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1 | // Copyright 2013 The Rust Project Developers. See the COPYRIGHT |
2 | // file at the top-level directory of this distribution and at | |
3 | // http://rust-lang.org/COPYRIGHT. | |
4 | // | |
5 | // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or | |
6 | // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license | |
7 | // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your | |
8 | // option. This file may not be copied, modified, or distributed | |
9 | // except according to those terms. | |
10 | ||
11 | //! rustc compiler intrinsics. | |
12 | //! | |
13 | //! The corresponding definitions are in librustc_trans/trans/intrinsic.rs. | |
14 | //! | |
15 | //! # Volatiles | |
16 | //! | |
17 | //! The volatile intrinsics provide operations intended to act on I/O | |
18 | //! memory, which are guaranteed to not be reordered by the compiler | |
19 | //! across other volatile intrinsics. See the LLVM documentation on | |
20 | //! [[volatile]]. | |
21 | //! | |
22 | //! [volatile]: http://llvm.org/docs/LangRef.html#volatile-memory-accesses | |
23 | //! | |
24 | //! # Atomics | |
25 | //! | |
26 | //! The atomic intrinsics provide common atomic operations on machine | |
27 | //! words, with multiple possible memory orderings. They obey the same | |
28 | //! semantics as C++11. See the LLVM documentation on [[atomics]]. | |
29 | //! | |
30 | //! [atomics]: http://llvm.org/docs/Atomics.html | |
31 | //! | |
32 | //! A quick refresher on memory ordering: | |
33 | //! | |
34 | //! * Acquire - a barrier for acquiring a lock. Subsequent reads and writes | |
35 | //! take place after the barrier. | |
36 | //! * Release - a barrier for releasing a lock. Preceding reads and writes | |
37 | //! take place before the barrier. | |
38 | //! * Sequentially consistent - sequentially consistent operations are | |
39 | //! guaranteed to happen in order. This is the standard mode for working | |
40 | //! with atomic types and is equivalent to Java's `volatile`. | |
41 | ||
85aaf69f | 42 | #![unstable(feature = "core")] |
1a4d82fc JJ |
43 | #![allow(missing_docs)] |
44 | ||
1a4d82fc JJ |
45 | use marker::Sized; |
46 | ||
1a4d82fc JJ |
47 | extern "rust-intrinsic" { |
48 | ||
49 | // NB: These intrinsics take unsafe pointers because they mutate aliased | |
50 | // memory, which is not valid for either `&` or `&mut`. | |
51 | ||
52 | pub fn atomic_cxchg<T>(dst: *mut T, old: T, src: T) -> T; | |
53 | pub fn atomic_cxchg_acq<T>(dst: *mut T, old: T, src: T) -> T; | |
54 | pub fn atomic_cxchg_rel<T>(dst: *mut T, old: T, src: T) -> T; | |
55 | pub fn atomic_cxchg_acqrel<T>(dst: *mut T, old: T, src: T) -> T; | |
56 | pub fn atomic_cxchg_relaxed<T>(dst: *mut T, old: T, src: T) -> T; | |
57 | ||
58 | pub fn atomic_load<T>(src: *const T) -> T; | |
59 | pub fn atomic_load_acq<T>(src: *const T) -> T; | |
60 | pub fn atomic_load_relaxed<T>(src: *const T) -> T; | |
61 | pub fn atomic_load_unordered<T>(src: *const T) -> T; | |
62 | ||
63 | pub fn atomic_store<T>(dst: *mut T, val: T); | |
64 | pub fn atomic_store_rel<T>(dst: *mut T, val: T); | |
65 | pub fn atomic_store_relaxed<T>(dst: *mut T, val: T); | |
66 | pub fn atomic_store_unordered<T>(dst: *mut T, val: T); | |
67 | ||
68 | pub fn atomic_xchg<T>(dst: *mut T, src: T) -> T; | |
69 | pub fn atomic_xchg_acq<T>(dst: *mut T, src: T) -> T; | |
70 | pub fn atomic_xchg_rel<T>(dst: *mut T, src: T) -> T; | |
71 | pub fn atomic_xchg_acqrel<T>(dst: *mut T, src: T) -> T; | |
72 | pub fn atomic_xchg_relaxed<T>(dst: *mut T, src: T) -> T; | |
73 | ||
74 | pub fn atomic_xadd<T>(dst: *mut T, src: T) -> T; | |
