rustc_hir_analysis/check/
intrinsic.rs

1//! Type-checking for the `#[rustc_intrinsic]` intrinsics that the compiler exposes.
2
3use rustc_abi::ExternAbi;
4use rustc_errors::DiagMessage;
5use rustc_hir::{self as hir, LangItem};
6use rustc_middle::traits::{ObligationCause, ObligationCauseCode};
7use rustc_middle::ty::{self, Ty, TyCtxt};
8use rustc_span::def_id::LocalDefId;
9use rustc_span::{Span, Symbol, sym};
10
11use crate::check::check_function_signature;
12use crate::errors::{
13    UnrecognizedAtomicOperation, UnrecognizedIntrinsicFunction,
14    WrongNumberOfGenericArgumentsToIntrinsic,
15};
16
17fn equate_intrinsic_type<'tcx>(
18    tcx: TyCtxt<'tcx>,
19    span: Span,
20    def_id: LocalDefId,
21    n_tps: usize,
22    n_lts: usize,
23    n_cts: usize,
24    sig: ty::PolyFnSig<'tcx>,
25) {
26    let (generics, span) = match tcx.hir_node_by_def_id(def_id) {
27        hir::Node::Item(hir::Item { kind: hir::ItemKind::Fn { generics, .. }, .. }) => {
28            (tcx.generics_of(def_id), generics.span)
29        }
30        _ => tcx.dcx().span_bug(span, "intrinsic must be a function"),
31    };
32    let own_counts = generics.own_counts();
33
34    let gen_count_ok = |found: usize, expected: usize, descr: &str| -> bool {
35        if found != expected {
36            tcx.dcx().emit_err(WrongNumberOfGenericArgumentsToIntrinsic {
37                span,
38                found,
39                expected,
40                descr,
41            });
42            false
43        } else {
44            true
45        }
46    };
47
48    // the host effect param should be invisible as it shouldn't matter
49    // whether effects is enabled for the intrinsic provider crate.
50    if gen_count_ok(own_counts.lifetimes, n_lts, "lifetime")
51        && gen_count_ok(own_counts.types, n_tps, "type")
52        && gen_count_ok(own_counts.consts, n_cts, "const")
53    {
54        let _ = check_function_signature(
55            tcx,
56            ObligationCause::new(span, def_id, ObligationCauseCode::IntrinsicType),
57            def_id.into(),
58            sig,
59        );
60    }
61}
62
63/// Returns the unsafety of the given intrinsic.
64fn intrinsic_operation_unsafety(tcx: TyCtxt<'_>, intrinsic_id: LocalDefId) -> hir::Safety {
65    let is_in_list = match tcx.item_name(intrinsic_id.into()) {
66        // When adding a new intrinsic to this list,
67        // it's usually worth updating that intrinsic's documentation
68        // to note that it's safe to call, since
69        // safe extern fns are otherwise unprecedented.
70        sym::abort
71        | sym::assert_inhabited
72        | sym::assert_zero_valid
73        | sym::assert_mem_uninitialized_valid
74        | sym::box_new
75        | sym::breakpoint
76        | sym::size_of
77        | sym::min_align_of
78        | sym::needs_drop
79        | sym::caller_location
80        | sym::add_with_overflow
81        | sym::sub_with_overflow
82        | sym::mul_with_overflow
83        | sym::carrying_mul_add
84        | sym::wrapping_add
85        | sym::wrapping_sub
86        | sym::wrapping_mul
87        | sym::saturating_add
88        | sym::saturating_sub
89        | sym::rotate_left
90        | sym::rotate_right
91        | sym::ctpop
92        | sym::ctlz
93        | sym::cttz
94        | sym::bswap
95        | sym::bitreverse
96        | sym::three_way_compare
97        | sym::discriminant_value
98        | sym::type_id
99        | sym::select_unpredictable
100        | sym::cold_path
101        | sym::ptr_guaranteed_cmp
102        | sym::minnumf16
103        | sym::minnumf32
104        | sym::minnumf64
105        | sym::minnumf128
106        | sym::maxnumf16
107        | sym::maxnumf32
108        | sym::maxnumf64
109        | sym::maxnumf128
110        | sym::rustc_peek
111        | sym::type_name
112        | sym::forget
113        | sym::black_box
114        | sym::variant_count
115        | sym::is_val_statically_known
116        | sym::ptr_mask
117        | sym::aggregate_raw_ptr
118        | sym::ptr_metadata
119        | sym::ub_checks
120        | sym::contract_checks
121        | sym::contract_check_requires
122        | sym::contract_check_ensures
123        | sym::fadd_algebraic
124        | sym::fsub_algebraic
125        | sym::fmul_algebraic
126        | sym::fdiv_algebraic
127        | sym::frem_algebraic
128        | sym::round_ties_even_f16
129        | sym::round_ties_even_f32
130        | sym::round_ties_even_f64
131        | sym::round_ties_even_f128
132        | sym::const_eval_select => hir::Safety::Safe,
133        _ => hir::Safety::Unsafe,
134    };
135
136    if tcx.fn_sig(intrinsic_id).skip_binder().safety() != is_in_list {
137        tcx.dcx().struct_span_err(
138            tcx.def_span(intrinsic_id),
139            DiagMessage::from(format!(
140                "intrinsic safety mismatch between list of intrinsics within the compiler and core library intrinsics for intrinsic `{}`",
141                tcx.item_name(intrinsic_id.into())
142            )
143        )).emit();
144    }
145
146    is_in_list
147}
148
149/// Remember to add all intrinsics here, in `compiler/rustc_codegen_llvm/src/intrinsic.rs`,
150/// and in `library/core/src/intrinsics.rs`.
