: Self::I32) -> Self { unimplemented!() }
    fn cast_from_i64_<const N: usize>(_a: Self::I64) -> Self { unimplemented!() }
    fn cast_from_u32_<const N: usize>(_a: Self::U32) -> Self { unimplemented!() }
    fn cast_from_u64_<const N: usize>(_a: Self::U64) -> Self { unimplemented!() }

    fn max_(self, _other: Self) -> Self { unimplemented!() }
    fn min_(self, _other: Self) -> Self { unimplemented!() }
    #[inline(always)]
    fn clamp_noexcept_(self, min: Self, max: Self) -> Self { self.max_(min).min_(max) }
    fn add_noexcept_(self, _rhs: Self) -> Self { unimplemented!() }
    fn sub_noexcept_(self, _rhs: Self) -> Self { unimplemented!() }
    fn mul_noexcept_(self, _rhs: Self) -> Self { unimplemented!() }
    fn eq_(self, _other: Self) -> MaskStorage<Self::Mask> { unimplemented!() }
    #[inline(always)]
    fn ne_(self, other: Self) -> MaskStorage<Self::Mask> { !Self::eq_(self, other) }
    fn gt_(self, _other: Self) -> MaskStorage<Self::Mask> { unimplemented!() }
    fn lt_(self, _other: Self) -> MaskStorage<Self::Mask> { unimplemented!() }
    #[inline(always)]
    fn ge_(self, other: Self) -> MaskStorage<Self::Mask> { !Self::lt_(self, other) }
    #[inline(always)]
    fn le_(self, other: Self) -> MaskStorage<Self::Mask> { !Self::gt_(self, other) }
    fn select_(_mask: MaskStorage<Self::Mask>, _true_values: Self, _false_values: Self) -> Self {
        unimplemented!()
    }

    // Signed operations.
    fn neg_noexcept_(self) -> Self { unimplemented!() }
    fn abs_noexcept_(self) -> Self { unimplemented!() }
    fn signum_(self) -> Self { unimplemented!() }

    // Floating-point operations.
    #[allow(dead_code)]
    fn round_ties_even_(self) -> Self { unimplemented!() }
    fn is_nan_(self) -> MaskStorage<Self::Mask> { unimplemented!() }
    /// a * b + c
    fn mul_add_(_a: Self, _b: Self, _c: Self) -> Self { unimplemented!() }
    /// a * b - c
    fn mul_sub_(_a: Self, _b: Self, _c: Self) -> Self { unimplemented!() }
    /// -a * b + c
    fn neg_mul_add_(_a: Self, _b: Self, _c: Self) -> Self { unimplemented!() }
    // Integer operations.
    fn shl_noexcept_(self, _rhs: Self) -> Self { unimplemented!() }
    fn shr_noexcept_(self, _rhs: Self) -> Self { unimplemented!() }
    // LLVM already folds the `filled` implementation to `psrld`, so the scalar variant is unused.
    #[expect(dead_code)]
    fn shl_scalar_noexcept_(self, _rhs: Self::Scalar) -> Self { unimplemented!() }
    #[expect(dead_code)]
    fn shr_scalar_noexcept_(self, _rhs: Self::Scalar) -> Self { unimplemented!() }
}

