1 | //! Compiler intrinsics. |
2 | //! |
3 | //! The corresponding definitions are in <https://github.com/rust-lang/rust/blob/master/compiler/rustc_codegen_llvm/src/intrinsic.rs>. |
4 | //! The corresponding const implementations are in <https://github.com/rust-lang/rust/blob/master/compiler/rustc_const_eval/src/interpret/intrinsics.rs>. |
5 | //! |
6 | //! # Const intrinsics |
7 | //! |
8 | //! Note: any changes to the constness of intrinsics should be discussed with the language team. |
9 | //! This includes changes in the stability of the constness. |
10 | //! |
11 | //! In order to make an intrinsic usable at compile-time, it needs to be declared in the "new" |
12 | //! style, i.e. as a `#[rustc_intrinsic]` function, not inside an `extern` block. Then copy the |
13 | //! implementation from <https://github.com/rust-lang/miri/blob/master/src/intrinsics> to |
14 | //! <https://github.com/rust-lang/rust/blob/master/compiler/rustc_const_eval/src/interpret/intrinsics.rs> |
15 | //! and make the intrinsic declaration a `const fn`. |
16 | //! |
17 | //! If an intrinsic is supposed to be used from a `const fn` with a `rustc_const_stable` attribute, |
18 | //! `#[rustc_intrinsic_const_stable_indirect]` needs to be added to the intrinsic. Such a change requires |
19 | //! T-lang approval, because it may bake a feature into the language that cannot be replicated in |
20 | //! user code without compiler support. |
21 | //! |
22 | //! # Volatiles |
23 | //! |
24 | //! The volatile intrinsics provide operations intended to act on I/O |
25 | //! memory, which are guaranteed to not be reordered by the compiler |
26 | //! across other volatile intrinsics. See the LLVM documentation on |
27 | //! [[volatile]]. |
28 | //! |
29 | //! [volatile]: https://llvm.org/docs/LangRef.html#volatile-memory-accesses |
30 | //! |
31 | //! # Atomics |
32 | //! |
33 | //! The atomic intrinsics provide common atomic operations on machine |
34 | //! words, with multiple possible memory orderings. They obey the same |
35 | //! semantics as C++11. See the LLVM documentation on [[atomics]]. |
36 | //! |
37 | //! [atomics]: https://llvm.org/docs/Atomics.html |
38 | //! |
39 | //! A quick refresher on memory ordering: |
40 | //! |
41 | //! * Acquire - a barrier for acquiring a lock. Subsequent reads and writes |
42 | //! take place after the barrier. |
43 | //! * Release - a barrier for releasing a lock. Preceding reads and writes |
44 | //! take place before the barrier. |
45 | //! * Sequentially consistent - sequentially consistent operations are |
46 | //! guaranteed to happen in order. This is the standard mode for working |
47 | //! with atomic types and is equivalent to Java's `volatile`. |
48 | //! |
49 | //! # Unwinding |
50 | //! |
51 | //! Rust intrinsics may, in general, unwind. If an intrinsic can never unwind, add the |
52 | //! `#[rustc_nounwind]` attribute so that the compiler can make use of this fact. |
53 | //! |
54 | //! However, even for intrinsics that may unwind, rustc assumes that a Rust intrinsics will never |
55 | //! initiate a foreign (non-Rust) unwind, and thus for panic=abort we can always assume that these |
56 | //! intrinsics cannot unwind. |
57 | |
58 | #![unstable ( |
59 | feature = "core_intrinsics" , |
60 | reason = "intrinsics are unlikely to ever be stabilized, instead \ |
61 | they should be used through stabilized interfaces \ |
62 | in the rest of the standard library" , |
63 | issue = "none" |
64 | )] |
65 | #![allow (missing_docs)] |
66 | |
67 | use crate::marker::{DiscriminantKind, Tuple}; |
68 | use crate::mem::SizedTypeProperties; |
69 | use crate::{ptr, ub_checks}; |
70 | |
71 | pub mod fallback; |
72 | pub mod mir; |
73 | pub mod simd; |
74 | |
75 | // These imports are used for simplifying intra-doc links |
76 | #[allow (unused_imports)] |
77 | #[cfg (all(target_has_atomic = "8" , target_has_atomic = "32" , target_has_atomic = "ptr" ))] |
78 | use crate::sync::atomic::{self, AtomicBool, AtomicI32, AtomicIsize, AtomicU32, Ordering}; |
79 | |
80 | #[stable (feature = "drop_in_place" , since = "1.8.0" )] |
81 | #[rustc_allowed_through_unstable_modules = "import this function via `std::ptr` instead" ] |
82 | #[deprecated (note = "no longer an intrinsic - use `ptr::drop_in_place` directly" , since = "1.52.0" )] |
83 | #[inline ] |
84 | pub unsafe fn drop_in_place<T: ?Sized>(to_drop: *mut T) { |
85 | // SAFETY: see `ptr::drop_in_place` |
86 | unsafe { crate::ptr::drop_in_place(to_drop) } |
87 | } |
88 | |
89 | // N.B., these intrinsics take raw pointers because they mutate aliased |
90 | // memory, which is not valid for either `&` or `&mut`. |
91 | |
92 | /// Stores a value if the current value is the same as the `old` value. |
93 | /// `T` must be an integer or pointer type. |
94 | /// |
95 | /// The stabilized version of this intrinsic is available on the |
96 | /// [`atomic`] types via the `compare_exchange` method by passing |
97 | /// [`Ordering::Relaxed`] as both the success and failure parameters. |
98 | /// For example, [`AtomicBool::compare_exchange`]. |
99 | #[rustc_intrinsic ] |
100 | #[rustc_nounwind ] |
101 | pub unsafe fn atomic_cxchg_relaxed_relaxed<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); |
102 | /// Stores a value if the current value is the same as the `old` value. |
103 | /// `T` must be an integer or pointer type. |
104 | /// |
105 | /// The stabilized version of this intrinsic is available on the |
106 | /// [`atomic`] types via the `compare_exchange` method by passing |
107 | /// [`Ordering::Relaxed`] and [`Ordering::Acquire`] as the success and failure parameters. |
108 | /// For example, [`AtomicBool::compare_exchange`]. |
109 | #[rustc_intrinsic ] |
110 | #[rustc_nounwind ] |
111 | pub unsafe fn atomic_cxchg_relaxed_acquire<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); |
112 | /// Stores a value if the current value is the same as the `old` value. |
113 | /// `T` must be an integer or pointer type. |
114 | /// |
115 | /// The stabilized version of this intrinsic is available on the |
116 | /// [`atomic`] types via the `compare_exchange` method by passing |
117 | /// [`Ordering::Relaxed`] and [`Ordering::SeqCst`] as the success and failure parameters. |
118 | /// For example, [`AtomicBool::compare_exchange`]. |
119 | #[rustc_intrinsic ] |
120 | #[rustc_nounwind ] |
121 | pub unsafe fn atomic_cxchg_relaxed_seqcst<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); |
122 | /// Stores a value if the current value is the same as the `old` value. |
123 | /// `T` must be an integer or pointer type. |
124 | /// |
125 | /// The stabilized version of this intrinsic is available on the |
126 | /// [`atomic`] types via the `compare_exchange` method by passing |
127 | /// [`Ordering::Acquire`] and [`Ordering::Relaxed`] as the success and failure parameters. |
128 | /// For example, [`AtomicBool::compare_exchange`]. |
129 | #[rustc_intrinsic ] |
130 | #[rustc_nounwind ] |
131 | pub unsafe fn atomic_cxchg_acquire_relaxed<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); |
132 | /// Stores a value if the current value is the same as the `old` value. |
133 | /// `T` must be an integer or pointer type. |
134 | /// |
135 | /// The stabilized version of this intrinsic is available on the |
136 | /// [`atomic`] types via the `compare_exchange` method by passing |
137 | /// [`Ordering::Acquire`] as both the success and failure parameters. |
138 | /// For example, [`AtomicBool::compare_exchange`]. |
139 | #[rustc_intrinsic ] |
140 | #[rustc_nounwind ] |
141 | pub unsafe fn atomic_cxchg_acquire_acquire<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); |
142 | /// Stores a value if the current value is the same as the `old` value. |
143 | /// `T` must be an integer or pointer type. |
144 | /// |
145 | /// The stabilized version of this intrinsic is available on the |
146 | /// [`atomic`] types via the `compare_exchange` method by passing |
147 | /// [`Ordering::Acquire`] and [`Ordering::SeqCst`] as the success and failure parameters. |
148 | /// For example, [`AtomicBool::compare_exchange`]. |
149 | #[rustc_intrinsic ] |
150 | #[rustc_nounwind ] |
151 | pub unsafe fn atomic_cxchg_acquire_seqcst<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); |
152 | /// Stores a value if the current value is the same as the `old` value. |
153 | /// `T` must be an integer or pointer type. |
154 | /// |
155 | /// The stabilized version of this intrinsic is available on the |
156 | /// [`atomic`] types via the `compare_exchange` method by passing |
157 | /// [`Ordering::Release`] and [`Ordering::Relaxed`] as the success and failure parameters. |
158 | /// For example, [`AtomicBool::compare_exchange`]. |
159 | #[rustc_intrinsic ] |
160 | #[rustc_nounwind ] |
161 | pub unsafe fn atomic_cxchg_release_relaxed<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); |
162 | /// Stores a value if the current value is the same as the `old` value. |
163 | /// `T` must be an integer or pointer type. |
164 | /// |
165 | /// The stabilized version of this intrinsic is available on the |
166 | /// [`atomic`] types via the `compare_exchange` method by passing |
167 | /// [`Ordering::Release`] and [`Ordering::Acquire`] as the success and failure parameters. |
168 | /// For example, [`AtomicBool::compare_exchange`]. |
169 | #[rustc_intrinsic ] |
170 | #[rustc_nounwind ] |
171 | pub unsafe fn atomic_cxchg_release_acquire<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); |
172 | /// Stores a value if the current value is the same as the `old` value. |
173 | /// `T` must be an integer or pointer type. |
174 | /// |
175 | /// The stabilized version of this intrinsic is available on the |
176 | /// [`atomic`] types via the `compare_exchange` method by passing |
177 | /// [`Ordering::Release`] and [`Ordering::SeqCst`] as the success and failure parameters. |
178 | /// For example, [`AtomicBool::compare_exchange`]. |
179 | #[rustc_intrinsic ] |
180 | #[rustc_nounwind ] |
181 | pub unsafe fn atomic_cxchg_release_seqcst<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); |
182 | /// Stores a value if the current value is the same as the `old` value. |
183 | /// `T` must be an integer or pointer type. |
184 | /// |
185 | /// The stabilized version of this intrinsic is available on the |
186 | /// [`atomic`] types via the `compare_exchange` method by passing |
187 | /// [`Ordering::AcqRel`] and [`Ordering::Relaxed`] as the success and failure parameters. |
188 | /// For example, [`AtomicBool::compare_exchange`]. |
189 | #[rustc_intrinsic ] |
190 | #[rustc_nounwind ] |
191 | pub unsafe fn atomic_cxchg_acqrel_relaxed<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); |
192 | /// Stores a value if the current value is the same as the `old` value. |
193 | /// `T` must be an integer or pointer type. |
194 | /// |
195 | /// The stabilized version of this intrinsic is available on the |
196 | /// [`atomic`] types via the `compare_exchange` method by passing |
197 | /// [`Ordering::AcqRel`] and [`Ordering::Acquire`] as the success and failure parameters. |
198 | /// For example, [`AtomicBool::compare_exchange`]. |
199 | #[rustc_intrinsic ] |
200 | #[rustc_nounwind ] |
201 | pub unsafe fn atomic_cxchg_acqrel_acquire<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); |
202 | /// Stores a value if the current value is the same as the `old` value. |
203 | /// `T` must be an integer or pointer type. |
204 | /// |
205 | /// The stabilized version of this intrinsic is available on the |
206 | /// [`atomic`] types via the `compare_exchange` method by passing |
207 | /// [`Ordering::AcqRel`] and [`Ordering::SeqCst`] as the success and failure parameters. |
208 | /// For example, [`AtomicBool::compare_exchange`]. |
209 | #[rustc_intrinsic ] |
210 | #[rustc_nounwind ] |
211 | pub unsafe fn atomic_cxchg_acqrel_seqcst<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); |
212 | /// Stores a value if the current value is the same as the `old` value. |
213 | /// `T` must be an integer or pointer type. |
214 | /// |
215 | /// The stabilized version of this intrinsic is available on the |
216 | /// [`atomic`] types via the `compare_exchange` method by passing |
217 | /// [`Ordering::SeqCst`] and [`Ordering::Relaxed`] as the success and failure parameters. |
218 | /// For example, [`AtomicBool::compare_exchange`]. |
219 | #[rustc_intrinsic ] |
220 | #[rustc_nounwind ] |
221 | pub unsafe fn atomic_cxchg_seqcst_relaxed<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); |
222 | /// Stores a value if the current value is the same as the `old` value. |
223 | /// `T` must be an integer or pointer type. |
224 | /// |
225 | /// The stabilized version of this intrinsic is available on the |
226 | /// [`atomic`] types via the `compare_exchange` method by passing |
227 | /// [`Ordering::SeqCst`] and [`Ordering::Acquire`] as the success and failure parameters. |
228 | /// For example, [`AtomicBool::compare_exchange`]. |
229 | #[rustc_intrinsic ] |
230 | #[rustc_nounwind ] |
231 | pub unsafe fn atomic_cxchg_seqcst_acquire<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); |
232 | /// Stores a value if the current value is the same as the `old` value. |
233 | /// `T` must be an integer or pointer type. |
234 | /// |
235 | /// The stabilized version of this intrinsic is available on the |
236 | /// [`atomic`] types via the `compare_exchange` method by passing |
237 | /// [`Ordering::SeqCst`] as both the success and failure parameters. |
238 | /// For example, [`AtomicBool::compare_exchange`]. |
239 | #[rustc_intrinsic ] |
240 | #[rustc_nounwind ] |
241 | pub unsafe fn atomic_cxchg_seqcst_seqcst<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); |
242 | |
243 | /// Stores a value if the current value is the same as the `old` value. |
244 | /// `T` must be an integer or pointer type. |
245 | /// |
246 | /// The stabilized version of this intrinsic is available on the |
247 | /// [`atomic`] types via the `compare_exchange_weak` method by passing |
248 | /// [`Ordering::Relaxed`] as both the success and failure parameters. |
249 | /// For example, [`AtomicBool::compare_exchange_weak`]. |
250 | #[rustc_intrinsic ] |
251 | #[rustc_nounwind ] |
252 | pub unsafe fn atomic_cxchgweak_relaxed_relaxed<T: Copy>( |
253 | _dst: *mut T, |
254 | _old: T, |
255 | _src: T, |
256 | ) -> (T, bool); |
257 | /// Stores a value if the current value is the same as the `old` value. |
258 | /// `T` must be an integer or pointer type. |
259 | /// |
260 | /// The stabilized version of this intrinsic is available on the |
261 | /// [`atomic`] types via the `compare_exchange_weak` method by passing |
262 | /// [`Ordering::Relaxed`] and [`Ordering::Acquire`] as the success and failure parameters. |
263 | /// For example, [`AtomicBool::compare_exchange_weak`]. |
264 | #[rustc_intrinsic ] |
265 | #[rustc_nounwind ] |
266 | pub unsafe fn atomic_cxchgweak_relaxed_acquire<T: Copy>( |
267 | _dst: *mut T, |
268 | _old: T, |
269 | _src: T, |
270 | ) -> (T, bool); |
271 | /// Stores a value if the current value is the same as the `old` value. |
272 | /// `T` must be an integer or pointer type. |
273 | /// |
274 | /// The stabilized version of this intrinsic is available on the |
275 | /// [`atomic`] types via the `compare_exchange_weak` method by passing |
276 | /// [`Ordering::Relaxed`] and [`Ordering::SeqCst`] as the success and failure parameters. |
277 | /// For example, [`AtomicBool::compare_exchange_weak`]. |
278 | #[rustc_intrinsic ] |
279 | #[rustc_nounwind ] |
280 | pub unsafe fn atomic_cxchgweak_relaxed_seqcst<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); |
281 | /// Stores a value if the current value is the same as the `old` value. |
282 | /// `T` must be an integer or pointer type. |
283 | /// |
284 | /// The stabilized version of this intrinsic is available on the |
285 | /// [`atomic`] types via the `compare_exchange_weak` method by passing |
286 | /// [`Ordering::Acquire`] and [`Ordering::Relaxed`] as the success and failure parameters. |
287 | /// For example, [`AtomicBool::compare_exchange_weak`]. |
288 | #[rustc_intrinsic ] |
289 | #[rustc_nounwind ] |
290 | pub unsafe fn atomic_cxchgweak_acquire_relaxed<T: Copy>( |
291 | _dst: *mut T, |
292 | _old: T, |
293 | _src: T, |
294 | ) -> (T, bool); |
295 | /// Stores a value if the current value is the same as the `old` value. |
296 | /// `T` must be an integer or pointer type. |
297 | /// |
298 | /// The stabilized version of this intrinsic is available on the |
299 | /// [`atomic`] types via the `compare_exchange_weak` method by passing |
300 | /// [`Ordering::Acquire`] as both the success and failure parameters. |
301 | /// For example, [`AtomicBool::compare_exchange_weak`]. |
302 | #[rustc_intrinsic ] |
303 | #[rustc_nounwind ] |
304 | pub unsafe fn atomic_cxchgweak_acquire_acquire<T: Copy>( |
305 | _dst: *mut T, |
306 | _old: T, |
307 | _src: T, |
308 | ) -> (T, bool); |
309 | /// Stores a value if the current value is the same as the `old` value. |
310 | /// `T` must be an integer or pointer type. |
311 | /// |
312 | /// The stabilized version of this intrinsic is available on the |
313 | /// [`atomic`] types via the `compare_exchange_weak` method by passing |
314 | /// [`Ordering::Acquire`] and [`Ordering::SeqCst`] as the success and failure parameters. |
315 | /// For example, [`AtomicBool::compare_exchange_weak`]. |
316 | #[rustc_intrinsic ] |
317 | #[rustc_nounwind ] |
318 | pub unsafe fn atomic_cxchgweak_acquire_seqcst<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); |
319 | /// Stores a value if the current value is the same as the `old` value. |
320 | /// `T` must be an integer or pointer type. |
321 | /// |
322 | /// The stabilized version of this intrinsic is available on the |
323 | /// [`atomic`] types via the `compare_exchange_weak` method by passing |
324 | /// [`Ordering::Release`] and [`Ordering::Relaxed`] as the success and failure parameters. |
325 | /// For example, [`AtomicBool::compare_exchange_weak`]. |
326 | #[rustc_intrinsic ] |
327 | #[rustc_nounwind ] |
328 | pub unsafe fn atomic_cxchgweak_release_relaxed<T: Copy>( |
329 | _dst: *mut T, |
330 | _old: T, |
331 | _src: T, |
332 | ) -> (T, bool); |
333 | /// Stores a value if the current value is the same as the `old` value. |
334 | /// `T` must be an integer or pointer type. |
335 | /// |
336 | /// The stabilized version of this intrinsic is available on the |
337 | /// [`atomic`] types via the `compare_exchange_weak` method by passing |
338 | /// [`Ordering::Release`] and [`Ordering::Acquire`] as the success and failure parameters. |
339 | /// For example, [`AtomicBool::compare_exchange_weak`]. |
340 | #[rustc_intrinsic ] |
341 | #[rustc_nounwind ] |
342 | pub unsafe fn atomic_cxchgweak_release_acquire<T: Copy>( |
343 | _dst: *mut T, |
344 | _old: T, |
345 | _src: T, |
346 | ) -> (T, bool); |
347 | /// Stores a value if the current value is the same as the `old` value. |
348 | /// `T` must be an integer or pointer type. |
349 | /// |
350 | /// The stabilized version of this intrinsic is available on the |
351 | /// [`atomic`] types via the `compare_exchange_weak` method by passing |
352 | /// [`Ordering::Release`] and [`Ordering::SeqCst`] as the success and failure parameters. |
353 | /// For example, [`AtomicBool::compare_exchange_weak`]. |
354 | #[rustc_intrinsic ] |
355 | #[rustc_nounwind ] |
356 | pub unsafe fn atomic_cxchgweak_release_seqcst<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); |
357 | /// Stores a value if the current value is the same as the `old` value. |
358 | /// `T` must be an integer or pointer type. |
359 | /// |
360 | /// The stabilized version of this intrinsic is available on the |
361 | /// [`atomic`] types via the `compare_exchange_weak` method by passing |
362 | /// [`Ordering::AcqRel`] and [`Ordering::Relaxed`] as the success and failure parameters. |
363 | /// For example, [`AtomicBool::compare_exchange_weak`]. |
364 | #[rustc_intrinsic ] |
365 | #[rustc_nounwind ] |
366 | pub unsafe fn atomic_cxchgweak_acqrel_relaxed<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); |
367 | /// Stores a value if the current value is the same as the `old` value. |
368 | /// `T` must be an integer or pointer type. |
369 | /// |
370 | /// The stabilized version of this intrinsic is available on the |
371 | /// [`atomic`] types via the `compare_exchange_weak` method by passing |
372 | /// [`Ordering::AcqRel`] and [`Ordering::Acquire`] as the success and failure parameters. |
373 | /// For example, [`AtomicBool::compare_exchange_weak`]. |
374 | #[rustc_intrinsic ] |
375 | #[rustc_nounwind ] |
376 | pub unsafe fn atomic_cxchgweak_acqrel_acquire<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); |
377 | /// Stores a value if the current value is the same as the `old` value. |
378 | /// `T` must be an integer or pointer type. |
379 | /// |
380 | /// The stabilized version of this intrinsic is available on the |
381 | /// [`atomic`] types via the `compare_exchange_weak` method by passing |
382 | /// [`Ordering::AcqRel`] and [`Ordering::SeqCst`] as the success and failure parameters. |
383 | /// For example, [`AtomicBool::compare_exchange_weak`]. |
384 | #[rustc_intrinsic ] |
385 | #[rustc_nounwind ] |
386 | pub unsafe fn atomic_cxchgweak_acqrel_seqcst<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); |
387 | /// Stores a value if the current value is the same as the `old` value. |
388 | /// `T` must be an integer or pointer type. |
389 | /// |
390 | /// The stabilized version of this intrinsic is available on the |
391 | /// [`atomic`] types via the `compare_exchange_weak` method by passing |
392 | /// [`Ordering::SeqCst`] and [`Ordering::Relaxed`] as the success and failure parameters. |
393 | /// For example, [`AtomicBool::compare_exchange_weak`]. |
394 | #[rustc_intrinsic ] |
395 | #[rustc_nounwind ] |
396 | pub unsafe fn atomic_cxchgweak_seqcst_relaxed<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); |
397 | /// Stores a value if the current value is the same as the `old` value. |
398 | /// `T` must be an integer or pointer type. |
399 | /// |
400 | /// The stabilized version of this intrinsic is available on the |
401 | /// [`atomic`] types via the `compare_exchange_weak` method by passing |
402 | /// [`Ordering::SeqCst`] and [`Ordering::Acquire`] as the success and failure parameters. |
403 | /// For example, [`AtomicBool::compare_exchange_weak`]. |
404 | #[rustc_intrinsic ] |
405 | #[rustc_nounwind ] |
406 | pub unsafe fn atomic_cxchgweak_seqcst_acquire<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); |
407 | /// Stores a value if the current value is the same as the `old` value. |
408 | /// `T` must be an integer or pointer type. |
409 | /// |
410 | /// The stabilized version of this intrinsic is available on the |
411 | /// [`atomic`] types via the `compare_exchange_weak` method by passing |
412 | /// [`Ordering::SeqCst`] as both the success and failure parameters. |
413 | /// For example, [`AtomicBool::compare_exchange_weak`]. |
414 | #[rustc_intrinsic ] |
415 | #[rustc_nounwind ] |
416 | pub unsafe fn atomic_cxchgweak_seqcst_seqcst<T: Copy>(dst: *mut T, old: T, src: T) -> (T, bool); |
417 | |
418 | /// Loads the current value of the pointer. |
419 | /// `T` must be an integer or pointer type. |
420 | /// |
421 | /// The stabilized version of this intrinsic is available on the |
422 | /// [`atomic`] types via the `load` method by passing |
423 | /// [`Ordering::SeqCst`] as the `order`. For example, [`AtomicBool::load`]. |
424 | #[rustc_intrinsic ] |
425 | #[rustc_nounwind ] |
426 | pub unsafe fn atomic_load_seqcst<T: Copy>(src: *const T) -> T; |
427 | /// Loads the current value of the pointer. |
428 | /// `T` must be an integer or pointer type. |
429 | /// |
430 | /// The stabilized version of this intrinsic is available on the |
431 | /// [`atomic`] types via the `load` method by passing |
432 | /// [`Ordering::Acquire`] as the `order`. For example, [`AtomicBool::load`]. |
433 | #[rustc_intrinsic ] |
434 | #[rustc_nounwind ] |
435 | pub unsafe fn atomic_load_acquire<T: Copy>(src: *const T) -> T; |
436 | /// Loads the current value of the pointer. |
437 | /// `T` must be an integer or pointer type. |
438 | /// |
439 | /// The stabilized version of this intrinsic is available on the |
440 | /// [`atomic`] types via the `load` method by passing |
441 | /// [`Ordering::Relaxed`] as the `order`. For example, [`AtomicBool::load`]. |
442 | #[rustc_intrinsic ] |
443 | #[rustc_nounwind ] |
444 | pub unsafe fn atomic_load_relaxed<T: Copy>(src: *const T) -> T; |
445 | /// Do NOT use this intrinsic; "unordered" operations do not exist in our memory model! |
446 | /// In terms of the Rust Abstract Machine, this operation is equivalent to `src.read()`, |
447 | /// i.e., it performs a non-atomic read. |
448 | #[rustc_intrinsic ] |
449 | #[rustc_nounwind ] |
450 | pub unsafe fn atomic_load_unordered<T: Copy>(src: *const T) -> T; |
451 | |
452 | /// Stores the value at the specified memory location. |
453 | /// `T` must be an integer or pointer type. |
454 | /// |