151pub(crate) fn check_intrinsic_type(
152    tcx: TyCtxt<'_>,
153    intrinsic_id: LocalDefId,
154    span: Span,
155    intrinsic_name: Symbol,
156) {
157    let generics = tcx.generics_of(intrinsic_id);
158    let param = |n| {
159        if let &ty::GenericParamDef { name, kind: ty::GenericParamDefKind::Type { .. }, .. } =
160            generics.param_at(n as usize, tcx)
161        {
162            Ty::new_param(tcx, n, name)
163        } else {
164            Ty::new_error_with_message(tcx, span, "expected param")
165        }
166    };
167    let name_str = intrinsic_name.as_str();
168
169    let bound_vars = tcx.mk_bound_variable_kinds(&[
170        ty::BoundVariableKind::Region(ty::BoundRegionKind::Anon),
171        ty::BoundVariableKind::Region(ty::BoundRegionKind::Anon),
172        ty::BoundVariableKind::Region(ty::BoundRegionKind::ClosureEnv),
173    ]);
174    let mk_va_list_ty = |mutbl| {
175        let did = tcx.require_lang_item(LangItem::VaList, Some(span));
176        let region = ty::Region::new_bound(
177            tcx,
178            ty::INNERMOST,
179            ty::BoundRegion { var: ty::BoundVar::ZERO, kind: ty::BoundRegionKind::Anon },
180        );
181        let env_region = ty::Region::new_bound(
182            tcx,
183            ty::INNERMOST,
184            ty::BoundRegion {
185                var: ty::BoundVar::from_u32(2),
186                kind: ty::BoundRegionKind::ClosureEnv,
187            },
188        );
189        let va_list_ty = tcx.type_of(did).instantiate(tcx, &[region.into()]);
190        (Ty::new_ref(tcx, env_region, va_list_ty, mutbl), va_list_ty)
191    };
192
193    let (n_tps, n_lts, n_cts, inputs, output, safety) = if name_str.starts_with("atomic_") {
194        let split: Vec<&str> = name_str.split('_').collect();
195        assert!(split.len() >= 2, "Atomic intrinsic in an incorrect format");
196
197        // Each atomic op has variants with different suffixes (`_seq_cst`, `_acquire`, etc.). Use
198        // string ops to strip the suffixes, because the variants all get the same treatment here.