75 | pub fn atomic_xadd_acq<T>(dst: *mut T, src: T) -> T; | |
76 | pub fn atomic_xadd_rel<T>(dst: *mut T, src: T) -> T; | |
77 | pub fn atomic_xadd_acqrel<T>(dst: *mut T, src: T) -> T; | |
78 | pub fn atomic_xadd_relaxed<T>(dst: *mut T, src: T) -> T; | |
79 | ||
80 | pub fn atomic_xsub<T>(dst: *mut T, src: T) -> T; | |
81 | pub fn atomic_xsub_acq<T>(dst: *mut T, src: T) -> T; | |
82 | pub fn atomic_xsub_rel<T>(dst: *mut T, src: T) -> T; | |
83 | pub fn atomic_xsub_acqrel<T>(dst: *mut T, src: T) -> T; | |
84 | pub fn atomic_xsub_relaxed<T>(dst: *mut T, src: T) -> T; | |
85 | ||
86 | pub fn atomic_and<T>(dst: *mut T, src: T) -> T; | |
87 | pub fn atomic_and_acq<T>(dst: *mut T, src: T) -> T; | |
88 | pub fn atomic_and_rel<T>(dst: *mut T, src: T) -> T; | |
89 | pub fn atomic_and_acqrel<T>(dst: *mut T, src: T) -> T; | |
90 | pub fn atomic_and_relaxed<T>(dst: *mut T, src: T) -> T; | |
91 | ||
92 | pub fn atomic_nand<T>(dst: *mut T, src: T) -> T; | |
93 | pub fn atomic_nand_acq<T>(dst: *mut T, src: T) -> T; | |
94 | pub fn atomic_nand_rel<T>(dst: *mut T, src: T) -> T; | |
95 | pub fn atomic_nand_acqrel<T>(dst: *mut T, src: T) -> T; | |
96 | pub fn atomic_nand_relaxed<T>(dst: *mut T, src: T) -> T; | |
97 | ||
98 | pub fn atomic_or<T>(dst: *mut T, src: T) -> T; | |
99 | pub fn atomic_or_acq<T>(dst: *mut T, src: T) -> T; | |
100 | pub fn atomic_or_rel<T>(dst: *mut T, src: T) -> T; | |
101 | pub fn atomic_or_acqrel<T>(dst: *mut T, src: T) -> T; | |
102 | pub fn atomic_or_relaxed<T>(dst: *mut T, src: T) -> T; | |
103 | ||
104 | pub fn atomic_xor<T>(dst: *mut T, src: T) -> T; | |
105 | pub fn atomic_xor_acq<T>(dst: *mut T, src: T) -> T; | |
106 | pub fn atomic_xor_rel<T>(dst: *mut T, src: T) -> T; | |
107 | pub fn atomic_xor_acqrel<T>(dst: *mut T, src: T) -> T; | |
108 | pub fn atomic_xor_relaxed<T>(dst: *mut T, src: T) -> T; | |
109 | ||
110 | pub fn atomic_max<T>(dst: *mut T, src: T) -> T; | |
111 | pub fn atomic_max_acq<T>(dst: *mut T, src: T) -> T; | |
112 | pub fn atomic_max_rel<T>(dst: *mut T, src: T) -> T; | |
113 | pub fn atomic_max_acqrel<T>(dst: *mut T, src: T) -> T; | |
114 | pub fn atomic_max_relaxed<T>(dst: *mut T, src: T) -> T; | |
115 | ||
116 | pub fn atomic_min<T>(dst: *mut T, src: T) -> T; | |
117 | pub fn atomic_min_acq<T>(dst: *mut T, src: T) -> T; | |
118 | pub fn atomic_min_rel<T>(dst: *mut T, src: T) -> T; | |
119 | pub fn atomic_min_acqrel<T>(dst: *mut T, src: T) -> T; | |
120 | pub fn atomic_min_relaxed<T>(dst: *mut T, src: T) -> T; | |
121 | ||
122 | pub fn atomic_umin<T>(dst: *mut T, src: T) -> T; | |
123 | pub fn atomic_umin_acq<T>(dst: *mut T, src: T) -> T; | |
124 | pub fn atomic_umin_rel<T>(dst: *mut T, src: T) -> T; | |
125 | pub fn atomic_umin_acqrel<T>(dst: *mut T, src: T) -> T; | |
126 | pub fn atomic_umin_relaxed<T>(dst: *mut T, src: T) -> T; | |
127 | ||
128 | pub fn atomic_umax<T>(dst: *mut T, src: T) -> T; | |
129 | pub fn atomic_umax_acq<T>(dst: *mut T, src: T) -> T; | |
130 | pub fn atomic_umax_rel<T>(dst: *mut T, src: T) -> T; | |
131 | pub fn atomic_umax_acqrel<T>(dst: *mut T, src: T) -> T; | |
132 | pub fn atomic_umax_relaxed<T>(dst: *mut T, src: T) -> T; | |
133 | } | |
134 | ||
135 | extern "rust-intrinsic" { | |
136 | ||
137 | pub fn atomic_fence(); | |
138 | pub fn atomic_fence_acq(); | |
139 | pub fn atomic_fence_rel(); | |
140 | pub fn atomic_fence_acqrel(); | |
141 | ||
d9579d0f AL |
142 | /// A compiler-only memory barrier. |
143 | /// | |
144 | /// Memory accesses will never be reordered across this barrier by the compiler, | |
145 | /// but no instructions will be emitted for it. This is appropriate for operations | |
146 | /// on the same thread that may be preempted, such as when interacting with signal | |