455 | /// The stabilized version of this intrinsic is available on the |
456 | /// [`atomic`] types via the `store` method by passing |
457 | /// [`Ordering::SeqCst`] as the `order`. For example, [`AtomicBool::store`]. |
458 | #[rustc_intrinsic ] |
459 | #[rustc_nounwind ] |
460 | pub unsafe fn atomic_store_seqcst<T: Copy>(dst: *mut T, val: T); |
461 | /// Stores the value at the specified memory location. |
462 | /// `T` must be an integer or pointer type. |
463 | /// |
464 | /// The stabilized version of this intrinsic is available on the |
465 | /// [`atomic`] types via the `store` method by passing |
466 | /// [`Ordering::Release`] as the `order`. For example, [`AtomicBool::store`]. |
467 | #[rustc_intrinsic ] |
468 | #[rustc_nounwind ] |
469 | pub unsafe fn atomic_store_release<T: Copy>(dst: *mut T, val: T); |
470 | /// Stores the value at the specified memory location. |
471 | /// `T` must be an integer or pointer type. |
472 | /// |
473 | /// The stabilized version of this intrinsic is available on the |
474 | /// [`atomic`] types via the `store` method by passing |
475 | /// [`Ordering::Relaxed`] as the `order`. For example, [`AtomicBool::store`]. |
476 | #[rustc_intrinsic ] |
477 | #[rustc_nounwind ] |
478 | pub unsafe fn atomic_store_relaxed<T: Copy>(dst: *mut T, val: T); |
479 | /// Do NOT use this intrinsic; "unordered" operations do not exist in our memory model! |
480 | /// In terms of the Rust Abstract Machine, this operation is equivalent to `dst.write(val)`, |
481 | /// i.e., it performs a non-atomic write. |
482 | #[rustc_intrinsic ] |
483 | #[rustc_nounwind ] |
484 | pub unsafe fn atomic_store_unordered<T: Copy>(dst: *mut T, val: T); |
485 | |
486 | /// Stores the value at the specified memory location, returning the old value. |
487 | /// `T` must be an integer or pointer type. |
488 | /// |
489 | /// The stabilized version of this intrinsic is available on the |
490 | /// [`atomic`] types via the `swap` method by passing |
491 | /// [`Ordering::SeqCst`] as the `order`. For example, [`AtomicBool::swap`]. |
492 | #[rustc_intrinsic ] |
493 | #[rustc_nounwind ] |
494 | pub unsafe fn atomic_xchg_seqcst<T: Copy>(dst: *mut T, src: T) -> T; |
495 | /// Stores the value at the specified memory location, returning the old value. |
496 | /// `T` must be an integer or pointer type. |
497 | /// |
498 | /// The stabilized version of this intrinsic is available on the |
499 | /// [`atomic`] types via the `swap` method by passing |
500 | /// [`Ordering::Acquire`] as the `order`. For example, [`AtomicBool::swap`]. |
501 | #[rustc_intrinsic ] |
502 | #[rustc_nounwind ] |
503 | pub unsafe fn atomic_xchg_acquire<T: Copy>(dst: *mut T, src: T) -> T; |
504 | /// Stores the value at the specified memory location, returning the old value. |
505 | /// `T` must be an integer or pointer type. |
506 | /// |
507 | /// The stabilized version of this intrinsic is available on the |
508 | /// [`atomic`] types via the `swap` method by passing |
509 | /// [`Ordering::Release`] as the `order`. For example, [`AtomicBool::swap`]. |
510 | #[rustc_intrinsic ] |
511 | #[rustc_nounwind ] |
512 | pub unsafe fn atomic_xchg_release<T: Copy>(dst: *mut T, src: T) -> T; |
513 | /// Stores the value at the specified memory location, returning the old value. |
514 | /// `T` must be an integer or pointer type. |
515 | /// |
516 | /// The stabilized version of this intrinsic is available on the |
517 | /// [`atomic`] types via the `swap` method by passing |
518 | /// [`Ordering::AcqRel`] as the `order`. For example, [`AtomicBool::swap`]. |
519 | #[rustc_intrinsic ] |
520 | #[rustc_nounwind ] |
521 | pub unsafe fn atomic_xchg_acqrel<T: Copy>(dst: *mut T, src: T) -> T; |
522 | /// Stores the value at the specified memory location, returning the old value. |
523 | /// `T` must be an integer or pointer type. |
524 | /// |
525 | /// The stabilized version of this intrinsic is available on the |
526 | /// [`atomic`] types via the `swap` method by passing |
527 | /// [`Ordering::Relaxed`] as the `order`. For example, [`AtomicBool::swap`]. |
528 | #[rustc_intrinsic ] |
529 | #[rustc_nounwind ] |
530 | pub unsafe fn atomic_xchg_relaxed<T: Copy>(dst: *mut T, src: T) -> T; |
531 | |
532 | /// Adds to the current value, returning the previous value. |
533 | /// `T` must be an integer or pointer type. |
534 | /// If `T` is a pointer type, the provenance of `src` is ignored: both the return value and the new |
535 | /// value stored at `*dst` will have the provenance of the old value stored there. |
536 | /// |
537 | /// The stabilized version of this intrinsic is available on the |
538 | /// [`atomic`] types via the `fetch_add` method by passing |
539 | /// [`Ordering::SeqCst`] as the `order`. For example, [`AtomicIsize::fetch_add`]. |
540 | #[rustc_intrinsic ] |
541 | #[rustc_nounwind ] |
542 | pub unsafe fn atomic_xadd_seqcst<T: Copy>(dst: *mut T, src: T) -> T; |
543 | /// Adds to the current value, returning the previous value. |
544 | /// `T` must be an integer or pointer type. |
545 | /// If `T` is a pointer type, the provenance of `src` is ignored: both the return value and the new |
546 | /// value stored at `*dst` will have the provenance of the old value stored there. |
547 | /// |
548 | /// The stabilized version of this intrinsic is available on the |
549 | /// [`atomic`] types via the `fetch_add` method by passing |
550 | /// [`Ordering::Acquire`] as the `order`. For example, [`AtomicIsize::fetch_add`]. |
551 | #[rustc_intrinsic ] |
552 | #[rustc_nounwind ] |
553 | pub unsafe fn atomic_xadd_acquire<T: Copy>(dst: *mut T, src: T) -> T; |
554 | /// Adds to the current value, returning the previous value. |
555 | /// `T` must be an integer or pointer type. |
556 | /// If `T` is a pointer type, the provenance of `src` is ignored: both the return value and the new |
557 | /// value stored at `*dst` will have the provenance of the old value stored there. |
558 | /// |
559 | /// The stabilized version of this intrinsic is available on the |
560 | /// [`atomic`] types via the `fetch_add` method by passing |
561 | /// [`Ordering::Release`] as the `order`. For example, [`AtomicIsize::fetch_add`]. |
562 | #[rustc_intrinsic ] |
563 | #[rustc_nounwind ] |
564 | pub unsafe fn atomic_xadd_release<T: Copy>(dst: *mut T, src: T) -> T; |
565 | /// Adds to the current value, returning the previous value. |
566 | /// `T` must be an integer or pointer type. |
567 | /// If `T` is a pointer type, the provenance of `src` is ignored: both the return value and the new |
568 | /// value stored at `*dst` will have the provenance of the old value stored there. |
569 | /// |
570 | /// The stabilized version of this intrinsic is available on the |
571 | /// [`atomic`] types via the `fetch_add` method by passing |
572 | /// [`Ordering::AcqRel`] as the `order`. For example, [`AtomicIsize::fetch_add`]. |
573 | #[rustc_intrinsic ] |
574 | #[rustc_nounwind ] |
575 | pub unsafe fn atomic_xadd_acqrel<T: Copy>(dst: *mut T, src: T) -> T; |
576 | /// Adds to the current value, returning the previous value. |
577 | /// `T` must be an integer or pointer type. |
578 | /// If `T` is a pointer type, the provenance of `src` is ignored: both the return value and the new |
579 | /// value stored at `*dst` will have the provenance of the old value stored there. |
580 | /// |
581 | /// The stabilized version of this intrinsic is available on the |
582 | /// [`atomic`] types via the `fetch_add` method by passing |
583 | /// [`Ordering::Relaxed`] as the `order`. For example, [`AtomicIsize::fetch_add`]. |
584 | #[rustc_intrinsic ] |
585 | #[rustc_nounwind ] |
586 | pub unsafe fn atomic_xadd_relaxed<T: Copy>(dst: *mut T, src: T) -> T; |
587 | |
588 | /// Subtract from the current value, returning the previous value. |
589 | /// `T` must be an integer or pointer type. |
590 | /// If `T` is a pointer type, the provenance of `src` is ignored: both the return value and the new |
591 | /// value stored at `*dst` will have the provenance of the old value stored there. |
592 | /// |
593 | /// The stabilized version of this intrinsic is available on the |
594 | /// [`atomic`] types via the `fetch_sub` method by passing |
595 | /// [`Ordering::SeqCst`] as the `order`. For example, [`AtomicIsize::fetch_sub`]. |
596 | #[rustc_intrinsic ] |
597 | #[rustc_nounwind ] |
598 | pub unsafe fn atomic_xsub_seqcst<T: Copy>(dst: *mut T, src: T) -> T; |
599 | /// Subtract from the current value, returning the previous value. |
600 | /// `T` must be an integer or pointer type. |
601 | /// If `T` is a pointer type, the provenance of `src` is ignored: both the return value and the new |
602 | /// value stored at `*dst` will have the provenance of the old value stored there. |
603 | /// |
604 | /// The stabilized version of this intrinsic is available on the |
605 | /// [`atomic`] types via the `fetch_sub` method by passing |
606 | /// [`Ordering::Acquire`] as the `order`. For example, [`AtomicIsize::fetch_sub`]. |
607 | #[rustc_intrinsic ] |
608 | #[rustc_nounwind ] |
609 | pub unsafe fn atomic_xsub_acquire<T: Copy>(dst: *mut T, src: T) -> T; |
610 | /// Subtract from the current value, returning the previous value. |
611 | /// `T` must be an integer or pointer type. |
612 | /// If `T` is a pointer type, the provenance of `src` is ignored: both the return value and the new |
613 | /// value stored at `*dst` will have the provenance of the old value stored there. |
614 | /// |
615 | /// The stabilized version of this intrinsic is available on the |
616 | /// [`atomic`] types via the `fetch_sub` method by passing |
617 | /// [`Ordering::Release`] as the `order`. For example, [`AtomicIsize::fetch_sub`]. |
618 | #[rustc_intrinsic ] |
619 | #[rustc_nounwind ] |
620 | pub unsafe fn atomic_xsub_release<T: Copy>(dst: *mut T, src: T) -> T; |
621 | /// Subtract from the current value, returning the previous value. |
622 | /// `T` must be an integer or pointer type. |
623 | /// If `T` is a pointer type, the provenance of `src` is ignored: both the return value and the new |
624 | /// value stored at `*dst` will have the provenance of the old value stored there. |
625 | /// |
626 | /// The stabilized version of this intrinsic is available on the |
627 | /// [`atomic`] types via the `fetch_sub` method by passing |
628 | /// [`Ordering::AcqRel`] as the `order`. For example, [`AtomicIsize::fetch_sub`]. |
629 | #[rustc_intrinsic ] |
630 | #[rustc_nounwind ] |
631 | pub unsafe fn atomic_xsub_acqrel<T: Copy>(dst: *mut T, src: T) -> T; |
632 | /// Subtract from the current value, returning the previous value. |
633 | /// `T` must be an integer or pointer type. |
634 | /// If `T` is a pointer type, the provenance of `src` is ignored: both the return value and the new |
635 | /// value stored at `*dst` will have the provenance of the old value stored there. |
636 | /// |
637 | /// The stabilized version of this intrinsic is available on the |
638 | /// [`atomic`] types via the `fetch_sub` method by passing |
639 | /// [`Ordering::Relaxed`] as the `order`. For example, [`AtomicIsize::fetch_sub`]. |
640 | #[rustc_intrinsic ] |
641 | #[rustc_nounwind ] |
642 | pub unsafe fn atomic_xsub_relaxed<T: Copy>(dst: *mut T, src: T) -> T; |
643 | |
644 | /// Bitwise and with the current value, returning the previous value. |
645 | /// `T` must be an integer or pointer type. |
646 | /// If `T` is a pointer type, the provenance of `src` is ignored: both the return value and the new |
647 | /// value stored at `*dst` will have the provenance of the old value stored there. |
648 | /// |
649 | /// The stabilized version of this intrinsic is available on the |
650 | /// [`atomic`] types via the `fetch_and` method by passing |
651 | /// [`Ordering::SeqCst`] as the `order`. For example, [`AtomicBool::fetch_and`]. |
652 | #[rustc_intrinsic ] |
653 | #[rustc_nounwind ] |
654 | pub unsafe fn atomic_and_seqcst<T: Copy>(dst: *mut T, src: T) -> T; |
655 | /// Bitwise and with the current value, returning the previous value. |
656 | /// `T` must be an integer or pointer type. |
657 | /// If `T` is a pointer type, the provenance of `src` is ignored: both the return value and the new |
658 | /// value stored at `*dst` will have the provenance of the old value stored there. |
659 | /// |
660 | /// The stabilized version of this intrinsic is available on the |
661 | /// [`atomic`] types via the `fetch_and` method by passing |
662 | /// [`Ordering::Acquire`] as the `order`. For example, [`AtomicBool::fetch_and`]. |
663 | #[rustc_intrinsic ] |
664 | #[rustc_nounwind ] |
665 | pub unsafe fn atomic_and_acquire<T: Copy>(dst: *mut T, src: T) -> T; |
666 | /// Bitwise and with the current value, returning the previous value. |
667 | /// `T` must be an integer or pointer type. |
668 | /// If `T` is a pointer type, the provenance of `src` is ignored: both the return value and the new |
669 | /// value stored at `*dst` will have the provenance of the old value stored there. |
670 | /// |
671 | /// The stabilized version of this intrinsic is available on the |
672 | /// [`atomic`] types via the `fetch_and` method by passing |
673 | /// [`Ordering::Release`] as the `order`. For example, [`AtomicBool::fetch_and`]. |
674 | #[rustc_intrinsic ] |
675 | #[rustc_nounwind ] |
676 | pub unsafe fn atomic_and_release<T: Copy>(dst: *mut T, src: T) -> T; |
677 | /// Bitwise and with the current value, returning the previous value. |
678 | /// `T` must be an integer or pointer type. |
679 | /// If `T` is a pointer type, the provenance of `src` is ignored: both the return value and the new |
680 | /// value stored at `*dst` will have the provenance of the old value stored there. |
681 | /// |
682 | /// The stabilized version of this intrinsic is available on the |
683 | /// [`atomic`] types via the `fetch_and` method by passing |
684 | /// [`Ordering::AcqRel`] as the `order`. For example, [`AtomicBool::fetch_and`]. |
685 | #[rustc_intrinsic ] |
686 | #[rustc_nounwind ] |
687 | pub unsafe fn atomic_and_acqrel<T: Copy>(dst: *mut T, src: T) -> T; |
688 | /// Bitwise and with the current value, returning the previous value. |
689 | /// `T` must be an integer or pointer type. |
690 | /// If `T` is a pointer type, the provenance of `src` is ignored: both the return value and the new |
691 | /// value stored at `*dst` will have the provenance of the old value stored there. |
692 | /// |
693 | /// The stabilized version of this intrinsic is available on the |
694 | /// [`atomic`] types via the `fetch_and` method by passing |
695 | /// [`Ordering::Relaxed`] as the `order`. For example, [`AtomicBool::fetch_and`]. |
696 | #[rustc_intrinsic ] |
697 | #[rustc_nounwind ] |
698 | pub unsafe fn atomic_and_relaxed<T: Copy>(dst: *mut T, src: T) -> T; |
699 | |
700 | /// Bitwise nand with the current value, returning the previous value. |
701 | /// `T` must be an integer or pointer type. |
702 | /// If `T` is a pointer type, the provenance of `src` is ignored: both the return value and the new |
703 | /// value stored at `*dst` will have the provenance of the old value stored there. |
704 | /// |
705 | /// The stabilized version of this intrinsic is available on the |
706 | /// [`AtomicBool`] type via the `fetch_nand` method by passing |
707 | /// [`Ordering::SeqCst`] as the `order`. For example, [`AtomicBool::fetch_nand`]. |
708 | #[rustc_intrinsic ] |
709 | #[rustc_nounwind ] |
710 | pub unsafe fn atomic_nand_seqcst<T: Copy>(dst: *mut T, src: T) -> T; |
711 | /// Bitwise nand with the current value, returning the previous value. |
712 | /// `T` must be an integer or pointer type. |
713 | /// If `T` is a pointer type, the provenance of `src` is ignored: both the return value and the new |
714 | /// value stored at `*dst` will have the provenance of the old value stored there. |
715 | /// |
716 | /// The stabilized version of this intrinsic is available on the |
717 | /// [`AtomicBool`] type via the `fetch_nand` method by passing |
718 | /// [`Ordering::Acquire`] as the `order`. For example, [`AtomicBool::fetch_nand`]. |
719 | #[rustc_intrinsic ] |
720 | #[rustc_nounwind ] |
721 | pub unsafe fn atomic_nand_acquire<T: Copy>(dst: *mut T, src: T) -> T; |
722 | /// Bitwise nand with the current value, returning the previous value. |
723 | /// `T` must be an integer or pointer type. |
724 | /// If `T` is a pointer type, the provenance of `src` is ignored: both the return value and the new |
725 | /// value stored at `*dst` will have the provenance of the old value stored there. |
726 | /// |
727 | /// The stabilized version of this intrinsic is available on the |
728 | /// [`AtomicBool`] type via the `fetch_nand` method by passing |
729 | /// [`Ordering::Release`] as the `order`. For example, [`AtomicBool::fetch_nand`]. |
730 | #[rustc_intrinsic ] |
731 | #[rustc_nounwind ] |
732 | pub unsafe fn atomic_nand_release<T: Copy>(dst: *mut T, src: T) -> T; |
733 | /// Bitwise nand with the current value, returning the previous value. |
734 | /// `T` must be an integer or pointer type. |
735 | /// If `T` is a pointer type, the provenance of `src` is ignored: both the return value and the new |
736 | /// value stored at `*dst` will have the provenance of the old value stored there. |
737 | /// |
738 | /// The stabilized version of this intrinsic is available on the |
739 | /// [`AtomicBool`] type via the `fetch_nand` method by passing |
740 | /// [`Ordering::AcqRel`] as the `order`. For example, [`AtomicBool::fetch_nand`]. |
741 | #[rustc_intrinsic ] |
742 | #[rustc_nounwind ] |
743 | pub unsafe fn atomic_nand_acqrel<T: Copy>(dst: *mut T, src: T) -> T; |
744 | /// Bitwise nand with the current value, returning the previous value. |
745 | /// `T` must be an integer or pointer type. |
746 | /// If `T` is a pointer type, the provenance of `src` is ignored: both the return value and the new |
747 | /// value stored at `*dst` will have the provenance of the old value stored there. |
748 | /// |
749 | /// The stabilized version of this intrinsic is available on the |
750 | /// [`AtomicBool`] type via the `fetch_nand` method by passing |
751 | /// [`Ordering::Relaxed`] as the `order`. For example, [`AtomicBool::fetch_nand`]. |
752 | #[rustc_intrinsic ] |
753 | #[rustc_nounwind ] |
754 | pub unsafe fn atomic_nand_relaxed<T: Copy>(dst: *mut T, src: T) -> T; |
755 | |
756 | /// Bitwise or with the current value, returning the previous value. |
757 | /// `T` must be an integer or pointer type. |
758 | /// If `T` is a pointer type, the provenance of `src` is ignored: both the return value and the new |
759 | /// value stored at `*dst` will have the provenance of the old value stored there. |
760 | /// |
761 | /// The stabilized version of this intrinsic is available on the |
762 | /// [`atomic`] types via the `fetch_or` method by passing |
763 | /// [`Ordering::SeqCst`] as the `order`. For example, [`AtomicBool::fetch_or`]. |
764 | #[rustc_intrinsic ] |
765 | #[rustc_nounwind ] |
766 | pub unsafe fn atomic_or_seqcst<T: Copy>(dst: *mut T, src: T) -> T; |
767 | /// Bitwise or with the current value, returning the previous value. |
768 | /// `T` must be an integer or pointer type. |
769 | /// If `T` is a pointer type, the provenance of `src` is ignored: both the return value and the new |
770 | /// value stored at `*dst` will have the provenance of the old value stored there. |
771 | /// |
772 | /// The stabilized version of this intrinsic is available on the |
773 | /// [`atomic`] types via the `fetch_or` method by passing |
774 | /// [`Ordering::Acquire`] as the `order`. For example, [`AtomicBool::fetch_or`]. |
775 | #[rustc_intrinsic ] |
776 | #[rustc_nounwind ] |
777 | pub unsafe fn atomic_or_acquire<T: Copy>(dst: *mut T, src: T) -> T; |
778 | /// Bitwise or with the current value, returning the previous value. |
779 | /// `T` must be an integer or pointer type. |
780 | /// If `T` is a pointer type, the provenance of `src` is ignored: both the return value and the new |
781 | /// value stored at `*dst` will have the provenance of the old value stored there. |
782 | /// |
783 | /// The stabilized version of this intrinsic is available on the |
784 | /// [`atomic`] types via the `fetch_or` method by passing |
785 | /// [`Ordering::Release`] as the `order`. For example, [`AtomicBool::fetch_or`]. |
786 | #[rustc_intrinsic ] |
787 | #[rustc_nounwind ] |
788 | pub unsafe fn atomic_or_release<T: Copy>(dst: *mut T, src: T) -> T; |
789 | /// Bitwise or with the current value, returning the previous value. |
790 | /// `T` must be an integer or pointer type. |
791 | /// If `T` is a pointer type, the provenance of `src` is ignored: both the return value and the new |
792 | /// value stored at `*dst` will have the provenance of the old value stored there. |
793 | /// |
794 | /// The stabilized version of this intrinsic is available on the |
795 | /// [`atomic`] types via the `fetch_or` method by passing |
796 | /// [`Ordering::AcqRel`] as the `order`. For example, [`AtomicBool::fetch_or`]. |
797 | #[rustc_intrinsic ] |
798 | #[rustc_nounwind ] |
799 | pub unsafe fn atomic_or_acqrel<T: Copy>(dst: *mut T, src: T) -> T; |
800 | /// Bitwise or with the current value, returning the previous value. |
801 | /// `T` must be an integer or pointer type. |
802 | /// If `T` is a pointer type, the provenance of `src` is ignored: both the return value and the new |
803 | /// value stored at `*dst` will have the provenance of the old value stored there. |
804 | /// |
805 | /// The stabilized version of this intrinsic is available on the |
806 | /// [`atomic`] types via the `fetch_or` method by passing |
807 | /// [`Ordering::Relaxed`] as the `order`. For example, [`AtomicBool::fetch_or`]. |
808 | #[rustc_intrinsic ] |
809 | #[rustc_nounwind ] |
810 | pub unsafe fn atomic_or_relaxed<T: Copy>(dst: *mut T, src: T) -> T; |
811 | |
812 | /// Bitwise xor with the current value, returning the previous value. |
813 | /// `T` must be an integer or pointer type. |
814 | /// If `T` is a pointer type, the provenance of `src` is ignored: both the return value and the new |
815 | /// value stored at `*dst` will have the provenance of the old value stored there. |
816 | /// |
817 | /// The stabilized version of this intrinsic is available on the |
818 | /// [`atomic`] types via the `fetch_xor` method by passing |
819 | /// [`Ordering::SeqCst`] as the `order`. For example, [`AtomicBool::fetch_xor`]. |
820 | #[rustc_intrinsic ] |
821 | #[rustc_nounwind ] |
822 | pub unsafe fn atomic_xor_seqcst<T: Copy>(dst: *mut T, src: T) -> T; |
823 | /// Bitwise xor with the current value, returning the previous value. |
824 | /// `T` must be an integer or pointer type. |
825 | /// If `T` is a pointer type, the provenance of `src` is ignored: both the return value and the new |
826 | /// value stored at `*dst` will have the provenance of the old value stored there. |
827 | /// |
828 | /// The stabilized version of this intrinsic is available on the |
829 | /// [`atomic`] types via the `fetch_xor` method by passing |
830 | /// [`Ordering::Acquire`] as the `order`. For example, [`AtomicBool::fetch_xor`]. |
831 | #[rustc_intrinsic ] |
832 | #[rustc_nounwind ] |
833 | pub unsafe fn atomic_xor_acquire<T: Copy>(dst: *mut T, src: T) -> T; |
834 | /// Bitwise xor with the current value, returning the previous value. |
835 | /// `T` must be an integer or pointer type. |
836 | /// If `T` is a pointer type, the provenance of `src` is ignored: both the return value and the new |
837 | /// value stored at `*dst` will have the provenance of the old value stored there. |
838 | /// |
839 | /// The stabilized version of this intrinsic is available on the |
840 | /// [`atomic`] types via the `fetch_xor` method by passing |
841 | /// [`Ordering::Release`] as the `order`. For example, [`AtomicBool::fetch_xor`]. |
842 | #[rustc_intrinsic ] |
843 | #[rustc_nounwind ] |
844 | pub unsafe fn atomic_xor_release<T: Copy>(dst: *mut T, src: T) -> T; |
845 | /// Bitwise xor with the current value, returning the previous value. |
846 | /// `T` must be an integer or pointer type. |
847 | /// If `T` is a pointer type, the provenance of `src` is ignored: both the return value and the new |
848 | /// value stored at `*dst` will have the provenance of the old value stored there. |
849 | /// |
850 | /// The stabilized version of this intrinsic is available on the |
851 | /// [`atomic`] types via the `fetch_xor` method by passing |
852 | /// [`Ordering::AcqRel`] as the `order`. For example, [`AtomicBool::fetch_xor`]. |
853 | #[rustc_intrinsic ] |
854 | #[rustc_nounwind ] |
855 | pub unsafe fn atomic_xor_acqrel<T: Copy>(dst: *mut T, src: T) -> T; |
856 | /// Bitwise xor with the current value, returning the previous value. |
857 | /// `T` must be an integer or pointer type. |
858 | /// If `T` is a pointer type, the provenance of `src` is ignored: both the return value and the new |
859 | /// value stored at `*dst` will have the provenance of the old value stored there. |
860 | /// |
861 | /// The stabilized version of this intrinsic is available on the |
862 | /// [`atomic`] types via the `fetch_xor` method by passing |
863 | /// [`Ordering::Relaxed`] as the `order`. For example, [`AtomicBool::fetch_xor`]. |