macro_rules! impl_arith_primitive {
    ($self_ty:ty, mask=$mask:ty { $($item:item)* }) => {
        impl ArithPrimitive for $self_ty {
            type Scalar = Self;
            type F32 = f32;
            type F64 = f64;
            type I32 = i32;
            type I64 = i64;
            type U32 = u32;
            type U64 = u64;
            type Mask = $mask;
            const ZERO_: Self = 0 as _;
            const ONE_: Self = 1 as _;
            #[inline(always)]
            fn filled_(a: Self::Scalar) -> Self { a }
            #[inline(always)]
            fn as_array_(&self) -> &[Self::Scalar] { core::array::from_ref(self) }
            #[inline(always)]
            fn as_mut_array_(&mut self) -> &mut [Self::Scalar] { core::array::from_mut(self) }
            #[inline(always)]
            fn cast_from_f32_<const N: usize>(a: Self::F32) -> Self { a as _ }
            #[inline(always)]
            fn cast_from_f64_<const N: usize>(a: Self::F64) -> Self { a as _ }
            #[inline(always)]
            fn cast_from_i32_<const N: usize>(a: Self::I32) -> Self { a as _ }
            #[inline(always)]
            fn cast_from_i64_<const N: usize>(a: Self::I64) -> Self { a as _ }
            #[inline(always)]
            fn cast_from_u32_<const N: usize>(a: Self::U32) -> Self { a as _ }
            #[inline(always)]
            fn cast_from_u64_<const N: usize>(a: Self::U64) -> Self { a as _ }
            #[inline(always)]
            fn max_(self, other: Self) -> Self { self.max(other) }
            #[inline(always)]
            fn min_(self, other: Self) -> Self { self.min(other) }
            #[inline(always)]
            fn eq_(self, other: Self) -> MaskStorage<Self::Mask> { MaskStorage::<Self::Mask>::new(self == other) }
            #[inline(always)]
            fn ne_(self, other: Self) -> MaskStorage<Self::Mask> { MaskStorage::<Self::Mask>::new(self != other) }
            #[inline(always)]
            fn gt_(self, other: Self) -> MaskStorage<Self::Mask> { MaskStorage::<Self::Mask>::new(self > other) }
            #[inline(always)]
            fn lt_(self, other: Self) -> MaskStorage<Self::Mask> { MaskStorage::<Self::Mask>::new(self < other) }
            #[inline(always)]
            fn ge_(self, other: Self) -> MaskStorage<Self::Mask> { MaskStorage::<Self::Mask>::new(self >= other) }
            #[inline(always)]
            fn le_(self, other: Self) -> MaskStorage<Self::Mask> { MaskStorage::<Self::Mask>::new(self <= other) }
            #[inline(always)]
            fn select_(mask: MaskStorage<Self::Mask>, true_values: Self, false_values: Self) -> Self {
                if mask.into_inner() < 0 { true_values } else { false_values }
            }
            $($item)*
        }
    };
}
macro_rules! impl_arith_primitive_int {
    ($self_ty:ty, mask=$mask:ty { $($item:item)* }) => {
        impl_arith_primitive! {
            $self_ty, mask=$mask {
                #[inline(always)]
                fn add_noexcept_(self, rhs: Self) -> Self { self.wrapping_add(rhs) }
                #[inline(always)]
                fn sub_noexcept_(self, rhs: Self) -> Self { self.wrapping_sub(rhs) }
                #[inline(always)]
                fn mul_noexcept_(self, rhs: Self) -> Self { self.wrapping_mul(rhs) }