199        let (n_tps, inputs, output) = match split[1] {
200            "cxchg" | "cxchgweak" => (
201                1,
202                vec![Ty::new_mut_ptr(tcx, param(0)), param(0), param(0)],
203                Ty::new_tup(tcx, &[param(0), tcx.types.bool]),
204            ),
205            "load" => (1, vec![Ty::new_imm_ptr(tcx, param(0))], param(0)),
206            "store" => (1, vec![Ty::new_mut_ptr(tcx, param(0)), param(0)], tcx.types.unit),
207
208            "xchg" | "xadd" | "xsub" | "and" | "nand" | "or" | "xor" | "max" | "min" | "umax"
209            | "umin" => (1, vec![Ty::new_mut_ptr(tcx, param(0)), param(0)], param(0)),
210            "fence" | "singlethreadfence" => (0, Vec::new(), tcx.types.unit),
211            op => {
212                tcx.dcx().emit_err(UnrecognizedAtomicOperation { span, op });
213                return;
214            }
215        };
216        (n_tps, 0, 0, inputs, output, hir::Safety::Unsafe)
217    } else if intrinsic_name == sym::contract_check_ensures {
218        // contract_check_ensures::<Ret, C>(Ret, C) -> Ret
219        // where C: for<'a> Fn(&'a Ret) -> bool,
220        //
221        // so: two type params, 0 lifetime param, 0 const params, two inputs, no return
222        (2, 0, 0, vec![param(0), param(1)], param(1), hir::Safety::Safe)
223    } else {
224        let safety = intrinsic_operation_unsafety(tcx, intrinsic_id);
225        let (n_tps, n_cts, inputs, output) = match intrinsic_name {
226            sym::abort => (0, 0, vec![], tcx.types.never),
227            sym::unreachable => (0, 0, vec![], tcx.types.never),
228            sym::breakpoint => (0, 0, vec![], tcx.types.unit),
229            sym::size_of | sym::pref_align_of | sym::min_align_of | sym::variant_count => {
230                (1, 0, vec![], tcx.types.usize)
231            }
232            sym::size_of_val | sym::min_align_of_val => {
233                (1, 0, vec![Ty::new_imm_ptr(tcx, param(0))], tcx.types.usize)
234            }
235            sym::rustc_peek => (1, 0, vec![param(0)], param(0)),
236            sym::caller_location => (0, 0, vec![], tcx.caller_location_ty()),
237            sym::assert_inhabited
238            | sym::assert_zero_valid
239            | sym::assert_mem_uninitialized_valid => (1, 0, vec![], tcx.types.unit),
240            sym::forget => (1, 0, vec![param(0)], tcx.types.unit),
241            sym::transmute | sym::transmute_unchecked => (2, 0, vec![param(0)], param(1)),
242            sym::prefetch_read_data
243            | sym::prefetch_write_data
244            | sym::prefetch_read_instruction
245            | sym::prefetch_write_instruction => {
246                (1, 0, vec![Ty::new_imm_ptr(tcx, param(0)), tcx.types.i32], tcx.types.unit)
247            }
248            sym::needs_drop => (1, 0, vec![], tcx.types.bool),
249
250            sym::type_name => (1, 0, vec![], Ty::new_static_str(tcx)),
251            sym::type_id => (1, 0, vec![], tcx.types.u128),
252            sym::offset => (2, 0, vec![param(0), param(1)], param(0)),
253            sym::arith_offset => (
254                1,
255                0,
256                vec![Ty::new_imm_ptr(tcx, param(0)), tcx.types.isize],
257                Ty::new_imm_ptr(tcx, param(0)),
258            ),
259            sym::ptr_mask => (
260                1,
261                0,
262                vec![Ty::new_imm_ptr(tcx, param(0)), tcx.types.usize],
263                Ty::new_imm_ptr(tcx, param(0)),
264            ),
265
266            sym::copy | sym::copy_nonoverlapping => (
267                1,
268                0,
269                vec![
270                    Ty::new_imm_ptr(tcx, param(0)),
271                    Ty::new_mut_ptr(tcx, param(0)),
272                    tcx.types.usize,
273                ],
274                tcx.types.unit,
275            ),
276            sym::volatile_copy_memory | sym::volatile_copy_nonoverlapping_memory => (
277                1,
278                0,
279                vec![