864 | #[rustc_intrinsic ] |
865 | #[rustc_nounwind ] |
866 | pub unsafe fn atomic_xor_relaxed<T: Copy>(dst: *mut T, src: T) -> T; |
867 | |
868 | /// Maximum with the current value using a signed comparison. |
869 | /// `T` must be a signed integer type. |
870 | /// |
871 | /// The stabilized version of this intrinsic is available on the |
872 | /// [`atomic`] signed integer types via the `fetch_max` method by passing |
873 | /// [`Ordering::SeqCst`] as the `order`. For example, [`AtomicI32::fetch_max`]. |
874 | #[rustc_intrinsic ] |
875 | #[rustc_nounwind ] |
876 | pub unsafe fn atomic_max_seqcst<T: Copy>(dst: *mut T, src: T) -> T; |
877 | /// Maximum with the current value using a signed comparison. |
878 | /// `T` must be a signed integer type. |
879 | /// |
880 | /// The stabilized version of this intrinsic is available on the |
881 | /// [`atomic`] signed integer types via the `fetch_max` method by passing |
882 | /// [`Ordering::Acquire`] as the `order`. For example, [`AtomicI32::fetch_max`]. |
883 | #[rustc_intrinsic ] |
884 | #[rustc_nounwind ] |
885 | pub unsafe fn atomic_max_acquire<T: Copy>(dst: *mut T, src: T) -> T; |
886 | /// Maximum with the current value using a signed comparison. |
887 | /// `T` must be a signed integer type. |
888 | /// |
889 | /// The stabilized version of this intrinsic is available on the |
890 | /// [`atomic`] signed integer types via the `fetch_max` method by passing |
891 | /// [`Ordering::Release`] as the `order`. For example, [`AtomicI32::fetch_max`]. |
892 | #[rustc_intrinsic ] |
893 | #[rustc_nounwind ] |
894 | pub unsafe fn atomic_max_release<T: Copy>(dst: *mut T, src: T) -> T; |
895 | /// Maximum with the current value using a signed comparison. |
896 | /// `T` must be a signed integer type. |
897 | /// |
898 | /// The stabilized version of this intrinsic is available on the |
899 | /// [`atomic`] signed integer types via the `fetch_max` method by passing |
900 | /// [`Ordering::AcqRel`] as the `order`. For example, [`AtomicI32::fetch_max`]. |
901 | #[rustc_intrinsic ] |
902 | #[rustc_nounwind ] |
903 | pub unsafe fn atomic_max_acqrel<T: Copy>(dst: *mut T, src: T) -> T; |
904 | /// Maximum with the current value using a signed comparison. |
905 | /// `T` must be a signed integer type. |
906 | /// |
907 | /// The stabilized version of this intrinsic is available on the |
908 | /// [`atomic`] signed integer types via the `fetch_max` method by passing |
909 | /// [`Ordering::Relaxed`] as the `order`. For example, [`AtomicI32::fetch_max`]. |
910 | #[rustc_intrinsic ] |
911 | #[rustc_nounwind ] |
912 | pub unsafe fn atomic_max_relaxed<T: Copy>(dst: *mut T, src: T) -> T; |
913 | |
914 | /// Minimum with the current value using a signed comparison. |
915 | /// `T` must be a signed integer type. |
916 | /// |
917 | /// The stabilized version of this intrinsic is available on the |
918 | /// [`atomic`] signed integer types via the `fetch_min` method by passing |
919 | /// [`Ordering::SeqCst`] as the `order`. For example, [`AtomicI32::fetch_min`]. |
920 | #[rustc_intrinsic ] |
921 | #[rustc_nounwind ] |
922 | pub unsafe fn atomic_min_seqcst<T: Copy>(dst: *mut T, src: T) -> T; |
923 | /// Minimum with the current value using a signed comparison. |
924 | /// `T` must be a signed integer type. |
925 | /// |
926 | /// The stabilized version of this intrinsic is available on the |
927 | /// [`atomic`] signed integer types via the `fetch_min` method by passing |
928 | /// [`Ordering::Acquire`] as the `order`. For example, [`AtomicI32::fetch_min`]. |
929 | #[rustc_intrinsic ] |
930 | #[rustc_nounwind ] |
931 | pub unsafe fn atomic_min_acquire<T: Copy>(dst: *mut T, src: T) -> T; |
932 | /// Minimum with the current value using a signed comparison. |
933 | /// `T` must be a signed integer type. |
934 | /// |
935 | /// The stabilized version of this intrinsic is available on the |
936 | /// [`atomic`] signed integer types via the `fetch_min` method by passing |
937 | /// [`Ordering::Release`] as the `order`. For example, [`AtomicI32::fetch_min`]. |
938 | #[rustc_intrinsic ] |
939 | #[rustc_nounwind ] |
940 | pub unsafe fn atomic_min_release<T: Copy>(dst: *mut T, src: T) -> T; |
941 | /// Minimum with the current value using a signed comparison. |
942 | /// `T` must be a signed integer type. |
943 | /// |
944 | /// The stabilized version of this intrinsic is available on the |
945 | /// [`atomic`] signed integer types via the `fetch_min` method by passing |
946 | /// [`Ordering::AcqRel`] as the `order`. For example, [`AtomicI32::fetch_min`]. |
947 | #[rustc_intrinsic ] |
948 | #[rustc_nounwind ] |
949 | pub unsafe fn atomic_min_acqrel<T: Copy>(dst: *mut T, src: T) -> T; |
950 | /// Minimum with the current value using a signed comparison. |
951 | /// `T` must be a signed integer type. |
952 | /// |
953 | /// The stabilized version of this intrinsic is available on the |
954 | /// [`atomic`] signed integer types via the `fetch_min` method by passing |
955 | /// [`Ordering::Relaxed`] as the `order`. For example, [`AtomicI32::fetch_min`]. |
956 | #[rustc_intrinsic ] |
957 | #[rustc_nounwind ] |
958 | pub unsafe fn atomic_min_relaxed<T: Copy>(dst: *mut T, src: T) -> T; |
959 | |
960 | /// Minimum with the current value using an unsigned comparison. |
961 | /// `T` must be an unsigned integer type. |
962 | /// |
963 | /// The stabilized version of this intrinsic is available on the |
964 | /// [`atomic`] unsigned integer types via the `fetch_min` method by passing |
965 | /// [`Ordering::SeqCst`] as the `order`. For example, [`AtomicU32::fetch_min`]. |
966 | #[rustc_intrinsic ] |
967 | #[rustc_nounwind ] |
968 | pub unsafe fn atomic_umin_seqcst<T: Copy>(dst: *mut T, src: T) -> T; |
969 | /// Minimum with the current value using an unsigned comparison. |
970 | /// `T` must be an unsigned integer type. |
971 | /// |
972 | /// The stabilized version of this intrinsic is available on the |
973 | /// [`atomic`] unsigned integer types via the `fetch_min` method by passing |
974 | /// [`Ordering::Acquire`] as the `order`. For example, [`AtomicU32::fetch_min`]. |
975 | #[rustc_intrinsic ] |
976 | #[rustc_nounwind ] |
977 | pub unsafe fn atomic_umin_acquire<T: Copy>(dst: *mut T, src: T) -> T; |
978 | /// Minimum with the current value using an unsigned comparison. |
979 | /// `T` must be an unsigned integer type. |
980 | /// |
981 | /// The stabilized version of this intrinsic is available on the |
982 | /// [`atomic`] unsigned integer types via the `fetch_min` method by passing |
983 | /// [`Ordering::Release`] as the `order`. For example, [`AtomicU32::fetch_min`]. |
984 | #[rustc_intrinsic ] |
985 | #[rustc_nounwind ] |
986 | pub unsafe fn atomic_umin_release<T: Copy>(dst: *mut T, src: T) -> T; |
987 | /// Minimum with the current value using an unsigned comparison. |
988 | /// `T` must be an unsigned integer type. |
989 | /// |
990 | /// The stabilized version of this intrinsic is available on the |
991 | /// [`atomic`] unsigned integer types via the `fetch_min` method by passing |
992 | /// [`Ordering::AcqRel`] as the `order`. For example, [`AtomicU32::fetch_min`]. |
993 | #[rustc_intrinsic ] |
994 | #[rustc_nounwind ] |
995 | pub unsafe fn atomic_umin_acqrel<T: Copy>(dst: *mut T, src: T) -> T; |
996 | /// Minimum with the current value using an unsigned comparison. |
997 | /// `T` must be an unsigned integer type. |
998 | /// |
999 | /// The stabilized version of this intrinsic is available on the |
1000 | /// [`atomic`] unsigned integer types via the `fetch_min` method by passing |
1001 | /// [`Ordering::Relaxed`] as the `order`. For example, [`AtomicU32::fetch_min`]. |
1002 | #[rustc_intrinsic ] |
1003 | #[rustc_nounwind ] |
1004 | pub unsafe fn atomic_umin_relaxed<T: Copy>(dst: *mut T, src: T) -> T; |
1005 | |
1006 | /// Maximum with the current value using an unsigned comparison. |
1007 | /// `T` must be an unsigned integer type. |
1008 | /// |
1009 | /// The stabilized version of this intrinsic is available on the |
1010 | /// [`atomic`] unsigned integer types via the `fetch_max` method by passing |
1011 | /// [`Ordering::SeqCst`] as the `order`. For example, [`AtomicU32::fetch_max`]. |
1012 | #[rustc_intrinsic ] |
1013 | #[rustc_nounwind ] |
1014 | pub unsafe fn atomic_umax_seqcst<T: Copy>(dst: *mut T, src: T) -> T; |
1015 | /// Maximum with the current value using an unsigned comparison. |
1016 | /// `T` must be an unsigned integer type. |
1017 | /// |
1018 | /// The stabilized version of this intrinsic is available on the |
1019 | /// [`atomic`] unsigned integer types via the `fetch_max` method by passing |
1020 | /// [`Ordering::Acquire`] as the `order`. For example, [`AtomicU32::fetch_max`]. |
1021 | #[rustc_intrinsic ] |
1022 | #[rustc_nounwind ] |
1023 | pub unsafe fn atomic_umax_acquire<T: Copy>(dst: *mut T, src: T) -> T; |
1024 | /// Maximum with the current value using an unsigned comparison. |
1025 | /// `T` must be an unsigned integer type. |
1026 | /// |
1027 | /// The stabilized version of this intrinsic is available on the |
1028 | /// [`atomic`] unsigned integer types via the `fetch_max` method by passing |
1029 | /// [`Ordering::Release`] as the `order`. For example, [`AtomicU32::fetch_max`]. |
1030 | #[rustc_intrinsic ] |
1031 | #[rustc_nounwind ] |
1032 | pub unsafe fn atomic_umax_release<T: Copy>(dst: *mut T, src: T) -> T; |
1033 | /// Maximum with the current value using an unsigned comparison. |
1034 | /// `T` must be an unsigned integer type. |
1035 | /// |
1036 | /// The stabilized version of this intrinsic is available on the |
1037 | /// [`atomic`] unsigned integer types via the `fetch_max` method by passing |
1038 | /// [`Ordering::AcqRel`] as the `order`. For example, [`AtomicU32::fetch_max`]. |
1039 | #[rustc_intrinsic ] |
1040 | #[rustc_nounwind ] |
1041 | pub unsafe fn atomic_umax_acqrel<T: Copy>(dst: *mut T, src: T) -> T; |
1042 | /// Maximum with the current value using an unsigned comparison. |
1043 | /// `T` must be an unsigned integer type. |
1044 | /// |
1045 | /// The stabilized version of this intrinsic is available on the |
1046 | /// [`atomic`] unsigned integer types via the `fetch_max` method by passing |
1047 | /// [`Ordering::Relaxed`] as the `order`. For example, [`AtomicU32::fetch_max`]. |
1048 | #[rustc_intrinsic ] |
1049 | #[rustc_nounwind ] |
1050 | pub unsafe fn atomic_umax_relaxed<T: Copy>(dst: *mut T, src: T) -> T; |
1051 | |
1052 | /// An atomic fence. |
1053 | /// |
1054 | /// The stabilized version of this intrinsic is available in |
1055 | /// [`atomic::fence`] by passing [`Ordering::SeqCst`] |
1056 | /// as the `order`. |
1057 | #[rustc_intrinsic ] |
1058 | #[rustc_nounwind ] |
1059 | pub unsafe fn atomic_fence_seqcst(); |
1060 | /// An atomic fence. |
1061 | /// |
1062 | /// The stabilized version of this intrinsic is available in |
1063 | /// [`atomic::fence`] by passing [`Ordering::Acquire`] |
1064 | /// as the `order`. |
1065 | #[rustc_intrinsic ] |
1066 | #[rustc_nounwind ] |
1067 | pub unsafe fn atomic_fence_acquire(); |
1068 | /// An atomic fence. |
1069 | /// |
1070 | /// The stabilized version of this intrinsic is available in |
1071 | /// [`atomic::fence`] by passing [`Ordering::Release`] |
1072 | /// as the `order`. |
1073 | #[rustc_intrinsic ] |
1074 | #[rustc_nounwind ] |
1075 | pub unsafe fn atomic_fence_release(); |
1076 | /// An atomic fence. |
1077 | /// |
1078 | /// The stabilized version of this intrinsic is available in |
1079 | /// [`atomic::fence`] by passing [`Ordering::AcqRel`] |
1080 | /// as the `order`. |
1081 | #[rustc_intrinsic ] |
1082 | #[rustc_nounwind ] |
1083 | pub unsafe fn atomic_fence_acqrel(); |
1084 | |
1085 | /// A compiler-only memory barrier. |
1086 | /// |
1087 | /// Memory accesses will never be reordered across this barrier by the |
1088 | /// compiler, but no instructions will be emitted for it. This is |
1089 | /// appropriate for operations on the same thread that may be preempted, |
1090 | /// such as when interacting with signal handlers. |
1091 | /// |
1092 | /// The stabilized version of this intrinsic is available in |
1093 | /// [`atomic::compiler_fence`] by passing [`Ordering::SeqCst`] |
1094 | /// as the `order`. |
1095 | #[rustc_intrinsic ] |
1096 | #[rustc_nounwind ] |
1097 | pub unsafe fn atomic_singlethreadfence_seqcst(); |
1098 | /// A compiler-only memory barrier. |
1099 | /// |
1100 | /// Memory accesses will never be reordered across this barrier by the |
1101 | /// compiler, but no instructions will be emitted for it. This is |
1102 | /// appropriate for operations on the same thread that may be preempted, |
1103 | /// such as when interacting with signal handlers. |
1104 | /// |
1105 | /// The stabilized version of this intrinsic is available in |
1106 | /// [`atomic::compiler_fence`] by passing [`Ordering::Acquire`] |
1107 | /// as the `order`. |
1108 | #[rustc_intrinsic ] |
1109 | #[rustc_nounwind ] |
1110 | pub unsafe fn atomic_singlethreadfence_acquire(); |
1111 | /// A compiler-only memory barrier. |
1112 | /// |
1113 | /// Memory accesses will never be reordered across this barrier by the |
1114 | /// compiler, but no instructions will be emitted for it. This is |
1115 | /// appropriate for operations on the same thread that may be preempted, |
1116 | /// such as when interacting with signal handlers. |
1117 | /// |
1118 | /// The stabilized version of this intrinsic is available in |
1119 | /// [`atomic::compiler_fence`] by passing [`Ordering::Release`] |
1120 | /// as the `order`. |
1121 | #[rustc_intrinsic ] |
1122 | #[rustc_nounwind ] |
1123 | pub unsafe fn atomic_singlethreadfence_release(); |
1124 | /// A compiler-only memory barrier. |
1125 | /// |
1126 | /// Memory accesses will never be reordered across this barrier by the |
1127 | /// compiler, but no instructions will be emitted for it. This is |
1128 | /// appropriate for operations on the same thread that may be preempted, |
1129 | /// such as when interacting with signal handlers. |
1130 | /// |
1131 | /// The stabilized version of this intrinsic is available in |
1132 | /// [`atomic::compiler_fence`] by passing [`Ordering::AcqRel`] |
1133 | /// as the `order`. |
1134 | #[rustc_intrinsic ] |
1135 | #[rustc_nounwind ] |
1136 | pub unsafe fn atomic_singlethreadfence_acqrel(); |
1137 | |
1138 | /// The `prefetch` intrinsic is a hint to the code generator to insert a prefetch instruction |
1139 | /// if supported; otherwise, it is a no-op. |
1140 | /// Prefetches have no effect on the behavior of the program but can change its performance |
1141 | /// characteristics. |
1142 | /// |
1143 | /// The `locality` argument must be a constant integer and is a temporal locality specifier |
1144 | /// ranging from (0) - no locality, to (3) - extremely local keep in cache. |
1145 | /// |
1146 | /// This intrinsic does not have a stable counterpart. |
1147 | #[rustc_intrinsic ] |
1148 | #[rustc_nounwind ] |
1149 | pub unsafe fn prefetch_read_data<T>(data: *const T, locality: i32); |
1150 | /// The `prefetch` intrinsic is a hint to the code generator to insert a prefetch instruction |
1151 | /// if supported; otherwise, it is a no-op. |
1152 | /// Prefetches have no effect on the behavior of the program but can change its performance |
1153 | /// characteristics. |
1154 | /// |
1155 | /// The `locality` argument must be a constant integer and is a temporal locality specifier |
1156 | /// ranging from (0) - no locality, to (3) - extremely local keep in cache. |
1157 | /// |
1158 | /// This intrinsic does not have a stable counterpart. |
1159 | #[rustc_intrinsic ] |
1160 | #[rustc_nounwind ] |
1161 | pub unsafe fn prefetch_write_data<T>(data: *const T, locality: i32); |
1162 | /// The `prefetch` intrinsic is a hint to the code generator to insert a prefetch instruction |
1163 | /// if supported; otherwise, it is a no-op. |
1164 | /// Prefetches have no effect on the behavior of the program but can change its performance |
1165 | /// characteristics. |
1166 | /// |
1167 | /// The `locality` argument must be a constant integer and is a temporal locality specifier |
1168 | /// ranging from (0) - no locality, to (3) - extremely local keep in cache. |
1169 | /// |
1170 | /// This intrinsic does not have a stable counterpart. |
1171 | #[rustc_intrinsic ] |
1172 | #[rustc_nounwind ] |
1173 | pub unsafe fn prefetch_read_instruction<T>(data: *const T, locality: i32); |
1174 | /// The `prefetch` intrinsic is a hint to the code generator to insert a prefetch instruction |
1175 | /// if supported; otherwise, it is a no-op. |
1176 | /// Prefetches have no effect on the behavior of the program but can change its performance |
1177 | /// characteristics. |
1178 | /// |
1179 | /// The `locality` argument must be a constant integer and is a temporal locality specifier |
1180 | /// ranging from (0) - no locality, to (3) - extremely local keep in cache. |
1181 | /// |
1182 | /// This intrinsic does not have a stable counterpart. |
1183 | #[rustc_intrinsic ] |
1184 | #[rustc_nounwind ] |
1185 | pub unsafe fn prefetch_write_instruction<T>(data: *const T, locality: i32); |
1186 | |
1187 | /// Executes a breakpoint trap, for inspection by a debugger. |
1188 | /// |
1189 | /// This intrinsic does not have a stable counterpart. |
1190 | #[rustc_intrinsic ] |
1191 | #[rustc_nounwind ] |
1192 | pub fn breakpoint(); |
1193 | |
1194 | /// Magic intrinsic that derives its meaning from attributes |
1195 | /// attached to the function. |
1196 | /// |
1197 | /// For example, dataflow uses this to inject static assertions so |
1198 | /// that `rustc_peek(potentially_uninitialized)` would actually |
1199 | /// double-check that dataflow did indeed compute that it is |
1200 | /// uninitialized at that point in the control flow. |
1201 | /// |
1202 | /// This intrinsic should not be used outside of the compiler. |
1203 | #[rustc_nounwind ] |
1204 | #[rustc_intrinsic ] |
1205 | pub fn rustc_peek<T>(_: T) -> T; |
1206 | |
1207 | /// Aborts the execution of the process. |
1208 | /// |
1209 | /// Note that, unlike most intrinsics, this is safe to call; |
1210 | /// it does not require an `unsafe` block. |
1211 | /// Therefore, implementations must not require the user to uphold |
1212 | /// any safety invariants. |
1213 | /// |
1214 | /// [`std::process::abort`](../../std/process/fn.abort.html) is to be preferred if possible, |
1215 | /// as its behavior is more user-friendly and more stable. |
1216 | /// |
1217 | /// The current implementation of `intrinsics::abort` is to invoke an invalid instruction, |
1218 | /// on most platforms. |
1219 | /// On Unix, the |
1220 | /// process will probably terminate with a signal like `SIGABRT`, `SIGILL`, `SIGTRAP`, `SIGSEGV` or |
1221 | /// `SIGBUS`. The precise behavior is not guaranteed and not stable. |
1222 | #[rustc_nounwind ] |
1223 | #[rustc_intrinsic ] |
1224 | pub fn abort() -> !; |
1225 | |
1226 | /// Informs the optimizer that this point in the code is not reachable, |
1227 | /// enabling further optimizations. |
1228 | /// |
1229 | /// N.B., this is very different from the `unreachable!()` macro: Unlike the |
1230 | /// macro, which panics when it is executed, it is *undefined behavior* to |
1231 | /// reach code marked with this function. |
1232 | /// |
1233 | /// The stabilized version of this intrinsic is [`core::hint::unreachable_unchecked`]. |
1234 | #[rustc_intrinsic_const_stable_indirect] |
1235 | #[rustc_nounwind ] |
1236 | #[rustc_intrinsic ] |
1237 | pub const unsafe fn unreachable() -> !; |
1238 | |
1239 | /// Informs the optimizer that a condition is always true. |
1240 | /// If the condition is false, the behavior is undefined. |
1241 | /// |
1242 | /// No code is generated for this intrinsic, but the optimizer will try |
1243 | /// to preserve it (and its condition) between passes, which may interfere |
1244 | /// with optimization of surrounding code and reduce performance. It should |
1245 | /// not be used if the invariant can be discovered by the optimizer on its |
1246 | /// own, or if it does not enable any significant optimizations. |
1247 | /// |
1248 | /// The stabilized version of this intrinsic is [`core::hint::assert_unchecked`]. |
1249 | #[rustc_intrinsic_const_stable_indirect] |
1250 | #[rustc_nounwind ] |
1251 | #[unstable (feature = "core_intrinsics" , issue = "none" )] |
1252 | #[rustc_intrinsic ] |
1253 | pub const unsafe fn assume(b: bool) { |
1254 | if !b { |
1255 | // SAFETY: the caller must guarantee the argument is never `false` |
1256 | unsafe { unreachable() } |
1257 | } |
1258 | } |
1259 | |
1260 | /// Hints to the compiler that current code path is cold. |
1261 | /// |
1262 | /// Note that, unlike most intrinsics, this is safe to call; |
1263 | /// it does not require an `unsafe` block. |
1264 | /// Therefore, implementations must not require the user to uphold |
1265 | /// any safety invariants. |
1266 | /// |
1267 | /// This intrinsic does not have a stable counterpart. |
1268 | #[unstable (feature = "core_intrinsics" , issue = "none" )] |
1269 | #[rustc_intrinsic ] |
1270 | #[rustc_nounwind ] |
1271 | #[miri::intrinsic_fallback_is_spec] |
1272 | #[cold ] |
1273 | pub const fn cold_path() {} |
1274 | |
1275 | /// Hints to the compiler that branch condition is likely to be true. |
1276 | /// Returns the value passed to it. |
1277 | /// |
1278 | /// Any use other than with `if` statements will probably not have an effect. |
1279 | /// |
1280 | /// Note that, unlike most intrinsics, this is safe to call; |
1281 | /// it does not require an `unsafe` block. |
1282 | /// Therefore, implementations must not require the user to uphold |
1283 | /// any safety invariants. |
1284 | /// |
1285 | /// This intrinsic does not have a stable counterpart. |
1286 | #[unstable (feature = "core_intrinsics" , issue = "none" )] |
1287 | #[rustc_nounwind ] |
1288 | #[inline (always)] |
1289 | pub const fn likely(b: bool) -> bool { |
1290 | if b { |
1291 | true |
1292 | } else { |
1293 | cold_path(); |
1294 | false |
1295 | } |
1296 | } |
1297 | |
1298 | /// Hints to the compiler that branch condition is likely to be false. |
1299 | /// Returns the value passed to it. |
1300 | /// |
1301 | /// Any use other than with `if` statements will probably not have an effect. |
1302 | /// |
1303 | /// Note that, unlike most intrinsics, this is safe to call; |
1304 | /// it does not require an `unsafe` block. |
1305 | /// Therefore, implementations must not require the user to uphold |
1306 | /// any safety invariants. |
1307 | /// |
1308 | /// This intrinsic does not have a stable counterpart. |
1309 | #[unstable (feature = "core_intrinsics" , issue = "none" )] |
1310 | #[rustc_nounwind ] |
1311 | #[inline (always)] |
1312 | pub const fn unlikely(b: bool) -> bool { |
1313 | if b { |
1314 | cold_path(); |
1315 | true |
1316 | } else { |
1317 | false |
1318 | } |
1319 | } |
1320 | |
1321 | /// Returns either `true_val` or `false_val` depending on condition `b` with a |
1322 | /// hint to the compiler that this condition is unlikely to be correctly |
1323 | /// predicted by a CPU's branch predictor (e.g. a binary search). |
1324 | /// |
1325 | /// This is otherwise functionally equivalent to `if b { true_val } else { false_val }`. |
1326 | /// |
1327 | /// Note that, unlike most intrinsics, this is safe to call; |
1328 | /// it does not require an `unsafe` block. |
1329 | /// Therefore, implementations must not require the user to uphold |
1330 | /// any safety invariants. |
1331 | /// |
1332 | /// The public form of this instrinsic is [`bool::select_unpredictable`]. |
1333 | #[unstable (feature = "core_intrinsics" , issue = "none" )] |
1334 | #[rustc_intrinsic ] |
1335 | #[rustc_nounwind ] |
1336 | #[miri::intrinsic_fallback_is_spec] |
1337 | #[inline ] |
1338 | pub fn select_unpredictable<T>(b: bool, true_val: T, false_val: T) -> T { |
1339 | if b { true_val } else { false_val } |
1340 | } |
1341 | |
1342 | /// A guard for unsafe functions that cannot ever be executed if `T` is uninhabited: |
1343 | /// This will statically either panic, or do nothing. |
1344 | /// |
1345 | /// This intrinsic does not have a stable counterpart. |
1346 | #[rustc_intrinsic_const_stable_indirect] |
1347 | #[rustc_nounwind ] |
1348 | #[rustc_intrinsic ] |
1349 | pub const fn assert_inhabited<T>(); |
1350 | |
1351 | /// A guard for unsafe functions that cannot ever be executed if `T` does not permit |
1352 | /// zero-initialization: This will statically either panic, or do nothing. |
1353 | /// |
1354 | /// This intrinsic does not have a stable counterpart. |
1355 | #[rustc_intrinsic_const_stable_indirect] |
1356 | #[rustc_nounwind ] |
1357 | #[rustc_intrinsic ] |
1358 | pub const fn assert_zero_valid<T>(); |
1359 | |
1360 | /// A guard for `std::mem::uninitialized`. This will statically either panic, or do nothing. |
1361 | /// |
1362 | /// This intrinsic does not have a stable counterpart. |
1363 | #[rustc_intrinsic_const_stable_indirect] |
1364 | #[rustc_nounwind ] |
1365 | #[rustc_intrinsic ] |
1366 | pub const fn assert_mem_uninitialized_valid<T>(); |
1367 | |
1368 | /// Gets a reference to a static `Location` indicating where it was called. |