147 | /// handlers. | |
148 | #[cfg(not(stage0))] // SNAP 857ef6e | |
149 | pub fn atomic_singlethreadfence(); | |
150 | #[cfg(not(stage0))] // SNAP 857ef6e | |
151 | pub fn atomic_singlethreadfence_acq(); | |
152 | #[cfg(not(stage0))] // SNAP 857ef6e | |
153 | pub fn atomic_singlethreadfence_rel(); | |
154 | #[cfg(not(stage0))] // SNAP 857ef6e | |
155 | pub fn atomic_singlethreadfence_acqrel(); | |
156 | ||
9346a6ac | 157 | /// Aborts the execution of the process. |
1a4d82fc JJ |
158 | pub fn abort() -> !; |
159 | ||
9346a6ac | 160 | /// Tells LLVM that this point in the code is not reachable, |
1a4d82fc JJ |
161 | /// enabling further optimizations. |
162 | /// | |
163 | /// NB: This is very different from the `unreachable!()` macro! | |
164 | pub fn unreachable() -> !; | |
165 | ||
9346a6ac | 166 | /// Informs the optimizer that a condition is always true. |
1a4d82fc JJ |
167 | /// If the condition is false, the behavior is undefined. |
168 | /// | |
169 | /// No code is generated for this intrinsic, but the optimizer will try | |
170 | /// to preserve it (and its condition) between passes, which may interfere | |
171 | /// with optimization of surrounding code and reduce performance. It should | |
172 | /// not be used if the invariant can be discovered by the optimizer on its | |
173 | /// own, or if it does not enable any significant optimizations. | |
174 | pub fn assume(b: bool); | |
175 | ||
9346a6ac | 176 | /// Executes a breakpoint trap, for inspection by a debugger. |
1a4d82fc JJ |
177 | pub fn breakpoint(); |
178 | ||
179 | /// The size of a type in bytes. | |
180 | /// | |
181 | /// This is the exact number of bytes in memory taken up by a | |
182 | /// value of the given type. In other words, a memset of this size | |
183 | /// would *exactly* overwrite a value. When laid out in vectors | |
184 | /// and structures there may be additional padding between | |
185 | /// elements. | |
85aaf69f | 186 | pub fn size_of<T>() -> usize; |
1a4d82fc | 187 | |
9346a6ac | 188 | /// Moves a value to an uninitialized memory location. |
1a4d82fc JJ |
189 | /// |
190 | /// Drop glue is not run on the destination. | |
191 | pub fn move_val_init<T>(dst: &mut T, src: T); | |
192 | ||
85aaf69f SL |
193 | pub fn min_align_of<T>() -> usize; |
194 | pub fn pref_align_of<T>() -> usize; | |
1a4d82fc | 195 | |
d9579d0f AL |
196 | #[cfg(not(stage0))] |
197 | pub fn size_of_val<T: ?Sized>(_: &T) -> usize; | |
198 | #[cfg(not(stage0))] | |
199 | pub fn min_align_of_val<T: ?Sized>(_: &T) -> usize; | |
200 | #[cfg(not(stage0))] | |
201 | pub fn drop_in_place<T: ?Sized>(_: *mut T); | |
202 | ||
c34b1796 AL |
203 | /// Gets a static string slice containing the name of a type. |
204 | pub fn type_name<T: ?Sized>() -> &'static str; | |
1a4d82fc JJ |
205 | |
206 | /// Gets an identifier which is globally unique to the specified type. This | |
207 | /// function will return the same value for a type regardless of whichever | |
208 | /// crate it is invoked in. | |
85aaf69f | 209 | pub fn type_id<T: ?Sized + 'static>() -> u64; |
1a4d82fc | 210 | |
9346a6ac | 211 | /// Creates a value initialized to so that its drop flag, |
c34b1796 AL |
212 | /// if any, says that it has been dropped. |
213 | /// | |
214 | /// `init_dropped` is unsafe because it returns a datum with all | |
215 | /// of its bytes set to the drop flag, which generally does not | |
216 | /// correspond to a valid value. | |
217 | /// | |
218 | /// This intrinsic is likely to be deprecated in the future when | |
219 | /// Rust moves to non-zeroing dynamic drop (and thus removes the | |
220 | /// embedded drop flags that are being established by this | |