                #[inline(always)]
                fn shl_noexcept_(self, rhs: Self) -> Self { self.wrapping_shl(rhs as u32) }
                #[inline(always)]
                fn shr_noexcept_(self, rhs: Self) -> Self { self.wrapping_shr(rhs as u32) }
                #[inline(always)]
                fn shl_scalar_noexcept_(self, rhs: Self::Scalar) -> Self { self.wrapping_shl(rhs as u32) }
                #[inline(always)]
                fn shr_scalar_noexcept_(self, rhs: Self::Scalar) -> Self { self.wrapping_shr(rhs as u32) }
                $($item)*
            }
        }
    }
}
macro_rules! impl_arith_primitive_all {
    ($float:ty, $int:ty, $uint:ty) => {
        impl_arith_primitive! {
            $float, mask=$int {
                #[inline(always)]
                fn add_noexcept_(self, rhs: Self) -> Self { core::ops::Add::add(self, rhs) }
                #[inline(always)]
                fn sub_noexcept_(self, rhs: Self) -> Self { core::ops::Sub::sub(self, rhs) }
                #[inline(always)]
                fn mul_noexcept_(self, rhs: Self) -> Self { core::ops::Mul::mul(self, rhs) }
                #[inline(always)]
                fn clamp_noexcept_(mut self, min: Self, max: Self) -> Self {
                    if self < min {
                        self = min;
                    }
                    if self > max {
                        self = max;
                    }
                    self
                }
                #[inline(always)]
                fn neg_noexcept_(self) -> Self { core::ops::Neg::neg(self) }
                #[inline(always)]
                fn abs_noexcept_(self) -> Self { self.abs() }
                #[inline(always)]
                fn signum_(self) -> Self { self.signum() }
                #[inline(always)]
                fn round_ties_even_(self) -> Self { self.round_ties_even() }
                #[inline(always)]
                fn is_nan_(self) -> MaskStorage<Self::Mask> { MaskStorage::<Self::Mask>::new(self.is_nan()) }
                // Wasm has no scalar fused multiply-add: the only one it has is the relaxed
                // vector instruction, and reaching that from a scalar costs an `f32x4.splat` per
                // operand that neither Wasmtime nor V8 removes. A scalar `f32.fma` has been asked
                // for since 2020 (WebAssembly/design issue 1391) but is not a proposal at any
                // phase; revisit if one lands.
                #[inline(always)]
                fn mul_add_(a: Self, b: Self, c: Self) -> Self {
                    cfg_select! {
                        any(target_feature = "fma", all(target_feature = "neon", target_arch = "aarch64")) => {
                            a.mul_add(b, c)
                        }
                        _ => a * b + c,
                    }
                }
                // NOTE: LLVM lowers the following `mul_add` calls to the matching fused instructions.
                #[inline(always)]
                fn mul_sub_(a: Self, b: Self, c: Self) -> Self {
                    cfg_select! {
                        any(target_feature = "fma", all(target_feature = "neon", target_arch = "aarch64")) => {
                            a.mul_add(b, -c)
                        }
                        _ => a * b - c,
                    }
                }
                #[inline(always)]
                fn neg_mul_add_(a: Self, b: Self, c: Self) -> Self {
                    cfg_select! {
                        any(target_feature = "fma", all(target_feature = "neon", target_arch = "aarch64")) => {
                            (-a).mul_add(b, c)
                        }
                        _ => c - a * b,
                    }
                }
            }
        }
        impl_arith_primitive_int! {
            $int, mask=$int {
                #[inline(always)]
                fn neg_noexcept_(self) -> Self { self.wrapping_neg() }
                #[inline(always)]
                fn abs_noexcept_(self) -> Self { self.wrapping_abs() }
                #[inline(always)]
                fn signum_(self) -> Self { self.signum() }
            }
        }
        impl_arith_primitive_int! {
            $uint, mask=$int {}
        }
    }
}

impl_arith_primitive_all!(f32, i32, u32);
impl_arith_primitive_all!(f64, i64, u64);

pub(super) trait Load {
    type Output;
    fn load(self) -> Self::Output;
}
pub(super) trait Store<T> {
    fn store(self) -> T;
}
impl<T> Store<T> for T {
    #[inline(always)]
    fn store(self) -> T { self }
}

#[allow(unused_macros)]
macro_rules! impl_default_load {
    () => {
        impl<T> crate::utils::Load for T {
            type Output = T;
            #[inline(always)]
            fn load(self) -> Self::Output { self }
        }
    };
}
#[allow(unused_imports)]
pub(crate) use impl_default_load;

mod mask_utils {
    // TODO(mask-bitmask-storage): AVX-512 has dedicated mask registers whose bits carry no lane
    // width, so a bitmask representation would make the 32-bit/64-bit mask casts free and let
    // `any`/`all`/`to_bitmask` read the register directly. Keeping one lane per element instead
    // costs a shuffle on every cross-width `select` there. Not attempted: every other target
    // wants the wide form, so this would need a second storage type behind a target feature.

    // TODO(non-simd-bool-mask-storage): the non-SIMD backend could store `[[bool; M]; N]` for
    // every element type instead of mirroring the element's width in `i32`/`i64` lanes. Nothing
    // in the public API promises a storage layout, and without vector instructions there is no
    // reason for the lane width to match the values being selected: the width casts and the
    // canonical `0`/`-1` invariant would both disappear.