1369 | /// |
1370 | /// Note that, unlike most intrinsics, this is safe to call; |
1371 | /// it does not require an `unsafe` block. |
1372 | /// Therefore, implementations must not require the user to uphold |
1373 | /// any safety invariants. |
1374 | /// |
1375 | /// Consider using [`core::panic::Location::caller`] instead. |
1376 | #[rustc_intrinsic_const_stable_indirect] |
1377 | #[rustc_nounwind ] |
1378 | #[rustc_intrinsic ] |
1379 | pub const fn caller_location() -> &'static crate::panic::Location<'static>; |
1380 | |
1381 | /// Moves a value out of scope without running drop glue. |
1382 | /// |
1383 | /// This exists solely for [`crate::mem::forget_unsized`]; normal `forget` uses |
1384 | /// `ManuallyDrop` instead. |
1385 | /// |
1386 | /// Note that, unlike most intrinsics, this is safe to call; |
1387 | /// it does not require an `unsafe` block. |
1388 | /// Therefore, implementations must not require the user to uphold |
1389 | /// any safety invariants. |
1390 | #[rustc_intrinsic_const_stable_indirect] |
1391 | #[rustc_nounwind ] |
1392 | #[rustc_intrinsic ] |
1393 | pub const fn forget<T: ?Sized>(_: T); |
1394 | |
1395 | /// Reinterprets the bits of a value of one type as another type. |
1396 | /// |
1397 | /// Both types must have the same size. Compilation will fail if this is not guaranteed. |
1398 | /// |
1399 | /// `transmute` is semantically equivalent to a bitwise move of one type |
1400 | /// into another. It copies the bits from the source value into the |
1401 | /// destination value, then forgets the original. Note that source and destination |
1402 | /// are passed by-value, which means if `Src` or `Dst` contain padding, that padding |
1403 | /// is *not* guaranteed to be preserved by `transmute`. |
1404 | /// |
1405 | /// Both the argument and the result must be [valid](../../nomicon/what-unsafe-does.html) at |
1406 | /// their given type. Violating this condition leads to [undefined behavior][ub]. The compiler |
1407 | /// will generate code *assuming that you, the programmer, ensure that there will never be |
1408 | /// undefined behavior*. It is therefore your responsibility to guarantee that every value |
1409 | /// passed to `transmute` is valid at both types `Src` and `Dst`. Failing to uphold this condition |
1410 | /// may lead to unexpected and unstable compilation results. This makes `transmute` **incredibly |
1411 | /// unsafe**. `transmute` should be the absolute last resort. |
1412 | /// |
1413 | /// Because `transmute` is a by-value operation, alignment of the *transmuted values |
1414 | /// themselves* is not a concern. As with any other function, the compiler already ensures |
1415 | /// both `Src` and `Dst` are properly aligned. However, when transmuting values that *point |
1416 | /// elsewhere* (such as pointers, references, boxes…), the caller has to ensure proper |
1417 | /// alignment of the pointed-to values. |
1418 | /// |
1419 | /// The [nomicon](../../nomicon/transmutes.html) has additional documentation. |
1420 | /// |
1421 | /// [ub]: ../../reference/behavior-considered-undefined.html |
1422 | /// |
1423 | /// # Transmutation between pointers and integers |
1424 | /// |
1425 | /// Special care has to be taken when transmuting between pointers and integers, e.g. |
1426 | /// transmuting between `*const ()` and `usize`. |
1427 | /// |
1428 | /// Transmuting *pointers to integers* in a `const` context is [undefined behavior][ub], unless |
1429 | /// the pointer was originally created *from* an integer. (That includes this function |
1430 | /// specifically, integer-to-pointer casts, and helpers like [`dangling`][crate::ptr::dangling], |
1431 | /// but also semantically-equivalent conversions such as punning through `repr(C)` union |
1432 | /// fields.) Any attempt to use the resulting value for integer operations will abort |
1433 | /// const-evaluation. (And even outside `const`, such transmutation is touching on many |
1434 | /// unspecified aspects of the Rust memory model and should be avoided. See below for |
1435 | /// alternatives.) |
1436 | /// |
1437 | /// Transmuting *integers to pointers* is a largely unspecified operation. It is likely *not* |
1438 | /// equivalent to an `as` cast. Doing non-zero-sized memory accesses with a pointer constructed |
1439 | /// this way is currently considered undefined behavior. |
1440 | /// |
1441 | /// All this also applies when the integer is nested inside an array, tuple, struct, or enum. |
1442 | /// However, `MaybeUninit<usize>` is not considered an integer type for the purpose of this |
1443 | /// section. Transmuting `*const ()` to `MaybeUninit<usize>` is fine---but then calling |
1444 | /// `assume_init()` on that result is considered as completing the pointer-to-integer transmute |
1445 | /// and thus runs into the issues discussed above. |
1446 | /// |
1447 | /// In particular, doing a pointer-to-integer-to-pointer roundtrip via `transmute` is *not* a |
1448 | /// lossless process. If you want to round-trip a pointer through an integer in a way that you |
1449 | /// can get back the original pointer, you need to use `as` casts, or replace the integer type |
1450 | /// by `MaybeUninit<$int>` (and never call `assume_init()`). If you are looking for a way to |
1451 | /// store data of arbitrary type, also use `MaybeUninit<T>` (that will also handle uninitialized |
1452 | /// memory due to padding). If you specifically need to store something that is "either an |
1453 | /// integer or a pointer", use `*mut ()`: integers can be converted to pointers and back without |
1454 | /// any loss (via `as` casts or via `transmute`). |
1455 | /// |
1456 | /// # Examples |
1457 | /// |
1458 | /// There are a few things that `transmute` is really useful for. |
1459 | /// |
1460 | /// Turning a pointer into a function pointer. This is *not* portable to |
1461 | /// machines where function pointers and data pointers have different sizes. |
1462 | /// |
1463 | /// ``` |
1464 | /// fn foo() -> i32 { |
1465 | /// 0 |
1466 | /// } |
1467 | /// // Crucially, we `as`-cast to a raw pointer before `transmute`ing to a function pointer. |
1468 | /// // This avoids an integer-to-pointer `transmute`, which can be problematic. |
1469 | /// // Transmuting between raw pointers and function pointers (i.e., two pointer types) is fine. |
1470 | /// let pointer = foo as *const (); |
1471 | /// let function = unsafe { |
1472 | /// std::mem::transmute::<*const (), fn() -> i32>(pointer) |
1473 | /// }; |
1474 | /// assert_eq!(function(), 0); |
1475 | /// ``` |
1476 | /// |
1477 | /// Extending a lifetime, or shortening an invariant lifetime. This is |
1478 | /// advanced, very unsafe Rust! |
1479 | /// |
1480 | /// ``` |
1481 | /// struct R<'a>(&'a i32); |
1482 | /// unsafe fn extend_lifetime<'b>(r: R<'b>) -> R<'static> { |
1483 | /// unsafe { std::mem::transmute::<R<'b>, R<'static>>(r) } |
1484 | /// } |
1485 | /// |
1486 | /// unsafe fn shorten_invariant_lifetime<'b, 'c>(r: &'b mut R<'static>) |
1487 | /// -> &'b mut R<'c> { |
1488 | /// unsafe { std::mem::transmute::<&'b mut R<'static>, &'b mut R<'c>>(r) } |
1489 | /// } |
1490 | /// ``` |
1491 | /// |
1492 | /// # Alternatives |
1493 | /// |
1494 | /// Don't despair: many uses of `transmute` can be achieved through other means. |
1495 | /// Below are common applications of `transmute` which can be replaced with safer |
1496 | /// constructs. |
1497 | /// |
1498 | /// Turning raw bytes (`[u8; SZ]`) into `u32`, `f64`, etc.: |
1499 | /// |
1500 | /// ``` |
1501 | /// let raw_bytes = [0x78, 0x56, 0x34, 0x12]; |
1502 | /// |
1503 | /// let num = unsafe { |
1504 | /// std::mem::transmute::<[u8; 4], u32>(raw_bytes) |
1505 | /// }; |
1506 | /// |
1507 | /// // use `u32::from_ne_bytes` instead |
1508 | /// let num = u32::from_ne_bytes(raw_bytes); |
1509 | /// // or use `u32::from_le_bytes` or `u32::from_be_bytes` to specify the endianness |
1510 | /// let num = u32::from_le_bytes(raw_bytes); |
1511 | /// assert_eq!(num, 0x12345678); |
1512 | /// let num = u32::from_be_bytes(raw_bytes); |
1513 | /// assert_eq!(num, 0x78563412); |
1514 | /// ``` |
1515 | /// |
1516 | /// Turning a pointer into a `usize`: |
1517 | /// |
1518 | /// ```no_run |
1519 | /// let ptr = &0; |
1520 | /// let ptr_num_transmute = unsafe { |
1521 | /// std::mem::transmute::<&i32, usize>(ptr) |
1522 | /// }; |
1523 | /// |
1524 | /// // Use an `as` cast instead |
1525 | /// let ptr_num_cast = ptr as *const i32 as usize; |
1526 | /// ``` |
1527 | /// |
1528 | /// Note that using `transmute` to turn a pointer to a `usize` is (as noted above) [undefined |
1529 | /// behavior][ub] in `const` contexts. Also outside of consts, this operation might not behave |
1530 | /// as expected -- this is touching on many unspecified aspects of the Rust memory model. |
1531 | /// Depending on what the code is doing, the following alternatives are preferable to |
1532 | /// pointer-to-integer transmutation: |
1533 | /// - If the code just wants to store data of arbitrary type in some buffer and needs to pick a |
1534 | /// type for that buffer, it can use [`MaybeUninit`][crate::mem::MaybeUninit]. |
1535 | /// - If the code actually wants to work on the address the pointer points to, it can use `as` |
1536 | /// casts or [`ptr.addr()`][pointer::addr]. |
1537 | /// |
1538 | /// Turning a `*mut T` into a `&mut T`: |
1539 | /// |
1540 | /// ``` |
1541 | /// let ptr: *mut i32 = &mut 0; |
1542 | /// let ref_transmuted = unsafe { |
1543 | /// std::mem::transmute::<*mut i32, &mut i32>(ptr) |
1544 | /// }; |
1545 | /// |
1546 | /// // Use a reborrow instead |
1547 | /// let ref_casted = unsafe { &mut *ptr }; |
1548 | /// ``` |
1549 | /// |
1550 | /// Turning a `&mut T` into a `&mut U`: |
1551 | /// |
1552 | /// ``` |
1553 | /// let ptr = &mut 0; |
1554 | /// let val_transmuted = unsafe { |
1555 | /// std::mem::transmute::<&mut i32, &mut u32>(ptr) |
1556 | /// }; |
1557 | /// |
1558 | /// // Now, put together `as` and reborrowing - note the chaining of `as` |
1559 | /// // `as` is not transitive |
1560 | /// let val_casts = unsafe { &mut *(ptr as *mut i32 as *mut u32) }; |
1561 | /// ``` |
1562 | /// |
1563 | /// Turning a `&str` into a `&[u8]`: |
1564 | /// |
1565 | /// ``` |
1566 | /// // this is not a good way to do this. |
1567 | /// let slice = unsafe { std::mem::transmute::<&str, &[u8]>("Rust" ) }; |
1568 | /// assert_eq!(slice, &[82, 117, 115, 116]); |
1569 | /// |
1570 | /// // You could use `str::as_bytes` |
1571 | /// let slice = "Rust" .as_bytes(); |
1572 | /// assert_eq!(slice, &[82, 117, 115, 116]); |
1573 | /// |
1574 | /// // Or, just use a byte string, if you have control over the string |
1575 | /// // literal |
1576 | /// assert_eq!(b"Rust" , &[82, 117, 115, 116]); |
1577 | /// ``` |
1578 | /// |
1579 | /// Turning a `Vec<&T>` into a `Vec<Option<&T>>`. |
1580 | /// |
1581 | /// To transmute the inner type of the contents of a container, you must make sure to not |
1582 | /// violate any of the container's invariants. For `Vec`, this means that both the size |
1583 | /// *and alignment* of the inner types have to match. Other containers might rely on the |
1584 | /// size of the type, alignment, or even the `TypeId`, in which case transmuting wouldn't |
1585 | /// be possible at all without violating the container invariants. |
1586 | /// |
1587 | /// ``` |
1588 | /// let store = [0, 1, 2, 3]; |
1589 | /// let v_orig = store.iter().collect::<Vec<&i32>>(); |
1590 | /// |
1591 | /// // clone the vector as we will reuse them later |
1592 | /// let v_clone = v_orig.clone(); |
1593 | /// |
1594 | /// // Using transmute: this relies on the unspecified data layout of `Vec`, which is a |
1595 | /// // bad idea and could cause Undefined Behavior. |
1596 | /// // However, it is no-copy. |
1597 | /// let v_transmuted = unsafe { |
1598 | /// std::mem::transmute::<Vec<&i32>, Vec<Option<&i32>>>(v_clone) |
1599 | /// }; |
1600 | /// |
1601 | /// let v_clone = v_orig.clone(); |
1602 | /// |
1603 | /// // This is the suggested, safe way. |
1604 | /// // It may copy the entire vector into a new one though, but also may not. |
1605 | /// let v_collected = v_clone.into_iter() |
1606 | /// .map(Some) |
1607 | /// .collect::<Vec<Option<&i32>>>(); |
1608 | /// |
1609 | /// let v_clone = v_orig.clone(); |
1610 | /// |
1611 | /// // This is the proper no-copy, unsafe way of "transmuting" a `Vec`, without relying on the |
1612 | /// // data layout. Instead of literally calling `transmute`, we perform a pointer cast, but |
1613 | /// // in terms of converting the original inner type (`&i32`) to the new one (`Option<&i32>`), |
1614 | /// // this has all the same caveats. Besides the information provided above, also consult the |
1615 | /// // [`from_raw_parts`] documentation. |
1616 | /// let v_from_raw = unsafe { |
1617 | // FIXME Update this when vec_into_raw_parts is stabilized |
1618 | /// // Ensure the original vector is not dropped. |
1619 | /// let mut v_clone = std::mem::ManuallyDrop::new(v_clone); |
1620 | /// Vec::from_raw_parts(v_clone.as_mut_ptr() as *mut Option<&i32>, |
1621 | /// v_clone.len(), |
1622 | /// v_clone.capacity()) |
1623 | /// }; |
1624 | /// ``` |
1625 | /// |
1626 | /// [`from_raw_parts`]: ../../std/vec/struct.Vec.html#method.from_raw_parts |
1627 | /// |
1628 | /// Implementing `split_at_mut`: |
1629 | /// |
1630 | /// ``` |
1631 | /// use std::{slice, mem}; |
1632 | /// |
1633 | /// // There are multiple ways to do this, and there are multiple problems |
1634 | /// // with the following (transmute) way. |
1635 | /// fn split_at_mut_transmute<T>(slice: &mut [T], mid: usize) |
1636 | /// -> (&mut [T], &mut [T]) { |
1637 | /// let len = slice.len(); |
1638 | /// assert!(mid <= len); |
1639 | /// unsafe { |
1640 | /// let slice2 = mem::transmute::<&mut [T], &mut [T]>(slice); |
1641 | /// // first: transmute is not type safe; all it checks is that T and |
1642 | /// // U are of the same size. Second, right here, you have two |
1643 | /// // mutable references pointing to the same memory. |
1644 | /// (&mut slice[0..mid], &mut slice2[mid..len]) |
1645 | /// } |
1646 | /// } |
1647 | /// |
1648 | /// // This gets rid of the type safety problems; `&mut *` will *only* give |
1649 | /// // you a `&mut T` from a `&mut T` or `*mut T`. |
1650 | /// fn split_at_mut_casts<T>(slice: &mut [T], mid: usize) |
1651 | /// -> (&mut [T], &mut [T]) { |
1652 | /// let len = slice.len(); |
1653 | /// assert!(mid <= len); |
1654 | /// unsafe { |
1655 | /// let slice2 = &mut *(slice as *mut [T]); |
1656 | /// // however, you still have two mutable references pointing to |
1657 | /// // the same memory. |
1658 | /// (&mut slice[0..mid], &mut slice2[mid..len]) |
1659 | /// } |
1660 | /// } |
1661 | /// |
1662 | /// // This is how the standard library does it. This is the best method, if |
1663 | /// // you need to do something like this |
1664 | /// fn split_at_stdlib<T>(slice: &mut [T], mid: usize) |
1665 | /// -> (&mut [T], &mut [T]) { |
1666 | /// let len = slice.len(); |
1667 | /// assert!(mid <= len); |
1668 | /// unsafe { |
1669 | /// let ptr = slice.as_mut_ptr(); |
1670 | /// // This now has three mutable references pointing at the same |
1671 | /// // memory. `slice`, the rvalue ret.0, and the rvalue ret.1. |
1672 | /// // `slice` is never used after `let ptr = ...`, and so one can |
1673 | /// // treat it as "dead", and therefore, you only have two real |
1674 | /// // mutable slices. |
1675 | /// (slice::from_raw_parts_mut(ptr, mid), |
1676 | /// slice::from_raw_parts_mut(ptr.add(mid), len - mid)) |
1677 | /// } |
1678 | /// } |
1679 | /// ``` |
1680 | #[stable (feature = "rust1" , since = "1.0.0" )] |
1681 | #[rustc_allowed_through_unstable_modules = "import this function via `std::mem` instead" ] |
1682 | #[rustc_const_stable (feature = "const_transmute" , since = "1.56.0" )] |
1683 | #[rustc_diagnostic_item = "transmute" ] |
1684 | #[rustc_nounwind ] |
1685 | #[rustc_intrinsic ] |
1686 | pub const unsafe fn transmute<Src, Dst>(src: Src) -> Dst; |
1687 | |
1688 | /// Like [`transmute`], but even less checked at compile-time: rather than |
1689 | /// giving an error for `size_of::<Src>() != size_of::<Dst>()`, it's |
1690 | /// **Undefined Behavior** at runtime. |
1691 | /// |
1692 | /// Prefer normal `transmute` where possible, for the extra checking, since |
1693 | /// both do exactly the same thing at runtime, if they both compile. |
1694 | /// |
1695 | /// This is not expected to ever be exposed directly to users, rather it |
1696 | /// may eventually be exposed through some more-constrained API. |
1697 | #[rustc_intrinsic_const_stable_indirect] |
1698 | #[rustc_nounwind ] |
1699 | #[rustc_intrinsic ] |
1700 | pub const unsafe fn transmute_unchecked<Src, Dst>(src: Src) -> Dst; |
1701 | |
1702 | /// Returns `true` if the actual type given as `T` requires drop |
1703 | /// glue; returns `false` if the actual type provided for `T` |
1704 | /// implements `Copy`. |
1705 | /// |
1706 | /// If the actual type neither requires drop glue nor implements |
1707 | /// `Copy`, then the return value of this function is unspecified. |
1708 | /// |
1709 | /// Note that, unlike most intrinsics, this is safe to call; |
1710 | /// it does not require an `unsafe` block. |
1711 | /// Therefore, implementations must not require the user to uphold |
1712 | /// any safety invariants. |
1713 | /// |
1714 | /// The stabilized version of this intrinsic is [`mem::needs_drop`](crate::mem::needs_drop). |
1715 | #[rustc_intrinsic_const_stable_indirect] |
1716 | #[rustc_nounwind ] |
1717 | #[rustc_intrinsic ] |
1718 | pub const fn needs_drop<T: ?Sized>() -> bool; |
1719 | |
1720 | /// Calculates the offset from a pointer. |
1721 | /// |
1722 | /// This is implemented as an intrinsic to avoid converting to and from an |
1723 | /// integer, since the conversion would throw away aliasing information. |
1724 | /// |
1725 | /// This can only be used with `Ptr` as a raw pointer type (`*mut` or `*const`) |
1726 | /// to a `Sized` pointee and with `Delta` as `usize` or `isize`. Any other |
1727 | /// instantiations may arbitrarily misbehave, and that's *not* a compiler bug. |
1728 | /// |
1729 | /// # Safety |
1730 | /// |
1731 | /// If the computed offset is non-zero, then both the starting and resulting pointer must be |
1732 | /// either in bounds or at the end of an allocated object. If either pointer is out |
1733 | /// of bounds or arithmetic overflow occurs then this operation is undefined behavior. |
1734 | /// |
1735 | /// The stabilized version of this intrinsic is [`pointer::offset`]. |
1736 | #[must_use = "returns a new pointer rather than modifying its argument" ] |
1737 | #[rustc_intrinsic_const_stable_indirect] |
1738 | #[rustc_nounwind ] |
1739 | #[rustc_intrinsic ] |
1740 | pub const unsafe fn offset<Ptr, Delta>(dst: Ptr, offset: Delta) -> Ptr; |
1741 | |
1742 | /// Calculates the offset from a pointer, potentially wrapping. |
1743 | /// |
1744 | /// This is implemented as an intrinsic to avoid converting to and from an |
1745 | /// integer, since the conversion inhibits certain optimizations. |
1746 | /// |
1747 | /// # Safety |
1748 | /// |
1749 | /// Unlike the `offset` intrinsic, this intrinsic does not restrict the |
1750 | /// resulting pointer to point into or at the end of an allocated |
1751 | /// object, and it wraps with two's complement arithmetic. The resulting |
1752 | /// value is not necessarily valid to be used to actually access memory. |
1753 | /// |
1754 | /// The stabilized version of this intrinsic is [`pointer::wrapping_offset`]. |
1755 | #[must_use = "returns a new pointer rather than modifying its argument" ] |
1756 | #[rustc_intrinsic_const_stable_indirect] |
1757 | #[rustc_nounwind ] |
1758 | #[rustc_intrinsic ] |
1759 | pub const unsafe fn arith_offset<T>(dst: *const T, offset: isize) -> *const T; |
1760 | |
1761 | /// Masks out bits of the pointer according to a mask. |
1762 | /// |
1763 | /// Note that, unlike most intrinsics, this is safe to call; |
1764 | /// it does not require an `unsafe` block. |
1765 | /// Therefore, implementations must not require the user to uphold |
1766 | /// any safety invariants. |
1767 | /// |
1768 | /// Consider using [`pointer::mask`] instead. |
1769 | #[rustc_nounwind ] |
1770 | #[rustc_intrinsic ] |
1771 | pub fn ptr_mask<T>(ptr: *const T, mask: usize) -> *const T; |
1772 | |
1773 | /// Equivalent to the appropriate `llvm.memcpy.p0i8.0i8.*` intrinsic, with |
1774 | /// a size of `count` * `size_of::<T>()` and an alignment of |
1775 | /// `min_align_of::<T>()` |
1776 | /// |
1777 | /// This intrinsic does not have a stable counterpart. |
1778 | /// # Safety |
1779 | /// |
1780 | /// The safety requirements are consistent with [`copy_nonoverlapping`] |
1781 | /// while the read and write behaviors are volatile, |
1782 | /// which means it will not be optimized out unless `_count` or `size_of::<T>()` is equal to zero. |
1783 | /// |
1784 | /// [`copy_nonoverlapping`]: ptr::copy_nonoverlapping |
1785 | #[rustc_intrinsic ] |
1786 | #[rustc_nounwind ] |
1787 | pub unsafe fn volatile_copy_nonoverlapping_memory<T>(dst: *mut T, src: *const T, count: usize); |
1788 | /// Equivalent to the appropriate `llvm.memmove.p0i8.0i8.*` intrinsic, with |
1789 | /// a size of `count * size_of::<T>()` and an alignment of |
1790 | /// `min_align_of::<T>()` |
1791 | /// |
1792 | /// The volatile parameter is set to `true`, so it will not be optimized out |
1793 | /// unless size is equal to zero. |
1794 | /// |
1795 | /// This intrinsic does not have a stable counterpart. |
1796 | #[rustc_intrinsic ] |
1797 | #[rustc_nounwind ] |
1798 | pub unsafe fn volatile_copy_memory<T>(dst: *mut T, src: *const T, count: usize); |
1799 | /// Equivalent to the appropriate `llvm.memset.p0i8.*` intrinsic, with a |
1800 | /// size of `count * size_of::<T>()` and an alignment of |
1801 | /// `min_align_of::<T>()`. |
1802 | /// |
1803 | /// This intrinsic does not have a stable counterpart. |
1804 | /// # Safety |
1805 | /// |
1806 | /// The safety requirements are consistent with [`write_bytes`] while the write behavior is volatile, |
1807 | /// which means it will not be optimized out unless `_count` or `size_of::<T>()` is equal to zero. |
1808 | /// |
1809 | /// [`write_bytes`]: ptr::write_bytes |
1810 | #[rustc_intrinsic ] |
1811 | #[rustc_nounwind ] |
1812 | pub unsafe fn volatile_set_memory<T>(dst: *mut T, val: u8, count: usize); |
1813 | |
1814 | /// Performs a volatile load from the `src` pointer. |
1815 | /// |
1816 | /// The stabilized version of this intrinsic is [`core::ptr::read_volatile`]. |
1817 | #[rustc_intrinsic ] |
1818 | #[rustc_nounwind ] |
1819 | pub unsafe fn volatile_load<T>(src: *const T) -> T; |
1820 | /// Performs a volatile store to the `dst` pointer. |
1821 | /// |
1822 | /// The stabilized version of this intrinsic is [`core::ptr::write_volatile`]. |
1823 | #[rustc_intrinsic ] |
1824 | #[rustc_nounwind ] |
1825 | pub unsafe fn volatile_store<T>(dst: *mut T, val: T); |
1826 | |
1827 | /// Performs a volatile load from the `src` pointer |
1828 | /// The pointer is not required to be aligned. |
1829 | /// |
1830 | /// This intrinsic does not have a stable counterpart. |
1831 | #[rustc_intrinsic ] |
1832 | #[rustc_nounwind ] |
1833 | #[rustc_diagnostic_item = "intrinsics_unaligned_volatile_load" ] |
1834 | pub unsafe fn unaligned_volatile_load<T>(src: *const T) -> T; |
1835 | /// Performs a volatile store to the `dst` pointer. |
1836 | /// The pointer is not required to be aligned. |
1837 | /// |
1838 | /// This intrinsic does not have a stable counterpart. |
1839 | #[rustc_intrinsic ] |
1840 | #[rustc_nounwind ] |
1841 | #[rustc_diagnostic_item = "intrinsics_unaligned_volatile_store" ] |
1842 | pub unsafe fn unaligned_volatile_store<T>(dst: *mut T, val: T); |
1843 | |
1844 | /// Returns the square root of an `f16` |
1845 | /// |
1846 | /// The stabilized version of this intrinsic is |
1847 | /// [`f16::sqrt`](../../std/primitive.f16.html#method.sqrt) |
1848 | #[rustc_intrinsic ] |
1849 | #[rustc_nounwind ] |
1850 | pub unsafe fn sqrtf16(x: f16) -> f16; |
1851 | /// Returns the square root of an `f32` |
1852 | /// |
1853 | /// The stabilized version of this intrinsic is |
1854 | /// [`f32::sqrt`](../../std/primitive.f32.html#method.sqrt) |
1855 | #[rustc_intrinsic ] |
1856 | #[rustc_nounwind ] |
1857 | pub unsafe fn sqrtf32(x: f32) -> f32; |
1858 | /// Returns the square root of an `f64` |
1859 | /// |
1860 | /// The stabilized version of this intrinsic is |
1861 | /// [`f64::sqrt`](../../std/primitive.f64.html#method.sqrt) |
1862 | #[rustc_intrinsic ] |
1863 | #[rustc_nounwind ] |
1864 | pub unsafe fn sqrtf64(x: f64) -> f64; |
1865 | /// Returns the square root of an `f128` |
1866 | /// |
1867 | /// The stabilized version of this intrinsic is |
1868 | /// [`f128::sqrt`](../../std/primitive.f128.html#method.sqrt) |
1869 | #[rustc_intrinsic ] |
1870 | #[rustc_nounwind ] |
1871 | pub unsafe fn sqrtf128(x: f128) -> f128; |
1872 | |
1873 | /// Raises an `f16` to an integer power. |
1874 | /// |
1875 | /// The stabilized version of this intrinsic is |