221 | /// intrinsic). | |
222 | pub fn init_dropped<T>() -> T; | |
223 | ||
9346a6ac | 224 | /// Creates a value initialized to zero. |
1a4d82fc JJ |
225 | /// |
226 | /// `init` is unsafe because it returns a zeroed-out datum, | |
c34b1796 AL |
227 | /// which is unsafe unless T is `Copy`. Also, even if T is |
228 | /// `Copy`, an all-zero value may not correspond to any legitimate | |
229 | /// state for the type in question. | |
1a4d82fc JJ |
230 | pub fn init<T>() -> T; |
231 | ||
9346a6ac | 232 | /// Creates an uninitialized value. |
c34b1796 AL |
233 | /// |
234 | /// `uninit` is unsafe because there is no guarantee of what its | |
235 | /// contents are. In particular its drop-flag may be set to any | |
236 | /// state, which means it may claim either dropped or | |
237 | /// undropped. In the general case one must use `ptr::write` to | |
238 | /// initialize memory previous set to the result of `uninit`. | |
1a4d82fc JJ |
239 | pub fn uninit<T>() -> T; |
240 | ||
9346a6ac | 241 | /// Moves a value out of scope without running drop glue. |
1a4d82fc JJ |
242 | pub fn forget<T>(_: T) -> (); |
243 | ||
244 | /// Unsafely transforms a value of one type into a value of another type. | |
245 | /// | |
85aaf69f | 246 | /// Both types must have the same size. |
1a4d82fc JJ |
247 | /// |
248 | /// # Examples | |
249 | /// | |
85aaf69f | 250 | /// ``` |
1a4d82fc JJ |
251 | /// use std::mem; |
252 | /// | |
253 | /// let v: &[u8] = unsafe { mem::transmute("L") }; | |
c34b1796 | 254 | /// assert!(v == [76]); |
1a4d82fc | 255 | /// ``` |
85aaf69f | 256 | #[stable(feature = "rust1", since = "1.0.0")] |
1a4d82fc JJ |
257 | pub fn transmute<T,U>(e: T) -> U; |
258 | ||
259 | /// Gives the address for the return value of the enclosing function. | |
260 | /// | |
261 | /// Using this intrinsic in a function that does not use an out pointer | |
262 | /// will trigger a compiler error. | |
263 | pub fn return_address() -> *const u8; | |
264 | ||
c34b1796 AL |
265 | /// Returns `true` if the actual type given as `T` requires drop |
266 | /// glue; returns `false` if the actual type provided for `T` | |
267 | /// implements `Copy`. | |
268 | /// | |
269 | /// If the actual type neither requires drop glue nor implements | |
270 | /// `Copy`, then may return `true` or `false`. | |
1a4d82fc JJ |
271 | pub fn needs_drop<T>() -> bool; |
272 | ||
d9579d0f | 273 | /// Calculates the offset from a pointer. |
1a4d82fc JJ |
274 | /// |
275 | /// This is implemented as an intrinsic to avoid converting to and from an | |
276 | /// integer, since the conversion would throw away aliasing information. | |
d9579d0f AL |
277 | /// |
278 | /// # Safety | |
279 | /// | |
280 | /// Both the starting and resulting pointer must be either in bounds or one | |
281 | /// byte past the end of an allocated object. If either pointer is out of | |
282 | /// bounds or arithmetic overflow occurs then any further use of the | |
283 | /// returned value will result in undefined behavior. | |
85aaf69f | 284 | pub fn offset<T>(dst: *const T, offset: isize) -> *const T; |
1a4d82fc JJ |
285 | |
286 | /// Copies `count * size_of<T>` bytes from `src` to `dst`. The source | |
287 | /// and destination may *not* overlap. | |
288 | /// | |
c34b1796 | 289 | /// `copy_nonoverlapping` is semantically equivalent to C's `memcpy`. |
1a4d82fc JJ |
290 | /// |
291 | /// # Safety | |
292 | /// | |
85aaf69f SL |
293 | /// Beyond requiring that the program must be allowed to access both regions |
294 | /// of memory, it is Undefined Behaviour for source and destination to | |
295 | /// overlap. Care must also be taken with the ownership of `src` and | |