280                    Ty::new_mut_ptr(tcx, param(0)),
281                    Ty::new_imm_ptr(tcx, param(0)),
282                    tcx.types.usize,
283                ],
284                tcx.types.unit,
285            ),
286            sym::compare_bytes => {
287                let byte_ptr = Ty::new_imm_ptr(tcx, tcx.types.u8);
288                (0, 0, vec![byte_ptr, byte_ptr, tcx.types.usize], tcx.types.i32)
289            }
290            sym::write_bytes | sym::volatile_set_memory => (
291                1,
292                0,
293                vec![Ty::new_mut_ptr(tcx, param(0)), tcx.types.u8, tcx.types.usize],
294                tcx.types.unit,
295            ),
296
297            sym::sqrtf16 => (0, 0, vec![tcx.types.f16], tcx.types.f16),
298            sym::sqrtf32 => (0, 0, vec![tcx.types.f32], tcx.types.f32),
299            sym::sqrtf64 => (0, 0, vec![tcx.types.f64], tcx.types.f64),
300            sym::sqrtf128 => (0, 0, vec![tcx.types.f128], tcx.types.f128),
301
302            sym::powif16 => (0, 0, vec![tcx.types.f16, tcx.types.i32], tcx.types.f16),
303            sym::powif32 => (0, 0, vec![tcx.types.f32, tcx.types.i32], tcx.types.f32),
304            sym::powif64 => (0, 0, vec![tcx.types.f64, tcx.types.i32], tcx.types.f64),
305            sym::powif128 => (0, 0, vec![tcx.types.f128, tcx.types.i32], tcx.types.f128),
306
307            sym::sinf16 => (0, 0, vec![tcx.types.f16], tcx.types.f16),
308            sym::sinf32 => (0, 0, vec![tcx.types.f32], tcx.types.f32),
309            sym::sinf64 => (0, 0, vec![tcx.types.f64], tcx.types.f64),
310            sym::sinf128 => (0, 0, vec![tcx.types.f128], tcx.types.f128),
311
312            sym::cosf16 => (0, 0, vec![tcx.types.f16], tcx.types.f16),
313            sym::cosf32 => (0, 0, vec![tcx.types.f32], tcx.types.f32),
314            sym::cosf64 => (0, 0, vec![tcx.types.f64], tcx.types.f64),
315            sym::cosf128 => (0, 0, vec![tcx.types.f128], tcx.types.f128),
316
317            sym::powf16 => (0, 0, vec![tcx.types.f16, tcx.types.f16], tcx.types.f16),
318            sym::powf32 => (0, 0, vec![tcx.types.f32, tcx.types.f32], tcx.types.f32),
319            sym::powf64 => (0, 0, vec![tcx.types.f64, tcx.types.f64], tcx.types.f64),
320            sym::powf128 => (0, 0, vec![tcx.types.f128, tcx.types.f128], tcx.types.f128),
321
322            sym::expf16 => (0, 0, vec![tcx.types.f16], tcx.types.f16),
323            sym::expf32 => (0, 0, vec![tcx.types.f32], tcx.types.f32),
324            sym::expf64 => (0, 0, vec![tcx.types.f64], tcx.types.f64),
325            sym::expf128 => (0, 0, vec![tcx.types.f128], tcx.types.f128),
326
327            sym::exp2f16 => (0, 0, vec![tcx.types.f16], tcx.types.f16),
328            sym::exp2f32 => (0, 0, vec![tcx.types.f32], tcx.types.f32),
329            sym::exp2f64 => (0, 0, vec![tcx.types.f64], tcx.types.f64),
330            sym::exp2f128 => (0, 0, vec![tcx.types.f128], tcx.types.f128),
331
332            sym::logf16 => (0, 0, vec![tcx.types.f16], tcx.types.f16),
333            sym::logf32 => (0, 0, vec![tcx.types.f32], tcx.types.f32),
334            sym::logf64 => (0, 0, vec![tcx.types.f64], tcx.types.f64),
335            sym::logf128 => (0, 0, vec![tcx.types.f128], tcx.types.f128),
336
337            sym::log10f16 => (0, 0, vec![tcx.types.f16], tcx.types.f16),
338            sym::log10f32 => (0, 0, vec![tcx.types.f32], tcx.types.f32),
339            sym::log10f64 => (0, 0, vec![tcx.types.f64], tcx.types.f64),
340            sym::log10f128 => (0, 0, vec![tcx.types.f128], tcx.types.f128),
341
342            sym::log2f16 => (0, 0, vec![tcx.types.f16], tcx.types.f16),
343            sym::log2f32 => (0, 0, vec![tcx.types.f32], tcx.types.f32),
344            sym::log2f64 => (0, 0, vec![tcx.types.f64], tcx.types.f64),
345            sym::log2f128 => (0, 0, vec![tcx.types.f128], tcx.types.f128),
346
347            sym::fmaf16 => (0, 0, vec![tcx.types.f16, tcx.types.f16, tcx.types.f16], tcx.types.f16),