1876 | /// [`f16::powi`](../../std/primitive.f16.html#method.powi) |
1877 | #[rustc_intrinsic ] |
1878 | #[rustc_nounwind ] |
1879 | pub unsafe fn powif16(a: f16, x: i32) -> f16; |
1880 | /// Raises an `f32` to an integer power. |
1881 | /// |
1882 | /// The stabilized version of this intrinsic is |
1883 | /// [`f32::powi`](../../std/primitive.f32.html#method.powi) |
1884 | #[rustc_intrinsic ] |
1885 | #[rustc_nounwind ] |
1886 | pub unsafe fn powif32(a: f32, x: i32) -> f32; |
1887 | /// Raises an `f64` to an integer power. |
1888 | /// |
1889 | /// The stabilized version of this intrinsic is |
1890 | /// [`f64::powi`](../../std/primitive.f64.html#method.powi) |
1891 | #[rustc_intrinsic ] |
1892 | #[rustc_nounwind ] |
1893 | pub unsafe fn powif64(a: f64, x: i32) -> f64; |
1894 | /// Raises an `f128` to an integer power. |
1895 | /// |
1896 | /// The stabilized version of this intrinsic is |
1897 | /// [`f128::powi`](../../std/primitive.f128.html#method.powi) |
1898 | #[rustc_intrinsic ] |
1899 | #[rustc_nounwind ] |
1900 | pub unsafe fn powif128(a: f128, x: i32) -> f128; |
1901 | |
1902 | /// Returns the sine of an `f16`. |
1903 | /// |
1904 | /// The stabilized version of this intrinsic is |
1905 | /// [`f16::sin`](../../std/primitive.f16.html#method.sin) |
1906 | #[rustc_intrinsic ] |
1907 | #[rustc_nounwind ] |
1908 | pub unsafe fn sinf16(x: f16) -> f16; |
1909 | /// Returns the sine of an `f32`. |
1910 | /// |
1911 | /// The stabilized version of this intrinsic is |
1912 | /// [`f32::sin`](../../std/primitive.f32.html#method.sin) |
1913 | #[rustc_intrinsic ] |
1914 | #[rustc_nounwind ] |
1915 | pub unsafe fn sinf32(x: f32) -> f32; |
1916 | /// Returns the sine of an `f64`. |
1917 | /// |
1918 | /// The stabilized version of this intrinsic is |
1919 | /// [`f64::sin`](../../std/primitive.f64.html#method.sin) |
1920 | #[rustc_intrinsic ] |
1921 | #[rustc_nounwind ] |
1922 | pub unsafe fn sinf64(x: f64) -> f64; |
1923 | /// Returns the sine of an `f128`. |
1924 | /// |
1925 | /// The stabilized version of this intrinsic is |
1926 | /// [`f128::sin`](../../std/primitive.f128.html#method.sin) |
1927 | #[rustc_intrinsic ] |
1928 | #[rustc_nounwind ] |
1929 | pub unsafe fn sinf128(x: f128) -> f128; |
1930 | |
1931 | /// Returns the cosine of an `f16`. |
1932 | /// |
1933 | /// The stabilized version of this intrinsic is |
1934 | /// [`f16::cos`](../../std/primitive.f16.html#method.cos) |
1935 | #[rustc_intrinsic ] |
1936 | #[rustc_nounwind ] |
1937 | pub unsafe fn cosf16(x: f16) -> f16; |
1938 | /// Returns the cosine of an `f32`. |
1939 | /// |
1940 | /// The stabilized version of this intrinsic is |
1941 | /// [`f32::cos`](../../std/primitive.f32.html#method.cos) |
1942 | #[rustc_intrinsic ] |
1943 | #[rustc_nounwind ] |
1944 | pub unsafe fn cosf32(x: f32) -> f32; |
1945 | /// Returns the cosine of an `f64`. |
1946 | /// |
1947 | /// The stabilized version of this intrinsic is |
1948 | /// [`f64::cos`](../../std/primitive.f64.html#method.cos) |
1949 | #[rustc_intrinsic ] |
1950 | #[rustc_nounwind ] |
1951 | pub unsafe fn cosf64(x: f64) -> f64; |
1952 | /// Returns the cosine of an `f128`. |
1953 | /// |
1954 | /// The stabilized version of this intrinsic is |
1955 | /// [`f128::cos`](../../std/primitive.f128.html#method.cos) |
1956 | #[rustc_intrinsic ] |
1957 | #[rustc_nounwind ] |
1958 | pub unsafe fn cosf128(x: f128) -> f128; |
1959 | |
1960 | /// Raises an `f16` to an `f16` power. |
1961 | /// |
1962 | /// The stabilized version of this intrinsic is |
1963 | /// [`f16::powf`](../../std/primitive.f16.html#method.powf) |
1964 | #[rustc_intrinsic ] |
1965 | #[rustc_nounwind ] |
1966 | pub unsafe fn powf16(a: f16, x: f16) -> f16; |
1967 | /// Raises an `f32` to an `f32` power. |
1968 | /// |
1969 | /// The stabilized version of this intrinsic is |
1970 | /// [`f32::powf`](../../std/primitive.f32.html#method.powf) |
1971 | #[rustc_intrinsic ] |
1972 | #[rustc_nounwind ] |
1973 | pub unsafe fn powf32(a: f32, x: f32) -> f32; |
1974 | /// Raises an `f64` to an `f64` power. |
1975 | /// |
1976 | /// The stabilized version of this intrinsic is |
1977 | /// [`f64::powf`](../../std/primitive.f64.html#method.powf) |
1978 | #[rustc_intrinsic ] |
1979 | #[rustc_nounwind ] |
1980 | pub unsafe fn powf64(a: f64, x: f64) -> f64; |
1981 | /// Raises an `f128` to an `f128` power. |
1982 | /// |
1983 | /// The stabilized version of this intrinsic is |
1984 | /// [`f128::powf`](../../std/primitive.f128.html#method.powf) |
1985 | #[rustc_intrinsic ] |
1986 | #[rustc_nounwind ] |
1987 | pub unsafe fn powf128(a: f128, x: f128) -> f128; |
1988 | |
1989 | /// Returns the exponential of an `f16`. |
1990 | /// |
1991 | /// The stabilized version of this intrinsic is |
1992 | /// [`f16::exp`](../../std/primitive.f16.html#method.exp) |
1993 | #[rustc_intrinsic ] |
1994 | #[rustc_nounwind ] |
1995 | pub unsafe fn expf16(x: f16) -> f16; |
1996 | /// Returns the exponential of an `f32`. |
1997 | /// |
1998 | /// The stabilized version of this intrinsic is |
1999 | /// [`f32::exp`](../../std/primitive.f32.html#method.exp) |
2000 | #[rustc_intrinsic ] |
2001 | #[rustc_nounwind ] |
2002 | pub unsafe fn expf32(x: f32) -> f32; |
2003 | /// Returns the exponential of an `f64`. |
2004 | /// |
2005 | /// The stabilized version of this intrinsic is |
2006 | /// [`f64::exp`](../../std/primitive.f64.html#method.exp) |
2007 | #[rustc_intrinsic ] |
2008 | #[rustc_nounwind ] |
2009 | pub unsafe fn expf64(x: f64) -> f64; |
2010 | /// Returns the exponential of an `f128`. |
2011 | /// |
2012 | /// The stabilized version of this intrinsic is |
2013 | /// [`f128::exp`](../../std/primitive.f128.html#method.exp) |
2014 | #[rustc_intrinsic ] |
2015 | #[rustc_nounwind ] |
2016 | pub unsafe fn expf128(x: f128) -> f128; |
2017 | |
2018 | /// Returns 2 raised to the power of an `f16`. |
2019 | /// |
2020 | /// The stabilized version of this intrinsic is |
2021 | /// [`f16::exp2`](../../std/primitive.f16.html#method.exp2) |
2022 | #[rustc_intrinsic ] |
2023 | #[rustc_nounwind ] |
2024 | pub unsafe fn exp2f16(x: f16) -> f16; |
2025 | /// Returns 2 raised to the power of an `f32`. |
2026 | /// |
2027 | /// The stabilized version of this intrinsic is |
2028 | /// [`f32::exp2`](../../std/primitive.f32.html#method.exp2) |
2029 | #[rustc_intrinsic ] |
2030 | #[rustc_nounwind ] |
2031 | pub unsafe fn exp2f32(x: f32) -> f32; |
2032 | /// Returns 2 raised to the power of an `f64`. |
2033 | /// |
2034 | /// The stabilized version of this intrinsic is |
2035 | /// [`f64::exp2`](../../std/primitive.f64.html#method.exp2) |
2036 | #[rustc_intrinsic ] |
2037 | #[rustc_nounwind ] |
2038 | pub unsafe fn exp2f64(x: f64) -> f64; |
2039 | /// Returns 2 raised to the power of an `f128`. |
2040 | /// |
2041 | /// The stabilized version of this intrinsic is |
2042 | /// [`f128::exp2`](../../std/primitive.f128.html#method.exp2) |
2043 | #[rustc_intrinsic ] |
2044 | #[rustc_nounwind ] |
2045 | pub unsafe fn exp2f128(x: f128) -> f128; |
2046 | |
2047 | /// Returns the natural logarithm of an `f16`. |
2048 | /// |
2049 | /// The stabilized version of this intrinsic is |
2050 | /// [`f16::ln`](../../std/primitive.f16.html#method.ln) |
2051 | #[rustc_intrinsic ] |
2052 | #[rustc_nounwind ] |
2053 | pub unsafe fn logf16(x: f16) -> f16; |
2054 | /// Returns the natural logarithm of an `f32`. |
2055 | /// |
2056 | /// The stabilized version of this intrinsic is |
2057 | /// [`f32::ln`](../../std/primitive.f32.html#method.ln) |
2058 | #[rustc_intrinsic ] |
2059 | #[rustc_nounwind ] |
2060 | pub unsafe fn logf32(x: f32) -> f32; |
2061 | /// Returns the natural logarithm of an `f64`. |
2062 | /// |
2063 | /// The stabilized version of this intrinsic is |
2064 | /// [`f64::ln`](../../std/primitive.f64.html#method.ln) |
2065 | #[rustc_intrinsic ] |
2066 | #[rustc_nounwind ] |
2067 | pub unsafe fn logf64(x: f64) -> f64; |
2068 | /// Returns the natural logarithm of an `f128`. |
2069 | /// |
2070 | /// The stabilized version of this intrinsic is |
2071 | /// [`f128::ln`](../../std/primitive.f128.html#method.ln) |
2072 | #[rustc_intrinsic ] |
2073 | #[rustc_nounwind ] |
2074 | pub unsafe fn logf128(x: f128) -> f128; |
2075 | |
2076 | /// Returns the base 10 logarithm of an `f16`. |
2077 | /// |
2078 | /// The stabilized version of this intrinsic is |
2079 | /// [`f16::log10`](../../std/primitive.f16.html#method.log10) |
2080 | #[rustc_intrinsic ] |
2081 | #[rustc_nounwind ] |
2082 | pub unsafe fn log10f16(x: f16) -> f16; |
2083 | /// Returns the base 10 logarithm of an `f32`. |
2084 | /// |
2085 | /// The stabilized version of this intrinsic is |
2086 | /// [`f32::log10`](../../std/primitive.f32.html#method.log10) |
2087 | #[rustc_intrinsic ] |
2088 | #[rustc_nounwind ] |
2089 | pub unsafe fn log10f32(x: f32) -> f32; |
2090 | /// Returns the base 10 logarithm of an `f64`. |
2091 | /// |
2092 | /// The stabilized version of this intrinsic is |
2093 | /// [`f64::log10`](../../std/primitive.f64.html#method.log10) |
2094 | #[rustc_intrinsic ] |
2095 | #[rustc_nounwind ] |
2096 | pub unsafe fn log10f64(x: f64) -> f64; |
2097 | /// Returns the base 10 logarithm of an `f128`. |
2098 | /// |
2099 | /// The stabilized version of this intrinsic is |
2100 | /// [`f128::log10`](../../std/primitive.f128.html#method.log10) |
2101 | #[rustc_intrinsic ] |
2102 | #[rustc_nounwind ] |
2103 | pub unsafe fn log10f128(x: f128) -> f128; |
2104 | |
2105 | /// Returns the base 2 logarithm of an `f16`. |
2106 | /// |
2107 | /// The stabilized version of this intrinsic is |
2108 | /// [`f16::log2`](../../std/primitive.f16.html#method.log2) |
2109 | #[rustc_intrinsic ] |
2110 | #[rustc_nounwind ] |
2111 | pub unsafe fn log2f16(x: f16) -> f16; |
2112 | /// Returns the base 2 logarithm of an `f32`. |
2113 | /// |
2114 | /// The stabilized version of this intrinsic is |
2115 | /// [`f32::log2`](../../std/primitive.f32.html#method.log2) |
2116 | #[rustc_intrinsic ] |
2117 | #[rustc_nounwind ] |
2118 | pub unsafe fn log2f32(x: f32) -> f32; |
2119 | /// Returns the base 2 logarithm of an `f64`. |
2120 | /// |
2121 | /// The stabilized version of this intrinsic is |
2122 | /// [`f64::log2`](../../std/primitive.f64.html#method.log2) |
2123 | #[rustc_intrinsic ] |
2124 | #[rustc_nounwind ] |
2125 | pub unsafe fn log2f64(x: f64) -> f64; |
2126 | /// Returns the base 2 logarithm of an `f128`. |
2127 | /// |
2128 | /// The stabilized version of this intrinsic is |
2129 | /// [`f128::log2`](../../std/primitive.f128.html#method.log2) |
2130 | #[rustc_intrinsic ] |
2131 | #[rustc_nounwind ] |
2132 | pub unsafe fn log2f128(x: f128) -> f128; |
2133 | |
2134 | /// Returns `a * b + c` for `f16` values. |
2135 | /// |
2136 | /// The stabilized version of this intrinsic is |
2137 | /// [`f16::mul_add`](../../std/primitive.f16.html#method.mul_add) |
2138 | #[rustc_intrinsic ] |
2139 | #[rustc_nounwind ] |
2140 | pub unsafe fn fmaf16(a: f16, b: f16, c: f16) -> f16; |
2141 | /// Returns `a * b + c` for `f32` values. |
2142 | /// |
2143 | /// The stabilized version of this intrinsic is |
2144 | /// [`f32::mul_add`](../../std/primitive.f32.html#method.mul_add) |
2145 | #[rustc_intrinsic ] |
2146 | #[rustc_nounwind ] |
2147 | pub unsafe fn fmaf32(a: f32, b: f32, c: f32) -> f32; |
2148 | /// Returns `a * b + c` for `f64` values. |
2149 | /// |
2150 | /// The stabilized version of this intrinsic is |
2151 | /// [`f64::mul_add`](../../std/primitive.f64.html#method.mul_add) |
2152 | #[rustc_intrinsic ] |
2153 | #[rustc_nounwind ] |
2154 | pub unsafe fn fmaf64(a: f64, b: f64, c: f64) -> f64; |
2155 | /// Returns `a * b + c` for `f128` values. |
2156 | /// |
2157 | /// The stabilized version of this intrinsic is |
2158 | /// [`f128::mul_add`](../../std/primitive.f128.html#method.mul_add) |
2159 | #[rustc_intrinsic ] |
2160 | #[rustc_nounwind ] |
2161 | pub unsafe fn fmaf128(a: f128, b: f128, c: f128) -> f128; |
2162 | |
2163 | /// Returns `a * b + c` for `f16` values, non-deterministically executing |
2164 | /// either a fused multiply-add or two operations with rounding of the |
2165 | /// intermediate result. |
2166 | /// |
2167 | /// The operation is fused if the code generator determines that target |
2168 | /// instruction set has support for a fused operation, and that the fused |
2169 | /// operation is more efficient than the equivalent, separate pair of mul |
2170 | /// and add instructions. It is unspecified whether or not a fused operation |
2171 | /// is selected, and that may depend on optimization level and context, for |
2172 | /// example. |
2173 | #[rustc_intrinsic ] |
2174 | #[rustc_nounwind ] |
2175 | pub unsafe fn fmuladdf16(a: f16, b: f16, c: f16) -> f16; |
2176 | /// Returns `a * b + c` for `f32` values, non-deterministically executing |
2177 | /// either a fused multiply-add or two operations with rounding of the |
2178 | /// intermediate result. |
2179 | /// |
2180 | /// The operation is fused if the code generator determines that target |
2181 | /// instruction set has support for a fused operation, and that the fused |
2182 | /// operation is more efficient than the equivalent, separate pair of mul |
2183 | /// and add instructions. It is unspecified whether or not a fused operation |
2184 | /// is selected, and that may depend on optimization level and context, for |
2185 | /// example. |
2186 | #[rustc_intrinsic ] |
2187 | #[rustc_nounwind ] |
2188 | pub unsafe fn fmuladdf32(a: f32, b: f32, c: f32) -> f32; |
2189 | /// Returns `a * b + c` for `f64` values, non-deterministically executing |
2190 | /// either a fused multiply-add or two operations with rounding of the |
2191 | /// intermediate result. |
2192 | /// |
2193 | /// The operation is fused if the code generator determines that target |
2194 | /// instruction set has support for a fused operation, and that the fused |
2195 | /// operation is more efficient than the equivalent, separate pair of mul |
2196 | /// and add instructions. It is unspecified whether or not a fused operation |
2197 | /// is selected, and that may depend on optimization level and context, for |
2198 | /// example. |
2199 | #[rustc_intrinsic ] |
2200 | #[rustc_nounwind ] |
2201 | pub unsafe fn fmuladdf64(a: f64, b: f64, c: f64) -> f64; |
2202 | /// Returns `a * b + c` for `f128` values, non-deterministically executing |
2203 | /// either a fused multiply-add or two operations with rounding of the |
2204 | /// intermediate result. |
2205 | /// |
2206 | /// The operation is fused if the code generator determines that target |
2207 | /// instruction set has support for a fused operation, and that the fused |
2208 | /// operation is more efficient than the equivalent, separate pair of mul |
2209 | /// and add instructions. It is unspecified whether or not a fused operation |
2210 | /// is selected, and that may depend on optimization level and context, for |
2211 | /// example. |
2212 | #[rustc_intrinsic ] |
2213 | #[rustc_nounwind ] |
2214 | pub unsafe fn fmuladdf128(a: f128, b: f128, c: f128) -> f128; |
2215 | |
2216 | /// Returns the largest integer less than or equal to an `f16`. |
2217 | /// |
2218 | /// The stabilized version of this intrinsic is |
2219 | /// [`f16::floor`](../../std/primitive.f16.html#method.floor) |
2220 | #[rustc_intrinsic ] |
2221 | #[rustc_nounwind ] |
2222 | pub unsafe fn floorf16(x: f16) -> f16; |
2223 | /// Returns the largest integer less than or equal to an `f32`. |
2224 | /// |
2225 | /// The stabilized version of this intrinsic is |
2226 | /// [`f32::floor`](../../std/primitive.f32.html#method.floor) |
2227 | #[rustc_intrinsic ] |
2228 | #[rustc_nounwind ] |
2229 | pub unsafe fn floorf32(x: f32) -> f32; |
2230 | /// Returns the largest integer less than or equal to an `f64`. |
2231 | /// |
2232 | /// The stabilized version of this intrinsic is |
2233 | /// [`f64::floor`](../../std/primitive.f64.html#method.floor) |
2234 | #[rustc_intrinsic ] |
2235 | #[rustc_nounwind ] |
2236 | pub unsafe fn floorf64(x: f64) -> f64; |
2237 | /// Returns the largest integer less than or equal to an `f128`. |
2238 | /// |
2239 | /// The stabilized version of this intrinsic is |
2240 | /// [`f128::floor`](../../std/primitive.f128.html#method.floor) |
2241 | #[rustc_intrinsic ] |
2242 | #[rustc_nounwind ] |
2243 | pub unsafe fn floorf128(x: f128) -> f128; |
2244 | |
2245 | /// Returns the smallest integer greater than or equal to an `f16`. |
2246 | /// |
2247 | /// The stabilized version of this intrinsic is |
2248 | /// [`f16::ceil`](../../std/primitive.f16.html#method.ceil) |
2249 | #[rustc_intrinsic ] |
2250 | #[rustc_nounwind ] |
2251 | pub unsafe fn ceilf16(x: f16) -> f16; |
2252 | /// Returns the smallest integer greater than or equal to an `f32`. |
2253 | /// |
2254 | /// The stabilized version of this intrinsic is |
2255 | /// [`f32::ceil`](../../std/primitive.f32.html#method.ceil) |
2256 | #[rustc_intrinsic ] |
2257 | #[rustc_nounwind ] |
2258 | pub unsafe fn ceilf32(x: f32) -> f32; |
2259 | /// Returns the smallest integer greater than or equal to an `f64`. |
2260 | /// |
2261 | /// The stabilized version of this intrinsic is |
2262 | /// [`f64::ceil`](../../std/primitive.f64.html#method.ceil) |
2263 | #[rustc_intrinsic ] |
2264 | #[rustc_nounwind ] |
2265 | pub unsafe fn ceilf64(x: f64) -> f64; |
2266 | /// Returns the smallest integer greater than or equal to an `f128`. |
2267 | /// |
2268 | /// The stabilized version of this intrinsic is |
2269 | /// [`f128::ceil`](../../std/primitive.f128.html#method.ceil) |
2270 | #[rustc_intrinsic ] |
2271 | #[rustc_nounwind ] |
2272 | pub unsafe fn ceilf128(x: f128) -> f128; |
2273 | |
2274 | /// Returns the integer part of an `f16`. |
2275 | /// |
2276 | /// The stabilized version of this intrinsic is |
2277 | /// [`f16::trunc`](../../std/primitive.f16.html#method.trunc) |
2278 | #[rustc_intrinsic ] |
2279 | #[rustc_nounwind ] |
2280 | pub unsafe fn truncf16(x: f16) -> f16; |
2281 | /// Returns the integer part of an `f32`. |
2282 | /// |
2283 | /// The stabilized version of this intrinsic is |
2284 | /// [`f32::trunc`](../../std/primitive.f32.html#method.trunc) |
2285 | #[rustc_intrinsic ] |
2286 | #[rustc_nounwind ] |
2287 | pub unsafe fn truncf32(x: f32) -> f32; |
2288 | /// Returns the integer part of an `f64`. |
2289 | /// |
2290 | /// The stabilized version of this intrinsic is |
2291 | /// [`f64::trunc`](../../std/primitive.f64.html#method.trunc) |
2292 | #[rustc_intrinsic ] |
2293 | #[rustc_nounwind ] |
2294 | pub unsafe fn truncf64(x: f64) -> f64; |
2295 | /// Returns the integer part of an `f128`. |
2296 | /// |
2297 | /// The stabilized version of this intrinsic is |
2298 | /// [`f128::trunc`](../../std/primitive.f128.html#method.trunc) |
2299 | #[rustc_intrinsic ] |
2300 | #[rustc_nounwind ] |
2301 | pub unsafe fn truncf128(x: f128) -> f128; |
2302 | |
2303 | /// Returns the nearest integer to an `f16`. Rounds half-way cases to the number with an even |
2304 | /// least significant digit. |
2305 | /// |
2306 | /// The stabilized version of this intrinsic is |
2307 | /// [`f16::round_ties_even`](../../std/primitive.f16.html#method.round_ties_even) |
2308 | #[rustc_intrinsic ] |
2309 | #[rustc_nounwind ] |
2310 | #[cfg (not(bootstrap))] |
2311 | pub fn round_ties_even_f16(x: f16) -> f16; |
2312 | |
2313 | /// To be removed on next bootstrap bump. |
2314 | #[cfg (bootstrap)] |
2315 | pub fn round_ties_even_f16(x: f16) -> f16 { |
2316 | #[rustc_intrinsic ] |
2317 | #[rustc_nounwind ] |
2318 | unsafe fn rintf16(x: f16) -> f16; |
2319 | |
2320 | // SAFETY: this intrinsic isn't actually unsafe |
2321 | unsafe { rintf16(x) } |
2322 | } |
2323 | |
2324 | /// Returns the nearest integer to an `f32`. Rounds half-way cases to the number with an even |
2325 | /// least significant digit. |
2326 | /// |
2327 | /// The stabilized version of this intrinsic is |
2328 | /// [`f32::round_ties_even`](../../std/primitive.f32.html#method.round_ties_even) |
2329 | #[rustc_intrinsic ] |
2330 | #[rustc_nounwind ] |
2331 | #[cfg (not(bootstrap))] |
2332 | pub fn round_ties_even_f32(x: f32) -> f32; |
2333 | |
2334 | /// To be removed on next bootstrap bump. |
2335 | #[cfg (bootstrap)] |
2336 | pub fn round_ties_even_f32(x: f32) -> f32 { |
2337 | #[rustc_intrinsic ] |
2338 | #[rustc_nounwind ] |
2339 | unsafe fn rintf32(x: f32) -> f32; |
2340 | |
2341 | // SAFETY: this intrinsic isn't actually unsafe |
2342 | unsafe { rintf32(x) } |
2343 | } |
2344 | |
2345 | /// Provided for compatibility with stdarch. DO NOT USE. |
2346 | #[inline (always)] |
2347 | pub unsafe fn rintf32(x: f32) -> f32 { |
2348 | round_ties_even_f32(x) |
2349 | } |
2350 | |
2351 | /// Returns the nearest integer to an `f64`. Rounds half-way cases to the number with an even |
2352 | /// least significant digit. |
2353 | /// |
2354 | /// The stabilized version of this intrinsic is |
2355 | /// [`f64::round_ties_even`](../../std/primitive.f64.html#method.round_ties_even) |
2356 | #[rustc_intrinsic ] |
2357 | #[rustc_nounwind ] |
2358 | #[cfg (not(bootstrap))] |
2359 | pub fn round_ties_even_f64(x: f64) -> f64; |
2360 | |
2361 | /// To be removed on next bootstrap bump. |
2362 | #[cfg (bootstrap)] |
2363 | pub fn round_ties_even_f64(x: f64) -> f64 { |
2364 | #[rustc_intrinsic ] |
2365 | #[rustc_nounwind ] |
2366 | unsafe fn rintf64(x: f64) -> f64; |
2367 | |
2368 | // SAFETY: this intrinsic isn't actually unsafe |
2369 | unsafe { rintf64(x) } |
2370 | } |
2371 | |
2372 | /// Provided for compatibility with stdarch. DO NOT USE. |
2373 | #[inline (always)] |
2374 | pub unsafe fn rintf64(x: f64) -> f64 { |
2375 | round_ties_even_f64(x) |
2376 | } |
2377 | |
2378 | /// Returns the nearest integer to an `f128`. Rounds half-way cases to the number with an even |
2379 | /// least significant digit. |
2380 | /// |
2381 | /// The stabilized version of this intrinsic is |
2382 | /// [`f128::round_ties_even`](../../std/primitive.f128.html#method.round_ties_even) |
2383 | #[rustc_intrinsic ] |
2384 | #[rustc_nounwind ] |
2385 | #[cfg (not(bootstrap))] |
2386 | pub fn round_ties_even_f128(x: f128) -> f128; |
2387 | |
2388 | /// To be removed on next bootstrap bump. |
2389 | #[cfg (bootstrap)] |
2390 | pub fn round_ties_even_f128(x: f128) -> f128 { |
2391 | #[rustc_intrinsic ] |
2392 | #[rustc_nounwind ] |
2393 | unsafe fn rintf128(x: f128) -> f128; |
2394 | |
2395 | // SAFETY: this intrinsic isn't actually unsafe |
2396 | unsafe { rintf128(x) } |
2397 | } |
2398 | |
2399 | /// Returns the nearest integer to an `f16`. Rounds half-way cases away from zero. |
2400 | /// |
2401 | /// The stabilized version of this intrinsic is |
2402 | /// [`f16::round`](../../std/primitive.f16.html#method.round) |
2403 | #[rustc_intrinsic ] |
2404 | #[rustc_nounwind ] |
2405 | pub unsafe fn roundf16(x: f16) -> f16; |
2406 | /// Returns the nearest integer to an `f32`. Rounds half-way cases away from zero. |
2407 | /// |
2408 | /// The stabilized version of this intrinsic is |
2409 | /// [`f32::round`](../../std/primitive.f32.html#method.round) |
2410 | #[rustc_intrinsic ] |
2411 | #[rustc_nounwind ] |
2412 | pub unsafe fn roundf32(x: f32) -> f32; |
2413 | /// Returns the nearest integer to an `f64`. Rounds half-way cases away from zero. |
2414 | /// |
2415 | /// The stabilized version of this intrinsic is |
2416 | /// [`f64::round`](../../std/primitive.f64.html#method.round) |
2417 | #[rustc_intrinsic ] |
2418 | #[rustc_nounwind ] |
2419 | pub unsafe fn roundf64(x: f64) -> f64; |
2420 | /// Returns the nearest integer to an `f128`. Rounds half-way cases away from zero. |
2421 | /// |
2422 | /// The stabilized version of this intrinsic is |
2423 | /// [`f128::round`](../../std/primitive.f128.html#method.round) |
2424 | #[rustc_intrinsic ] |
2425 | #[rustc_nounwind ] |
2426 | pub unsafe fn roundf128(x: f128) -> f128; |
2427 | |
2428 | /// Float addition that allows optimizations based on algebraic rules. |
2429 | /// May assume inputs are finite. |
2430 | /// |
2431 | /// This intrinsic does not have a stable counterpart. |
2432 | #[rustc_intrinsic ] |
2433 | #[rustc_nounwind ] |
2434 | pub unsafe fn fadd_fast<T: Copy>(a: T, b: T) -> T; |
2435 | |
2436 | /// Float subtraction that allows optimizations based on algebraic rules. |
2437 | /// May assume inputs are finite. |
2438 | /// |
2439 | /// This intrinsic does not have a stable counterpart. |
2440 | #[rustc_intrinsic ] |
2441 | #[rustc_nounwind ] |
2442 | pub unsafe fn fsub_fast<T: Copy>(a: T, b: T) -> T; |
2443 | |
2444 | /// Float multiplication that allows optimizations based on algebraic rules. |
2445 | /// May assume inputs are finite. |
2446 | /// |
2447 | /// This intrinsic does not have a stable counterpart. |
2448 | #[rustc_intrinsic ] |
2449 | #[rustc_nounwind ] |
2450 | pub unsafe fn fmul_fast<T: Copy>(a: T, b: T) -> T; |
2451 | |
2452 | /// Float division that allows optimizations based on algebraic rules. |
2453 | /// May assume inputs are finite. |
2454 | /// |
2455 | /// This intrinsic does not have a stable counterpart. |
2456 | #[rustc_intrinsic ] |
2457 | #[rustc_nounwind ] |
2458 | pub unsafe fn fdiv_fast<T: Copy>(a: T, b: T) -> T; |
2459 | |
2460 | /// Float remainder that allows optimizations based on algebraic rules. |