    /// Storage whose physical lanes are all-zero or all-one bit patterns.
    #[derive(Copy, Clone)]
    #[repr(transparent)]
    pub(crate) struct CanonicalMaskStorage<T>(T);
    pub(crate) use CanonicalMaskStorage as MaskStorage;

    /// Primitive storage that can uphold the canonical mask invariant.
    ///
    /// # Safety
    ///
    /// Implementations must ensure that:
    ///
    /// - `is_valid` returns `true` if and only if every physical lane, including
    ///   padding lanes, is either an all-zero or all-one bit pattern.
    /// - `not` maps every valid value to another valid value.
    /// - `select` maps a valid selector and two valid input values to a valid
    ///   output by selecting each physical lane in full from one of the inputs.
    /// - copying a value preserves its physical lane representation.
    pub unsafe trait MaskPrimitive: Copy {
        fn is_valid(self) -> bool;
        fn not(self) -> Self;
        fn bitand(self, rhs: Self) -> Self;
        fn bitor(self, rhs: Self) -> Self;
        fn bitxor(self, rhs: Self) -> Self;
        // same as `Primitive::select_`
        fn select(self, true_values: Self, false_values: Self) -> Self;
        // Only the SIMD backend's `SealedElement::any`/`all` (see `simd.rs`) calls these; the
        // non-SIMD backend implements `any`/`all` directly over its flat array storage instead.
        #[allow(dead_code)]
        fn any<const N: usize>(self) -> bool;
        #[allow(dead_code)]
        fn all<const N: usize>(self) -> bool;
    }

    // SAFETY: `is_valid` accepts exactly 0 and -1, `!` swaps those values, and
    // `select` returns one of its two canonical inputs in full.
    unsafe impl MaskPrimitive for i32 {
        fn is_valid(self) -> bool { self == 0 || self == -1 }
        #[inline(always)]
        fn not(self) -> Self { !self }
        #[inline(always)]
        fn bitand(self, rhs: Self) -> Self { self & rhs }
        #[inline(always)]
        fn bitor(self, rhs: Self) -> Self { self | rhs }
        #[inline(always)]
        fn bitxor(self, rhs: Self) -> Self { self ^ rhs }
        #[inline(always)]
        fn select(self, true_values: Self, false_values: Self) -> Self {
            if self < 0 { true_values } else { false_values }
        }
        #[inline(always)]
        fn any<const N: usize>(self) -> bool {
            assert_eq!(N, 1);
            self < 0
        }
        #[inline(always)]
        fn all<const N: usize>(self) -> bool {
            assert_eq!(N, 1);
            self < 0
        }
    }
    unsafe impl MaskPrimitive for i64 {
        fn is_valid(self) -> bool { self == 0 || self == -1 }
        #[inline(always)]
        fn not(self) -> Self { !self }
        #[inline(always)]
        fn bitand(self, rhs: Self) -> Self { self & rhs }
        #[inline(always)]
        fn bitor(self, rhs: Self) -> Self { self | rhs }
        #[inline(always)]
        fn bitxor(self, rhs: Self) -> Self { self ^ rhs }
        #[inline(always)]
        fn select(self, true_values: Self, false_values: Self) -> Self {
            if self < 0 { true_values } else { false_values }
        }
        #[inline(always)]
        fn any<const N: usize>(self) -> bool {
            assert_eq!(N, 1);
            self < 0
        }
        #[inline(always)]
        fn all<const N: usize>(self) -> bool {
            assert_eq!(N, 1);
            self < 0
        }
    }
    // SAFETY: every array element is validated, transformed, and selected
    // through its `MaskPrimitive` implementation, including elements used as
    // padding.
    unsafe impl<T: MaskPrimitive, const N: usize> MaskPrimitive for [T; N] {
        fn is_valid(self) -> bool { self.into_iter().all(MaskPrimitive::is_valid) }
        #[inline(always)]
        fn not(self) -> Self { self.map(MaskPrimitive::not) }
        #[inline(always)]
        fn bitand(self, rhs: Self) -> Self {
            core::array::from_fn(
                #[inline(always)]
                |i| self[i].bitand(rhs[i]),
            )
        }
        #[inline(always)]
        fn bitor(self, rhs: Self) -> Self {
            core::array::from_fn(
                #[inline(always)]
                |i| self[i].bitor(rhs[i]),
            )
        }
        #[inline(always)]
        fn bitxor(self, rhs: Self) -> Self {
            core::array::from_fn(
                #[inline(always)]
                |i| self[i].bitxor(rhs[i]),
            )
        }
        #[inline(always)]
        fn select(self, true_values: Self, false_values: Self) -> Self {
            core::array::from_fn(
                #[inline(always)]
                |i| MaskPrimitive::select(self[i], true_values[i], false_values[i]),
            )
        }
        fn any<const M: usize>(self) -> bool { unimplemented!() }
        fn all<const M: usize>(self) -> bool { unimplemented!() }
    }