348            sym::fmaf32 => (0, 0, vec![tcx.types.f32, tcx.types.f32, tcx.types.f32], tcx.types.f32),
349            sym::fmaf64 => (0, 0, vec![tcx.types.f64, tcx.types.f64, tcx.types.f64], tcx.types.f64),
350            sym::fmaf128 => {
351                (0, 0, vec![tcx.types.f128, tcx.types.f128, tcx.types.f128], tcx.types.f128)
352            }
353
354            sym::fmuladdf16 => {
355                (0, 0, vec![tcx.types.f16, tcx.types.f16, tcx.types.f16], tcx.types.f16)
356            }
357            sym::fmuladdf32 => {
358                (0, 0, vec![tcx.types.f32, tcx.types.f32, tcx.types.f32], tcx.types.f32)
359            }
360            sym::fmuladdf64 => {
361                (0, 0, vec![tcx.types.f64, tcx.types.f64, tcx.types.f64], tcx.types.f64)
362            }
363            sym::fmuladdf128 => {
364                (0, 0, vec![tcx.types.f128, tcx.types.f128, tcx.types.f128], tcx.types.f128)
365            }
366
367            sym::fabsf16 => (0, 0, vec![tcx.types.f16], tcx.types.f16),
368            sym::fabsf32 => (0, 0, vec![tcx.types.f32], tcx.types.f32),
369            sym::fabsf64 => (0, 0, vec![tcx.types.f64], tcx.types.f64),
370            sym::fabsf128 => (0, 0, vec![tcx.types.f128], tcx.types.f128),
371
372            sym::minnumf16 => (0, 0, vec![tcx.types.f16, tcx.types.f16], tcx.types.f16),
373            sym::minnumf32 => (0, 0, vec![tcx.types.f32, tcx.types.f32], tcx.types.f32),
374            sym::minnumf64 => (0, 0, vec![tcx.types.f64, tcx.types.f64], tcx.types.f64),
375            sym::minnumf128 => (0, 0, vec![tcx.types.f128, tcx.types.f128], tcx.types.f128),
376
377            sym::maxnumf16 => (0, 0, vec![tcx.types.f16, tcx.types.f16], tcx.types.f16),
378            sym::maxnumf32 => (0, 0, vec![tcx.types.f32, tcx.types.f32], tcx.types.f32),
379            sym::maxnumf64 => (0, 0, vec![tcx.types.f64, tcx.types.f64], tcx.types.f64),
380            sym::maxnumf128 => (0, 0, vec![tcx.types.f128, tcx.types.f128], tcx.types.f128),
381
382            sym::copysignf16 => (0, 0, vec![tcx.types.f16, tcx.types.f16], tcx.types.f16),
383            sym::copysignf32 => (0, 0, vec![tcx.types.f32, tcx.types.f32], tcx.types.f32),
384            sym::copysignf64 => (0, 0, vec![tcx.types.f64, tcx.types.f64], tcx.types.f64),
385            sym::copysignf128 => (0, 0, vec![tcx.types.f128, tcx.types.f128], tcx.types.f128),
386
387            sym::floorf16 => (0, 0, vec![tcx.types.f16], tcx.types.f16),
388            sym::floorf32 => (0, 0, vec![tcx.types.f32], tcx.types.f32),
389            sym::floorf64 => (0, 0, vec![tcx.types.f64], tcx.types.f64),
390            sym::floorf128 => (0, 0, vec![tcx.types.f128], tcx.types.f128),
391
392            sym::ceilf16 => (0, 0, vec![tcx.types.f16], tcx.types.f16),
393            sym::ceilf32 => (0, 0, vec![tcx.types.f32], tcx.types.f32),
394            sym::ceilf64 => (0, 0, vec![tcx.types.f64], tcx.types.f64),
395            sym::ceilf128 => (0, 0, vec![tcx.types.f128], tcx.types.f128),
396
397            sym::truncf16 => (0, 0, vec![tcx.types.f16], tcx.types.f16),
398            sym::truncf32 => (0, 0, vec![tcx.types.f32], tcx.types.f32),
399            sym::truncf64 => (0, 0, vec![tcx.types.f64], tcx.types.f64),
400            sym::truncf128 => (0, 0, vec![tcx.types.f128], tcx.types.f128),
401
402            sym::round_ties_even_f16 => (0, 0, vec![tcx.types.f16], tcx.types.f16),
403            sym::round_ties_even_f32 => (0, 0, vec![tcx.types.f32], tcx.types.f32),
404            sym::round_ties_even_f64 => (0, 0, vec![tcx.types.f64], tcx.types.f64),
405            sym::round_ties_even_f128 => (0, 0, vec![tcx.types.f128], tcx.types.f128),
406
407            sym::roundf16 => (0, 0, vec![tcx.types.f16], tcx.types.f16),
408            sym::roundf32 => (0, 0, vec![tcx.types.f32], tcx.types.f32),
409            sym::roundf64 => (0, 0, vec![tcx.types.f64], tcx.types.f64),
410            sym::roundf128 => (0, 0, vec![tcx.types.f128], tcx.types.f128),
411
412            sym::volatile_load | sym::unaligned_volatile_load => {