2461 | /// May assume inputs are finite. |
2462 | /// |
2463 | /// This intrinsic does not have a stable counterpart. |
2464 | #[rustc_intrinsic ] |
2465 | #[rustc_nounwind ] |
2466 | pub unsafe fn frem_fast<T: Copy>(a: T, b: T) -> T; |
2467 | |
2468 | /// Converts with LLVM’s fptoui/fptosi, which may return undef for values out of range |
2469 | /// (<https://github.com/rust-lang/rust/issues/10184>) |
2470 | /// |
2471 | /// Stabilized as [`f32::to_int_unchecked`] and [`f64::to_int_unchecked`]. |
2472 | #[rustc_intrinsic ] |
2473 | #[rustc_nounwind ] |
2474 | pub unsafe fn float_to_int_unchecked<Float: Copy, Int: Copy>(value: Float) -> Int; |
2475 | |
2476 | /// Float addition that allows optimizations based on algebraic rules. |
2477 | /// |
2478 | /// This intrinsic does not have a stable counterpart. |
2479 | #[rustc_nounwind ] |
2480 | #[rustc_intrinsic ] |
2481 | pub fn fadd_algebraic<T: Copy>(a: T, b: T) -> T; |
2482 | |
2483 | /// Float subtraction that allows optimizations based on algebraic rules. |
2484 | /// |
2485 | /// This intrinsic does not have a stable counterpart. |
2486 | #[rustc_nounwind ] |
2487 | #[rustc_intrinsic ] |
2488 | pub fn fsub_algebraic<T: Copy>(a: T, b: T) -> T; |
2489 | |
2490 | /// Float multiplication that allows optimizations based on algebraic rules. |
2491 | /// |
2492 | /// This intrinsic does not have a stable counterpart. |
2493 | #[rustc_nounwind ] |
2494 | #[rustc_intrinsic ] |
2495 | pub fn fmul_algebraic<T: Copy>(a: T, b: T) -> T; |
2496 | |
2497 | /// Float division that allows optimizations based on algebraic rules. |
2498 | /// |
2499 | /// This intrinsic does not have a stable counterpart. |
2500 | #[rustc_nounwind ] |
2501 | #[rustc_intrinsic ] |
2502 | pub fn fdiv_algebraic<T: Copy>(a: T, b: T) -> T; |
2503 | |
2504 | /// Float remainder that allows optimizations based on algebraic rules. |
2505 | /// |
2506 | /// This intrinsic does not have a stable counterpart. |
2507 | #[rustc_nounwind ] |
2508 | #[rustc_intrinsic ] |
2509 | pub fn frem_algebraic<T: Copy>(a: T, b: T) -> T; |
2510 | |
2511 | /// Returns the number of bits set in an integer type `T` |
2512 | /// |
2513 | /// Note that, unlike most intrinsics, this is safe to call; |
2514 | /// it does not require an `unsafe` block. |
2515 | /// Therefore, implementations must not require the user to uphold |
2516 | /// any safety invariants. |
2517 | /// |
2518 | /// The stabilized versions of this intrinsic are available on the integer |
2519 | /// primitives via the `count_ones` method. For example, |
2520 | /// [`u32::count_ones`] |
2521 | #[rustc_intrinsic_const_stable_indirect] |
2522 | #[rustc_nounwind ] |
2523 | #[rustc_intrinsic ] |
2524 | pub const fn ctpop<T: Copy>(x: T) -> u32; |
2525 | |
2526 | /// Returns the number of leading unset bits (zeroes) in an integer type `T`. |
2527 | /// |
2528 | /// Note that, unlike most intrinsics, this is safe to call; |
2529 | /// it does not require an `unsafe` block. |
2530 | /// Therefore, implementations must not require the user to uphold |
2531 | /// any safety invariants. |
2532 | /// |
2533 | /// The stabilized versions of this intrinsic are available on the integer |
2534 | /// primitives via the `leading_zeros` method. For example, |
2535 | /// [`u32::leading_zeros`] |
2536 | /// |
2537 | /// # Examples |
2538 | /// |
2539 | /// ``` |
2540 | /// #![feature(core_intrinsics)] |
2541 | /// # #![allow(internal_features)] |
2542 | /// |
2543 | /// use std::intrinsics::ctlz; |
2544 | /// |
2545 | /// let x = 0b0001_1100_u8; |
2546 | /// let num_leading = ctlz(x); |
2547 | /// assert_eq!(num_leading, 3); |
2548 | /// ``` |
2549 | /// |
2550 | /// An `x` with value `0` will return the bit width of `T`. |
2551 | /// |
2552 | /// ``` |
2553 | /// #![feature(core_intrinsics)] |
2554 | /// # #![allow(internal_features)] |
2555 | /// |
2556 | /// use std::intrinsics::ctlz; |
2557 | /// |
2558 | /// let x = 0u16; |
2559 | /// let num_leading = ctlz(x); |
2560 | /// assert_eq!(num_leading, 16); |
2561 | /// ``` |
2562 | #[rustc_intrinsic_const_stable_indirect] |
2563 | #[rustc_nounwind ] |
2564 | #[rustc_intrinsic ] |
2565 | pub const fn ctlz<T: Copy>(x: T) -> u32; |
2566 | |
2567 | /// Like `ctlz`, but extra-unsafe as it returns `undef` when |
2568 | /// given an `x` with value `0`. |
2569 | /// |
2570 | /// This intrinsic does not have a stable counterpart. |
2571 | /// |
2572 | /// # Examples |
2573 | /// |
2574 | /// ``` |
2575 | /// #![feature(core_intrinsics)] |
2576 | /// # #![allow(internal_features)] |
2577 | /// |
2578 | /// use std::intrinsics::ctlz_nonzero; |
2579 | /// |
2580 | /// let x = 0b0001_1100_u8; |
2581 | /// let num_leading = unsafe { ctlz_nonzero(x) }; |
2582 | /// assert_eq!(num_leading, 3); |
2583 | /// ``` |
2584 | #[rustc_intrinsic_const_stable_indirect] |
2585 | #[rustc_nounwind ] |
2586 | #[rustc_intrinsic ] |
2587 | pub const unsafe fn ctlz_nonzero<T: Copy>(x: T) -> u32; |
2588 | |
2589 | /// Returns the number of trailing unset bits (zeroes) in an integer type `T`. |
2590 | /// |
2591 | /// Note that, unlike most intrinsics, this is safe to call; |
2592 | /// it does not require an `unsafe` block. |
2593 | /// Therefore, implementations must not require the user to uphold |
2594 | /// any safety invariants. |
2595 | /// |
2596 | /// The stabilized versions of this intrinsic are available on the integer |
2597 | /// primitives via the `trailing_zeros` method. For example, |
2598 | /// [`u32::trailing_zeros`] |
2599 | /// |
2600 | /// # Examples |
2601 | /// |
2602 | /// ``` |
2603 | /// #![feature(core_intrinsics)] |
2604 | /// # #![allow(internal_features)] |
2605 | /// |
2606 | /// use std::intrinsics::cttz; |
2607 | /// |
2608 | /// let x = 0b0011_1000_u8; |
2609 | /// let num_trailing = cttz(x); |
2610 | /// assert_eq!(num_trailing, 3); |
2611 | /// ``` |
2612 | /// |
2613 | /// An `x` with value `0` will return the bit width of `T`: |
2614 | /// |
2615 | /// ``` |
2616 | /// #![feature(core_intrinsics)] |
2617 | /// # #![allow(internal_features)] |
2618 | /// |
2619 | /// use std::intrinsics::cttz; |
2620 | /// |
2621 | /// let x = 0u16; |
2622 | /// let num_trailing = cttz(x); |
2623 | /// assert_eq!(num_trailing, 16); |
2624 | /// ``` |
2625 | #[rustc_intrinsic_const_stable_indirect] |
2626 | #[rustc_nounwind ] |
2627 | #[rustc_intrinsic ] |
2628 | pub const fn cttz<T: Copy>(x: T) -> u32; |
2629 | |
2630 | /// Like `cttz`, but extra-unsafe as it returns `undef` when |
2631 | /// given an `x` with value `0`. |
2632 | /// |
2633 | /// This intrinsic does not have a stable counterpart. |
2634 | /// |
2635 | /// # Examples |
2636 | /// |
2637 | /// ``` |
2638 | /// #![feature(core_intrinsics)] |
2639 | /// # #![allow(internal_features)] |
2640 | /// |
2641 | /// use std::intrinsics::cttz_nonzero; |
2642 | /// |
2643 | /// let x = 0b0011_1000_u8; |
2644 | /// let num_trailing = unsafe { cttz_nonzero(x) }; |
2645 | /// assert_eq!(num_trailing, 3); |
2646 | /// ``` |
2647 | #[rustc_intrinsic_const_stable_indirect] |
2648 | #[rustc_nounwind ] |
2649 | #[rustc_intrinsic ] |
2650 | pub const unsafe fn cttz_nonzero<T: Copy>(x: T) -> u32; |
2651 | |
2652 | /// Reverses the bytes in an integer type `T`. |
2653 | /// |
2654 | /// Note that, unlike most intrinsics, this is safe to call; |
2655 | /// it does not require an `unsafe` block. |
2656 | /// Therefore, implementations must not require the user to uphold |
2657 | /// any safety invariants. |
2658 | /// |
2659 | /// The stabilized versions of this intrinsic are available on the integer |
2660 | /// primitives via the `swap_bytes` method. For example, |
2661 | /// [`u32::swap_bytes`] |
2662 | #[rustc_intrinsic_const_stable_indirect] |
2663 | #[rustc_nounwind ] |
2664 | #[rustc_intrinsic ] |
2665 | pub const fn bswap<T: Copy>(x: T) -> T; |
2666 | |
2667 | /// Reverses the bits in an integer type `T`. |
2668 | /// |
2669 | /// Note that, unlike most intrinsics, this is safe to call; |
2670 | /// it does not require an `unsafe` block. |
2671 | /// Therefore, implementations must not require the user to uphold |
2672 | /// any safety invariants. |
2673 | /// |
2674 | /// The stabilized versions of this intrinsic are available on the integer |
2675 | /// primitives via the `reverse_bits` method. For example, |
2676 | /// [`u32::reverse_bits`] |
2677 | #[rustc_intrinsic_const_stable_indirect] |
2678 | #[rustc_nounwind ] |
2679 | #[rustc_intrinsic ] |
2680 | pub const fn bitreverse<T: Copy>(x: T) -> T; |
2681 | |
2682 | /// Does a three-way comparison between the two integer arguments. |
2683 | /// |
2684 | /// This is included as an intrinsic as it's useful to let it be one thing |
2685 | /// in MIR, rather than the multiple checks and switches that make its IR |
2686 | /// large and difficult to optimize. |
2687 | /// |
2688 | /// The stabilized version of this intrinsic is [`Ord::cmp`]. |
2689 | #[rustc_intrinsic ] |
2690 | pub const fn three_way_compare<T: Copy>(lhs: T, rhss: T) -> crate::cmp::Ordering; |
2691 | |
2692 | /// Combine two values which have no bits in common. |
2693 | /// |
2694 | /// This allows the backend to implement it as `a + b` *or* `a | b`, |
2695 | /// depending which is easier to implement on a specific target. |
2696 | /// |
2697 | /// # Safety |
2698 | /// |
2699 | /// Requires that `(a & b) == 0`, or equivalently that `(a | b) == (a + b)`. |
2700 | /// |
2701 | /// Otherwise it's immediate UB. |
2702 | #[rustc_const_unstable (feature = "disjoint_bitor" , issue = "135758" )] |
2703 | #[rustc_nounwind ] |
2704 | #[rustc_intrinsic ] |
2705 | #[cfg_attr (miri, track_caller)] // even without panics, this helps for Miri backtraces |
2706 | #[miri::intrinsic_fallback_is_spec] // the fallbacks all `assume` to tell Miri |
2707 | pub const unsafe fn disjoint_bitor<T: ~const fallback::DisjointBitOr>(a: T, b: T) -> T { |
2708 | // SAFETY: same preconditions as this function. |
2709 | unsafe { fallback::DisjointBitOr::disjoint_bitor(self:a, other:b) } |
2710 | } |
2711 | |
2712 | /// Performs checked integer addition. |
2713 | /// |
2714 | /// Note that, unlike most intrinsics, this is safe to call; |
2715 | /// it does not require an `unsafe` block. |
2716 | /// Therefore, implementations must not require the user to uphold |
2717 | /// any safety invariants. |
2718 | /// |
2719 | /// The stabilized versions of this intrinsic are available on the integer |
2720 | /// primitives via the `overflowing_add` method. For example, |
2721 | /// [`u32::overflowing_add`] |
2722 | #[rustc_intrinsic_const_stable_indirect] |
2723 | #[rustc_nounwind ] |
2724 | #[rustc_intrinsic ] |
2725 | pub const fn add_with_overflow<T: Copy>(x: T, y: T) -> (T, bool); |
2726 | |
2727 | /// Performs checked integer subtraction |
2728 | /// |
2729 | /// Note that, unlike most intrinsics, this is safe to call; |
2730 | /// it does not require an `unsafe` block. |
2731 | /// Therefore, implementations must not require the user to uphold |
2732 | /// any safety invariants. |
2733 | /// |
2734 | /// The stabilized versions of this intrinsic are available on the integer |
2735 | /// primitives via the `overflowing_sub` method. For example, |
2736 | /// [`u32::overflowing_sub`] |
2737 | #[rustc_intrinsic_const_stable_indirect] |
2738 | #[rustc_nounwind ] |
2739 | #[rustc_intrinsic ] |
2740 | pub const fn sub_with_overflow<T: Copy>(x: T, y: T) -> (T, bool); |
2741 | |
2742 | /// Performs checked integer multiplication |
2743 | /// |
2744 | /// Note that, unlike most intrinsics, this is safe to call; |
2745 | /// it does not require an `unsafe` block. |
2746 | /// Therefore, implementations must not require the user to uphold |
2747 | /// any safety invariants. |
2748 | /// |
2749 | /// The stabilized versions of this intrinsic are available on the integer |
2750 | /// primitives via the `overflowing_mul` method. For example, |
2751 | /// [`u32::overflowing_mul`] |
2752 | #[rustc_intrinsic_const_stable_indirect] |
2753 | #[rustc_nounwind ] |
2754 | #[rustc_intrinsic ] |
2755 | pub const fn mul_with_overflow<T: Copy>(x: T, y: T) -> (T, bool); |
2756 | |
2757 | /// Performs full-width multiplication and addition with a carry: |
2758 | /// `multiplier * multiplicand + addend + carry`. |
2759 | /// |
2760 | /// This is possible without any overflow. For `uN`: |
2761 | /// MAX * MAX + MAX + MAX |
2762 | /// => (2ⁿ-1) × (2ⁿ-1) + (2ⁿ-1) + (2ⁿ-1) |
2763 | /// => (2²ⁿ - 2ⁿ⁺¹ + 1) + (2ⁿ⁺¹ - 2) |
2764 | /// => 2²ⁿ - 1 |
2765 | /// |
2766 | /// For `iN`, the upper bound is MIN * MIN + MAX + MAX => 2²ⁿ⁻² + 2ⁿ - 2, |
2767 | /// and the lower bound is MAX * MIN + MIN + MIN => -2²ⁿ⁻² - 2ⁿ + 2ⁿ⁺¹. |
2768 | /// |
2769 | /// This currently supports unsigned integers *only*, no signed ones. |
2770 | /// The stabilized versions of this intrinsic are available on integers. |
2771 | #[unstable (feature = "core_intrinsics" , issue = "none" )] |
2772 | #[rustc_const_unstable (feature = "const_carrying_mul_add" , issue = "85532" )] |
2773 | #[rustc_nounwind ] |
2774 | #[rustc_intrinsic ] |
2775 | #[miri::intrinsic_fallback_is_spec] |
2776 | pub const fn carrying_mul_add<T: ~const fallback::CarryingMulAdd<Unsigned = U>, U>( |
2777 | multiplier: T, |
2778 | multiplicand: T, |
2779 | addend: T, |
2780 | carry: T, |
2781 | ) -> (U, T) { |
2782 | multiplier.carrying_mul_add(multiplicand, addend, carry) |
2783 | } |
2784 | |
2785 | /// Performs an exact division, resulting in undefined behavior where |
2786 | /// `x % y != 0` or `y == 0` or `x == T::MIN && y == -1` |
2787 | /// |
2788 | /// This intrinsic does not have a stable counterpart. |
2789 | #[rustc_nounwind ] |
2790 | #[rustc_intrinsic ] |
2791 | pub const unsafe fn exact_div<T: Copy>(x: T, y: T) -> T; |
2792 | |
2793 | /// Performs an unchecked division, resulting in undefined behavior |
2794 | /// where `y == 0` or `x == T::MIN && y == -1` |
2795 | /// |
2796 | /// Safe wrappers for this intrinsic are available on the integer |
2797 | /// primitives via the `checked_div` method. For example, |
2798 | /// [`u32::checked_div`] |
2799 | #[rustc_intrinsic_const_stable_indirect] |
2800 | #[rustc_nounwind ] |
2801 | #[rustc_intrinsic ] |
2802 | pub const unsafe fn unchecked_div<T: Copy>(x: T, y: T) -> T; |
2803 | /// Returns the remainder of an unchecked division, resulting in |
2804 | /// undefined behavior when `y == 0` or `x == T::MIN && y == -1` |
2805 | /// |
2806 | /// Safe wrappers for this intrinsic are available on the integer |
2807 | /// primitives via the `checked_rem` method. For example, |
2808 | /// [`u32::checked_rem`] |
2809 | #[rustc_intrinsic_const_stable_indirect] |
2810 | #[rustc_nounwind ] |
2811 | #[rustc_intrinsic ] |
2812 | pub const unsafe fn unchecked_rem<T: Copy>(x: T, y: T) -> T; |
2813 | |
2814 | /// Performs an unchecked left shift, resulting in undefined behavior when |
2815 | /// `y < 0` or `y >= N`, where N is the width of T in bits. |
2816 | /// |
2817 | /// Safe wrappers for this intrinsic are available on the integer |
2818 | /// primitives via the `checked_shl` method. For example, |
2819 | /// [`u32::checked_shl`] |
2820 | #[rustc_intrinsic_const_stable_indirect] |
2821 | #[rustc_nounwind ] |
2822 | #[rustc_intrinsic ] |
2823 | pub const unsafe fn unchecked_shl<T: Copy, U: Copy>(x: T, y: U) -> T; |
2824 | /// Performs an unchecked right shift, resulting in undefined behavior when |
2825 | /// `y < 0` or `y >= N`, where N is the width of T in bits. |
2826 | /// |
2827 | /// Safe wrappers for this intrinsic are available on the integer |
2828 | /// primitives via the `checked_shr` method. For example, |
2829 | /// [`u32::checked_shr`] |
2830 | #[rustc_intrinsic_const_stable_indirect] |
2831 | #[rustc_nounwind ] |
2832 | #[rustc_intrinsic ] |
2833 | pub const unsafe fn unchecked_shr<T: Copy, U: Copy>(x: T, y: U) -> T; |
2834 | |
2835 | /// Returns the result of an unchecked addition, resulting in |
2836 | /// undefined behavior when `x + y > T::MAX` or `x + y < T::MIN`. |
2837 | /// |
2838 | /// The stable counterpart of this intrinsic is `unchecked_add` on the various |
2839 | /// integer types, such as [`u16::unchecked_add`] and [`i64::unchecked_add`]. |
2840 | #[rustc_intrinsic_const_stable_indirect] |
2841 | #[rustc_nounwind ] |
2842 | #[rustc_intrinsic ] |
2843 | pub const unsafe fn unchecked_add<T: Copy>(x: T, y: T) -> T; |
2844 | |
2845 | /// Returns the result of an unchecked subtraction, resulting in |
2846 | /// undefined behavior when `x - y > T::MAX` or `x - y < T::MIN`. |
2847 | /// |
2848 | /// The stable counterpart of this intrinsic is `unchecked_sub` on the various |
2849 | /// integer types, such as [`u16::unchecked_sub`] and [`i64::unchecked_sub`]. |
2850 | #[rustc_intrinsic_const_stable_indirect] |
2851 | #[rustc_nounwind ] |
2852 | #[rustc_intrinsic ] |
2853 | pub const unsafe fn unchecked_sub<T: Copy>(x: T, y: T) -> T; |
2854 | |
2855 | /// Returns the result of an unchecked multiplication, resulting in |
2856 | /// undefined behavior when `x * y > T::MAX` or `x * y < T::MIN`. |
2857 | /// |
2858 | /// The stable counterpart of this intrinsic is `unchecked_mul` on the various |
2859 | /// integer types, such as [`u16::unchecked_mul`] and [`i64::unchecked_mul`]. |
2860 | #[rustc_intrinsic_const_stable_indirect] |
2861 | #[rustc_nounwind ] |
2862 | #[rustc_intrinsic ] |
2863 | pub const unsafe fn unchecked_mul<T: Copy>(x: T, y: T) -> T; |
2864 | |
2865 | /// Performs rotate left. |
2866 | /// |
2867 | /// Note that, unlike most intrinsics, this is safe to call; |
2868 | /// it does not require an `unsafe` block. |
2869 | /// Therefore, implementations must not require the user to uphold |
2870 | /// any safety invariants. |
2871 | /// |
2872 | /// The stabilized versions of this intrinsic are available on the integer |
2873 | /// primitives via the `rotate_left` method. For example, |
2874 | /// [`u32::rotate_left`] |
2875 | #[rustc_intrinsic_const_stable_indirect] |
2876 | #[rustc_nounwind ] |
2877 | #[rustc_intrinsic ] |
2878 | pub const fn rotate_left<T: Copy>(x: T, shift: u32) -> T; |
2879 | |
2880 | /// Performs rotate right. |
2881 | /// |
2882 | /// Note that, unlike most intrinsics, this is safe to call; |
2883 | /// it does not require an `unsafe` block. |
2884 | /// Therefore, implementations must not require the user to uphold |
2885 | /// any safety invariants. |
2886 | /// |
2887 | /// The stabilized versions of this intrinsic are available on the integer |
2888 | /// primitives via the `rotate_right` method. For example, |
2889 | /// [`u32::rotate_right`] |
2890 | #[rustc_intrinsic_const_stable_indirect] |
2891 | #[rustc_nounwind ] |
2892 | #[rustc_intrinsic ] |
2893 | pub const fn rotate_right<T: Copy>(x: T, shift: u32) -> T; |
2894 | |
2895 | /// Returns (a + b) mod 2<sup>N</sup>, where N is the width of T in bits. |
2896 | /// |
2897 | /// Note that, unlike most intrinsics, this is safe to call; |
2898 | /// it does not require an `unsafe` block. |
2899 | /// Therefore, implementations must not require the user to uphold |
2900 | /// any safety invariants. |
2901 | /// |
2902 | /// The stabilized versions of this intrinsic are available on the integer |
2903 | /// primitives via the `wrapping_add` method. For example, |
2904 | /// [`u32::wrapping_add`] |
2905 | #[rustc_intrinsic_const_stable_indirect] |
2906 | #[rustc_nounwind ] |
2907 | #[rustc_intrinsic ] |
2908 | pub const fn wrapping_add<T: Copy>(a: T, b: T) -> T; |
2909 | /// Returns (a - b) mod 2<sup>N</sup>, where N is the width of T in bits. |
2910 | /// |
2911 | /// Note that, unlike most intrinsics, this is safe to call; |
2912 | /// it does not require an `unsafe` block. |
2913 | /// Therefore, implementations must not require the user to uphold |
2914 | /// any safety invariants. |
2915 | /// |
2916 | /// The stabilized versions of this intrinsic are available on the integer |
2917 | /// primitives via the `wrapping_sub` method. For example, |
2918 | /// [`u32::wrapping_sub`] |
2919 | #[rustc_intrinsic_const_stable_indirect] |
2920 | #[rustc_nounwind ] |
2921 | #[rustc_intrinsic ] |
2922 | pub const fn wrapping_sub<T: Copy>(a: T, b: T) -> T; |
2923 | /// Returns (a * b) mod 2<sup>N</sup>, where N is the width of T in bits. |
2924 | /// |
2925 | /// Note that, unlike most intrinsics, this is safe to call; |
2926 | /// it does not require an `unsafe` block. |
2927 | /// Therefore, implementations must not require the user to uphold |
2928 | /// any safety invariants. |
2929 | /// |
2930 | /// The stabilized versions of this intrinsic are available on the integer |
2931 | /// primitives via the `wrapping_mul` method. For example, |
2932 | /// [`u32::wrapping_mul`] |
2933 | #[rustc_intrinsic_const_stable_indirect] |
2934 | #[rustc_nounwind ] |
2935 | #[rustc_intrinsic ] |
2936 | pub const fn wrapping_mul<T: Copy>(a: T, b: T) -> T; |
2937 | |
2938 | /// Computes `a + b`, saturating at numeric bounds. |
2939 | /// |
2940 | /// Note that, unlike most intrinsics, this is safe to call; |
2941 | /// it does not require an `unsafe` block. |
2942 | /// Therefore, implementations must not require the user to uphold |
2943 | /// any safety invariants. |
2944 | /// |
2945 | /// The stabilized versions of this intrinsic are available on the integer |
2946 | /// primitives via the `saturating_add` method. For example, |
2947 | /// [`u32::saturating_add`] |
2948 | #[rustc_intrinsic_const_stable_indirect] |
2949 | #[rustc_nounwind ] |
2950 | #[rustc_intrinsic ] |
2951 | pub const fn saturating_add<T: Copy>(a: T, b: T) -> T; |
2952 | /// Computes `a - b`, saturating at numeric bounds. |
2953 | /// |
2954 | /// Note that, unlike most intrinsics, this is safe to call; |
2955 | /// it does not require an `unsafe` block. |
2956 | /// Therefore, implementations must not require the user to uphold |
2957 | /// any safety invariants. |
2958 | /// |
2959 | /// The stabilized versions of this intrinsic are available on the integer |
2960 | /// primitives via the `saturating_sub` method. For example, |
2961 | /// [`u32::saturating_sub`] |
2962 | #[rustc_intrinsic_const_stable_indirect] |
2963 | #[rustc_nounwind ] |
2964 | #[rustc_intrinsic ] |
2965 | pub const fn saturating_sub<T: Copy>(a: T, b: T) -> T; |
2966 | |
2967 | /// This is an implementation detail of [`crate::ptr::read`] and should |
2968 | /// not be used anywhere else. See its comments for why this exists. |
2969 | /// |
2970 | /// This intrinsic can *only* be called where the pointer is a local without |
2971 | /// projections (`read_via_copy(ptr)`, not `read_via_copy(*ptr)`) so that it |
2972 | /// trivially obeys runtime-MIR rules about derefs in operands. |
2973 | #[rustc_intrinsic_const_stable_indirect] |
2974 | #[rustc_nounwind ] |
2975 | #[rustc_intrinsic ] |
2976 | pub const unsafe fn read_via_copy<T>(ptr: *const T) -> T; |
2977 | |
2978 | /// This is an implementation detail of [`crate::ptr::write`] and should |
2979 | /// not be used anywhere else. See its comments for why this exists. |
2980 | /// |
2981 | /// This intrinsic can *only* be called where the pointer is a local without |
2982 | /// projections (`write_via_move(ptr, x)`, not `write_via_move(*ptr, x)`) so |
2983 | /// that it trivially obeys runtime-MIR rules about derefs in operands. |
2984 | #[rustc_intrinsic_const_stable_indirect] |
2985 | #[rustc_nounwind ] |
2986 | #[rustc_intrinsic ] |
2987 | pub const unsafe fn write_via_move<T>(ptr: *mut T, value: T); |
2988 | |
2989 | /// Returns the value of the discriminant for the variant in 'v'; |
2990 | /// if `T` has no discriminant, returns `0`. |
2991 | /// |
2992 | /// Note that, unlike most intrinsics, this is safe to call; |
2993 | /// it does not require an `unsafe` block. |
2994 | /// Therefore, implementations must not require the user to uphold |
2995 | /// any safety invariants. |
2996 | /// |
2997 | /// The stabilized version of this intrinsic is [`core::mem::discriminant`]. |
2998 | #[rustc_intrinsic_const_stable_indirect] |
2999 | #[rustc_nounwind ] |
3000 | #[rustc_intrinsic ] |
3001 | pub const fn discriminant_value<T>(v: &T) -> <T as DiscriminantKind>::Discriminant; |
3002 | |
3003 | /// Rust's "try catch" construct for unwinding. Invokes the function pointer `try_fn` with the |
3004 | /// data pointer `data`, and calls `catch_fn` if unwinding occurs while `try_fn` runs. |
3005 | /// Returns `1` if unwinding occurred and `catch_fn` was called; returns `0` otherwise. |
3006 | /// |
3007 | /// `catch_fn` must not unwind. |
3008 | /// |
3009 | /// The third argument is a function called if an unwind occurs (both Rust `panic` and foreign |
3010 | /// unwinds). This function takes the data pointer and a pointer to the target- and |
3011 | /// runtime-specific exception object that was caught. |
3012 | /// |
3013 | /// Note that in the case of a foreign unwinding operation, the exception object data may not be |
3014 | /// safely usable from Rust, and should not be directly exposed via the standard library. To |
3015 | /// prevent unsafe access, the library implementation may either abort the process or present an |
3016 | /// opaque error type to the user. |
3017 | /// |
3018 | /// For more information, see the compiler's source, as well as the documentation for the stable |