296 | /// `dst`. This method semantically moves the values of `src` into `dst`. | |
297 | /// However it does not drop the contents of `dst`, or prevent the contents | |
298 | /// of `src` from being dropped or used. | |
1a4d82fc JJ |
299 | /// |
300 | /// # Examples | |
301 | /// | |
302 | /// A safe swap function: | |
303 | /// | |
304 | /// ``` | |
c34b1796 | 305 | /// # #![feature(core)] |
1a4d82fc JJ |
306 | /// use std::mem; |
307 | /// use std::ptr; | |
308 | /// | |
309 | /// fn swap<T>(x: &mut T, y: &mut T) { | |
310 | /// unsafe { | |
311 | /// // Give ourselves some scratch space to work with | |
312 | /// let mut t: T = mem::uninitialized(); | |
313 | /// | |
314 | /// // Perform the swap, `&mut` pointers never alias | |
c34b1796 AL |
315 | /// ptr::copy_nonoverlapping(x, &mut t, 1); |
316 | /// ptr::copy_nonoverlapping(y, x, 1); | |
317 | /// ptr::copy_nonoverlapping(&t, y, 1); | |
1a4d82fc JJ |
318 | /// |
319 | /// // y and t now point to the same thing, but we need to completely forget `tmp` | |
320 | /// // because it's no longer relevant. | |
321 | /// mem::forget(t); | |
322 | /// } | |
323 | /// } | |
324 | /// ``` | |
c34b1796 | 325 | #[stable(feature = "rust1", since = "1.0.0")] |
c34b1796 AL |
326 | pub fn copy_nonoverlapping<T>(src: *const T, dst: *mut T, count: usize); |
327 | ||
1a4d82fc JJ |
328 | /// Copies `count * size_of<T>` bytes from `src` to `dst`. The source |
329 | /// and destination may overlap. | |
330 | /// | |
c34b1796 | 331 | /// `copy` is semantically equivalent to C's `memmove`. |
1a4d82fc JJ |
332 | /// |
333 | /// # Safety | |
334 | /// | |
335 | /// Care must be taken with the ownership of `src` and `dst`. | |
336 | /// This method semantically moves the values of `src` into `dst`. | |
337 | /// However it does not drop the contents of `dst`, or prevent the contents of `src` | |
338 | /// from being dropped or used. | |
339 | /// | |
340 | /// # Examples | |
341 | /// | |
342 | /// Efficiently create a Rust vector from an unsafe buffer: | |
343 | /// | |
344 | /// ``` | |
c34b1796 | 345 | /// # #![feature(core)] |
1a4d82fc JJ |
346 | /// use std::ptr; |
347 | /// | |
c34b1796 | 348 | /// unsafe fn from_buf_raw<T>(ptr: *const T, elts: usize) -> Vec<T> { |
1a4d82fc JJ |
349 | /// let mut dst = Vec::with_capacity(elts); |
350 | /// dst.set_len(elts); | |
c34b1796 | 351 | /// ptr::copy(ptr, dst.as_mut_ptr(), elts); |
1a4d82fc JJ |
352 | /// dst |
353 | /// } | |
354 | /// ``` | |
355 | /// | |
c34b1796 | 356 | #[stable(feature = "rust1", since = "1.0.0")] |
c34b1796 AL |
357 | pub fn copy<T>(src: *const T, dst: *mut T, count: usize); |
358 | ||
1a4d82fc JJ |
359 | /// Invokes memset on the specified pointer, setting `count * size_of::<T>()` |
360 | /// bytes of memory starting at `dst` to `c`. | |
c34b1796 AL |
361 | #[stable(feature = "rust1", since = "1.0.0")] |
362 | pub fn write_bytes<T>(dst: *mut T, val: u8, count: usize); | |
1a4d82fc JJ |
363 | |
364 | /// Equivalent to the appropriate `llvm.memcpy.p0i8.0i8.*` intrinsic, with | |
365 | /// a size of `count` * `size_of::<T>()` and an alignment of | |
366 | /// `min_align_of::<T>()` | |
367 | /// | |
368 | /// The volatile parameter parameter is set to `true`, so it will not be optimized out. | |
369 | pub fn volatile_copy_nonoverlapping_memory<T>(dst: *mut T, src: *const T, | |
85aaf69f | 370 | count: usize); |
1a4d82fc JJ |
371 | /// Equivalent to the appropriate `llvm.memmove.p0i8.0i8.*` intrinsic, with |
372 | /// a size of `count` * `size_of::<T>()` and an alignment of | |
373 | /// `min_align_of::<T>()` | |
374 | /// | |
375 | /// The volatile parameter parameter is set to `true`, so it will not be optimized out. | |