413                (1, 0, vec![Ty::new_imm_ptr(tcx, param(0))], param(0))
414            }
415            sym::volatile_store | sym::unaligned_volatile_store => {
416                (1, 0, vec![Ty::new_mut_ptr(tcx, param(0)), param(0)], tcx.types.unit)
417            }
418
419            sym::ctpop | sym::ctlz | sym::ctlz_nonzero | sym::cttz | sym::cttz_nonzero => {
420                (1, 0, vec![param(0)], tcx.types.u32)
421            }
422
423            sym::bswap | sym::bitreverse => (1, 0, vec![param(0)], param(0)),
424
425            sym::three_way_compare => {
426                (1, 0, vec![param(0), param(0)], tcx.ty_ordering_enum(Some(span)))
427            }
428
429            sym::add_with_overflow | sym::sub_with_overflow | sym::mul_with_overflow => {
430                (1, 0, vec![param(0), param(0)], Ty::new_tup(tcx, &[param(0), tcx.types.bool]))
431            }
432
433            sym::carrying_mul_add => {
434                (2, 0, vec![param(0); 4], Ty::new_tup(tcx, &[param(1), param(0)]))
435            }
436
437            sym::ptr_guaranteed_cmp => (
438                1,
439                0,
440                vec![Ty::new_imm_ptr(tcx, param(0)), Ty::new_imm_ptr(tcx, param(0))],
441                tcx.types.u8,
442            ),
443
444            sym::const_allocate => {
445                (0, 0, vec![tcx.types.usize, tcx.types.usize], Ty::new_mut_ptr(tcx, tcx.types.u8))
446            }
447            sym::const_deallocate => (
448                0,
449                0,
450                vec![Ty::new_mut_ptr(tcx, tcx.types.u8), tcx.types.usize, tcx.types.usize],
451                tcx.types.unit,
452            ),
453
454            sym::ptr_offset_from => (
455                1,
456                0,
457                vec![Ty::new_imm_ptr(tcx, param(0)), Ty::new_imm_ptr(tcx, param(0))],
458                tcx.types.isize,
459            ),
460            sym::ptr_offset_from_unsigned => (
461                1,
462                0,
463                vec![Ty::new_imm_ptr(tcx, param(0)), Ty::new_imm_ptr(tcx, param(0))],
464                tcx.types.usize,
465            ),
466            sym::unchecked_div | sym::unchecked_rem | sym::exact_div | sym::disjoint_bitor => {
467                (1, 0, vec![param(0), param(0)], param(0))
468            }
469            sym::unchecked_shl | sym::unchecked_shr => (2, 0, vec![param(0), param(1)], param(0)),
470            sym::rotate_left | sym::rotate_right => (1, 0, vec![param(0), tcx.types.u32], param(0)),
471            sym::unchecked_add | sym::unchecked_sub | sym::unchecked_mul => {
472                (1, 0, vec![param(0), param(0)], param(0))
473            }
474            sym::wrapping_add | sym::wrapping_sub | sym::wrapping_mul => {
475                (1, 0, vec![param(0), param(0)], param(0))
476            }
477            sym::saturating_add | sym::saturating_sub => (1, 0, vec![param(0), param(0)], param(0)),
478            sym::fadd_fast | sym::fsub_fast | sym::fmul_fast | sym::fdiv_fast | sym::frem_fast => {
479                (1, 0, vec![param(0), param(0)], param(0))
480            }
481            sym::fadd_algebraic
482            | sym::fsub_algebraic
483            | sym::fmul_algebraic
484            | sym::fdiv_algebraic
485            | sym::frem_algebraic => (1, 0, vec![param(0), param(0)], param(0)),
486            sym::float_to_int_unchecked => (2, 0, vec![param(0)], param(1)),
487
488            sym::assume => (0, 0, vec![tcx.types.bool], tcx.types.unit),
489            sym::select_unpredictable => (1, 0, vec![tcx.types.bool, param(0), param(0)], param(0)),
490            sym::cold_path => (0, 0, vec![], tcx.types.unit),
491
492            sym::read_via_copy => (1, 0, vec![Ty::new_imm_ptr(tcx, param(0))], param(0)),
493            sym::write_via_move => {
494                (1, 0, vec![Ty::new_mut_ptr(tcx, param(0)), param(0)], tcx.types.unit)
495            }
496
497            sym::typed_swap_nonoverlapping => {