3019 | /// version of this intrinsic, `std::panic::catch_unwind`. |
3020 | #[rustc_intrinsic ] |
3021 | #[rustc_nounwind ] |
3022 | pub unsafe fn catch_unwind( |
3023 | _try_fn: fn(*mut u8), |
3024 | _data: *mut u8, |
3025 | _catch_fn: fn(*mut u8, *mut u8), |
3026 | ) -> i32; |
3027 | |
3028 | /// Emits a `nontemporal` store, which gives a hint to the CPU that the data should not be held |
3029 | /// in cache. Except for performance, this is fully equivalent to `ptr.write(val)`. |
3030 | /// |
3031 | /// Not all architectures provide such an operation. For instance, x86 does not: while `MOVNT` |
3032 | /// exists, that operation is *not* equivalent to `ptr.write(val)` (`MOVNT` writes can be reordered |
3033 | /// in ways that are not allowed for regular writes). |
3034 | #[rustc_intrinsic ] |
3035 | #[rustc_nounwind ] |
3036 | pub unsafe fn nontemporal_store<T>(ptr: *mut T, val: T); |
3037 | |
3038 | /// See documentation of `<*const T>::offset_from` for details. |
3039 | #[rustc_intrinsic_const_stable_indirect] |
3040 | #[rustc_nounwind ] |
3041 | #[rustc_intrinsic ] |
3042 | pub const unsafe fn ptr_offset_from<T>(ptr: *const T, base: *const T) -> isize; |
3043 | |
3044 | /// See documentation of `<*const T>::sub_ptr` for details. |
3045 | #[rustc_nounwind ] |
3046 | #[rustc_intrinsic ] |
3047 | #[rustc_intrinsic_const_stable_indirect] |
3048 | pub const unsafe fn ptr_offset_from_unsigned<T>(ptr: *const T, base: *const T) -> usize; |
3049 | |
3050 | /// See documentation of `<*const T>::guaranteed_eq` for details. |
3051 | /// Returns `2` if the result is unknown. |
3052 | /// Returns `1` if the pointers are guaranteed equal. |
3053 | /// Returns `0` if the pointers are guaranteed inequal. |
3054 | #[rustc_intrinsic ] |
3055 | #[rustc_nounwind ] |
3056 | #[rustc_do_not_const_check ] |
3057 | #[inline ] |
3058 | #[miri::intrinsic_fallback_is_spec] |
3059 | pub const fn ptr_guaranteed_cmp<T>(ptr: *const T, other: *const T) -> u8 { |
3060 | (ptr == other) as u8 |
3061 | } |
3062 | |
3063 | /// Determines whether the raw bytes of the two values are equal. |
3064 | /// |
3065 | /// This is particularly handy for arrays, since it allows things like just |
3066 | /// comparing `i96`s instead of forcing `alloca`s for `[6 x i16]`. |
3067 | /// |
3068 | /// Above some backend-decided threshold this will emit calls to `memcmp`, |
3069 | /// like slice equality does, instead of causing massive code size. |
3070 | /// |
3071 | /// Since this works by comparing the underlying bytes, the actual `T` is |
3072 | /// not particularly important. It will be used for its size and alignment, |
3073 | /// but any validity restrictions will be ignored, not enforced. |
3074 | /// |
3075 | /// # Safety |
3076 | /// |
3077 | /// It's UB to call this if any of the *bytes* in `*a` or `*b` are uninitialized. |
3078 | /// Note that this is a stricter criterion than just the *values* being |
3079 | /// fully-initialized: if `T` has padding, it's UB to call this intrinsic. |
3080 | /// |
3081 | /// At compile-time, it is furthermore UB to call this if any of the bytes |
3082 | /// in `*a` or `*b` have provenance. |
3083 | /// |
3084 | /// (The implementation is allowed to branch on the results of comparisons, |
3085 | /// which is UB if any of their inputs are `undef`.) |
3086 | #[rustc_nounwind ] |
3087 | #[rustc_intrinsic ] |
3088 | pub const unsafe fn raw_eq<T>(a: &T, b: &T) -> bool; |
3089 | |
3090 | /// Lexicographically compare `[left, left + bytes)` and `[right, right + bytes)` |
3091 | /// as unsigned bytes, returning negative if `left` is less, zero if all the |
3092 | /// bytes match, or positive if `left` is greater. |
3093 | /// |
3094 | /// This underlies things like `<[u8]>::cmp`, and will usually lower to `memcmp`. |
3095 | /// |
3096 | /// # Safety |
3097 | /// |
3098 | /// `left` and `right` must each be [valid] for reads of `bytes` bytes. |
3099 | /// |
3100 | /// Note that this applies to the whole range, not just until the first byte |
3101 | /// that differs. That allows optimizations that can read in large chunks. |
3102 | /// |
3103 | /// [valid]: crate::ptr#safety |
3104 | #[rustc_nounwind ] |
3105 | #[rustc_intrinsic ] |
3106 | pub const unsafe fn compare_bytes(left: *const u8, right: *const u8, bytes: usize) -> i32; |
3107 | |
3108 | /// See documentation of [`std::hint::black_box`] for details. |
3109 | /// |
3110 | /// [`std::hint::black_box`]: crate::hint::black_box |
3111 | #[rustc_nounwind ] |
3112 | #[rustc_intrinsic ] |
3113 | #[rustc_intrinsic_const_stable_indirect] |
3114 | pub const fn black_box<T>(dummy: T) -> T; |
3115 | |
3116 | /// Selects which function to call depending on the context. |
3117 | /// |
3118 | /// If this function is evaluated at compile-time, then a call to this |
3119 | /// intrinsic will be replaced with a call to `called_in_const`. It gets |
3120 | /// replaced with a call to `called_at_rt` otherwise. |
3121 | /// |
3122 | /// This function is safe to call, but note the stability concerns below. |
3123 | /// |
3124 | /// # Type Requirements |
3125 | /// |
3126 | /// The two functions must be both function items. They cannot be function |
3127 | /// pointers or closures. The first function must be a `const fn`. |
3128 | /// |
3129 | /// `arg` will be the tupled arguments that will be passed to either one of |
3130 | /// the two functions, therefore, both functions must accept the same type of |
3131 | /// arguments. Both functions must return RET. |
3132 | /// |
3133 | /// # Stability concerns |
3134 | /// |
3135 | /// Rust has not yet decided that `const fn` are allowed to tell whether |
3136 | /// they run at compile-time or at runtime. Therefore, when using this |
3137 | /// intrinsic anywhere that can be reached from stable, it is crucial that |
3138 | /// the end-to-end behavior of the stable `const fn` is the same for both |
3139 | /// modes of execution. (Here, Undefined Behavior is considered "the same" |
3140 | /// as any other behavior, so if the function exhibits UB at runtime then |
3141 | /// it may do whatever it wants at compile-time.) |
3142 | /// |
3143 | /// Here is an example of how this could cause a problem: |
3144 | /// ```no_run |
3145 | /// #![feature(const_eval_select)] |
3146 | /// #![feature(core_intrinsics)] |
3147 | /// # #![allow(internal_features)] |
3148 | /// use std::intrinsics::const_eval_select; |
3149 | /// |
3150 | /// // Standard library |
3151 | /// pub const fn inconsistent() -> i32 { |
3152 | /// fn runtime() -> i32 { 1 } |
3153 | /// const fn compiletime() -> i32 { 2 } |
3154 | /// |
3155 | /// // ⚠ This code violates the required equivalence of `compiletime` |
3156 | /// // and `runtime`. |
3157 | /// const_eval_select((), compiletime, runtime) |
3158 | /// } |
3159 | /// |
3160 | /// // User Crate |
3161 | /// const X: i32 = inconsistent(); |
3162 | /// let x = inconsistent(); |
3163 | /// assert_eq!(x, X); |
3164 | /// ``` |
3165 | /// |
3166 | /// Currently such an assertion would always succeed; until Rust decides |
3167 | /// otherwise, that principle should not be violated. |
3168 | #[rustc_const_unstable (feature = "const_eval_select" , issue = "124625" )] |
3169 | #[rustc_intrinsic ] |
3170 | pub const fn const_eval_select<ARG: Tuple, F, G, RET>( |
3171 | _arg: ARG, |
3172 | _called_in_const: F, |
3173 | _called_at_rt: G, |
3174 | ) -> RET |
3175 | where |
3176 | G: FnOnce<ARG, Output = RET>, |
3177 | F: FnOnce<ARG, Output = RET>; |
3178 | |
3179 | /// A macro to make it easier to invoke const_eval_select. Use as follows: |
3180 | /// ```rust,ignore (just a macro example) |
3181 | /// const_eval_select!( |
3182 | /// @capture { arg1: i32 = some_expr, arg2: T = other_expr } -> U: |
3183 | /// if const #[attributes_for_const_arm] { |
3184 | /// // Compile-time code goes here. |
3185 | /// } else #[attributes_for_runtime_arm] { |
3186 | /// // Run-time code goes here. |
3187 | /// } |
3188 | /// ) |
3189 | /// ``` |
3190 | /// The `@capture` block declares which surrounding variables / expressions can be |
3191 | /// used inside the `if const`. |
3192 | /// Note that the two arms of this `if` really each become their own function, which is why the |
3193 | /// macro supports setting attributes for those functions. The runtime function is always |
3194 | /// markes as `#[inline]`. |
3195 | /// |
3196 | /// See [`const_eval_select()`] for the rules and requirements around that intrinsic. |
3197 | pub(crate) macro const_eval_select { |
3198 | ( |
3199 | @capture$([$($binders:tt)*])? { $($arg:ident : $ty:ty = $val:expr),* $(,)? } $( -> $ret:ty )? : |
3200 | if const |
3201 | $(#[$compiletime_attr:meta])* $compiletime:block |
3202 | else |
3203 | $(#[$runtime_attr:meta])* $runtime:block |
3204 | ) => { |
3205 | // Use the `noinline` arm, after adding explicit `inline` attributes |
3206 | $crate::intrinsics::const_eval_select!( |
3207 | @capture$([$($binders)*])? { $($arg : $ty = $val),* } $(-> $ret)? : |
3208 | #[noinline] |
3209 | if const |
3210 | #[inline] // prevent codegen on this function |
3211 | $(#[$compiletime_attr])* |
3212 | $compiletime |
3213 | else |
3214 | #[inline] // avoid the overhead of an extra fn call |
3215 | $(#[$runtime_attr])* |
3216 | $runtime |
3217 | ) |
3218 | }, |
3219 | // With a leading #[noinline], we don't add inline attributes |
3220 | ( |
3221 | @capture$([$($binders:tt)*])? { $($arg:ident : $ty:ty = $val:expr),* $(,)? } $( -> $ret:ty )? : |
3222 | #[noinline] |
3223 | if const |
3224 | $(#[$compiletime_attr:meta])* $compiletime:block |
3225 | else |
3226 | $(#[$runtime_attr:meta])* $runtime:block |
3227 | ) => {{ |
3228 | $(#[$runtime_attr])* |
3229 | fn runtime$(<$($binders)*>)?($($arg: $ty),*) $( -> $ret )? { |
3230 | $runtime |
3231 | } |
3232 | |
3233 | $(#[$compiletime_attr])* |
3234 | const fn compiletime$(<$($binders)*>)?($($arg: $ty),*) $( -> $ret )? { |
3235 | // Don't warn if one of the arguments is unused. |
3236 | $(let _ = $arg;)* |
3237 | |
3238 | $compiletime |
3239 | } |
3240 | |
3241 | const_eval_select(($($val,)*), compiletime, runtime) |
3242 | }}, |
3243 | // We support leaving away the `val` expressions for *all* arguments |
3244 | // (but not for *some* arguments, that's too tricky). |
3245 | ( |
3246 | @capture$([$($binders:tt)*])? { $($arg:ident : $ty:ty),* $(,)? } $( -> $ret:ty )? : |
3247 | if const |
3248 | $(#[$compiletime_attr:meta])* $compiletime:block |
3249 | else |
3250 | $(#[$runtime_attr:meta])* $runtime:block |
3251 | ) => { |
3252 | $crate::intrinsics::const_eval_select!( |
3253 | @capture$([$($binders)*])? { $($arg : $ty = $arg),* } $(-> $ret)? : |
3254 | if const |
3255 | $(#[$compiletime_attr])* $compiletime |
3256 | else |
3257 | $(#[$runtime_attr])* $runtime |
3258 | ) |
3259 | }, |
3260 | } |
3261 | |
3262 | /// Returns whether the argument's value is statically known at |
3263 | /// compile-time. |
3264 | /// |
3265 | /// This is useful when there is a way of writing the code that will |
3266 | /// be *faster* when some variables have known values, but *slower* |
3267 | /// in the general case: an `if is_val_statically_known(var)` can be used |
3268 | /// to select between these two variants. The `if` will be optimized away |
3269 | /// and only the desired branch remains. |
3270 | /// |
3271 | /// Formally speaking, this function non-deterministically returns `true` |
3272 | /// or `false`, and the caller has to ensure sound behavior for both cases. |
3273 | /// In other words, the following code has *Undefined Behavior*: |
3274 | /// |
3275 | /// ```no_run |
3276 | /// #![feature(core_intrinsics)] |
3277 | /// # #![allow(internal_features)] |
3278 | /// use std::hint::unreachable_unchecked; |
3279 | /// use std::intrinsics::is_val_statically_known; |
3280 | /// |
3281 | /// if !is_val_statically_known(0) { unsafe { unreachable_unchecked(); } } |
3282 | /// ``` |
3283 | /// |
3284 | /// This also means that the following code's behavior is unspecified; it |
3285 | /// may panic, or it may not: |
3286 | /// |
3287 | /// ```no_run |
3288 | /// #![feature(core_intrinsics)] |
3289 | /// # #![allow(internal_features)] |
3290 | /// use std::intrinsics::is_val_statically_known; |
3291 | /// |
3292 | /// assert_eq!(is_val_statically_known(0), is_val_statically_known(0)); |
3293 | /// ``` |
3294 | /// |
3295 | /// Unsafe code may not rely on `is_val_statically_known` returning any |
3296 | /// particular value, ever. However, the compiler will generally make it |
3297 | /// return `true` only if the value of the argument is actually known. |
3298 | /// |
3299 | /// # Stability concerns |
3300 | /// |
3301 | /// While it is safe to call, this intrinsic may behave differently in |
3302 | /// a `const` context than otherwise. See the [`const_eval_select()`] |
3303 | /// documentation for an explanation of the issues this can cause. Unlike |
3304 | /// `const_eval_select`, this intrinsic isn't guaranteed to behave |
3305 | /// deterministically even in a `const` context. |
3306 | /// |
3307 | /// # Type Requirements |
3308 | /// |
3309 | /// `T` must be either a `bool`, a `char`, a primitive numeric type (e.g. `f32`, |
3310 | /// but not `NonZeroISize`), or any thin pointer (e.g. `*mut String`). |
3311 | /// Any other argument types *may* cause a compiler error. |
3312 | /// |
3313 | /// ## Pointers |
3314 | /// |
3315 | /// When the input is a pointer, only the pointer itself is |
3316 | /// ever considered. The pointee has no effect. Currently, these functions |
3317 | /// behave identically: |
3318 | /// |
3319 | /// ``` |
3320 | /// #![feature(core_intrinsics)] |
3321 | /// # #![allow(internal_features)] |
3322 | /// use std::intrinsics::is_val_statically_known; |
3323 | /// |
3324 | /// fn foo(x: &i32) -> bool { |
3325 | /// is_val_statically_known(x) |
3326 | /// } |
3327 | /// |
3328 | /// fn bar(x: &i32) -> bool { |
3329 | /// is_val_statically_known( |
3330 | /// (x as *const i32).addr() |
3331 | /// ) |
3332 | /// } |
3333 | /// # _ = foo(&5_i32); |
3334 | /// # _ = bar(&5_i32); |
3335 | /// ``` |
3336 | #[rustc_const_stable_indirect] |
3337 | #[rustc_nounwind ] |
3338 | #[unstable (feature = "core_intrinsics" , issue = "none" )] |
3339 | #[rustc_intrinsic ] |
3340 | pub const fn is_val_statically_known<T: Copy>(_arg: T) -> bool { |
3341 | false |
3342 | } |
3343 | |
3344 | /// Non-overlapping *typed* swap of a single value. |
3345 | /// |
3346 | /// The codegen backends will replace this with a better implementation when |
3347 | /// `T` is a simple type that can be loaded and stored as an immediate. |
3348 | /// |
3349 | /// The stabilized form of this intrinsic is [`crate::mem::swap`]. |
3350 | /// |
3351 | /// # Safety |
3352 | /// Behavior is undefined if any of the following conditions are violated: |
3353 | /// |
3354 | /// * Both `x` and `y` must be [valid] for both reads and writes. |
3355 | /// |
3356 | /// * Both `x` and `y` must be properly aligned. |
3357 | /// |
3358 | /// * The region of memory beginning at `x` must *not* overlap with the region of memory |
3359 | /// beginning at `y`. |
3360 | /// |
3361 | /// * The memory pointed by `x` and `y` must both contain values of type `T`. |
3362 | /// |
3363 | /// [valid]: crate::ptr#safety |
3364 | #[rustc_nounwind ] |
3365 | #[inline ] |
3366 | #[rustc_intrinsic ] |
3367 | #[rustc_intrinsic_const_stable_indirect] |
3368 | #[rustc_allow_const_fn_unstable (const_swap_nonoverlapping)] // this is anyway not called since CTFE implements the intrinsic |
3369 | pub const unsafe fn typed_swap_nonoverlapping<T>(x: *mut T, y: *mut T) { |
3370 | // SAFETY: The caller provided single non-overlapping items behind |
3371 | // pointers, so swapping them with `count: 1` is fine. |
3372 | unsafe { ptr::swap_nonoverlapping(x, y, count:1) }; |
3373 | } |
3374 | |
3375 | /// Returns whether we should perform some UB-checking at runtime. This eventually evaluates to |
3376 | /// `cfg!(ub_checks)`, but behaves different from `cfg!` when mixing crates built with different |
3377 | /// flags: if the crate has UB checks enabled or carries the `#[rustc_preserve_ub_checks]` |
3378 | /// attribute, evaluation is delayed until monomorphization (or until the call gets inlined into |
3379 | /// a crate that does not delay evaluation further); otherwise it can happen any time. |
3380 | /// |
3381 | /// The common case here is a user program built with ub_checks linked against the distributed |
3382 | /// sysroot which is built without ub_checks but with `#[rustc_preserve_ub_checks]`. |
3383 | /// For code that gets monomorphized in the user crate (i.e., generic functions and functions with |
3384 | /// `#[inline]`), gating assertions on `ub_checks()` rather than `cfg!(ub_checks)` means that |
3385 | /// assertions are enabled whenever the *user crate* has UB checks enabled. However, if the |
3386 | /// user has UB checks disabled, the checks will still get optimized out. This intrinsic is |
3387 | /// primarily used by [`ub_checks::assert_unsafe_precondition`]. |
3388 | #[rustc_intrinsic_const_stable_indirect] // just for UB checks |
3389 | #[inline (always)] |
3390 | #[rustc_intrinsic ] |
3391 | pub const fn ub_checks() -> bool { |
3392 | cfg!(ub_checks) |
3393 | } |
3394 | |
3395 | /// Allocates a block of memory at compile time. |
3396 | /// At runtime, just returns a null pointer. |
3397 | /// |
3398 | /// # Safety |
3399 | /// |
3400 | /// - The `align` argument must be a power of two. |
3401 | /// - At compile time, a compile error occurs if this constraint is violated. |
3402 | /// - At runtime, it is not checked. |
3403 | #[rustc_const_unstable (feature = "const_heap" , issue = "79597" )] |
3404 | #[rustc_nounwind ] |
3405 | #[rustc_intrinsic ] |
3406 | #[miri::intrinsic_fallback_is_spec] |
3407 | pub const unsafe fn const_allocate(_size: usize, _align: usize) -> *mut u8 { |
3408 | // const eval overrides this function, but runtime code for now just returns null pointers. |
3409 | // See <https://github.com/rust-lang/rust/issues/93935>. |
3410 | crate::ptr::null_mut() |
3411 | } |
3412 | |
3413 | /// Deallocates a memory which allocated by `intrinsics::const_allocate` at compile time. |
3414 | /// At runtime, does nothing. |
3415 | /// |
3416 | /// # Safety |
3417 | /// |
3418 | /// - The `align` argument must be a power of two. |
3419 | /// - At compile time, a compile error occurs if this constraint is violated. |
3420 | /// - At runtime, it is not checked. |
3421 | /// - If the `ptr` is created in an another const, this intrinsic doesn't deallocate it. |
3422 | /// - If the `ptr` is pointing to a local variable, this intrinsic doesn't deallocate it. |
3423 | #[rustc_const_unstable (feature = "const_heap" , issue = "79597" )] |
3424 | #[unstable (feature = "core_intrinsics" , issue = "none" )] |
3425 | #[rustc_nounwind ] |
3426 | #[rustc_intrinsic ] |
3427 | #[miri::intrinsic_fallback_is_spec] |
3428 | pub const unsafe fn const_deallocate(_ptr: *mut u8, _size: usize, _align: usize) { |
3429 | // Runtime NOP |
3430 | } |
3431 | |
3432 | /// Returns whether we should perform contract-checking at runtime. |
3433 | /// |
3434 | /// This is meant to be similar to the ub_checks intrinsic, in terms |
3435 | /// of not prematurely commiting at compile-time to whether contract |
3436 | /// checking is turned on, so that we can specify contracts in libstd |
3437 | /// and let an end user opt into turning them on. |
3438 | #[rustc_const_unstable (feature = "contracts_internals" , issue = "128044" /* compiler-team#759 */)] |
3439 | #[unstable (feature = "contracts_internals" , issue = "128044" /* compiler-team#759 */)] |
3440 | #[inline (always)] |
3441 | #[rustc_intrinsic ] |
3442 | pub const fn contract_checks() -> bool { |
3443 | // FIXME: should this be `false` or `cfg!(contract_checks)`? |
3444 | |
3445 | // cfg!(contract_checks) |
3446 | false |
3447 | } |
3448 | |
3449 | /// Check if the pre-condition `cond` has been met. |
3450 | /// |
3451 | /// By default, if `contract_checks` is enabled, this will panic with no unwind if the condition |
3452 | /// returns false. |
3453 | #[unstable (feature = "contracts_internals" , issue = "128044" /* compiler-team#759 */)] |
3454 | #[lang = "contract_check_requires" ] |
3455 | #[rustc_intrinsic ] |
3456 | pub fn contract_check_requires<C: Fn() -> bool>(cond: C) { |
3457 | if contract_checks() && !cond() { |
3458 | // Emit no unwind panic in case this was a safety requirement. |
3459 | crate::panicking::panic_nounwind(expr:"failed requires check" ); |
3460 | } |
3461 | } |
3462 | |
3463 | /// Check if the post-condition `cond` has been met. |
3464 | /// |
3465 | /// By default, if `contract_checks` is enabled, this will panic with no unwind if the condition |
3466 | /// returns false. |
3467 | #[unstable (feature = "contracts_internals" , issue = "128044" /* compiler-team#759 */)] |
3468 | #[rustc_intrinsic ] |
3469 | pub fn contract_check_ensures<'a, Ret, C: Fn(&'a Ret) -> bool>(ret: &'a Ret, cond: C) { |
3470 | if contract_checks() && !cond(ret) { |
3471 | crate::panicking::panic_nounwind(expr:"failed ensures check" ); |
3472 | } |
3473 | } |
3474 | |
3475 | /// The intrinsic will return the size stored in that vtable. |
3476 | /// |
3477 | /// # Safety |
3478 | /// |
3479 | /// `ptr` must point to a vtable. |
3480 | #[rustc_nounwind ] |
3481 | #[unstable (feature = "core_intrinsics" , issue = "none" )] |
3482 | #[rustc_intrinsic ] |
3483 | pub unsafe fn vtable_size(ptr: *const ()) -> usize; |
3484 | |
3485 | /// The intrinsic will return the alignment stored in that vtable. |
3486 | /// |
3487 | /// # Safety |
3488 | /// |
3489 | /// `ptr` must point to a vtable. |
3490 | #[rustc_nounwind ] |
3491 | #[unstable (feature = "core_intrinsics" , issue = "none" )] |
3492 | #[rustc_intrinsic ] |
3493 | pub unsafe fn vtable_align(ptr: *const ()) -> usize; |
3494 | |
3495 | /// The size of a type in bytes. |
3496 | /// |
3497 | /// Note that, unlike most intrinsics, this is safe to call; |
3498 | /// it does not require an `unsafe` block. |
3499 | /// Therefore, implementations must not require the user to uphold |
3500 | /// any safety invariants. |
3501 | /// |
3502 | /// More specifically, this is the offset in bytes between successive |
3503 | /// items of the same type, including alignment padding. |
3504 | /// |
3505 | /// The stabilized version of this intrinsic is [`size_of`]. |
3506 | #[rustc_nounwind ] |
3507 | #[unstable (feature = "core_intrinsics" , issue = "none" )] |
3508 | #[rustc_intrinsic_const_stable_indirect] |
3509 | #[rustc_intrinsic ] |
3510 | pub const fn size_of<T>() -> usize; |
3511 | |
3512 | /// The minimum alignment of a type. |
3513 | /// |
3514 | /// Note that, unlike most intrinsics, this is safe to call; |
3515 | /// it does not require an `unsafe` block. |
3516 | /// Therefore, implementations must not require the user to uphold |
3517 | /// any safety invariants. |
3518 | /// |
3519 | /// The stabilized version of this intrinsic is [`align_of`]. |
3520 | #[rustc_nounwind ] |
3521 | #[unstable (feature = "core_intrinsics" , issue = "none" )] |
3522 | #[rustc_intrinsic_const_stable_indirect] |
3523 | #[rustc_intrinsic ] |
3524 | pub const fn min_align_of<T>() -> usize; |
3525 | |
3526 | /// The preferred alignment of a type. |
3527 | /// |
3528 | /// This intrinsic does not have a stable counterpart. |
3529 | /// It's "tracking issue" is [#91971](https://github.com/rust-lang/rust/issues/91971). |
3530 | #[rustc_nounwind ] |
3531 | #[unstable (feature = "core_intrinsics" , issue = "none" )] |
3532 | #[rustc_intrinsic ] |
3533 | pub const unsafe fn pref_align_of<T>() -> usize; |
3534 | |
3535 | /// Returns the number of variants of the type `T` cast to a `usize`; |
3536 | /// if `T` has no variants, returns `0`. Uninhabited variants will be counted. |
3537 | /// |
3538 | /// Note that, unlike most intrinsics, this is safe to call; |
3539 | /// it does not require an `unsafe` block. |
3540 | /// Therefore, implementations must not require the user to uphold |
3541 | /// any safety invariants. |
3542 | /// |
3543 | /// The to-be-stabilized version of this intrinsic is [`crate::mem::variant_count`]. |
3544 | #[rustc_nounwind ] |
3545 | #[unstable (feature = "core_intrinsics" , issue = "none" )] |
3546 | #[rustc_intrinsic ] |
3547 | pub const fn variant_count<T>() -> usize; |
3548 | |
3549 | /// The size of the referenced value in bytes. |
3550 | /// |
3551 | /// The stabilized version of this intrinsic is [`size_of_val`]. |
3552 | /// |
3553 | /// # Safety |
3554 | /// |
3555 | /// See [`crate::mem::size_of_val_raw`] for safety conditions. |
3556 | #[rustc_nounwind ] |
3557 | #[unstable (feature = "core_intrinsics" , issue = "none" )] |
3558 | #[rustc_intrinsic ] |
3559 | #[rustc_intrinsic_const_stable_indirect] |
3560 | pub const unsafe fn size_of_val<T: ?Sized>(ptr: *const T) -> usize; |
3561 | |
3562 | /// The required alignment of the referenced value. |
3563 | /// |
3564 | /// The stabilized version of this intrinsic is [`align_of_val`]. |
3565 | /// |
3566 | /// # Safety |
3567 | /// |
3568 | /// See [`crate::mem::align_of_val_raw`] for safety conditions. |