85aaf69f | 376 | pub fn volatile_copy_memory<T>(dst: *mut T, src: *const T, count: usize); |
1a4d82fc JJ |
377 | /// Equivalent to the appropriate `llvm.memset.p0i8.*` intrinsic, with a |
378 | /// size of `count` * `size_of::<T>()` and an alignment of | |
379 | /// `min_align_of::<T>()`. | |
380 | /// | |
381 | /// The volatile parameter parameter is set to `true`, so it will not be optimized out. | |
85aaf69f | 382 | pub fn volatile_set_memory<T>(dst: *mut T, val: u8, count: usize); |
1a4d82fc JJ |
383 | |
384 | /// Perform a volatile load from the `src` pointer. | |
385 | pub fn volatile_load<T>(src: *const T) -> T; | |
386 | /// Perform a volatile store to the `dst` pointer. | |
387 | pub fn volatile_store<T>(dst: *mut T, val: T); | |
388 | ||
389 | /// Returns the square root of an `f32` | |
390 | pub fn sqrtf32(x: f32) -> f32; | |
391 | /// Returns the square root of an `f64` | |
392 | pub fn sqrtf64(x: f64) -> f64; | |
393 | ||
394 | /// Raises an `f32` to an integer power. | |
395 | pub fn powif32(a: f32, x: i32) -> f32; | |
396 | /// Raises an `f64` to an integer power. | |
397 | pub fn powif64(a: f64, x: i32) -> f64; | |
398 | ||
399 | /// Returns the sine of an `f32`. | |
400 | pub fn sinf32(x: f32) -> f32; | |
401 | /// Returns the sine of an `f64`. | |
402 | pub fn sinf64(x: f64) -> f64; | |
403 | ||
404 | /// Returns the cosine of an `f32`. | |
405 | pub fn cosf32(x: f32) -> f32; | |
406 | /// Returns the cosine of an `f64`. | |
407 | pub fn cosf64(x: f64) -> f64; | |
408 | ||
409 | /// Raises an `f32` to an `f32` power. | |
410 | pub fn powf32(a: f32, x: f32) -> f32; | |
411 | /// Raises an `f64` to an `f64` power. | |
412 | pub fn powf64(a: f64, x: f64) -> f64; | |
413 | ||
414 | /// Returns the exponential of an `f32`. | |
415 | pub fn expf32(x: f32) -> f32; | |
416 | /// Returns the exponential of an `f64`. | |
417 | pub fn expf64(x: f64) -> f64; | |
418 | ||
419 | /// Returns 2 raised to the power of an `f32`. | |
420 | pub fn exp2f32(x: f32) -> f32; | |
421 | /// Returns 2 raised to the power of an `f64`. | |
422 | pub fn exp2f64(x: f64) -> f64; | |
423 | ||
424 | /// Returns the natural logarithm of an `f32`. | |
425 | pub fn logf32(x: f32) -> f32; | |
426 | /// Returns the natural logarithm of an `f64`. | |
427 | pub fn logf64(x: f64) -> f64; | |
428 | ||
429 | /// Returns the base 10 logarithm of an `f32`. | |
430 | pub fn log10f32(x: f32) -> f32; | |
431 | /// Returns the base 10 logarithm of an `f64`. | |
432 | pub fn log10f64(x: f64) -> f64; | |
433 | ||
434 | /// Returns the base 2 logarithm of an `f32`. | |
435 | pub fn log2f32(x: f32) -> f32; | |
436 | /// Returns the base 2 logarithm of an `f64`. | |
437 | pub fn log2f64(x: f64) -> f64; | |
438 | ||
439 | /// Returns `a * b + c` for `f32` values. | |
440 | pub fn fmaf32(a: f32, b: f32, c: f32) -> f32; | |
441 | /// Returns `a * b + c` for `f64` values. | |
442 | pub fn fmaf64(a: f64, b: f64, c: f64) -> f64; | |
443 | ||
444 | /// Returns the absolute value of an `f32`. | |
445 | pub fn fabsf32(x: f32) -> f32; | |
446 | /// Returns the absolute value of an `f64`. | |
447 | pub fn fabsf64(x: f64) -> f64; | |
448 | ||
449 | /// Copies the sign from `y` to `x` for `f32` values. | |
450 | pub fn copysignf32(x: f32, y: f32) -> f32; | |
451 | /// Copies the sign from `y` to `x` for `f64` values. | |
452 | pub fn copysignf64(x: f64, y: f64) -> f64; | |
453 | ||
454 | /// Returns the largest integer less than or equal to an `f32`. | |
455 | pub fn floorf32(x: f32) -> f32; | |
456 | /// Returns the largest integer less than or equal to an `f64`. | |
457 | pub fn floorf64(x: f64) -> f64; | |
458 | ||