498                (1, 0, vec![Ty::new_mut_ptr(tcx, param(0)); 2], tcx.types.unit)
499            }
500
501            sym::discriminant_value => {
502                let assoc_items = tcx.associated_item_def_ids(
503                    tcx.require_lang_item(hir::LangItem::DiscriminantKind, None),
504                );
505                let discriminant_def_id = assoc_items[0];
506
507                let br =
508                    ty::BoundRegion { var: ty::BoundVar::ZERO, kind: ty::BoundRegionKind::Anon };
509                (
510                    1,
511                    0,
512                    vec![Ty::new_imm_ref(
513                        tcx,
514                        ty::Region::new_bound(tcx, ty::INNERMOST, br),
515                        param(0),
516                    )],
517                    Ty::new_projection_from_args(
518                        tcx,
519                        discriminant_def_id,
520                        tcx.mk_args(&[param(0).into()]),
521                    ),
522                )
523            }
524
525            sym::catch_unwind => {
526                let mut_u8 = Ty::new_mut_ptr(tcx, tcx.types.u8);
527                let try_fn_ty = ty::Binder::dummy(tcx.mk_fn_sig(
528                    [mut_u8],
529                    tcx.types.unit,
530                    false,
531                    hir::Safety::Safe,
532                    ExternAbi::Rust,
533                ));
534                let catch_fn_ty = ty::Binder::dummy(tcx.mk_fn_sig(
535                    [mut_u8, mut_u8],
536                    tcx.types.unit,
537                    false,
538                    hir::Safety::Safe,
539                    ExternAbi::Rust,
540                ));
541                (
542                    0,
543                    0,
544                    vec![Ty::new_fn_ptr(tcx, try_fn_ty), mut_u8, Ty::new_fn_ptr(tcx, catch_fn_ty)],
545                    tcx.types.i32,
546                )
547            }
548
549            sym::va_start | sym::va_end => {
550                (0, 0, vec![mk_va_list_ty(hir::Mutability::Mut).0], tcx.types.unit)
551            }
552
553            sym::va_copy => {
554                let (va_list_ref_ty, va_list_ty) = mk_va_list_ty(hir::Mutability::Not);
555                let va_list_ptr_ty = Ty::new_mut_ptr(tcx, va_list_ty);
556                (0, 0, vec![va_list_ptr_ty, va_list_ref_ty], tcx.types.unit)
557            }
558
559            sym::va_arg => (1, 0, vec![mk_va_list_ty(hir::Mutability::Mut).0], param(0)),
560
561            sym::nontemporal_store => {
562                (1, 0, vec![Ty::new_mut_ptr(tcx, param(0)), param(0)], tcx.types.unit)
563            }
564
565            sym::raw_eq => {
566                let br =
567                    ty::BoundRegion { var: ty::BoundVar::ZERO, kind: ty::BoundRegionKind::Anon };
568                let param_ty_lhs =
569                    Ty::new_imm_ref(tcx, ty::Region::new_bound(tcx, ty::INNERMOST, br), param(0));
570                let br = ty::BoundRegion {
571                    var: ty::BoundVar::from_u32(1),
572                    kind: ty::BoundRegionKind::Anon,
573                };
574                let param_ty_rhs =
575                    Ty::new_imm_ref(tcx, ty::Region::new_bound(tcx, ty::INNERMOST, br), param(0));
576                (1, 0, vec![param_ty_lhs, param_ty_rhs], tcx.types.bool)
577            }
578
579            sym::black_box => (1, 0, vec![param(0)], param(0)),
580
581            sym::is_val_statically_known => (1, 0, vec![param(0)], tcx.types.bool),
582
583            sym::const_eval_select => (4, 0, vec![param(0), param(1), param(2)], param(3)),
584
585            sym::vtable_size | sym::vtable_align => {
586                (0, 0, vec![Ty::new_imm_ptr(tcx, tcx.types.unit)], tcx.types.usize)
587            }
588
589            // This type check is not particularly useful, but the `where` bounds
590            // on the definition in `core` do the heavy lifting for checking it.