3569 | #[rustc_nounwind ] |
3570 | #[unstable (feature = "core_intrinsics" , issue = "none" )] |
3571 | #[rustc_intrinsic ] |
3572 | #[rustc_intrinsic_const_stable_indirect] |
3573 | pub const unsafe fn min_align_of_val<T: ?Sized>(ptr: *const T) -> usize; |
3574 | |
3575 | /// Gets a static string slice containing the name of a type. |
3576 | /// |
3577 | /// Note that, unlike most intrinsics, this is safe to call; |
3578 | /// it does not require an `unsafe` block. |
3579 | /// Therefore, implementations must not require the user to uphold |
3580 | /// any safety invariants. |
3581 | /// |
3582 | /// The stabilized version of this intrinsic is [`core::any::type_name`]. |
3583 | #[rustc_nounwind ] |
3584 | #[unstable (feature = "core_intrinsics" , issue = "none" )] |
3585 | #[rustc_intrinsic ] |
3586 | pub const fn type_name<T: ?Sized>() -> &'static str; |
3587 | |
3588 | /// Gets an identifier which is globally unique to the specified type. This |
3589 | /// function will return the same value for a type regardless of whichever |
3590 | /// crate it is invoked in. |
3591 | /// |
3592 | /// Note that, unlike most intrinsics, this is safe to call; |
3593 | /// it does not require an `unsafe` block. |
3594 | /// Therefore, implementations must not require the user to uphold |
3595 | /// any safety invariants. |
3596 | /// |
3597 | /// The stabilized version of this intrinsic is [`core::any::TypeId::of`]. |
3598 | #[rustc_nounwind ] |
3599 | #[unstable (feature = "core_intrinsics" , issue = "none" )] |
3600 | #[rustc_intrinsic ] |
3601 | pub const fn type_id<T: ?Sized + 'static>() -> u128; |
3602 | |
3603 | /// Lowers in MIR to `Rvalue::Aggregate` with `AggregateKind::RawPtr`. |
3604 | /// |
3605 | /// This is used to implement functions like `slice::from_raw_parts_mut` and |
3606 | /// `ptr::from_raw_parts` in a way compatible with the compiler being able to |
3607 | /// change the possible layouts of pointers. |
3608 | #[rustc_nounwind ] |
3609 | #[unstable (feature = "core_intrinsics" , issue = "none" )] |
3610 | #[rustc_intrinsic_const_stable_indirect] |
3611 | #[rustc_intrinsic ] |
3612 | pub const fn aggregate_raw_ptr<P: AggregateRawPtr<D, Metadata = M>, D, M>(data: D, meta: M) -> P; |
3613 | |
3614 | #[unstable (feature = "core_intrinsics" , issue = "none" )] |
3615 | pub trait AggregateRawPtr<D> { |
3616 | type Metadata: Copy; |
3617 | } |
3618 | impl<P: ?Sized, T: ptr::Thin> AggregateRawPtr<*const T> for *const P { |
3619 | type Metadata = <P as ptr::Pointee>::Metadata; |
3620 | } |
3621 | impl<P: ?Sized, T: ptr::Thin> AggregateRawPtr<*mut T> for *mut P { |
3622 | type Metadata = <P as ptr::Pointee>::Metadata; |
3623 | } |
3624 | |
3625 | /// Lowers in MIR to `Rvalue::UnaryOp` with `UnOp::PtrMetadata`. |
3626 | /// |
3627 | /// This is used to implement functions like `ptr::metadata`. |
3628 | #[rustc_nounwind ] |
3629 | #[unstable (feature = "core_intrinsics" , issue = "none" )] |
3630 | #[rustc_intrinsic_const_stable_indirect] |
3631 | #[rustc_intrinsic ] |
3632 | pub const fn ptr_metadata<P: ptr::Pointee<Metadata = M> + ?Sized, M>(ptr: *const P) -> M; |
3633 | |
3634 | // Some functions are defined here because they accidentally got made |
3635 | // available in this module on stable. See <https://github.com/rust-lang/rust/issues/15702>. |
3636 | // (`transmute` also falls into this category, but it cannot be wrapped due to the |
3637 | // check that `T` and `U` have the same size.) |
3638 | |
3639 | /// Copies `count * size_of::<T>()` bytes from `src` to `dst`. The source |
3640 | /// and destination must *not* overlap. |
3641 | /// |
3642 | /// For regions of memory which might overlap, use [`copy`] instead. |
3643 | /// |
3644 | /// `copy_nonoverlapping` is semantically equivalent to C's [`memcpy`], but |
3645 | /// with the source and destination arguments swapped, |
3646 | /// and `count` counting the number of `T`s instead of bytes. |
3647 | /// |
3648 | /// The copy is "untyped" in the sense that data may be uninitialized or otherwise violate the |
3649 | /// requirements of `T`. The initialization state is preserved exactly. |
3650 | /// |
3651 | /// [`memcpy`]: https://en.cppreference.com/w/c/string/byte/memcpy |
3652 | /// |
3653 | /// # Safety |
3654 | /// |
3655 | /// Behavior is undefined if any of the following conditions are violated: |
3656 | /// |
3657 | /// * `src` must be [valid] for reads of `count * size_of::<T>()` bytes. |
3658 | /// |
3659 | /// * `dst` must be [valid] for writes of `count * size_of::<T>()` bytes. |
3660 | /// |
3661 | /// * Both `src` and `dst` must be properly aligned. |
3662 | /// |
3663 | /// * The region of memory beginning at `src` with a size of `count * |
3664 | /// size_of::<T>()` bytes must *not* overlap with the region of memory |
3665 | /// beginning at `dst` with the same size. |
3666 | /// |
3667 | /// Like [`read`], `copy_nonoverlapping` creates a bitwise copy of `T`, regardless of |
3668 | /// whether `T` is [`Copy`]. If `T` is not [`Copy`], using *both* the values |
3669 | /// in the region beginning at `*src` and the region beginning at `*dst` can |
3670 | /// [violate memory safety][read-ownership]. |
3671 | /// |
3672 | /// Note that even if the effectively copied size (`count * size_of::<T>()`) is |
3673 | /// `0`, the pointers must be properly aligned. |
3674 | /// |
3675 | /// [`read`]: crate::ptr::read |
3676 | /// [read-ownership]: crate::ptr::read#ownership-of-the-returned-value |
3677 | /// [valid]: crate::ptr#safety |
3678 | /// |
3679 | /// # Examples |
3680 | /// |
3681 | /// Manually implement [`Vec::append`]: |
3682 | /// |
3683 | /// ``` |
3684 | /// use std::ptr; |
3685 | /// |
3686 | /// /// Moves all the elements of `src` into `dst`, leaving `src` empty. |
3687 | /// fn append<T>(dst: &mut Vec<T>, src: &mut Vec<T>) { |
3688 | /// let src_len = src.len(); |
3689 | /// let dst_len = dst.len(); |
3690 | /// |
3691 | /// // Ensure that `dst` has enough capacity to hold all of `src`. |
3692 | /// dst.reserve(src_len); |
3693 | /// |
3694 | /// unsafe { |
3695 | /// // The call to add is always safe because `Vec` will never |
3696 | /// // allocate more than `isize::MAX` bytes. |
3697 | /// let dst_ptr = dst.as_mut_ptr().add(dst_len); |
3698 | /// let src_ptr = src.as_ptr(); |
3699 | /// |
3700 | /// // Truncate `src` without dropping its contents. We do this first, |
3701 | /// // to avoid problems in case something further down panics. |
3702 | /// src.set_len(0); |
3703 | /// |
3704 | /// // The two regions cannot overlap because mutable references do |
3705 | /// // not alias, and two different vectors cannot own the same |
3706 | /// // memory. |
3707 | /// ptr::copy_nonoverlapping(src_ptr, dst_ptr, src_len); |
3708 | /// |
3709 | /// // Notify `dst` that it now holds the contents of `src`. |
3710 | /// dst.set_len(dst_len + src_len); |
3711 | /// } |
3712 | /// } |
3713 | /// |
3714 | /// let mut a = vec!['r' ]; |
3715 | /// let mut b = vec!['u' , 's' , 't' ]; |
3716 | /// |
3717 | /// append(&mut a, &mut b); |
3718 | /// |
3719 | /// assert_eq!(a, &['r' , 'u' , 's' , 't' ]); |
3720 | /// assert!(b.is_empty()); |
3721 | /// ``` |
3722 | /// |
3723 | /// [`Vec::append`]: ../../std/vec/struct.Vec.html#method.append |
3724 | #[doc (alias = "memcpy" )] |
3725 | #[stable (feature = "rust1" , since = "1.0.0" )] |
3726 | #[rustc_allowed_through_unstable_modules = "import this function via `std::mem` instead" ] |
3727 | #[rustc_const_stable (feature = "const_intrinsic_copy" , since = "1.83.0" )] |
3728 | #[inline (always)] |
3729 | #[cfg_attr (miri, track_caller)] // even without panics, this helps for Miri backtraces |
3730 | #[rustc_diagnostic_item = "ptr_copy_nonoverlapping" ] |
3731 | pub const unsafe fn copy_nonoverlapping<T>(src: *const T, dst: *mut T, count: usize) { |
3732 | #[rustc_intrinsic_const_stable_indirect] |
3733 | #[rustc_nounwind ] |
3734 | #[rustc_intrinsic ] |
3735 | const unsafe fn copy_nonoverlapping<T>(src: *const T, dst: *mut T, count: usize); |
3736 | |
3737 | ub_checks::assert_unsafe_precondition!( |
3738 | check_language_ub, |
3739 | "ptr::copy_nonoverlapping requires that both pointer arguments are aligned and non-null \ |
3740 | and the specified memory ranges do not overlap" , |
3741 | ( |
3742 | src: *const () = src as *const (), |
3743 | dst: *mut () = dst as *mut (), |
3744 | size: usize = size_of::<T>(), |
3745 | align: usize = align_of::<T>(), |
3746 | count: usize = count, |
3747 | ) => { |
3748 | let zero_size = count == 0 || size == 0; |
3749 | ub_checks::maybe_is_aligned_and_not_null(src, align, zero_size) |
3750 | && ub_checks::maybe_is_aligned_and_not_null(dst, align, zero_size) |
3751 | && ub_checks::maybe_is_nonoverlapping(src, dst, size, count) |
3752 | } |
3753 | ); |
3754 | |
3755 | // SAFETY: the safety contract for `copy_nonoverlapping` must be |
3756 | // upheld by the caller. |
3757 | unsafe { copy_nonoverlapping(src, dst, count) } |
3758 | } |
3759 | |
3760 | /// Copies `count * size_of::<T>()` bytes from `src` to `dst`. The source |
3761 | /// and destination may overlap. |
3762 | /// |
3763 | /// If the source and destination will *never* overlap, |
3764 | /// [`copy_nonoverlapping`] can be used instead. |
3765 | /// |
3766 | /// `copy` is semantically equivalent to C's [`memmove`], but |
3767 | /// with the source and destination arguments swapped, |
3768 | /// and `count` counting the number of `T`s instead of bytes. |
3769 | /// Copying takes place as if the bytes were copied from `src` |
3770 | /// to a temporary array and then copied from the array to `dst`. |
3771 | /// |
3772 | /// The copy is "untyped" in the sense that data may be uninitialized or otherwise violate the |
3773 | /// requirements of `T`. The initialization state is preserved exactly. |
3774 | /// |
3775 | /// [`memmove`]: https://en.cppreference.com/w/c/string/byte/memmove |
3776 | /// |
3777 | /// # Safety |
3778 | /// |
3779 | /// Behavior is undefined if any of the following conditions are violated: |
3780 | /// |
3781 | /// * `src` must be [valid] for reads of `count * size_of::<T>()` bytes. |
3782 | /// |
3783 | /// * `dst` must be [valid] for writes of `count * size_of::<T>()` bytes, and must remain valid even |
3784 | /// when `src` is read for `count * size_of::<T>()` bytes. (This means if the memory ranges |
3785 | /// overlap, the `dst` pointer must not be invalidated by `src` reads.) |
3786 | /// |
3787 | /// * Both `src` and `dst` must be properly aligned. |
3788 | /// |
3789 | /// Like [`read`], `copy` creates a bitwise copy of `T`, regardless of |
3790 | /// whether `T` is [`Copy`]. If `T` is not [`Copy`], using both the values |
3791 | /// in the region beginning at `*src` and the region beginning at `*dst` can |
3792 | /// [violate memory safety][read-ownership]. |
3793 | /// |
3794 | /// Note that even if the effectively copied size (`count * size_of::<T>()`) is |
3795 | /// `0`, the pointers must be properly aligned. |
3796 | /// |
3797 | /// [`read`]: crate::ptr::read |
3798 | /// [read-ownership]: crate::ptr::read#ownership-of-the-returned-value |
3799 | /// [valid]: crate::ptr#safety |
3800 | /// |
3801 | /// # Examples |
3802 | /// |
3803 | /// Efficiently create a Rust vector from an unsafe buffer: |
3804 | /// |
3805 | /// ``` |
3806 | /// use std::ptr; |
3807 | /// |
3808 | /// /// # Safety |
3809 | /// /// |
3810 | /// /// * `ptr` must be correctly aligned for its type and non-zero. |
3811 | /// /// * `ptr` must be valid for reads of `elts` contiguous elements of type `T`. |
3812 | /// /// * Those elements must not be used after calling this function unless `T: Copy`. |
3813 | /// # #[allow (dead_code)] |
3814 | /// unsafe fn from_buf_raw<T>(ptr: *const T, elts: usize) -> Vec<T> { |
3815 | /// let mut dst = Vec::with_capacity(elts); |
3816 | /// |
3817 | /// // SAFETY: Our precondition ensures the source is aligned and valid, |
3818 | /// // and `Vec::with_capacity` ensures that we have usable space to write them. |
3819 | /// unsafe { ptr::copy(ptr, dst.as_mut_ptr(), elts); } |
3820 | /// |
3821 | /// // SAFETY: We created it with this much capacity earlier, |
3822 | /// // and the previous `copy` has initialized these elements. |
3823 | /// unsafe { dst.set_len(elts); } |
3824 | /// dst |
3825 | /// } |
3826 | /// ``` |
3827 | #[doc (alias = "memmove" )] |
3828 | #[stable (feature = "rust1" , since = "1.0.0" )] |
3829 | #[rustc_allowed_through_unstable_modules = "import this function via `std::mem` instead" ] |
3830 | #[rustc_const_stable (feature = "const_intrinsic_copy" , since = "1.83.0" )] |
3831 | #[inline (always)] |
3832 | #[cfg_attr (miri, track_caller)] // even without panics, this helps for Miri backtraces |
3833 | #[rustc_diagnostic_item = "ptr_copy" ] |
3834 | pub const unsafe fn copy<T>(src: *const T, dst: *mut T, count: usize) { |
3835 | #[rustc_intrinsic_const_stable_indirect] |
3836 | #[rustc_nounwind ] |
3837 | #[rustc_intrinsic ] |
3838 | const unsafe fn copy<T>(src: *const T, dst: *mut T, count: usize); |
3839 | |
3840 | // SAFETY: the safety contract for `copy` must be upheld by the caller. |
3841 | unsafe { |
3842 | ub_checks::assert_unsafe_precondition!( |
3843 | check_language_ub, |
3844 | "ptr::copy requires that both pointer arguments are aligned and non-null" , |
3845 | ( |
3846 | src: *const () = src as *const (), |
3847 | dst: *mut () = dst as *mut (), |
3848 | align: usize = align_of::<T>(), |
3849 | zero_size: bool = T::IS_ZST || count == 0, |
3850 | ) => |
3851 | ub_checks::maybe_is_aligned_and_not_null(src, align, zero_size) |
3852 | && ub_checks::maybe_is_aligned_and_not_null(dst, align, zero_size) |
3853 | ); |
3854 | copy(src, dst, count) |
3855 | } |
3856 | } |
3857 | |
3858 | /// Sets `count * size_of::<T>()` bytes of memory starting at `dst` to |
3859 | /// `val`. |
3860 | /// |
3861 | /// `write_bytes` is similar to C's [`memset`], but sets `count * |
3862 | /// size_of::<T>()` bytes to `val`. |
3863 | /// |
3864 | /// [`memset`]: https://en.cppreference.com/w/c/string/byte/memset |
3865 | /// |
3866 | /// # Safety |
3867 | /// |
3868 | /// Behavior is undefined if any of the following conditions are violated: |
3869 | /// |
3870 | /// * `dst` must be [valid] for writes of `count * size_of::<T>()` bytes. |
3871 | /// |
3872 | /// * `dst` must be properly aligned. |
3873 | /// |
3874 | /// Note that even if the effectively copied size (`count * size_of::<T>()`) is |
3875 | /// `0`, the pointer must be properly aligned. |
3876 | /// |
3877 | /// Additionally, note that changing `*dst` in this way can easily lead to undefined behavior (UB) |
3878 | /// later if the written bytes are not a valid representation of some `T`. For instance, the |
3879 | /// following is an **incorrect** use of this function: |
3880 | /// |
3881 | /// ```rust,no_run |
3882 | /// unsafe { |
3883 | /// let mut value: u8 = 0; |
3884 | /// let ptr: *mut bool = &mut value as *mut u8 as *mut bool; |
3885 | /// let _bool = ptr.read(); // This is fine, `ptr` points to a valid `bool`. |
3886 | /// ptr.write_bytes(42u8, 1); // This function itself does not cause UB... |
3887 | /// let _bool = ptr.read(); // ...but it makes this operation UB! ⚠️ |
3888 | /// } |
3889 | /// ``` |
3890 | /// |
3891 | /// [valid]: crate::ptr#safety |
3892 | /// |
3893 | /// # Examples |
3894 | /// |
3895 | /// Basic usage: |
3896 | /// |
3897 | /// ``` |
3898 | /// use std::ptr; |
3899 | /// |
3900 | /// let mut vec = vec![0u32; 4]; |
3901 | /// unsafe { |
3902 | /// let vec_ptr = vec.as_mut_ptr(); |
3903 | /// ptr::write_bytes(vec_ptr, 0xfe, 2); |
3904 | /// } |
3905 | /// assert_eq!(vec, [0xfefefefe, 0xfefefefe, 0, 0]); |
3906 | /// ``` |
3907 | #[doc (alias = "memset" )] |
3908 | #[stable (feature = "rust1" , since = "1.0.0" )] |
3909 | #[rustc_allowed_through_unstable_modules = "import this function via `std::mem` instead" ] |
3910 | #[rustc_const_stable (feature = "const_ptr_write" , since = "1.83.0" )] |
3911 | #[inline (always)] |
3912 | #[cfg_attr (miri, track_caller)] // even without panics, this helps for Miri backtraces |
3913 | #[rustc_diagnostic_item = "ptr_write_bytes" ] |
3914 | pub const unsafe fn write_bytes<T>(dst: *mut T, val: u8, count: usize) { |
3915 | #[rustc_intrinsic_const_stable_indirect] |
3916 | #[rustc_nounwind ] |
3917 | #[rustc_intrinsic ] |
3918 | const unsafe fn write_bytes<T>(dst: *mut T, val: u8, count: usize); |
3919 | |
3920 | // SAFETY: the safety contract for `write_bytes` must be upheld by the caller. |
3921 | unsafe { |
3922 | ub_checks::assert_unsafe_precondition!( |
3923 | check_language_ub, |
3924 | "ptr::write_bytes requires that the destination pointer is aligned and non-null" , |
3925 | ( |
3926 | addr: *const () = dst as *const (), |
3927 | align: usize = align_of::<T>(), |
3928 | zero_size: bool = T::IS_ZST || count == 0, |
3929 | ) => ub_checks::maybe_is_aligned_and_not_null(addr, align, zero_size) |
3930 | ); |
3931 | write_bytes(dst, val, count) |
3932 | } |
3933 | } |
3934 | |
3935 | /// Returns the minimum of two `f16` values. |
3936 | /// |
3937 | /// Note that, unlike most intrinsics, this is safe to call; |
3938 | /// it does not require an `unsafe` block. |
3939 | /// Therefore, implementations must not require the user to uphold |
3940 | /// any safety invariants. |
3941 | /// |
3942 | /// The stabilized version of this intrinsic is |
3943 | /// [`f16::min`] |
3944 | #[rustc_nounwind ] |
3945 | #[rustc_intrinsic ] |
3946 | pub const fn minnumf16(x: f16, y: f16) -> f16; |
3947 | |
3948 | /// Returns the minimum of two `f32` values. |
3949 | /// |
3950 | /// Note that, unlike most intrinsics, this is safe to call; |
3951 | /// it does not require an `unsafe` block. |
3952 | /// Therefore, implementations must not require the user to uphold |
3953 | /// any safety invariants. |
3954 | /// |
3955 | /// The stabilized version of this intrinsic is |
3956 | /// [`f32::min`] |
3957 | #[rustc_nounwind ] |
3958 | #[rustc_intrinsic_const_stable_indirect] |
3959 | #[rustc_intrinsic ] |
3960 | pub const fn minnumf32(x: f32, y: f32) -> f32; |
3961 | |
3962 | /// Returns the minimum of two `f64` values. |
3963 | /// |
3964 | /// Note that, unlike most intrinsics, this is safe to call; |
3965 | /// it does not require an `unsafe` block. |
3966 | /// Therefore, implementations must not require the user to uphold |
3967 | /// any safety invariants. |
3968 | /// |
3969 | /// The stabilized version of this intrinsic is |
3970 | /// [`f64::min`] |
3971 | #[rustc_nounwind ] |
3972 | #[rustc_intrinsic_const_stable_indirect] |
3973 | #[rustc_intrinsic ] |
3974 | pub const fn minnumf64(x: f64, y: f64) -> f64; |
3975 | |
3976 | /// Returns the minimum of two `f128` values. |
3977 | /// |
3978 | /// Note that, unlike most intrinsics, this is safe to call; |
3979 | /// it does not require an `unsafe` block. |
3980 | /// Therefore, implementations must not require the user to uphold |
3981 | /// any safety invariants. |
3982 | /// |
3983 | /// The stabilized version of this intrinsic is |
3984 | /// [`f128::min`] |
3985 | #[rustc_nounwind ] |
3986 | #[rustc_intrinsic ] |
3987 | pub const fn minnumf128(x: f128, y: f128) -> f128; |
3988 | |
3989 | /// Returns the maximum of two `f16` values. |
3990 | /// |
3991 | /// Note that, unlike most intrinsics, this is safe to call; |
3992 | /// it does not require an `unsafe` block. |
3993 | /// Therefore, implementations must not require the user to uphold |
3994 | /// any safety invariants. |
3995 | /// |
3996 | /// The stabilized version of this intrinsic is |
3997 | /// [`f16::max`] |
3998 | #[rustc_nounwind ] |
3999 | #[rustc_intrinsic ] |
4000 | pub const fn maxnumf16(x: f16, y: f16) -> f16; |
4001 | |
4002 | /// Returns the maximum of two `f32` values. |
4003 | /// |
4004 | /// Note that, unlike most intrinsics, this is safe to call; |
4005 | /// it does not require an `unsafe` block. |
4006 | /// Therefore, implementations must not require the user to uphold |
4007 | /// any safety invariants. |
4008 | /// |
4009 | /// The stabilized version of this intrinsic is |
4010 | /// [`f32::max`] |
4011 | #[rustc_nounwind ] |
4012 | #[rustc_intrinsic_const_stable_indirect] |
4013 | #[rustc_intrinsic ] |
4014 | pub const fn maxnumf32(x: f32, y: f32) -> f32; |
4015 | |
4016 | /// Returns the maximum of two `f64` values. |
4017 | /// |
4018 | /// Note that, unlike most intrinsics, this is safe to call; |
4019 | /// it does not require an `unsafe` block. |
4020 | /// Therefore, implementations must not require the user to uphold |
4021 | /// any safety invariants. |
4022 | /// |
4023 | /// The stabilized version of this intrinsic is |
4024 | /// [`f64::max`] |
4025 | #[rustc_nounwind ] |
4026 | #[rustc_intrinsic_const_stable_indirect] |
4027 | #[rustc_intrinsic ] |
4028 | pub const fn maxnumf64(x: f64, y: f64) -> f64; |
4029 | |
4030 | /// Returns the maximum of two `f128` values. |
4031 | /// |
4032 | /// Note that, unlike most intrinsics, this is safe to call; |
4033 | /// it does not require an `unsafe` block. |
4034 | /// Therefore, implementations must not require the user to uphold |
4035 | /// any safety invariants. |
4036 | /// |
4037 | /// The stabilized version of this intrinsic is |
4038 | /// [`f128::max`] |
4039 | #[rustc_nounwind ] |
4040 | #[rustc_intrinsic ] |
4041 | pub const fn maxnumf128(x: f128, y: f128) -> f128; |
4042 | |
4043 | /// Returns the absolute value of an `f16`. |
4044 | /// |
4045 | /// The stabilized version of this intrinsic is |
4046 | /// [`f16::abs`](../../std/primitive.f16.html#method.abs) |
4047 | #[rustc_nounwind ] |
4048 | #[rustc_intrinsic ] |
4049 | pub const unsafe fn fabsf16(x: f16) -> f16; |
4050 | |
4051 | /// Returns the absolute value of an `f32`. |
4052 | /// |
4053 | /// The stabilized version of this intrinsic is |
4054 | /// [`f32::abs`](../../std/primitive.f32.html#method.abs) |
4055 | #[rustc_nounwind ] |
4056 | #[rustc_intrinsic_const_stable_indirect] |
4057 | #[rustc_intrinsic ] |
4058 | pub const unsafe fn fabsf32(x: f32) -> f32; |
4059 | |
4060 | /// Returns the absolute value of an `f64`. |
4061 | /// |
4062 | /// The stabilized version of this intrinsic is |
4063 | /// [`f64::abs`](../../std/primitive.f64.html#method.abs) |
4064 | #[rustc_nounwind ] |
4065 | #[rustc_intrinsic_const_stable_indirect] |
4066 | #[rustc_intrinsic ] |
4067 | pub const unsafe fn fabsf64(x: f64) -> f64; |
4068 | |
4069 | /// Returns the absolute value of an `f128`. |
4070 | /// |
4071 | /// The stabilized version of this intrinsic is |
4072 | /// [`f128::abs`](../../std/primitive.f128.html#method.abs) |
4073 | #[rustc_nounwind ] |
4074 | #[rustc_intrinsic ] |
4075 | pub const unsafe fn fabsf128(x: f128) -> f128; |
4076 | |
4077 | /// Copies the sign from `y` to `x` for `f16` values. |
4078 | /// |
4079 | /// The stabilized version of this intrinsic is |
4080 | /// [`f16::copysign`](../../std/primitive.f16.html#method.copysign) |
4081 | #[rustc_nounwind ] |
4082 | #[rustc_intrinsic ] |
4083 | pub const unsafe fn copysignf16(x: f16, y: f16) -> f16; |
4084 | |
4085 | /// Copies the sign from `y` to `x` for `f32` values. |
4086 | /// |
4087 | /// The stabilized version of this intrinsic is |
4088 | /// [`f32::copysign`](../../std/primitive.f32.html#method.copysign) |
4089 | #[rustc_nounwind ] |
4090 | #[rustc_intrinsic_const_stable_indirect] |
4091 | #[rustc_intrinsic ] |
4092 | pub const unsafe fn copysignf32(x: f32, y: f32) -> f32; |
4093 | /// Copies the sign from `y` to `x` for `f64` values. |
4094 | /// |
4095 | /// The stabilized version of this intrinsic is |
4096 | /// [`f64::copysign`](../../std/primitive.f64.html#method.copysign) |
4097 | #[rustc_nounwind ] |
4098 | #[rustc_intrinsic_const_stable_indirect] |
4099 | #[rustc_intrinsic ] |
4100 | pub const unsafe fn copysignf64(x: f64, y: f64) -> f64; |
4101 | |
4102 | /// Copies the sign from `y` to `x` for `f128` values. |
4103 | /// |
4104 | /// The stabilized version of this intrinsic is |
4105 | /// [`f128::copysign`](../../std/primitive.f128.html#method.copysign) |
4106 | #[rustc_nounwind ] |
4107 | #[rustc_intrinsic ] |
4108 | pub const unsafe fn copysignf128(x: f128, y: f128) -> f128; |
4109 | |
4110 | /// Inform Miri that a given pointer definitely has a certain alignment. |
4111 | #[cfg (miri)] |
4112 | #[rustc_allow_const_fn_unstable (const_eval_select)] |
4113 | pub(crate) const fn miri_promise_symbolic_alignment(ptr: *const (), align: usize) { |
4114 | unsafe extern "Rust" { |
4115 | /// Miri-provided extern function to promise that a given pointer is properly aligned for |
4116 | /// "symbolic" alignment checks. Will fail if the pointer is not actually aligned or `align` is |
4117 | /// not a power of two. Has no effect when alignment checks are concrete (which is the default). |
4118 | unsafefn miri_promise_symbolic_alignment(ptr: *const (), align: usize); |
4119 | } |
4120 | |
4121 | const_eval_select!( |
4122 | @capture { ptr: *const (), align: usize}: |
4123 | if const { |
4124 | // Do nothing. |
4125 | } else { |
4126 | // SAFETY: this call is always safe. |
4127 | unsafe { |
4128 | miri_promise_symbolic_alignment(ptr, align); |
4129 | } |
4130 | } |
4131 | ) |
4132 | } |
4133 | |