459 | /// Returns the smallest integer greater than or equal to an `f32`. | |
460 | pub fn ceilf32(x: f32) -> f32; | |
461 | /// Returns the smallest integer greater than or equal to an `f64`. | |
462 | pub fn ceilf64(x: f64) -> f64; | |
463 | ||
464 | /// Returns the integer part of an `f32`. | |
465 | pub fn truncf32(x: f32) -> f32; | |
466 | /// Returns the integer part of an `f64`. | |
467 | pub fn truncf64(x: f64) -> f64; | |
468 | ||
469 | /// Returns the nearest integer to an `f32`. May raise an inexact floating-point exception | |
470 | /// if the argument is not an integer. | |
471 | pub fn rintf32(x: f32) -> f32; | |
472 | /// Returns the nearest integer to an `f64`. May raise an inexact floating-point exception | |
473 | /// if the argument is not an integer. | |
474 | pub fn rintf64(x: f64) -> f64; | |
475 | ||
476 | /// Returns the nearest integer to an `f32`. | |
477 | pub fn nearbyintf32(x: f32) -> f32; | |
478 | /// Returns the nearest integer to an `f64`. | |
479 | pub fn nearbyintf64(x: f64) -> f64; | |
480 | ||
481 | /// Returns the nearest integer to an `f32`. Rounds half-way cases away from zero. | |
482 | pub fn roundf32(x: f32) -> f32; | |
483 | /// Returns the nearest integer to an `f64`. Rounds half-way cases away from zero. | |
484 | pub fn roundf64(x: f64) -> f64; | |
485 | ||
486 | /// Returns the number of bits set in a `u8`. | |
487 | pub fn ctpop8(x: u8) -> u8; | |
488 | /// Returns the number of bits set in a `u16`. | |
489 | pub fn ctpop16(x: u16) -> u16; | |
490 | /// Returns the number of bits set in a `u32`. | |
491 | pub fn ctpop32(x: u32) -> u32; | |
492 | /// Returns the number of bits set in a `u64`. | |
493 | pub fn ctpop64(x: u64) -> u64; | |
494 | ||
495 | /// Returns the number of leading bits unset in a `u8`. | |
496 | pub fn ctlz8(x: u8) -> u8; | |
497 | /// Returns the number of leading bits unset in a `u16`. | |
498 | pub fn ctlz16(x: u16) -> u16; | |
499 | /// Returns the number of leading bits unset in a `u32`. | |
500 | pub fn ctlz32(x: u32) -> u32; | |
501 | /// Returns the number of leading bits unset in a `u64`. | |
502 | pub fn ctlz64(x: u64) -> u64; | |
503 | ||
504 | /// Returns the number of trailing bits unset in a `u8`. | |
505 | pub fn cttz8(x: u8) -> u8; | |
506 | /// Returns the number of trailing bits unset in a `u16`. | |
507 | pub fn cttz16(x: u16) -> u16; | |
508 | /// Returns the number of trailing bits unset in a `u32`. | |
509 | pub fn cttz32(x: u32) -> u32; | |
510 | /// Returns the number of trailing bits unset in a `u64`. | |
511 | pub fn cttz64(x: u64) -> u64; | |
512 | ||
513 | /// Reverses the bytes in a `u16`. | |
514 | pub fn bswap16(x: u16) -> u16; | |
515 | /// Reverses the bytes in a `u32`. | |
516 | pub fn bswap32(x: u32) -> u32; | |
517 | /// Reverses the bytes in a `u64`. | |
518 | pub fn bswap64(x: u64) -> u64; | |
519 | ||
520 | /// Performs checked `i8` addition. | |
521 | pub fn i8_add_with_overflow(x: i8, y: i8) -> (i8, bool); | |
522 | /// Performs checked `i16` addition. | |
523 | pub fn i16_add_with_overflow(x: i16, y: i16) -> (i16, bool); | |
524 | /// Performs checked `i32` addition. | |
525 | pub fn i32_add_with_overflow(x: i32, y: i32) -> (i32, bool); | |
526 | /// Performs checked `i64` addition. | |
527 | pub fn i64_add_with_overflow(x: i64, y: i64) -> (i64, bool); | |
528 | ||
529 | /// Performs checked `u8` addition. | |
530 | pub fn u8_add_with_overflow(x: u8, y: u8) -> (u8, bool); | |
531 | /// Performs checked `u16` addition. | |
532 | pub fn u16_add_with_overflow(x: u16, y: u16) -> (u16, bool); | |
533 | /// Performs checked `u32` addition. | |
534 | pub fn u32_add_with_overflow(x: u32, y: u32) -> (u32, bool); | |