    impl<T: MaskPrimitive> core::ops::Not for MaskStorage<T> {
        type Output = Self;
        #[inline(always)]
        fn not(self) -> Self::Output { Self(self.0.not()) }
    }
    impl<T: MaskPrimitive> core::ops::BitAnd for MaskStorage<T> {
        type Output = Self;
        #[inline(always)]
        fn bitand(self, rhs: Self) -> Self::Output { Self(self.0.bitand(rhs.0)) }
    }
    impl<T: MaskPrimitive> core::ops::BitOr for MaskStorage<T> {
        type Output = Self;
        #[inline(always)]
        fn bitor(self, rhs: Self) -> Self::Output { Self(self.0.bitor(rhs.0)) }
    }
    impl<T: MaskPrimitive> core::ops::BitXor for MaskStorage<T> {
        type Output = Self;
        #[inline(always)]
        fn bitxor(self, rhs: Self) -> Self::Output { Self(self.0.bitxor(rhs.0)) }
    }
    impl<T: MaskPrimitive, const N: usize> From<[MaskStorage<T>; N]> for MaskStorage<[T; N]> {
        #[inline(always)]
        fn from(value: [MaskStorage<T>; N]) -> Self {
            MaskStorage(value.map(MaskStorage::into_inner))
        }
    }
    impl<T: MaskPrimitive> MaskStorage<T> {
        /// Creates canonical mask storage without checking it in release builds.
        ///
        /// # Safety
        ///
        /// Every physical lane in `inner`, including padding lanes, must be
        /// either an all-zero or all-one bit pattern.
        #[inline(always)]
        pub(crate) unsafe fn new_unchecked(inner: T) -> Self {
            debug_assert!(inner.is_valid());
            Self(inner)
        }
        #[inline(always)]
        pub(crate) fn select(self, true_values: Self, false_values: Self) -> Self {
            // SAFETY: all three wrappers contain canonical physical lanes.
            // `MaskPrimitive::select` selects each output lane in full from one
            // of the canonical inputs and therefore preserves the invariant.
            unsafe { Self::new_unchecked(T::select(self.0, true_values.0, false_values.0)) }
        }
        #[allow(dead_code)]
        #[inline(always)]
        pub(crate) fn any<const N: usize>(self) -> bool { self.0.any::<N>() }
        #[allow(dead_code)]
        #[inline(always)]
        pub(crate) fn all<const N: usize>(self) -> bool { self.0.all::<N>() }
    }
    impl<T> MaskStorage<T> {
        #[inline(always)]
        pub(crate) fn into_inner(self) -> T { self.0 }
    }
    impl<T, const N: usize> MaskStorage<[T; N]> {
        #[inline(always)]
        pub(crate) fn unpack(self) -> [MaskStorage<T>; N] { self.0.map(MaskStorage) }
    }
    impl MaskStorage<i32> {
        #[inline(always)]
        #[allow(dead_code)]
        pub(crate) fn unpack(self) -> Self { self }
        #[expect(dead_code)]
        pub(crate) const TRUE: Self = Self(-1);
        #[expect(dead_code)]
        pub(crate) const FALSE: Self = Self(0);
        #[inline(always)]
        pub(crate) fn new(value: bool) -> Self {
            unsafe {
                // SAFETY: false is 0 and true is -1
                Self::new_unchecked(-(value as i32))
            }
        }
    }
    impl MaskStorage<i64> {
        #[inline(always)]
        #[allow(dead_code)]
        pub(crate) fn unpack(self) -> Self { self }
        #[expect(dead_code)]
        pub(crate) const TRUE: Self = Self(-1);
        #[expect(dead_code)]
        pub(crate) const FALSE: Self = Self(0);
        #[inline(always)]
        pub(crate) fn new(value: bool) -> Self {
            unsafe {
                // SAFETY: false is 0 and true is -1
                Self::new_unchecked(-(value as i64))
            }
        }
    }
}

pub(crate) use mask_utils::*;