591            sym::aggregate_raw_ptr => (3, 0, vec![param(1), param(2)], param(0)),
592            sym::ptr_metadata => (2, 0, vec![Ty::new_imm_ptr(tcx, param(0))], param(1)),
593
594            sym::ub_checks => (0, 0, Vec::new(), tcx.types.bool),
595
596            sym::box_new => (1, 0, vec![param(0)], Ty::new_box(tcx, param(0))),
597
598            // contract_checks() -> bool
599            sym::contract_checks => (0, 0, Vec::new(), tcx.types.bool),
600            // contract_check_requires::<C>(C) -> bool, where C: impl Fn() -> bool
601            sym::contract_check_requires => (1, 0, vec![param(0)], tcx.types.unit),
602
603            sym::simd_eq
604            | sym::simd_ne
605            | sym::simd_lt
606            | sym::simd_le
607            | sym::simd_gt
608            | sym::simd_ge => (2, 0, vec![param(0), param(0)], param(1)),
609            sym::simd_add
610            | sym::simd_sub
611            | sym::simd_mul
612            | sym::simd_rem
613            | sym::simd_div
614            | sym::simd_shl
615            | sym::simd_shr
616            | sym::simd_and
617            | sym::simd_or
618            | sym::simd_xor
619            | sym::simd_fmin
620            | sym::simd_fmax
621            | sym::simd_saturating_add
622            | sym::simd_saturating_sub => (1, 0, vec![param(0), param(0)], param(0)),
623            sym::simd_arith_offset => (2, 0, vec![param(0), param(1)], param(0)),
624            sym::simd_neg
625            | sym::simd_bswap
626            | sym::simd_bitreverse
627            | sym::simd_ctlz
628            | sym::simd_cttz
629            | sym::simd_ctpop
630            | sym::simd_fsqrt
631            | sym::simd_fsin
632            | sym::simd_fcos
633            | sym::simd_fexp
634            | sym::simd_fexp2
635            | sym::simd_flog2
636            | sym::simd_flog10
637            | sym::simd_flog
638            | sym::simd_fabs
639            | sym::simd_ceil
640            | sym::simd_floor
641            | sym::simd_round
642            | sym::simd_trunc => (1, 0, vec![param(0)], param(0)),
643            sym::simd_fma | sym::simd_relaxed_fma => {
644                (1, 0, vec![param(0), param(0), param(0)], param(0))
645            }
646            sym::simd_gather => (3, 0, vec![param(0), param(1), param(2)], param(0)),
647            sym::simd_masked_load => (3, 0, vec![param(0), param(1), param(2)], param(2)),
648            sym::simd_masked_store => (3, 0, vec![param(0), param(1), param(2)], tcx.types.unit),
649            sym::simd_scatter => (3, 0, vec![param(0), param(1), param(2)], tcx.types.unit),
650            sym::simd_insert | sym::simd_insert_dyn => {
651                (2, 0, vec![param(0), tcx.types.u32, param(1)], param(0))
652            }
653            sym::simd_extract | sym::simd_extract_dyn => {
654                (2, 0, vec![param(0), tcx.types.u32], param(1))
655            }
656            sym::simd_cast
657            | sym::simd_as
658            | sym::simd_cast_ptr
659            | sym::simd_expose_provenance
660            | sym::simd_with_exposed_provenance => (2, 0, vec![param(0)], param(1)),
661            sym::simd_bitmask => (2, 0, vec![param(0)], param(1)),
662            sym::simd_select | sym::simd_select_bitmask => {
663                (2, 0, vec![param(0), param(1), param(1)], param(1))
664            }
665            sym::simd_reduce_all | sym::simd_reduce_any => (1, 0, vec![param(0)], tcx.types.bool),
666            sym::simd_reduce_add_ordered | sym::simd_reduce_mul_ordered => {
667                (2, 0, vec![param(0), param(1)], param(1))
668            }
669            sym::simd_reduce_add_unordered
670            | sym::simd_reduce_mul_unordered
671            | sym::simd_reduce_and
672            | sym::simd_reduce_or
673            | sym::simd_reduce_xor
674            | sym::simd_reduce_min
675            | sym::simd_reduce_max => (2, 0, vec![param(0)], param(1)),
676            sym::simd_shuffle => (3, 0, vec![param(0), param(0), param(1)], param(2)),
677            sym::simd_shuffle_const_generic => (2, 1, vec![param(0), param(0)], param(1)),
678
679            other => {
680                tcx.dcx().emit_err(UnrecognizedIntrinsicFunction { span, name: other });
681                return;
682            }
683        };
684        (n_tps, 0, n_cts, inputs, output, safety)
685    };
686    let sig = tcx.mk_fn_sig(inputs, output, false, safety, ExternAbi::Rust);
687    let sig = ty::Binder::bind_with_vars(sig, bound_vars);
688    equate_intrinsic_type(tcx, span, intrinsic_id, n_tps, n_lts, n_cts, sig)
689}