535 | /// Performs checked `u64` addition. | |
536 | pub fn u64_add_with_overflow(x: u64, y: u64) -> (u64, bool); | |
537 | ||
538 | /// Performs checked `i8` subtraction. | |
539 | pub fn i8_sub_with_overflow(x: i8, y: i8) -> (i8, bool); | |
540 | /// Performs checked `i16` subtraction. | |
541 | pub fn i16_sub_with_overflow(x: i16, y: i16) -> (i16, bool); | |
542 | /// Performs checked `i32` subtraction. | |
543 | pub fn i32_sub_with_overflow(x: i32, y: i32) -> (i32, bool); | |
544 | /// Performs checked `i64` subtraction. | |
545 | pub fn i64_sub_with_overflow(x: i64, y: i64) -> (i64, bool); | |
546 | ||
547 | /// Performs checked `u8` subtraction. | |
548 | pub fn u8_sub_with_overflow(x: u8, y: u8) -> (u8, bool); | |
549 | /// Performs checked `u16` subtraction. | |
550 | pub fn u16_sub_with_overflow(x: u16, y: u16) -> (u16, bool); | |
551 | /// Performs checked `u32` subtraction. | |
552 | pub fn u32_sub_with_overflow(x: u32, y: u32) -> (u32, bool); | |
553 | /// Performs checked `u64` subtraction. | |
554 | pub fn u64_sub_with_overflow(x: u64, y: u64) -> (u64, bool); | |
555 | ||
556 | /// Performs checked `i8` multiplication. | |
557 | pub fn i8_mul_with_overflow(x: i8, y: i8) -> (i8, bool); | |
558 | /// Performs checked `i16` multiplication. | |
559 | pub fn i16_mul_with_overflow(x: i16, y: i16) -> (i16, bool); | |
560 | /// Performs checked `i32` multiplication. | |
561 | pub fn i32_mul_with_overflow(x: i32, y: i32) -> (i32, bool); | |
562 | /// Performs checked `i64` multiplication. | |
563 | pub fn i64_mul_with_overflow(x: i64, y: i64) -> (i64, bool); | |
564 | ||
565 | /// Performs checked `u8` multiplication. | |
566 | pub fn u8_mul_with_overflow(x: u8, y: u8) -> (u8, bool); | |
567 | /// Performs checked `u16` multiplication. | |
568 | pub fn u16_mul_with_overflow(x: u16, y: u16) -> (u16, bool); | |
569 | /// Performs checked `u32` multiplication. | |
570 | pub fn u32_mul_with_overflow(x: u32, y: u32) -> (u32, bool); | |
571 | /// Performs checked `u64` multiplication. | |
572 | pub fn u64_mul_with_overflow(x: u64, y: u64) -> (u64, bool); | |
c34b1796 AL |
573 | |
574 | /// Returns (a + b) mod 2^N, where N is the width of N in bits. | |
575 | pub fn overflowing_add<T>(a: T, b: T) -> T; | |
576 | /// Returns (a - b) mod 2^N, where N is the width of N in bits. | |
577 | pub fn overflowing_sub<T>(a: T, b: T) -> T; | |
578 | /// Returns (a * b) mod 2^N, where N is the width of N in bits. | |
579 | pub fn overflowing_mul<T>(a: T, b: T) -> T; | |
9346a6ac AL |
580 | |
581 | /// Returns the value of the discriminant for the variant in 'v', | |
582 | /// cast to a `u64`; if `T` has no discriminant, returns 0. | |
9346a6ac | 583 | pub fn discriminant_value<T>(v: &T) -> u64; |
1a4d82fc | 584 | } |
d9579d0f AL |
585 | |
586 | #[cfg(not(stage0))] | |
587 | extern "rust-intrinsic" { | |
588 | /// Performs an unchecked signed division, which results in undefined behavior, | |
589 | /// in cases where y == 0, or x == int::MIN and y == -1 | |
590 | pub fn unchecked_sdiv<T>(x: T, y: T) -> T; | |
591 | /// Performs an unchecked unsigned division, which results in undefined behavior, | |
592 | /// in cases where y == 0 | |
593 | pub fn unchecked_udiv<T>(x: T, y: T) -> T; | |
594 | ||
595 | /// Returns the remainder of an unchecked signed division, which results in | |
596 | /// undefined behavior, in cases where y == 0, or x == int::MIN and y == -1 | |
597 | pub fn unchecked_urem<T>(x: T, y: T) -> T; | |
598 | /// Returns the remainder of an unchecked signed division, which results in | |
599 | /// undefined behavior, in cases where y == 0 | |
600 | pub fn unchecked_srem<T>(x: T, y: T) -> T; | |
601 | } |